Live coverage of spacecraft arrival at asteroid December 3

This “super-resolution” view of asteroid Bennu was created using eight images obtained by NASA’s OSIRIS-REx spacecraft on October 29, 2018, from a distance of about 205 miles (330 km). Image via NASA/Goddard/University of Arizona.

NASA’s OSIRIS-REx spacecraft is scheduled to rendezvous with its targeted asteroid, Bennu, on Monday, December 3, 2018, at approximately 17:00 UTC (noon EST). Translate UTC to your time.

NASA will air a live event from 16:45 to 17:15 UTC (11:45 a.m.to 12:15 p.m. EST) to highlight the arrival of the agency’s first asteroid sample return mission. You can watch on NASA TV, Facebook Live, Ustream, YouTube and NASA Live. NASA TV also will air an arrival preview program starting at 16:15 UTC (11:15 a.m. EST).

This animation consists of 5 of the 1st images of asteroid Bennu via the OSIRIS-REx mission, acquired August 17, 2018, at 1.4 million miles (2.3 million km), or almost 6 times the distance between the Earth and moon. The asteroid is visible as a moving object against the stars in front of the constellation Serpens. The spacecraft is due to arrive at the asteroid on December 3, 2018. Image via NASA/Goddard/University of Arizona.

OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer) launched in September 2016 and has been slowly approaching Bennu. OSIRIS-REx is NASA’s first mission to visit a near-Earth asteroid, survey the surface, collect a sample and deliver it back to Earth. The spacecraft will spend almost a year surveying the asteroid with the goal of selecting a location that is safe and scientifically interesting to collect the sample.

That asteroid sample is expected to return to Earth via free fall from space, until it reaches an altitude of 20.8 miles (33.5 km), when a first parachute will deploy. At 1.9 miles (3 km), the main parachute will be released, bringing the capsule with its precious cargo from Bennu in for a soft landing in the Utah desert on September 24, 2023.

EarthSky lunar calendars are cool! They make great gifts. Order now. Going fast!

Bottom line: The OSIRIS-REx spacecraft is scheduled to rendezvous with its targeted asteroid, Bennu, on Monday, December 3, 2018, at approximately 17:00 UTC (noon EST).

Via NASA

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This “super-resolution” view of asteroid Bennu was created using eight images obtained by NASA’s OSIRIS-REx spacecraft on October 29, 2018, from a distance of about 205 miles (330 km). Image via NASA/Goddard/University of Arizona.

NASA’s OSIRIS-REx spacecraft is scheduled to rendezvous with its targeted asteroid, Bennu, on Monday, December 3, 2018, at approximately 17:00 UTC (noon EST). Translate UTC to your time.

NASA will air a live event from 16:45 to 17:15 UTC (11:45 a.m.to 12:15 p.m. EST) to highlight the arrival of the agency’s first asteroid sample return mission. You can watch on NASA TV, Facebook Live, Ustream, YouTube and NASA Live. NASA TV also will air an arrival preview program starting at 16:15 UTC (11:15 a.m. EST).

This animation consists of 5 of the 1st images of asteroid Bennu via the OSIRIS-REx mission, acquired August 17, 2018, at 1.4 million miles (2.3 million km), or almost 6 times the distance between the Earth and moon. The asteroid is visible as a moving object against the stars in front of the constellation Serpens. The spacecraft is due to arrive at the asteroid on December 3, 2018. Image via NASA/Goddard/University of Arizona.

OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer) launched in September 2016 and has been slowly approaching Bennu. OSIRIS-REx is NASA’s first mission to visit a near-Earth asteroid, survey the surface, collect a sample and deliver it back to Earth. The spacecraft will spend almost a year surveying the asteroid with the goal of selecting a location that is safe and scientifically interesting to collect the sample.

That asteroid sample is expected to return to Earth via free fall from space, until it reaches an altitude of 20.8 miles (33.5 km), when a first parachute will deploy. At 1.9 miles (3 km), the main parachute will be released, bringing the capsule with its precious cargo from Bennu in for a soft landing in the Utah desert on September 24, 2023.

EarthSky lunar calendars are cool! They make great gifts. Order now. Going fast!

Bottom line: The OSIRIS-REx spacecraft is scheduled to rendezvous with its targeted asteroid, Bennu, on Monday, December 3, 2018, at approximately 17:00 UTC (noon EST).

Via NASA

from EarthSky https://ift.tt/2PdGCNK

Will December’s full moon be a supermoon?

Apparent size of a full supermoon, or close moon, contrasted with a full micro-moon, or far moon. Image by Peter Lowenstein.

The last of 2018’s 13 full moons will fall on December 22. This full moon will rank as the 3rd-closest one of 2018, but it’s less than clear whether it should be dubbed a supermoon, mainly because commentators disagree on what constitutes a supermoon.

EarthSky lunar calendars are cool! They make great gifts. Order now. Going fast!

Who are the commentators, and what do they say? The International Astronomical Union (IAU) is the group generally recognized for naming and defining things in astronomy. But the IAU has been, so far, silent on the subject of supermoons, which, professional astronomers tend to call perigean full moons.

Meanwhile, Fred Espenak, the go-to astronomer on all things related to lunar and solar eclipses (Mr. Eclipse!), lists the full moons of January 2 and 31, plus December 22, 2018, as full moon supermoons in his post, full moon at perigee.

We might also consider the astrologer Richard Nolle. Whatever your thoughts or feelings are on astrology, Nolle is, after all, the person who coined the term supermoon. Of the 13 full moons that take place in 2018, he lists only the two January full moons as supermoons. The supermoon definition, as originally defined by Nolle, comes with ambiguity. That’s why there are different answers to the question of the number of supermoons in 2018.

Click here to learn more about Richard Nolle

Click here to learn more about Fred Espenak

Astrophysicist Fred Espenak, aka Mr. Eclipse – a 30-year NASA veteran and world-renowned expert on eclipses – says the January 12, 2017, full moon is a supermoon in his post Moon in 2017.

We refer you to two different supermoon tables for the 21st century (2001 to 2100). Here is Richard Nolle’s table, and here is Fred Espenak’s table.

Richard Nolle lists only two full moon supermoons for 2018:

2018 January 2

2018 January 31

Meanwhile, Fred Espenak lists three full moon supermoons in 2018:

2018 January 2

2018 January 31

2018 December 22

Why are their lists different? It all goes back to the definition of the word supermoon.

Here’s one thing we all can agree on. Supermoons are based on lunar perigee and apogee. Each month, the moon comes closest to Earth at perigee and swings farthest away at apogee.

Image via NASA.

In his original definition, Richard Nolle defined a supermoon as:

… a new or full moon which occurs with the moon at or near (within 90% of) its closest approach to Earth in a given orbit.

If a new or full moon aligns with apogee, then it’s at 0% of its closest approach to Earth. On the other hand, if a new or full moon aligns with perigee, then it’s at 100% of its closest approach to Earth. That’s something we can all agree on.

But the phrase 90% of perigee is ambiguous. Read on.

A 2013 supermoon, as captured by EarthSky Facebook friend Anthony Lynch in Dublin, Ireland.

Nolle’s 90% is based on 2018’s closest perigee and farthest apogee. Looking at Richard Nolle’s list for all the supermoons in the 21st century, it appears that Richard Nolle bases his 90% figure on the year’s closest perigee and farthest apogee. Take the year 2018, for instance, whereby any new or full moon coming closer than 362,146.6 km qualifies as a supermoon.

This year, in 2018, the moon comes closest to Earth on January 1 (356,565 kilometers) and swings farthest away one fortnight (two weeks) later, on January 15 (406,464 kilometers). That’s a difference of 49,899 km (406,464 – 356,565 = 49,899 km). Ninety percent of 49,899 km equals 44,909.1 kilometers (0.9 x 49,899 = 44,909.1). Presumably, any new or full moon coming closer than 361,554.9 kilometers (406,464 – 44,909.1 = 361,554.9) would be “at or near (within 90% of) its closest approach to Earth.”

Farthest apogee (2018): 406,464 km
Closest perigee (2018): 356,565 km
Difference: 49,899 km

90% x 49,899 = 44,909.1 km

406,464 – 44,909.1 = 361,554.9 km = 90% of moon’s closest distance to Earth

Thus, figuring out “90% of the moon’s closest approach to Earth” by the year’s closest perigee and farthest apogee, any new or full moon swinging closer than 361,554.9 km to Earth in 2018 counts as a supermoon.

Since the full moon on December 22, 2018, only comes within 363,368 km of Earth, it doesn’t count as a supermoon on Richard Nolle’s list.

July 2014 supermoon via Evgeny Yorobe Photography.

Espenak’s 90% based on perigee and apogee of each month’s orbit. Ironically, Fred Espenak’s full supermoon list might more strictly adhere to Richard Nolle’s definition (at least as it is written) than Richard Nolle himself does.

Once again, Richard Nolle describes a supermoon as:

… a new or full moon which occurs with the Moon at or near (within 90% of) its closest approach to Earth in a given orbit.

If given orbit can be taken to mean current monthly orbit, then the December 2018 full moon comes to within 94.8% of its closest approach to Earth relative to the most recent perigee and the upcoming apogee.

December 12, 2018 apogee: 405,177 km
December 24, 2018 perigee: 361,062 km
Difference: 44,115 km

December 12, 2018 apogee: 405,177 km
December 22, 2018 full moon: 363,368 km
Difference: 41,809 km

41,809/44,115 = 0.9477 (94.77%) = distance of the December 2018 full moon relative to the most recent apogee and upcoming perigee

Depending on what meaning we give to the words in a given orbit, we could say the December 12 apogee = 0% of the moon’s closest approach to Earth for this orbit, and the December 24 perigee = 100% of the moon’s closest approach to Earth.

That being the case, then the December full moon comes to within 94.8% of its closest approach to Earth for the month.

Super cool super-moonrise composite from Fiona M. Donnelly in Ontario. This photo is from the August 2014 supermoon.

December full moon’s distance relative to 2018’s closest perigee/farthest apogee. However, if we compute the percentage distance of the December full moon relative to the year’s farthest apogee and closest perigee, then the December full moon only comes to within 86.2% of its closest approach to Earth:

Farthest apogee (2018): 406,464 km
Closest perigee (2018): 356,565 km
Difference: 49,899 km

Farthest apogee (2018): 406,464 km
December full moon (2018): 363,368 km
Difference: 43,096 km

43,096/49,899 = 0.864 (86.4%) = distance of the December full moon relative to the year’s farthest apogee and closest perigee

Another contrast of a full supermoon (full moon at perigee) with a micro-moon (full moon at apogee). Image via Stefano Sciarpetti.

Is the December full moon a supermoon? Depends on which perigee/apogee distances you choose. The moon’s perigee and apogee distances vary throughout the year, so it appears that the limiting distance for the supermoon depends on which perigee and apogee distances are being used to compute 90% of the moon’s closest approach to Earth.

If we choose the year’s closest perigee and farthest apogee, as Nolle did, we narrow the definition of supermoon.

If we choose the perigee and apogee for a given monthly orbit, as Espenak did, then we broaden the definition of supermoon.

Given the narrower definition, the full moon on December 22, 2018, is not a supermoon, but given the broader one, it is.

Take your choice!

The moon’s apparent size in our sky depends on its distance from Earth. The supermoon of March 19, 2011 (right), compared to an average moon of December 20, 2010 (left). Image by Marco Langbroek of the Netherlands via Wikimedia Commons.

Bottom line: At least two commentators – Richard Nolle and Fred Espenak – disagree on whether the December 22, 2018, full moon should be called a supermoon. Is it? If you define a supermoon based on the year’s closest perigee and farthest apogee, then the December 2018 full moon is not a supermoon. If you define a supermoon based on the perigee and apogee for a given monthly orbit, then it is a supermoon. Take your choice!

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Apparent size of a full supermoon, or close moon, contrasted with a full micro-moon, or far moon. Image by Peter Lowenstein.

The last of 2018’s 13 full moons will fall on December 22. This full moon will rank as the 3rd-closest one of 2018, but it’s less than clear whether it should be dubbed a supermoon, mainly because commentators disagree on what constitutes a supermoon.

EarthSky lunar calendars are cool! They make great gifts. Order now. Going fast!

Who are the commentators, and what do they say? The International Astronomical Union (IAU) is the group generally recognized for naming and defining things in astronomy. But the IAU has been, so far, silent on the subject of supermoons, which, professional astronomers tend to call perigean full moons.

Meanwhile, Fred Espenak, the go-to astronomer on all things related to lunar and solar eclipses (Mr. Eclipse!), lists the full moons of January 2 and 31, plus December 22, 2018, as full moon supermoons in his post, full moon at perigee.

We might also consider the astrologer Richard Nolle. Whatever your thoughts or feelings are on astrology, Nolle is, after all, the person who coined the term supermoon. Of the 13 full moons that take place in 2018, he lists only the two January full moons as supermoons. The supermoon definition, as originally defined by Nolle, comes with ambiguity. That’s why there are different answers to the question of the number of supermoons in 2018.

Click here to learn more about Richard Nolle

Click here to learn more about Fred Espenak

Astrophysicist Fred Espenak, aka Mr. Eclipse – a 30-year NASA veteran and world-renowned expert on eclipses – says the January 12, 2017, full moon is a supermoon in his post Moon in 2017.

We refer you to two different supermoon tables for the 21st century (2001 to 2100). Here is Richard Nolle’s table, and here is Fred Espenak’s table.

Richard Nolle lists only two full moon supermoons for 2018:

2018 January 2

2018 January 31

Meanwhile, Fred Espenak lists three full moon supermoons in 2018:

2018 January 2

2018 January 31

2018 December 22

Why are their lists different? It all goes back to the definition of the word supermoon.

Here’s one thing we all can agree on. Supermoons are based on lunar perigee and apogee. Each month, the moon comes closest to Earth at perigee and swings farthest away at apogee.

Image via NASA.

In his original definition, Richard Nolle defined a supermoon as:

… a new or full moon which occurs with the moon at or near (within 90% of) its closest approach to Earth in a given orbit.

If a new or full moon aligns with apogee, then it’s at 0% of its closest approach to Earth. On the other hand, if a new or full moon aligns with perigee, then it’s at 100% of its closest approach to Earth. That’s something we can all agree on.

But the phrase 90% of perigee is ambiguous. Read on.

A 2013 supermoon, as captured by EarthSky Facebook friend Anthony Lynch in Dublin, Ireland.

Nolle’s 90% is based on 2018’s closest perigee and farthest apogee. Looking at Richard Nolle’s list for all the supermoons in the 21st century, it appears that Richard Nolle bases his 90% figure on the year’s closest perigee and farthest apogee. Take the year 2018, for instance, whereby any new or full moon coming closer than 362,146.6 km qualifies as a supermoon.

This year, in 2018, the moon comes closest to Earth on January 1 (356,565 kilometers) and swings farthest away one fortnight (two weeks) later, on January 15 (406,464 kilometers). That’s a difference of 49,899 km (406,464 – 356,565 = 49,899 km). Ninety percent of 49,899 km equals 44,909.1 kilometers (0.9 x 49,899 = 44,909.1). Presumably, any new or full moon coming closer than 361,554.9 kilometers (406,464 – 44,909.1 = 361,554.9) would be “at or near (within 90% of) its closest approach to Earth.”

Farthest apogee (2018): 406,464 km
Closest perigee (2018): 356,565 km
Difference: 49,899 km

90% x 49,899 = 44,909.1 km

406,464 – 44,909.1 = 361,554.9 km = 90% of moon’s closest distance to Earth

Thus, figuring out “90% of the moon’s closest approach to Earth” by the year’s closest perigee and farthest apogee, any new or full moon swinging closer than 361,554.9 km to Earth in 2018 counts as a supermoon.

Since the full moon on December 22, 2018, only comes within 363,368 km of Earth, it doesn’t count as a supermoon on Richard Nolle’s list.

July 2014 supermoon via Evgeny Yorobe Photography.

Espenak’s 90% based on perigee and apogee of each month’s orbit. Ironically, Fred Espenak’s full supermoon list might more strictly adhere to Richard Nolle’s definition (at least as it is written) than Richard Nolle himself does.

Once again, Richard Nolle describes a supermoon as:

… a new or full moon which occurs with the Moon at or near (within 90% of) its closest approach to Earth in a given orbit.

If given orbit can be taken to mean current monthly orbit, then the December 2018 full moon comes to within 94.8% of its closest approach to Earth relative to the most recent perigee and the upcoming apogee.

December 12, 2018 apogee: 405,177 km
December 24, 2018 perigee: 361,062 km
Difference: 44,115 km

December 12, 2018 apogee: 405,177 km
December 22, 2018 full moon: 363,368 km
Difference: 41,809 km

41,809/44,115 = 0.9477 (94.77%) = distance of the December 2018 full moon relative to the most recent apogee and upcoming perigee

Depending on what meaning we give to the words in a given orbit, we could say the December 12 apogee = 0% of the moon’s closest approach to Earth for this orbit, and the December 24 perigee = 100% of the moon’s closest approach to Earth.

That being the case, then the December full moon comes to within 94.8% of its closest approach to Earth for the month.

Super cool super-moonrise composite from Fiona M. Donnelly in Ontario. This photo is from the August 2014 supermoon.

December full moon’s distance relative to 2018’s closest perigee/farthest apogee. However, if we compute the percentage distance of the December full moon relative to the year’s farthest apogee and closest perigee, then the December full moon only comes to within 86.2% of its closest approach to Earth:

Farthest apogee (2018): 406,464 km
Closest perigee (2018): 356,565 km
Difference: 49,899 km

Farthest apogee (2018): 406,464 km
December full moon (2018): 363,368 km
Difference: 43,096 km

43,096/49,899 = 0.864 (86.4%) = distance of the December full moon relative to the year’s farthest apogee and closest perigee

Another contrast of a full supermoon (full moon at perigee) with a micro-moon (full moon at apogee). Image via Stefano Sciarpetti.

Is the December full moon a supermoon? Depends on which perigee/apogee distances you choose. The moon’s perigee and apogee distances vary throughout the year, so it appears that the limiting distance for the supermoon depends on which perigee and apogee distances are being used to compute 90% of the moon’s closest approach to Earth.

If we choose the year’s closest perigee and farthest apogee, as Nolle did, we narrow the definition of supermoon.

If we choose the perigee and apogee for a given monthly orbit, as Espenak did, then we broaden the definition of supermoon.

Given the narrower definition, the full moon on December 22, 2018, is not a supermoon, but given the broader one, it is.

Take your choice!

The moon’s apparent size in our sky depends on its distance from Earth. The supermoon of March 19, 2011 (right), compared to an average moon of December 20, 2010 (left). Image by Marco Langbroek of the Netherlands via Wikimedia Commons.

Bottom line: At least two commentators – Richard Nolle and Fred Espenak – disagree on whether the December 22, 2018, full moon should be called a supermoon. Is it? If you define a supermoon based on the year’s closest perigee and farthest apogee, then the December 2018 full moon is not a supermoon. If you define a supermoon based on the perigee and apogee for a given monthly orbit, then it is a supermoon. Take your choice!

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Messier 33: 2nd-closest spiral galaxy

Triangulum galaxy – aka M33 – via the VLT Survey Telescope at European Southern Observatory’s Paranal Observatory in Chile.

Say hello to the much-photographed Triangulum galaxy – aka Messier 33 – a face-on pinwheel of swarming suns and the second-nearest spiral galaxy to our Milky Way. This galaxy is only about 2.7 million light-years away. It’s huge, with a diameter about half that of our Milky Way. But it’s turned face on to us and thus has a low surface brightness in our sky. Although theoretically visible to the unaided eye under dark sky conditions, it’s still not easy to spot in binoculars or even a telescope. Keep reading to learn more about this nearby, face-on, very beautiful spiral galaxy.

EarthSky lunar calendars are cool! They make great gifts. Order now. Going fast!

Constellation Triangulum. Notice its relationship to the constellation Andromeda and the star Mirach in Andromeda. The Andromeda galaxy is marked as M31. Via astronomy.net.

Here’s the star Mirach in Andromeda again. Notice that the Triangulum galaxy (M33) is about equidistant from this star as the Andromeda galaxy (M31). In other words, once you find Mirach and the Andromeda galaxy, a line between them will point, more or less, to the Triangulum galaxy. Via ESO Public Outreach.

How to find the Triangulum galaxy. Have you ever seen the Andromeda galaxy (Messier 31), closest spiral galaxy to our Milky Way? If not, try finding the Andromeda galaxy before you take on the Triangulum galaxy. Here are two ways to find the Andromeda galaxy:

Use constellation Cassiopeia to find Andromeda galaxy

Use Great Square of Pegasus to find Andromeda Galaxy

The Andromeda galaxy shines 8 to 9 times more brightly than the Triangulum galaxy, which is the most distant object that you can easily see with the unaided eye. Fortunately, the Triangulum and Andromeda galaxies are a relatively close 15 degrees apart (for reference, a fist-width at an arm length approximates 10 degrees).

Star-hop to the Andromeda galaxy to orient yourself to the Triangulum galaxy. As seen on the sky chart, the star Mirach stands about midway between the two galaxies. Once you find Mirach and the Andromeda galaxy, you can draw a line between them to point in the general direction of the Triangulum galaxy.

Now for a word of warning: even if you’re staring right at the Triangulum galaxy, it’s still possible to miss it. You won’t see the galaxy’s stars at all. Sometimes, this galaxy looks almost transparent, like a water spot on a window. The small blob in your binocular field might resemble an unwashed spot on an otherwise clean window. If you’ve never seen this deep-sky object before, it’s hard to know what to look for.

Once you finally spot the Triangulum galaxy, you may wonder how you overlooked it so many times before.

Artist’s concept of our Local Group via Chandra X-Ray Observatory.

Science of the Triangulum galaxy. The Triangulum galaxy is located at a distance of about 2.7 million light-years from our Milky Way. It’s a spiral galaxy, whose face-on orientation has given it the nickname Pinwheel Galaxy (another face-on spiral, Messier 101, also has this nickname).

The Triangulum galaxy is the third-largest member of our Local Group of galaxies. Our Local Group consists of several dozen galaxies; our Milky Way, the Andromeda galaxy and the Triangulum galaxy are the largest members.

After the Milky Way and Andromeda galaxies, the Triangulum galaxy ranks as the third-largest Local Group member. Its diameter is about 50,000 light-years, or about one-half that of our Milky Way. It’s thought to contain some 40 billion stars, in contrast to 400 billion for the Milky Way, and a trillion (1,000 billion) stars for Andromeda.

In 2004, astronomers found evidence for a clumpy stream of hydrogen gas linking the Triangulum galaxy with the nearby Andromeda galaxy. A year later, astronomers were able to estimate the proper motion – or sideways motion on our sky’s dome – of the Triangulum galaxy for the first time. They found that this galaxy is moving towards the Andromeda galaxy. Afterwards, some astronomers suggested the Triangulum galaxy might be a satellite of the Andromeda galaxy. In other words, over a timescale so vast we haven’t yet comprehended it, the Triangulum galaxy might orbit around the Andromeda galaxy.

It’s well known that the Andromeda galaxy is moving toward our Milky Way and that a collision between the two galaxies will occur some 4 billion years from now. Meanwhile, the fate of the Triangulum Galaxy isn’t known for certain. It might someday be torn apart and absorbed by the Andromeda galaxy. It might participate in the collision between the Milky Way and Andromeda galaxies.

Two other possibilities are a collision with the Milky Way before Andromeda arrives or an ejection from the Local Group.

It’s safe to say that the fate of these great galaxies is beyond human knowledge at this time!

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Bottom line: The Triangulum galaxy is the second-closest large spiral galaxy at 2.7 million light-years away. It’s turned face-on to us and so appears faint in our sky.

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Triangulum galaxy – aka M33 – via the VLT Survey Telescope at European Southern Observatory’s Paranal Observatory in Chile.

Say hello to the much-photographed Triangulum galaxy – aka Messier 33 – a face-on pinwheel of swarming suns and the second-nearest spiral galaxy to our Milky Way. This galaxy is only about 2.7 million light-years away. It’s huge, with a diameter about half that of our Milky Way. But it’s turned face on to us and thus has a low surface brightness in our sky. Although theoretically visible to the unaided eye under dark sky conditions, it’s still not easy to spot in binoculars or even a telescope. Keep reading to learn more about this nearby, face-on, very beautiful spiral galaxy.

EarthSky lunar calendars are cool! They make great gifts. Order now. Going fast!

Constellation Triangulum. Notice its relationship to the constellation Andromeda and the star Mirach in Andromeda. The Andromeda galaxy is marked as M31. Via astronomy.net.

Here’s the star Mirach in Andromeda again. Notice that the Triangulum galaxy (M33) is about equidistant from this star as the Andromeda galaxy (M31). In other words, once you find Mirach and the Andromeda galaxy, a line between them will point, more or less, to the Triangulum galaxy. Via ESO Public Outreach.

How to find the Triangulum galaxy. Have you ever seen the Andromeda galaxy (Messier 31), closest spiral galaxy to our Milky Way? If not, try finding the Andromeda galaxy before you take on the Triangulum galaxy. Here are two ways to find the Andromeda galaxy:

Use constellation Cassiopeia to find Andromeda galaxy

Use Great Square of Pegasus to find Andromeda Galaxy

The Andromeda galaxy shines 8 to 9 times more brightly than the Triangulum galaxy, which is the most distant object that you can easily see with the unaided eye. Fortunately, the Triangulum and Andromeda galaxies are a relatively close 15 degrees apart (for reference, a fist-width at an arm length approximates 10 degrees).

Star-hop to the Andromeda galaxy to orient yourself to the Triangulum galaxy. As seen on the sky chart, the star Mirach stands about midway between the two galaxies. Once you find Mirach and the Andromeda galaxy, you can draw a line between them to point in the general direction of the Triangulum galaxy.

Now for a word of warning: even if you’re staring right at the Triangulum galaxy, it’s still possible to miss it. You won’t see the galaxy’s stars at all. Sometimes, this galaxy looks almost transparent, like a water spot on a window. The small blob in your binocular field might resemble an unwashed spot on an otherwise clean window. If you’ve never seen this deep-sky object before, it’s hard to know what to look for.

Once you finally spot the Triangulum galaxy, you may wonder how you overlooked it so many times before.

Artist’s concept of our Local Group via Chandra X-Ray Observatory.

Science of the Triangulum galaxy. The Triangulum galaxy is located at a distance of about 2.7 million light-years from our Milky Way. It’s a spiral galaxy, whose face-on orientation has given it the nickname Pinwheel Galaxy (another face-on spiral, Messier 101, also has this nickname).

The Triangulum galaxy is the third-largest member of our Local Group of galaxies. Our Local Group consists of several dozen galaxies; our Milky Way, the Andromeda galaxy and the Triangulum galaxy are the largest members.

After the Milky Way and Andromeda galaxies, the Triangulum galaxy ranks as the third-largest Local Group member. Its diameter is about 50,000 light-years, or about one-half that of our Milky Way. It’s thought to contain some 40 billion stars, in contrast to 400 billion for the Milky Way, and a trillion (1,000 billion) stars for Andromeda.

In 2004, astronomers found evidence for a clumpy stream of hydrogen gas linking the Triangulum galaxy with the nearby Andromeda galaxy. A year later, astronomers were able to estimate the proper motion – or sideways motion on our sky’s dome – of the Triangulum galaxy for the first time. They found that this galaxy is moving towards the Andromeda galaxy. Afterwards, some astronomers suggested the Triangulum galaxy might be a satellite of the Andromeda galaxy. In other words, over a timescale so vast we haven’t yet comprehended it, the Triangulum galaxy might orbit around the Andromeda galaxy.

It’s well known that the Andromeda galaxy is moving toward our Milky Way and that a collision between the two galaxies will occur some 4 billion years from now. Meanwhile, the fate of the Triangulum Galaxy isn’t known for certain. It might someday be torn apart and absorbed by the Andromeda galaxy. It might participate in the collision between the Milky Way and Andromeda galaxies.

Two other possibilities are a collision with the Milky Way before Andromeda arrives or an ejection from the Local Group.

It’s safe to say that the fate of these great galaxies is beyond human knowledge at this time!

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Bottom line: The Triangulum galaxy is the second-closest large spiral galaxy at 2.7 million light-years away. It’s turned face-on to us and so appears faint in our sky.

from EarthSky https://ift.tt/1w9dITB

2018 SkS Weekly Climate Change & Global Warming News Roundup #48

A chronological listing of news articles posted on the Skeptical Science Facebook Page during the past week, i.e., Sunday, Nov 25 through Saturday, Dec. 1

Editor's Pick

Climate change signals and impacts continue in 2018

 

 

The long-term warming trend has continued in 2018, with the average global temperature set to be the fourth highest on record. The 20 warmest years on record have been in the past 22 years, with the top four in the past four years, according to the World Meteorological Organization (WMO).

Other tell-tale signs of climate change, including sea level rise, ocean heat and acidification and sea-ice and glacier melt continue, whilst extreme weather left a trail of devastation on all continents, according to the WMO provisional Statement on the State of the Climate in 2018. It includes details of impacts of climate change based on contributions from a wide range of United Nations partners.

The report shows that the global average temperature for the first ten months of the year was nearly 1°C above the pre-industrial baseline (1850-1900). This is based on five independently maintained global temperature data sets.

“We are not on track to meet climate change targets and rein in temperature increases,” said WMO Secretary-General Petteri Taalas. “Greenhouse gas concentrations are once again at record levels and if the current trend continues we may see temperature increases 3-5°C by the end of the century. If we exploit all known fossil fuel resources, the temperature rise will be considerably higher,” he said.

“It is worth repeating once again that we are the first generation to fully understand climate change and the last generation to be able to do something about it,” said Mr Taalas.

The Intergovernmental Panel on Climate Change (IPCC) special report on Global Warming of 1.5°C reported that the average global temperature for the decade 2006-2015 was 0.86°C above the pre-industrial baseline. The average increase above the same baseline for the most recent decade 2009-2018 was about 0.93°C and for the past five years, 2014-2018, was 1.04°C above the pre-industrial baseline.

“These are more than just numbers,” said WMO Deputy Secretary-General Elena Manaenkova.

“Every fraction of a degree of warming makes a difference to human health and access to food and fresh water, to the extinction of animals and plants, to the survival of coral reefs and marine life. It makes a difference to economic productivity, food security, and to the resilience of our infrastructure and cities. It makes a difference to the speed of glacier melt and water supplies, and the future of low-lying islands and coastal communities. Every extra bit matters,” said Ms Manaenkova.

The WMO report adds to the authoritative scientific evidence that will inform UN climate change negotiations from 2-14 December in Katowice, Poland. The key objective of the meeting is to adopt the implementation guidelines of the Paris Agreement on Climate Change, which aims to hold the global average temperature increase to as close as possible to 1.5°C.

The IPCC report on Global Warming of 1.5°C said that this target was physically possible but would require unprecedented changes in our lifestyle, energy and transport systems. It showed how keeping temperature increases below 2°C would reduce the risks to human well-being, ecosystems and sustainable development.

National meteorological and hydrological services have been contributing to national climate assessments. A new U.S. federal report detailed how climate change is affecting the environment, agriculture, energy, land and water resources, transportation, and human health and welfare, with a risk that it will lead to growing losses to American infrastructure and property and impede the rate of economic growth over this century.

A UK assessment published 26 November warned summer temperatures could be up to 5.4°C hotter and summer rainfall could decrease by up to 47% by 2070, and sea levels in London could rise by 1.15m by 2100. A Swiss report on climate scenarios released on 13 November said that Switzerland is becoming hotter and drier, but will also struggle with heavier rainfall in the future and its famed ski resorts will have less snow.

“The WMO community is enhancing the translation of science into services. This will support countries in generating national climate scenarios and predictions and developing tailored climate services to reduce risks associated with climate change and increasingly extreme weather. WMO is also working to develop integrated tools to monitor and manage greenhouse gas emissions and carbon sinks,” said WMO Chief Scientist and Research Director Pavel Kabat.

Highlights of the provisional statement on the state of the climate

Temperatures: 2018 started with a weak La Niña event, which continued until March. By October, however, sea-surface temperatures in the eastern Tropical Pacific were showing signs of a return to El Niño conditions, although the atmosphere as yet shows little response. If El Niño develops, 2019 is likely to be warmer than 2018.

Greenhouse gases:  In 2017, carbon dioxide, methane and nitrous oxide concentrations reached new highs, according to WMO Greenhouse Gas Bulletin. Data from a number of locations, including Mauna Loa (Hawaii) and Cape Grim (Tasmania) indicate that they continued to increase in 2018.

Oceans: The oceans absorb more than 90% of the energy trapped by greenhouse gases and 25% of anthropogenic CO2 emissions, making them warmer and more acidic. For each 3-month period until September 2018, ocean heat content was the highest or second highest on record. Global Mean Sea Level from January to July 2018 was around 2 to 3 mm higher than the same period in 2017.

Sea ice: Arctic sea-ice extent was well below average throughout 2018 with record-low levels in the first two months of the year. The annual maximum occurred in mid-March and was the third lowest on record. The minimum extent in September was the 6th smallest on record, meaning that all 12 smallest September extents have been in the past 12 years. Antarctic sea-ice extent was also well below average throughout 2018. The annual minimum extent occurred in late February and was ranked as one of the two lowest extents. 

Extreme Weather

Tropical Storms:  The number of tropical cyclones was above average in all four Northern Hemisphere basins, with 70 reported by 20 November, compared to the long-term average of 53, leading to many casualties. The Northeast Pacific basin was especially active, with an Accumulated Cyclone Energy that was the highest since reliable satellite records began.

Two of the strongest tropical cyclones were Mangkhut, which impacted the Philippines, Hong Kong SAR and China, and Yutu, which brought devastation in the Mariana Islands. Jebi was the strongest typhoon to hit Japan since 1993, Son-Tinh caused flooding in Viet Nam and Laos, whilst Soulik contributed to flooding on the Korean peninsula. Hurricanes Florence and Michael were associated with huge economic damage and considerable loss of life in the United States. Gita, in the South Pacific, was the most intense and most expensive cyclone to ever hit Tonga.

Floods and rainfall: In August, the southwest Indian state of Kerala suffered the worst flooding since the 1920s, displacing more than 1.4 million people from their homes and affecting more than 5.4 million. Large parts of western Japan experienced destructive flooding in late June and early July, killing at least 230 people and destroying thousands of homes. Flooding affected many parts of east Africa in March and April. This included Kenya and Somalia, which had previously been suffering from severe drought, as well as Ethiopia and northern and central Tanzania.  An intense low-pressure system in the Mediterranean Sea in late October brought flooding, high winds and loss of life.

Heatwaves and drought: Large parts of Europe experienced exceptional heat and drought through the late spring and summer of 2018, leading to wildfires in Scandinavia. In July and August, there were numerous record high temperatures north of the Arctic Circle, and record long runs of warm temperatures., including 25 consecutive days above 25 °C in Helsinki (Finland). Parts of Germany had a long spell of days above 30°C, whilst a heatwave in France was associated with a number of deaths.  It was also an exceptionally warm and dry period in the United Kingdom and Ireland. A short but intense heatwave affected Spain and Portugal in early August.

Dry conditions were especially persistent in Germany, the Czech Republic, western Poland, the Netherlands, Belgium and parts of France. The Rhine approached record low flows by mid-October, seriously disrupting river transport.

Eastern Australia experienced significant drought during 2018, especially New South Wales and southern Queensland, with much of the region receiving less than half its average rainfall for the period from January to September.  Severe drought affected Uruguay, and northern and central Argentina, in late 2017 and early 2018, leading to heavy agricultural losses.

Both Japan and the Republic of Korea saw new national heat records (41.1 °C and 41.0°C respectively.)

Oman reported one of the highest known minimum overnight temperature of 42.6 °C in June. Algeria saw a new national of 51.3 °C in July.

Cold and snow: One of the most significant cold outbreaks of recent years affected Europe in late February and early March.

Wildfires: Major wildfires affected Athens (Greece) on 23 July, with many fatalities. British Columbia in Canada broke its record for the most area burned in a fire season for the second successive year. California suffered devastating wildfires, with November’s Camp Fire being the deadliest fire in over a century for the U.S.A. 

Other Impacts

The provisional statement contained details of impacts of climate change, based on contributions from the Food and Agriculture Organization (FAO), International Organization for Migration (IOM), UN Environment Programme (UNEP), UNESCO’s Intergovernmental Oceanographic Commission (IOC), UN High Commission for Refugees UNHCR) and World Food Programme (WFP). This section will be expanded in the final statement, to be released in March 2019.

Exposure of agriculture sectors to climate extremes is threatening to reverse gains made in ending malnutrition. New evidence shows a rise in world hunger after a prolonged decline. In 2017, the number of undernourished people was estimated to have increased to 821 million, according The State of Food Security and Nutrition in the World 2018, by to FAO, WFP, the International Fund for Agricultural Development, the UN Children’s Fund and the World Health Organization. Africa is the region where climate events had the biggest impact on acute food insecurity and malnutrition in 2017, affecting 59 million people in 24 countries and requiring urgent humanitarian action. Much of the vulnerability to climate variability is associated with the dryland farming and pastoral rangeland systems supporting 70–80% of the continent’s rural population.

Out of the 17.7 million Internally Displaced Persons tracked by the IOM, 2.3 million people were displaced due to disasters linked to weather and climate events as of September 2018. In Somalia, some 642 000 new internal displacements were recorded between January and July 2018 by UNHCR, with flooding the primary reason for displacement (43%), followed by drought (29%), and conflict (26%).

UN agencies including UNESCO-IOC and UNEP are tracking environmental impacts associated with climate change include coral bleaching, reduced levels of oxygen in the oceans, loss of “Blue Carbon” associated with coastal ecosystems such as mangroves and salt marshes. Climate change also exposes peatlands currently protected by permafrost to thawing and possible increased methane emissions and loss of carbon, and the associated sea-level rise increases the risks of coastal erosion and salination of freshwater peatlands.

Climate change signals and impacts continue in 2018, Press Release, World Meteorological Organization (WM0), Nov 29, 2018

Notes for Editors

Information used in this report is sourced from a large number of National Meteorological and Hydrological Services (NMHSs) and associated institutions, as well as Regional Climate Centres, the World Climate Research Programme (WCRP), the Global Atmosphere Watch (GAW) and Global Cryosphere Watch. Information has also been supplied by a number of other United Nations agencies, including the Food and Agriculture Organization (FAO), the World Food Programme (WFP), the United Nations High Commissioner for Refugees (UNHCR), the International Organization for Migration (IOM), the Intergovernmental Oceanographic Commission of UNESCO (IOC-UNESCO) and UN Environment

WMO uses datasets (based on monthly climatological data from observing sites) from the United States National Oceanic and Atmospheric Administration, NASA’s Goddard Institute for Space Studies, and the United Kingdom’s Met Office Hadley Centre and the University of East Anglia’s Climatic Research Unit in the United Kingdom.

It also uses reanalysis datasets from the European Centre for Medium Range Weather Forecasts and its Copernicus Climate Change Service, and the Japan Meteorological Agency.  This method combines millions of meteorological and marine observations, including from satellites, with models to produce a complete reanalysis of the atmosphere. The combination of observations with models makes it possible to estimate temperatures at any time and in any place across the globe, even in data-sparse areas such as the polar regions.

Story map featuring the Climate statement

Weather and Climate events 2018 interactive map

See also:  Key Climate Indicators table  

---

Links posted on Facebook

Sun Nov 25, 2018

• New research November 12-18, 2018 by Ari Jokimäki, Skeptical Science, Nov 23, 2018
• Poland calls for planting more forests worldwide to improve carbon capture by Agnieszka Barteczko, Reuters, Nov 22, 2018
• Why aren't they doing anything?: Students strike to give climate lesson by Peter Hannam, Environment, Sydney Morning Herald, Nov 25, 2018
• 3 Reasons Your Uncle Might Think Cold Days Disprove Global Warming by Marshall Shepard, Forbes, Nov 23, 2018
• The warming may be global, but adaptation will need to be local, Opinion by Lauren E Oakes, Los Angeles Times, Nov 25, 2018
• How to talk climate change with skeptical relatives during the holidays by Cody Nelson & Paul Huttner, MPR News, Nov 21, 2018
• Climate cash for developing world set to meet U.N. 2020 goal by Megan Rowling, Thompson Reuter Foundation, Nov 23, 2018
• The Beginning of the End of America’s Best Idea, Opinion by Timothy Egan, New York Times, Nov 23, 2018

Mon Nov 26, 2018

• Rising CO2 levels in the ocean could benefit toxic algae, study says by Daisy Dunne, Carbon Brief, Nov 19, 2018
• False claims of a coming ice age spread through ecosystem of unreliable news sites, blogs, and social media accounts by Emmanuel M Vincent, Insights, Climate Feedback, Nov 21, 2018
• The World Needs to Quit Coal. Why Is It So Hard? by Somini Sengupta, Climate, New York Times, Nov 24, 2018
• Trump Administration’s Strategy on Climate: Try to Bury Its Own Scientific Report, News Analysis by Coral Davenport, Climate, New York Times, Nov 25, 2018
• In Mount Everest Region, World's Highest Glaciers Are Melting, Receding. Photo Essay by Kunda Dixit, Nepali Times/InsideClimate News, Nov 26, 2018
• Climate Change Already Reshaping U.S., Says National Climate Assessment by Chelsea Harvey, E&E News/Scientific American, Nov 26, 2018
• Five Big Ways the United States Will Need to Adapt to Climate Change by Brad Plumer, Climate, New York Times, Nov 26, 2018
• Draft G20 statement waters down Paris climate commitment by Karl Mathiesen, Climate Home, Nov 26, 2018

Tue Nov 27, 2018

• Sydney to collect a month's rainfall in half a day as big low builds by Peter Hannam, Environment, Sydney Morning Herald, Nov 27, 2018
• Queensland bushfires: Evacuations amid 'highly unusual' conditions, BBC News, Nov 26, 2018
• Here’s what the climate change report says will happen to the economy if temperatures get hotter. Trump doesn’t ‘believe it’ by Steve Goldstein, MarketWatch, N0v 26, 2018
• How Trump Is Ensuring That Greenhouse Gas Emissions Will Rise by Coral Davenport & Lisa Friedman, Climate, New York Times, Nov 27, 2018
• World must triple efforts or face catastrophic climate change, says UN by Fiona Harvey, Environment, Guardian, Nov 27, 2018
• 10 ways to accelerate progress against climate change by Eliza Barclay & Umair Irfan, Energy & Environment, Vox, Nov 26, 2018
• The Depravity of Climate-Change Denial, Opinion by Paul Krugman, New York Times, Nov 26, 2018
• A political blockade is colliding with the evidence on climate change, Analysis by Ronald Brownstein, CNN, Nov 27, 2018

Wed Nov 28, 2018

• Oil kingdom and a 'high priest' stall action for 30 years by Jean Chemnick, E&E News, Oct 29, 2018
• Rebuffing Prime Minister's Order to Stay in Class, Australian Students Forge Ahead With #ClimateStrike Walkouts by Julia Conley, Common Dreams, Nov 27, 2018
• Rejecting climate report, Trump makes clear his indifference to evidence by Steve Benen, Rachel Maddow Show/MSNBC, Nov 27, 2018
• Bipartisan group of lawmakers propose landmark carbon tax by Timothy Cama & Miranda Green, The Hill, Nov 27, 2018
• Countries vowed to cut carbon emissions. They aren’t even close to their goals, U.N. report finds by Chris Mooney, Energy & Environment, Washington Post, Nov 27, 2018
• Trump on climate change: ‘People like myself, we have very high levels of intelligence but we’re not necessarily such believers.’ by Josh Dawsey, Philip Rucker, Brady Dennis & Chris Mooney, Politics, Washington Post, Nov 27, 2018
• Fact-checking the White House push back on climate assessment by Ellie Kaufman & Brandon Miller, CNN, Nov 28, 2018

Thu Nov 29, 2018

• Britain eyes large-scale CO2 capture and use by mid 2020s by Susanna Twidale, Reuters, Nov 28, 2018
• The Arctic is turning brown because of weird weather – and it could accelerate climate change by Rachael Treharne, The Conversation UK, Nov 26, 2018
• It's Not Just America: Climate Policies Are Stumbling Worldwide by Robinson Meyer, Science, The Atlantic, Nov 27, 2018
• Discussing climate change on the net by BaerbelW, Skeptical Science, Nov 29, 2018
• Indisputable Facts On Climate Change by Robert Rapier, Forbes, Nov 29, 2018
• Climate change already a health emergency, say experts by Damian Carrington, Environment, Guardian, Nov 28, 2018

Fri Nov 30, 2018

• A Simple Guide To All The Scary And Depressing Climate Change News At The Moment by Michael Marshall, Forbes, Nov 29, 2018
• A Major National Climate Report Came Out. Then the Deniers Got on TV. by Joe McCarthy, The Weather Channel, Nov 29, 2018
• UNEP: Limiting warming to 1.5C requires ‘fivefold’ increase in climate commitments by Zeke Hausfather, Carbon Brief, Nov 27, 2018
• Unable to Bury Climate Report, Trump & Deniers Launch Assault on the Science by Marianne Lavelle, InsideClimate News, Nov 30, 2018
• The Energy 202: Trump's EPA chief said there was 'no political review' of climate report. by Dino Grandoni, PowerPost, Washington Post, Nov 29, 2018

Sat Dec 1, 2018

• Climate Change Is Killing Canadians, Say Doctors, Canadian Press/HuffPost CA, Nov 29, 2018
• What You Need To Know About the UN Climate Talks in Poland by Chloe Farand and Mat Hope, DeSmog UK, Nov 28, 2018
• Striking students defy PM to protest at inaction on climate change by Josh Dye, Sydney Morning Herald, Nov 30, 2018
• Queensland's 'abnormal' bushfires linked to climate change by Kate Doyle &amp Lucy Murray, ABC News (Australia), Dec 1, 2018
• Climate change signals and impacts continue in 2018, Press Release, World Meteorological Organization, Nov 29, 2018
• AP FACT CHECK: 11 Trump climate goofs and 1 correct claim by Seth Borenstein, AP News, Nov 30, 2018

from Skeptical Science https://ift.tt/2U5EB9W

A chronological listing of news articles posted on the Skeptical Science Facebook Page during the past week, i.e., Sunday, Nov 25 through Saturday, Dec. 1

Editor's Pick

Climate change signals and impacts continue in 2018

 

 

The long-term warming trend has continued in 2018, with the average global temperature set to be the fourth highest on record. The 20 warmest years on record have been in the past 22 years, with the top four in the past four years, according to the World Meteorological Organization (WMO).

Other tell-tale signs of climate change, including sea level rise, ocean heat and acidification and sea-ice and glacier melt continue, whilst extreme weather left a trail of devastation on all continents, according to the WMO provisional Statement on the State of the Climate in 2018. It includes details of impacts of climate change based on contributions from a wide range of United Nations partners.

The report shows that the global average temperature for the first ten months of the year was nearly 1°C above the pre-industrial baseline (1850-1900). This is based on five independently maintained global temperature data sets.

“We are not on track to meet climate change targets and rein in temperature increases,” said WMO Secretary-General Petteri Taalas. “Greenhouse gas concentrations are once again at record levels and if the current trend continues we may see temperature increases 3-5°C by the end of the century. If we exploit all known fossil fuel resources, the temperature rise will be considerably higher,” he said.

“It is worth repeating once again that we are the first generation to fully understand climate change and the last generation to be able to do something about it,” said Mr Taalas.

The Intergovernmental Panel on Climate Change (IPCC) special report on Global Warming of 1.5°C reported that the average global temperature for the decade 2006-2015 was 0.86°C above the pre-industrial baseline. The average increase above the same baseline for the most recent decade 2009-2018 was about 0.93°C and for the past five years, 2014-2018, was 1.04°C above the pre-industrial baseline.

“These are more than just numbers,” said WMO Deputy Secretary-General Elena Manaenkova.

“Every fraction of a degree of warming makes a difference to human health and access to food and fresh water, to the extinction of animals and plants, to the survival of coral reefs and marine life. It makes a difference to economic productivity, food security, and to the resilience of our infrastructure and cities. It makes a difference to the speed of glacier melt and water supplies, and the future of low-lying islands and coastal communities. Every extra bit matters,” said Ms Manaenkova.

The WMO report adds to the authoritative scientific evidence that will inform UN climate change negotiations from 2-14 December in Katowice, Poland. The key objective of the meeting is to adopt the implementation guidelines of the Paris Agreement on Climate Change, which aims to hold the global average temperature increase to as close as possible to 1.5°C.

The IPCC report on Global Warming of 1.5°C said that this target was physically possible but would require unprecedented changes in our lifestyle, energy and transport systems. It showed how keeping temperature increases below 2°C would reduce the risks to human well-being, ecosystems and sustainable development.

National meteorological and hydrological services have been contributing to national climate assessments. A new U.S. federal report detailed how climate change is affecting the environment, agriculture, energy, land and water resources, transportation, and human health and welfare, with a risk that it will lead to growing losses to American infrastructure and property and impede the rate of economic growth over this century.

A UK assessment published 26 November warned summer temperatures could be up to 5.4°C hotter and summer rainfall could decrease by up to 47% by 2070, and sea levels in London could rise by 1.15m by 2100. A Swiss report on climate scenarios released on 13 November said that Switzerland is becoming hotter and drier, but will also struggle with heavier rainfall in the future and its famed ski resorts will have less snow.

“The WMO community is enhancing the translation of science into services. This will support countries in generating national climate scenarios and predictions and developing tailored climate services to reduce risks associated with climate change and increasingly extreme weather. WMO is also working to develop integrated tools to monitor and manage greenhouse gas emissions and carbon sinks,” said WMO Chief Scientist and Research Director Pavel Kabat.

Highlights of the provisional statement on the state of the climate

Temperatures: 2018 started with a weak La Niña event, which continued until March. By October, however, sea-surface temperatures in the eastern Tropical Pacific were showing signs of a return to El Niño conditions, although the atmosphere as yet shows little response. If El Niño develops, 2019 is likely to be warmer than 2018.

Greenhouse gases:  In 2017, carbon dioxide, methane and nitrous oxide concentrations reached new highs, according to WMO Greenhouse Gas Bulletin. Data from a number of locations, including Mauna Loa (Hawaii) and Cape Grim (Tasmania) indicate that they continued to increase in 2018.

Oceans: The oceans absorb more than 90% of the energy trapped by greenhouse gases and 25% of anthropogenic CO2 emissions, making them warmer and more acidic. For each 3-month period until September 2018, ocean heat content was the highest or second highest on record. Global Mean Sea Level from January to July 2018 was around 2 to 3 mm higher than the same period in 2017.

Sea ice: Arctic sea-ice extent was well below average throughout 2018 with record-low levels in the first two months of the year. The annual maximum occurred in mid-March and was the third lowest on record. The minimum extent in September was the 6th smallest on record, meaning that all 12 smallest September extents have been in the past 12 years. Antarctic sea-ice extent was also well below average throughout 2018. The annual minimum extent occurred in late February and was ranked as one of the two lowest extents. 

Extreme Weather

Tropical Storms:  The number of tropical cyclones was above average in all four Northern Hemisphere basins, with 70 reported by 20 November, compared to the long-term average of 53, leading to many casualties. The Northeast Pacific basin was especially active, with an Accumulated Cyclone Energy that was the highest since reliable satellite records began.

Two of the strongest tropical cyclones were Mangkhut, which impacted the Philippines, Hong Kong SAR and China, and Yutu, which brought devastation in the Mariana Islands. Jebi was the strongest typhoon to hit Japan since 1993, Son-Tinh caused flooding in Viet Nam and Laos, whilst Soulik contributed to flooding on the Korean peninsula. Hurricanes Florence and Michael were associated with huge economic damage and considerable loss of life in the United States. Gita, in the South Pacific, was the most intense and most expensive cyclone to ever hit Tonga.

Floods and rainfall: In August, the southwest Indian state of Kerala suffered the worst flooding since the 1920s, displacing more than 1.4 million people from their homes and affecting more than 5.4 million. Large parts of western Japan experienced destructive flooding in late June and early July, killing at least 230 people and destroying thousands of homes. Flooding affected many parts of east Africa in March and April. This included Kenya and Somalia, which had previously been suffering from severe drought, as well as Ethiopia and northern and central Tanzania.  An intense low-pressure system in the Mediterranean Sea in late October brought flooding, high winds and loss of life.

Heatwaves and drought: Large parts of Europe experienced exceptional heat and drought through the late spring and summer of 2018, leading to wildfires in Scandinavia. In July and August, there were numerous record high temperatures north of the Arctic Circle, and record long runs of warm temperatures., including 25 consecutive days above 25 °C in Helsinki (Finland). Parts of Germany had a long spell of days above 30°C, whilst a heatwave in France was associated with a number of deaths.  It was also an exceptionally warm and dry period in the United Kingdom and Ireland. A short but intense heatwave affected Spain and Portugal in early August.

Dry conditions were especially persistent in Germany, the Czech Republic, western Poland, the Netherlands, Belgium and parts of France. The Rhine approached record low flows by mid-October, seriously disrupting river transport.

Eastern Australia experienced significant drought during 2018, especially New South Wales and southern Queensland, with much of the region receiving less than half its average rainfall for the period from January to September.  Severe drought affected Uruguay, and northern and central Argentina, in late 2017 and early 2018, leading to heavy agricultural losses.

Both Japan and the Republic of Korea saw new national heat records (41.1 °C and 41.0°C respectively.)

Oman reported one of the highest known minimum overnight temperature of 42.6 °C in June. Algeria saw a new national of 51.3 °C in July.

Cold and snow: One of the most significant cold outbreaks of recent years affected Europe in late February and early March.

Wildfires: Major wildfires affected Athens (Greece) on 23 July, with many fatalities. British Columbia in Canada broke its record for the most area burned in a fire season for the second successive year. California suffered devastating wildfires, with November’s Camp Fire being the deadliest fire in over a century for the U.S.A. 

Other Impacts

The provisional statement contained details of impacts of climate change, based on contributions from the Food and Agriculture Organization (FAO), International Organization for Migration (IOM), UN Environment Programme (UNEP), UNESCO’s Intergovernmental Oceanographic Commission (IOC), UN High Commission for Refugees UNHCR) and World Food Programme (WFP). This section will be expanded in the final statement, to be released in March 2019.

Exposure of agriculture sectors to climate extremes is threatening to reverse gains made in ending malnutrition. New evidence shows a rise in world hunger after a prolonged decline. In 2017, the number of undernourished people was estimated to have increased to 821 million, according The State of Food Security and Nutrition in the World 2018, by to FAO, WFP, the International Fund for Agricultural Development, the UN Children’s Fund and the World Health Organization. Africa is the region where climate events had the biggest impact on acute food insecurity and malnutrition in 2017, affecting 59 million people in 24 countries and requiring urgent humanitarian action. Much of the vulnerability to climate variability is associated with the dryland farming and pastoral rangeland systems supporting 70–80% of the continent’s rural population.

Out of the 17.7 million Internally Displaced Persons tracked by the IOM, 2.3 million people were displaced due to disasters linked to weather and climate events as of September 2018. In Somalia, some 642 000 new internal displacements were recorded between January and July 2018 by UNHCR, with flooding the primary reason for displacement (43%), followed by drought (29%), and conflict (26%).

UN agencies including UNESCO-IOC and UNEP are tracking environmental impacts associated with climate change include coral bleaching, reduced levels of oxygen in the oceans, loss of “Blue Carbon” associated with coastal ecosystems such as mangroves and salt marshes. Climate change also exposes peatlands currently protected by permafrost to thawing and possible increased methane emissions and loss of carbon, and the associated sea-level rise increases the risks of coastal erosion and salination of freshwater peatlands.

Climate change signals and impacts continue in 2018, Press Release, World Meteorological Organization (WM0), Nov 29, 2018

Notes for Editors

Information used in this report is sourced from a large number of National Meteorological and Hydrological Services (NMHSs) and associated institutions, as well as Regional Climate Centres, the World Climate Research Programme (WCRP), the Global Atmosphere Watch (GAW) and Global Cryosphere Watch. Information has also been supplied by a number of other United Nations agencies, including the Food and Agriculture Organization (FAO), the World Food Programme (WFP), the United Nations High Commissioner for Refugees (UNHCR), the International Organization for Migration (IOM), the Intergovernmental Oceanographic Commission of UNESCO (IOC-UNESCO) and UN Environment

WMO uses datasets (based on monthly climatological data from observing sites) from the United States National Oceanic and Atmospheric Administration, NASA’s Goddard Institute for Space Studies, and the United Kingdom’s Met Office Hadley Centre and the University of East Anglia’s Climatic Research Unit in the United Kingdom.

It also uses reanalysis datasets from the European Centre for Medium Range Weather Forecasts and its Copernicus Climate Change Service, and the Japan Meteorological Agency.  This method combines millions of meteorological and marine observations, including from satellites, with models to produce a complete reanalysis of the atmosphere. The combination of observations with models makes it possible to estimate temperatures at any time and in any place across the globe, even in data-sparse areas such as the polar regions.

Story map featuring the Climate statement

Weather and Climate events 2018 interactive map

See also:  Key Climate Indicators table  

---

Links posted on Facebook

Sun Nov 25, 2018

• New research November 12-18, 2018 by Ari Jokimäki, Skeptical Science, Nov 23, 2018
• Poland calls for planting more forests worldwide to improve carbon capture by Agnieszka Barteczko, Reuters, Nov 22, 2018
• Why aren't they doing anything?: Students strike to give climate lesson by Peter Hannam, Environment, Sydney Morning Herald, Nov 25, 2018
• 3 Reasons Your Uncle Might Think Cold Days Disprove Global Warming by Marshall Shepard, Forbes, Nov 23, 2018
• The warming may be global, but adaptation will need to be local, Opinion by Lauren E Oakes, Los Angeles Times, Nov 25, 2018
• How to talk climate change with skeptical relatives during the holidays by Cody Nelson & Paul Huttner, MPR News, Nov 21, 2018
• Climate cash for developing world set to meet U.N. 2020 goal by Megan Rowling, Thompson Reuter Foundation, Nov 23, 2018
• The Beginning of the End of America’s Best Idea, Opinion by Timothy Egan, New York Times, Nov 23, 2018

Mon Nov 26, 2018

• Rising CO2 levels in the ocean could benefit toxic algae, study says by Daisy Dunne, Carbon Brief, Nov 19, 2018
• False claims of a coming ice age spread through ecosystem of unreliable news sites, blogs, and social media accounts by Emmanuel M Vincent, Insights, Climate Feedback, Nov 21, 2018
• The World Needs to Quit Coal. Why Is It So Hard? by Somini Sengupta, Climate, New York Times, Nov 24, 2018
• Trump Administration’s Strategy on Climate: Try to Bury Its Own Scientific Report, News Analysis by Coral Davenport, Climate, New York Times, Nov 25, 2018
• In Mount Everest Region, World's Highest Glaciers Are Melting, Receding. Photo Essay by Kunda Dixit, Nepali Times/InsideClimate News, Nov 26, 2018
• Climate Change Already Reshaping U.S., Says National Climate Assessment by Chelsea Harvey, E&E News/Scientific American, Nov 26, 2018
• Five Big Ways the United States Will Need to Adapt to Climate Change by Brad Plumer, Climate, New York Times, Nov 26, 2018
• Draft G20 statement waters down Paris climate commitment by Karl Mathiesen, Climate Home, Nov 26, 2018

Tue Nov 27, 2018

• Sydney to collect a month's rainfall in half a day as big low builds by Peter Hannam, Environment, Sydney Morning Herald, Nov 27, 2018
• Queensland bushfires: Evacuations amid 'highly unusual' conditions, BBC News, Nov 26, 2018
• Here’s what the climate change report says will happen to the economy if temperatures get hotter. Trump doesn’t ‘believe it’ by Steve Goldstein, MarketWatch, N0v 26, 2018
• How Trump Is Ensuring That Greenhouse Gas Emissions Will Rise by Coral Davenport & Lisa Friedman, Climate, New York Times, Nov 27, 2018
• World must triple efforts or face catastrophic climate change, says UN by Fiona Harvey, Environment, Guardian, Nov 27, 2018
• 10 ways to accelerate progress against climate change by Eliza Barclay & Umair Irfan, Energy & Environment, Vox, Nov 26, 2018
• The Depravity of Climate-Change Denial, Opinion by Paul Krugman, New York Times, Nov 26, 2018
• A political blockade is colliding with the evidence on climate change, Analysis by Ronald Brownstein, CNN, Nov 27, 2018

Wed Nov 28, 2018

• Oil kingdom and a 'high priest' stall action for 30 years by Jean Chemnick, E&E News, Oct 29, 2018
• Rebuffing Prime Minister's Order to Stay in Class, Australian Students Forge Ahead With #ClimateStrike Walkouts by Julia Conley, Common Dreams, Nov 27, 2018
• Rejecting climate report, Trump makes clear his indifference to evidence by Steve Benen, Rachel Maddow Show/MSNBC, Nov 27, 2018
• Bipartisan group of lawmakers propose landmark carbon tax by Timothy Cama & Miranda Green, The Hill, Nov 27, 2018
• Countries vowed to cut carbon emissions. They aren’t even close to their goals, U.N. report finds by Chris Mooney, Energy & Environment, Washington Post, Nov 27, 2018
• Trump on climate change: ‘People like myself, we have very high levels of intelligence but we’re not necessarily such believers.’ by Josh Dawsey, Philip Rucker, Brady Dennis & Chris Mooney, Politics, Washington Post, Nov 27, 2018
• Fact-checking the White House push back on climate assessment by Ellie Kaufman & Brandon Miller, CNN, Nov 28, 2018

Thu Nov 29, 2018

• Britain eyes large-scale CO2 capture and use by mid 2020s by Susanna Twidale, Reuters, Nov 28, 2018
• The Arctic is turning brown because of weird weather – and it could accelerate climate change by Rachael Treharne, The Conversation UK, Nov 26, 2018
• It's Not Just America: Climate Policies Are Stumbling Worldwide by Robinson Meyer, Science, The Atlantic, Nov 27, 2018
• Discussing climate change on the net by BaerbelW, Skeptical Science, Nov 29, 2018
• Indisputable Facts On Climate Change by Robert Rapier, Forbes, Nov 29, 2018
• Climate change already a health emergency, say experts by Damian Carrington, Environment, Guardian, Nov 28, 2018

Fri Nov 30, 2018

• A Simple Guide To All The Scary And Depressing Climate Change News At The Moment by Michael Marshall, Forbes, Nov 29, 2018
• A Major National Climate Report Came Out. Then the Deniers Got on TV. by Joe McCarthy, The Weather Channel, Nov 29, 2018
• UNEP: Limiting warming to 1.5C requires ‘fivefold’ increase in climate commitments by Zeke Hausfather, Carbon Brief, Nov 27, 2018
• Unable to Bury Climate Report, Trump & Deniers Launch Assault on the Science by Marianne Lavelle, InsideClimate News, Nov 30, 2018
• The Energy 202: Trump's EPA chief said there was 'no political review' of climate report. by Dino Grandoni, PowerPost, Washington Post, Nov 29, 2018

Sat Dec 1, 2018

• Climate Change Is Killing Canadians, Say Doctors, Canadian Press/HuffPost CA, Nov 29, 2018
• What You Need To Know About the UN Climate Talks in Poland by Chloe Farand and Mat Hope, DeSmog UK, Nov 28, 2018
• Striking students defy PM to protest at inaction on climate change by Josh Dye, Sydney Morning Herald, Nov 30, 2018
• Queensland's 'abnormal' bushfires linked to climate change by Kate Doyle &amp Lucy Murray, ABC News (Australia), Dec 1, 2018
• Climate change signals and impacts continue in 2018, Press Release, World Meteorological Organization, Nov 29, 2018
• AP FACT CHECK: 11 Trump climate goofs and 1 correct claim by Seth Borenstein, AP News, Nov 30, 2018

from Skeptical Science https://ift.tt/2U5EB9W

Small asteroid to sweep close this weekend

Very small asteroid 2018 WV1 on November 30 – slightly more than a day prior to its closest approach to Earth – via Northolt Branch Observatories.

Daniel Bamberger of Northolt Branch Observatories, a private observatory in Northolt, London, U.K., wrote late last night (November 30, 2018) about a small asteroid – just discovered – that will sweep extremely close to Earth Sunday morning, December 2, 2018. The asteroid designated 2018 WV1 will sweep closest at 03:11 UTC on Sunday. It will come within 0.09 lunar distances (32,911 km / 20,450 miles), making it the third-closest asteroid to pass Earth this year. Its estimated diameter is between 8.2 and 18.3 feet (2.5 and 5.6 meters). Bamgerger wrote:

2018 WV1 was found on November 29 at the Catalina Sky Survey in Arizona, USA. It will make a close encounter on Sunday morning, coming within 27,000 km (16,800 mi) from the Earth’s surface – closer than the geostationary satellites.

Besides its very close approach, 2018 WV1 is interesting for several reasons. One is its very low velocity relative to Earth: This makes it very likely that 2018 WV1 is a piece of lunar ejecta, a fragment of the moon that was ejected into space when a larger asteroid hit the moon a long time ago.

When 2018 WV1 was discovered, the initial orbit showed a 2% chance of hitting the Earth in early December. Luckily, that possibility was ruled out soon after.

Even if it had hit us, the object is too small to be a threat.

To help further refine its orbit, we have observed 2018 WV1 tonight from [Northolt Branch Observatories]. The asteroid was at a distance of 285,000 km from Earth at that time, and approaching, still a faint object at 19th magnitude.

According to The Watchers, since the beginning of 2018, observatories on Earth have detected 70 asteroids with flyby distance within 1 lunar distance.

Bottom line: Astronomers found asteroid 2018 WV1 on November 29. On December 2, it will pass closer to Earth than geosynchronous satellites.

from EarthSky https://ift.tt/2Q58DME

Very small asteroid 2018 WV1 on November 30 – slightly more than a day prior to its closest approach to Earth – via Northolt Branch Observatories.

Daniel Bamberger of Northolt Branch Observatories, a private observatory in Northolt, London, U.K., wrote late last night (November 30, 2018) about a small asteroid – just discovered – that will sweep extremely close to Earth Sunday morning, December 2, 2018. The asteroid designated 2018 WV1 will sweep closest at 03:11 UTC on Sunday. It will come within 0.09 lunar distances (32,911 km / 20,450 miles), making it the third-closest asteroid to pass Earth this year. Its estimated diameter is between 8.2 and 18.3 feet (2.5 and 5.6 meters). Bamgerger wrote:

2018 WV1 was found on November 29 at the Catalina Sky Survey in Arizona, USA. It will make a close encounter on Sunday morning, coming within 27,000 km (16,800 mi) from the Earth’s surface – closer than the geostationary satellites.

Besides its very close approach, 2018 WV1 is interesting for several reasons. One is its very low velocity relative to Earth: This makes it very likely that 2018 WV1 is a piece of lunar ejecta, a fragment of the moon that was ejected into space when a larger asteroid hit the moon a long time ago.

When 2018 WV1 was discovered, the initial orbit showed a 2% chance of hitting the Earth in early December. Luckily, that possibility was ruled out soon after.

Even if it had hit us, the object is too small to be a threat.

To help further refine its orbit, we have observed 2018 WV1 tonight from [Northolt Branch Observatories]. The asteroid was at a distance of 285,000 km from Earth at that time, and approaching, still a faint object at 19th magnitude.

According to The Watchers, since the beginning of 2018, observatories on Earth have detected 70 asteroids with flyby distance within 1 lunar distance.

Bottom line: Astronomers found asteroid 2018 WV1 on November 29. On December 2, it will pass closer to Earth than geosynchronous satellites.

from EarthSky https://ift.tt/2Q58DME

Golden virga at sunset

Image via Peter Lowenstein.

Peter Lowenstein in Mutare, Zimbabwe has contributed many amazing photos to EarthSky. Here’s what he told us about this image:

The first rains of the rainy season have fallen in Mutare over the past three days and humidity has been high. This afternoon cloud started to clear allowing the setting sun to emerge and shine brightly from a gap beneath it. Then something strange happened. At 10 minutes to 6:00, a patch of mist produced by condensation from moist cooling air began to reflect the setting sunlight to produce a bright spherical and then oblong apparition which floated for a minute or two directly above Hospital Hill. A short time later more widespread sunlit veils of condensation started to form and then developed into beautiful thin curtains of golden virga which for a few minutes shone brightly and remained suspended in the air.

Camera: Panasonic Lumix DMC TZ60 in sunset scene mode.

We’ve all seen virga, but maybe not known what it’s called. Virga is rain that evaporates before it hits the ground.

Thanks Peter!

Bottom line: Photo of virga in Mutare, Zimbabwe.

EarthSky lunar calendars are cool! They make great gifts. Order now. Going fast!

from EarthSky https://ift.tt/2reMyfH

Image via Peter Lowenstein.

Peter Lowenstein in Mutare, Zimbabwe has contributed many amazing photos to EarthSky. Here’s what he told us about this image:

The first rains of the rainy season have fallen in Mutare over the past three days and humidity has been high. This afternoon cloud started to clear allowing the setting sun to emerge and shine brightly from a gap beneath it. Then something strange happened. At 10 minutes to 6:00, a patch of mist produced by condensation from moist cooling air began to reflect the setting sunlight to produce a bright spherical and then oblong apparition which floated for a minute or two directly above Hospital Hill. A short time later more widespread sunlit veils of condensation started to form and then developed into beautiful thin curtains of golden virga which for a few minutes shone brightly and remained suspended in the air.

Camera: Panasonic Lumix DMC TZ60 in sunset scene mode.

We’ve all seen virga, but maybe not known what it’s called. Virga is rain that evaporates before it hits the ground.

Thanks Peter!

Bottom line: Photo of virga in Mutare, Zimbabwe.

EarthSky lunar calendars are cool! They make great gifts. Order now. Going fast!

from EarthSky https://ift.tt/2reMyfH

Moon and Venus December 2 to 4

In the coming mornings – December 2, 3 and 4, 2018 – look eastward before sunrise for the moon and Venus. If your sky is clear, you can’t miss them! They’re always the brightest and second-brightest celestial bodies, respectively, to light up the night sky. Plus – around now – Venus is at its maximum brightness for this morning apparition, with its greatest illuminated extent falling around December 2.

The moon and Venus are so bright and beautiful that you’ll easily spot them at morning dawn. And, if you’re willing to get up an hour or two before sunrise, you can also see the bright star Arcturus to the north (left) of the moon and Venus, and the star Spica close to Venus.

If you peered at Venus through a telescope now, you’d find it in a waxing crescent phase. That’s because Venus passed between us and the sun on October 26, and its lighted half – or day side – is still facing mostly away from us. In early December, 2018, meanwhile, the moon is waning, and the phase of the waning crescent moon and waxing crescent Venus are almost identical. Both worlds are now showing us disks that are about one-quarter (25%) illuminated by sunshine. If you have a telescope, remember … you’ll get a crisper view of Venus’ phase at dawn, when this brilliant world has climbed higher above your horizon and its glare has been reduced by the breaking day.

Click here to find out the present phase of the moon and Venus

Venus in the predawn Tucson, Arizona sky on November 27, 2018. Eliot Herman wrote: “Venus is currently about as bright as it will be for this cycle, glowing in the eastern morning sky. Venus is amazingly bright! Crescent Venus inset captured with a Questar telescope, 50 mm lens and a Nikon D850.”

After today, the moon’s phase will continue to wane (get smaller) as the moon falls closer to the sunrise over the next several mornings. On December 5 and 6, 2018, the thin lunar crescent will swing by the planet Mercury, though Mercury will be quite hard to spot in the glow of morning twilight. Binoculars may help. See the chart below.

The good news is that Mercury is brightening day by day and, moreover, is coming up earlier by the day. So, by the middle of December, Mercury should become a fine morning object.

It’ll be tough to catch the slender crescent moon with the planet Mercury before sunrise December 5. But some of EarthSky’s eagle-eyed observers have surprised us before and might surprise us again! Submit your photo here, if you get one, or post in the comments below.

As the moon’s phase wanes, Venus’ phases waxes, as this world pulls ahead of us in its smaller, faster orbit, causing its illuminated or day side to slowly turn out way.

When Venus’ disk reaches its half-lit waxing quarter phase on January 6, 2019, this planet will be at its greatest elongation of 47 degrees west of the sun.

After Venus attains this milestone in the morning sky, this planet will begin slowly but surely sinking toward the sunrise. It’ll take many months to do this, as it moves ahead of us in orbit. Venus will finally pass more or less behind the sun from Earth – at what astronomers call superior conjunction – on August 14, 2019. At that juncture, Venus will transition out of the morning sky and into evening sky. See the diagram below.

The Earth and Venus orbit the sun counterclockwise as seen to the north of the solar system plane. When Venus is to the east (left) of the Earth-sun line, we see Venus as an evening “star” in the west after sunset. After Venus reaches its inferior conjunction, Venus then moves to the west (right) of the Earth- sun line, appearing as a morning “star” in the east before sunrise.

Now back to the current month! The moon will turn new, to swing more or less between the sun and Earth, on December 7, 2018. At that time, the moon will transition from the morning to the evening sky.

Mercury and Venus are called inferior planets because they orbit the sun inside of Earth’s orbit. Although Venus is about twice Mercury’s distance from the sun, Venus is nonetheless the hotter of these two worlds. Climate does not depend on the sun alone but also on a planet’s atmosphere. Venus’ thick atmosphere creates a greenhouse effect that brings Venus’ surface temperature to 864 degrees Fahrenheit (462 degrees Celsius). Read more here.

Even though the moon and Earth are virtually the same distance from the sun, the moon’s daytime temperature is much hotter, and its nighttime temperature is much colder, than here on Earth. That’s because Earth has a protective atmosphere whereas the moon has no atmosphere of significance. Read more.

Bottom line: These next several mornings – December 2 to 4, 2018 – watch for the waning crescent moon to sweep by Venus, the solar system’s hottest planet. Some of you might also catch the moon near Mercury, the solar system’s innermost planet, on December 5.

from EarthSky https://ift.tt/2FPcmJm

In the coming mornings – December 2, 3 and 4, 2018 – look eastward before sunrise for the moon and Venus. If your sky is clear, you can’t miss them! They’re always the brightest and second-brightest celestial bodies, respectively, to light up the night sky. Plus – around now – Venus is at its maximum brightness for this morning apparition, with its greatest illuminated extent falling around December 2.

The moon and Venus are so bright and beautiful that you’ll easily spot them at morning dawn. And, if you’re willing to get up an hour or two before sunrise, you can also see the bright star Arcturus to the north (left) of the moon and Venus, and the star Spica close to Venus.

If you peered at Venus through a telescope now, you’d find it in a waxing crescent phase. That’s because Venus passed between us and the sun on October 26, and its lighted half – or day side – is still facing mostly away from us. In early December, 2018, meanwhile, the moon is waning, and the phase of the waning crescent moon and waxing crescent Venus are almost identical. Both worlds are now showing us disks that are about one-quarter (25%) illuminated by sunshine. If you have a telescope, remember … you’ll get a crisper view of Venus’ phase at dawn, when this brilliant world has climbed higher above your horizon and its glare has been reduced by the breaking day.

Click here to find out the present phase of the moon and Venus

Venus in the predawn Tucson, Arizona sky on November 27, 2018. Eliot Herman wrote: “Venus is currently about as bright as it will be for this cycle, glowing in the eastern morning sky. Venus is amazingly bright! Crescent Venus inset captured with a Questar telescope, 50 mm lens and a Nikon D850.”

After today, the moon’s phase will continue to wane (get smaller) as the moon falls closer to the sunrise over the next several mornings. On December 5 and 6, 2018, the thin lunar crescent will swing by the planet Mercury, though Mercury will be quite hard to spot in the glow of morning twilight. Binoculars may help. See the chart below.

The good news is that Mercury is brightening day by day and, moreover, is coming up earlier by the day. So, by the middle of December, Mercury should become a fine morning object.

It’ll be tough to catch the slender crescent moon with the planet Mercury before sunrise December 5. But some of EarthSky’s eagle-eyed observers have surprised us before and might surprise us again! Submit your photo here, if you get one, or post in the comments below.

As the moon’s phase wanes, Venus’ phases waxes, as this world pulls ahead of us in its smaller, faster orbit, causing its illuminated or day side to slowly turn out way.

When Venus’ disk reaches its half-lit waxing quarter phase on January 6, 2019, this planet will be at its greatest elongation of 47 degrees west of the sun.

After Venus attains this milestone in the morning sky, this planet will begin slowly but surely sinking toward the sunrise. It’ll take many months to do this, as it moves ahead of us in orbit. Venus will finally pass more or less behind the sun from Earth – at what astronomers call superior conjunction – on August 14, 2019. At that juncture, Venus will transition out of the morning sky and into evening sky. See the diagram below.

The Earth and Venus orbit the sun counterclockwise as seen to the north of the solar system plane. When Venus is to the east (left) of the Earth-sun line, we see Venus as an evening “star” in the west after sunset. After Venus reaches its inferior conjunction, Venus then moves to the west (right) of the Earth- sun line, appearing as a morning “star” in the east before sunrise.

Now back to the current month! The moon will turn new, to swing more or less between the sun and Earth, on December 7, 2018. At that time, the moon will transition from the morning to the evening sky.

Mercury and Venus are called inferior planets because they orbit the sun inside of Earth’s orbit. Although Venus is about twice Mercury’s distance from the sun, Venus is nonetheless the hotter of these two worlds. Climate does not depend on the sun alone but also on a planet’s atmosphere. Venus’ thick atmosphere creates a greenhouse effect that brings Venus’ surface temperature to 864 degrees Fahrenheit (462 degrees Celsius). Read more here.

Even though the moon and Earth are virtually the same distance from the sun, the moon’s daytime temperature is much hotter, and its nighttime temperature is much colder, than here on Earth. That’s because Earth has a protective atmosphere whereas the moon has no atmosphere of significance. Read more.

Bottom line: These next several mornings – December 2 to 4, 2018 – watch for the waning crescent moon to sweep by Venus, the solar system’s hottest planet. Some of you might also catch the moon near Mercury, the solar system’s innermost planet, on December 5.

from EarthSky https://ift.tt/2FPcmJm