See this week’s Venus-Saturn pairing

Maybe you saw bright Jupiter near even-brighter Venus in the west after sunset in late November? The Venus-Saturn conjunction happens this week. It won’t be as dramatic as Venus-Jupiter, but it’ll still be very cool. Start watching tonight, as soon as the sky begins to darken. You’ll see a very bright light in the west after sunset. That’ll be Venus. Saturn will be the fainter light – still as bright as the brightest stars – nearby. They’ll pop out near the sunset point, as bright twilight ebbs toward darkness.

The actual conjunction happens on December 10 or 11, 2019, depending on your time zone. More about that below.

Dazzling Venus – brightest planet 3rd-brightest object in the sky after the sun and moon – will pop out first, around 30 minutes (or sooner) after the sun goes down. Saturn – shining as brilliantly as a 1st-magnitude star, or one of the brightest stars in our sky – will join up with Venus perhaps 15 minutes or so after Venus’ initial appearance.

Saturn, although respectably bright, pales next to Venus, which outshines Saturn by more than 60 times.

See another bright object up there, even closer to the sunset? That’ll be Jupiter.

The last time Venus and Saturn had a conjunction in the evening sky was on October 30, 2016. David Wilson of Weaverville, North Carolina wrote: “We drove up on the Blue Ridge Parkway tonight to get some shots of the Venus-Saturn conjunction. We stopped at the ‘highest point’ on the parkway…”

Two planets are said to be in conjunction when they are north and south of one another on the sky’s dome. At conjunction, Venus sweeps 1.8 degrees south of Saturn. For reference, your index finger at an arm length spans about 2 degrees of sky.

We like the trusty Observer’s Handbook from the Royal Astronomical Society of Canada; it gives the time of the Venus-Saturn conjunction as December 11, 2019 at 4:00 UTC.

Jean Meeus – another excellent source that I often use – also gives the same date for the Venus-Saturn conjunction as December 11, 2019, but at 5:00 UTC.

The helpful website In-the-Sky.org gives the date and time of the conjunction as December 11 at 04:41 UTC. You can see that all of these times indicate the same time, but that the various sources are rounding the times slightly differently. The exact time isn’t as important as simply getting out there after sunset, and looking on either December 10 or 11.

You’ll want to catch this stunning planetary conjunction at dusk or nightfall (60 to 90 minutes after sunset) because these worlds will follow the sun beneath the horizon by early evening (about 2 hours after sundown).

If you have binoculars, aim them at Venus to spot Saturn all the sooner after sunset.

To optimize your sky watching pleasure, find an unobstructed horizon in the direction of sunset. Better yet, find a hill or balcony that’ll enable you to peek a little farther beyond the horizon. Venus and Saturn will set at nearly the same time for the next day or two, about 2 hours after sundown from virtually everywhere worldwide.

After their conjunction, Venus will continue its climb upward away from the sunset. It’ll be the stunning “evening star” in early 2020. Meanwhile, Saturn will fall sunward, following Jupiter into the sunset. Jupiter will disappear around mid-December. Saturn will fade into the sunset glare by late December 2019 or early January 2020.

View at EarthSky Community Photos. | Peter Lowenstein in Mutare, Zimbabwe caught Venus and Saturn – the 2 bright objects near the top of this photo – on December 7, 2019. Notice the bright “star” below them, nearly buried in clouds. That is Jupiter. These worlds are oriented differently from the Southern Hemisphere than from the Northern Hemisphere. For the exact view from your location, try Stellarium. And don’t worry. If you just look west after sunset, you’ll know these worlds when you see them. That’s because Venus will be the brightest thing up there!

Venus and Saturn appear close together on the sky’s dome because they reside on nearly the same line of sight, as viewed from Earth.

But, of course, these worlds are not actually close together in space. Venus, the second planet outward from the sun, lies about 1.4 astronomical units (AU) from Earth, while Saturn, the 6th planet outward from the sun, resides nearly 8 times farther away, at 10.9 AU from Earth. For reference, one astronomical unit (AU) = sun-Earth distance.

People sometimes ask us how an inferior planet can have a conjunction with a superior planet in Earth’s sky. If a diagram is worth a thousand words, then perhaps the answer can be divined below.

Bird’s-eye view of the north side of the solar system as Venus and Saturn are in conjunction (from the vantage point of Earth) on December 11, 2019, at 4 hours UTC. Look closely and you can see that the Earth, Venus and Saturn pretty much make a straight line in space. . Diagram via EarthView.

Bottom line: Around December 9, 10 and 11, 2019, look in the sunset direction – close to the sunset point on the horizon, not long after the sun goes down – for the the conjunction of 2 bright planets, Venus and Saturn. Some will also spot Jupiter nearby.

from EarthSky https://ift.tt/2OZTQk9

Maybe you saw bright Jupiter near even-brighter Venus in the west after sunset in late November? The Venus-Saturn conjunction happens this week. It won’t be as dramatic as Venus-Jupiter, but it’ll still be very cool. Start watching tonight, as soon as the sky begins to darken. You’ll see a very bright light in the west after sunset. That’ll be Venus. Saturn will be the fainter light – still as bright as the brightest stars – nearby. They’ll pop out near the sunset point, as bright twilight ebbs toward darkness.

The actual conjunction happens on December 10 or 11, 2019, depending on your time zone. More about that below.

Dazzling Venus – brightest planet 3rd-brightest object in the sky after the sun and moon – will pop out first, around 30 minutes (or sooner) after the sun goes down. Saturn – shining as brilliantly as a 1st-magnitude star, or one of the brightest stars in our sky – will join up with Venus perhaps 15 minutes or so after Venus’ initial appearance.

Saturn, although respectably bright, pales next to Venus, which outshines Saturn by more than 60 times.

See another bright object up there, even closer to the sunset? That’ll be Jupiter.

The last time Venus and Saturn had a conjunction in the evening sky was on October 30, 2016. David Wilson of Weaverville, North Carolina wrote: “We drove up on the Blue Ridge Parkway tonight to get some shots of the Venus-Saturn conjunction. We stopped at the ‘highest point’ on the parkway…”

Two planets are said to be in conjunction when they are north and south of one another on the sky’s dome. At conjunction, Venus sweeps 1.8 degrees south of Saturn. For reference, your index finger at an arm length spans about 2 degrees of sky.

We like the trusty Observer’s Handbook from the Royal Astronomical Society of Canada; it gives the time of the Venus-Saturn conjunction as December 11, 2019 at 4:00 UTC.

Jean Meeus – another excellent source that I often use – also gives the same date for the Venus-Saturn conjunction as December 11, 2019, but at 5:00 UTC.

The helpful website In-the-Sky.org gives the date and time of the conjunction as December 11 at 04:41 UTC. You can see that all of these times indicate the same time, but that the various sources are rounding the times slightly differently. The exact time isn’t as important as simply getting out there after sunset, and looking on either December 10 or 11.

You’ll want to catch this stunning planetary conjunction at dusk or nightfall (60 to 90 minutes after sunset) because these worlds will follow the sun beneath the horizon by early evening (about 2 hours after sundown).

If you have binoculars, aim them at Venus to spot Saturn all the sooner after sunset.

To optimize your sky watching pleasure, find an unobstructed horizon in the direction of sunset. Better yet, find a hill or balcony that’ll enable you to peek a little farther beyond the horizon. Venus and Saturn will set at nearly the same time for the next day or two, about 2 hours after sundown from virtually everywhere worldwide.

After their conjunction, Venus will continue its climb upward away from the sunset. It’ll be the stunning “evening star” in early 2020. Meanwhile, Saturn will fall sunward, following Jupiter into the sunset. Jupiter will disappear around mid-December. Saturn will fade into the sunset glare by late December 2019 or early January 2020.

View at EarthSky Community Photos. | Peter Lowenstein in Mutare, Zimbabwe caught Venus and Saturn – the 2 bright objects near the top of this photo – on December 7, 2019. Notice the bright “star” below them, nearly buried in clouds. That is Jupiter. These worlds are oriented differently from the Southern Hemisphere than from the Northern Hemisphere. For the exact view from your location, try Stellarium. And don’t worry. If you just look west after sunset, you’ll know these worlds when you see them. That’s because Venus will be the brightest thing up there!

Venus and Saturn appear close together on the sky’s dome because they reside on nearly the same line of sight, as viewed from Earth.

But, of course, these worlds are not actually close together in space. Venus, the second planet outward from the sun, lies about 1.4 astronomical units (AU) from Earth, while Saturn, the 6th planet outward from the sun, resides nearly 8 times farther away, at 10.9 AU from Earth. For reference, one astronomical unit (AU) = sun-Earth distance.

People sometimes ask us how an inferior planet can have a conjunction with a superior planet in Earth’s sky. If a diagram is worth a thousand words, then perhaps the answer can be divined below.

Bird’s-eye view of the north side of the solar system as Venus and Saturn are in conjunction (from the vantage point of Earth) on December 11, 2019, at 4 hours UTC. Look closely and you can see that the Earth, Venus and Saturn pretty much make a straight line in space. . Diagram via EarthView.

Bottom line: Around December 9, 10 and 11, 2019, look in the sunset direction – close to the sunset point on the horizon, not long after the sun goes down – for the the conjunction of 2 bright planets, Venus and Saturn. Some will also spot Jupiter nearby.

from EarthSky https://ift.tt/2OZTQk9

Mars-Zubenelgenubi conjunction December 12

Yes, the dazzling conjunction of the brilliant planets Venus and Saturn at dusk/nightfall counts as this month’s marquee event, but let’s not forget about the less showy conjunction of two modestly-bright celestial lights – the red planet Mars and the star Zubenelgenubi – in the morning sky. Get up 1 1/2 hours (or more) before sunrise to view the close-knit morning couple lighting up the predawn darkness all this upcoming week. The conjunction happens on or near December 12, 2019.

There’s also a conjunction in the evening sky! In North America, Venus and Saturn have their conjunction on the evening of December 10, 2019. Read more.

For your convenience, we give you the approximate rising time of Mars for various latitudes (given an absolutely level and unobstructed horizon) for the next several days:

40 degrees north latitude
Mars rises 2 3/4 hours before the sun

Equator (0 degrees latitude)
Mars rises 2 1/3 hours before the sun

35 degrees south latitude
Mars rises 2 hours before the sun

Want more specific information? Click here for a recommended sky almanac.

Mars and Zubenelgenubi, the constellation Libra’s alpha star, shine plenty close together on the sky’s dome all this upcoming week. In fact, the twosome will easily fit inside a single binocular field all the while. You can distinguish ruddy Mars from Zubenelgenubi, because Mars is the brighter of the two – better than twice as bright as Zubenelgenubi. However, both Mars and Zubenelgenubi are rather easy to see with the eye alone in a dark sky.

Look for fainter Zubenelgenubi above brighter Mars before dawn December 10, 2019.

Mars and Zubenelgenubi snuggle up together before dawn on December 12, 2019.

Look for Mars below Zubenelgenubi before dawn December 14, 2019.

Binoculars may come in handy, though. When the twosome first rises into your southeast sky, the extra thickness of Earth’s atmosphere near the horizon may blur or extinguish the view of the morning couple. Or, if you get up too late, the early morning twilight may wash them out. However, if you see Mars but not Zubenelgenubi, aim binoculars at Mars to reel Zubenelgenubi into visibility.

Even if you can spot both Mars and Zubenelgenubi with the unaided eye, you may still want to use binoculars to check out Zubenelgenubi. Binoculars reveal that Zubenelgenubi is double star – two stars in one. It is believed that these two stars are physically related, so Zubenelgenubi is probably a binary star – two stars revolving around a common center of mass.

Sky chart of the constellation Libra via IAU (International Astronomical Union). Each year, the sun passes in front of Libra from October 31 to November 23, and the sun has its annual conjunction with Zubenelgenubi on or near November 7. Zubenelgenubi is only about 1/3rd of a degree north of the ecliptic – the Earth’s orbital plane projected onto the constellations of the zodiac.

Want a sky chart showing the present position of Mars upon the zodiac? Click on this interactive sky chart via Heavens-Above.

Mars travels eastward in front of the constellation Libra the Scales all through December 2019. On December 10, 2019, Mars is heading in the direction of Zubenelgenubi; by December 14, 2019, Mars is definitely moving away from Zubenelgenubi. Midway between these dates – on or near December 12, 2019 – Mars passes a scant 1/5th of one degree to the north of Zubenelgenubi. (For reference, the width of your little finger at arm’s length spans about one degree of sky.)

This next week, before dawn, watch as the red planet Mars sweeps by Zubenelgenubi, the constellation Libra’s alpha star.

from EarthSky https://ift.tt/2LzIz88

Yes, the dazzling conjunction of the brilliant planets Venus and Saturn at dusk/nightfall counts as this month’s marquee event, but let’s not forget about the less showy conjunction of two modestly-bright celestial lights – the red planet Mars and the star Zubenelgenubi – in the morning sky. Get up 1 1/2 hours (or more) before sunrise to view the close-knit morning couple lighting up the predawn darkness all this upcoming week. The conjunction happens on or near December 12, 2019.

There’s also a conjunction in the evening sky! In North America, Venus and Saturn have their conjunction on the evening of December 10, 2019. Read more.

For your convenience, we give you the approximate rising time of Mars for various latitudes (given an absolutely level and unobstructed horizon) for the next several days:

40 degrees north latitude
Mars rises 2 3/4 hours before the sun

Equator (0 degrees latitude)
Mars rises 2 1/3 hours before the sun

35 degrees south latitude
Mars rises 2 hours before the sun

Want more specific information? Click here for a recommended sky almanac.

Mars and Zubenelgenubi, the constellation Libra’s alpha star, shine plenty close together on the sky’s dome all this upcoming week. In fact, the twosome will easily fit inside a single binocular field all the while. You can distinguish ruddy Mars from Zubenelgenubi, because Mars is the brighter of the two – better than twice as bright as Zubenelgenubi. However, both Mars and Zubenelgenubi are rather easy to see with the eye alone in a dark sky.

Look for fainter Zubenelgenubi above brighter Mars before dawn December 10, 2019.

Mars and Zubenelgenubi snuggle up together before dawn on December 12, 2019.

Look for Mars below Zubenelgenubi before dawn December 14, 2019.

Binoculars may come in handy, though. When the twosome first rises into your southeast sky, the extra thickness of Earth’s atmosphere near the horizon may blur or extinguish the view of the morning couple. Or, if you get up too late, the early morning twilight may wash them out. However, if you see Mars but not Zubenelgenubi, aim binoculars at Mars to reel Zubenelgenubi into visibility.

Even if you can spot both Mars and Zubenelgenubi with the unaided eye, you may still want to use binoculars to check out Zubenelgenubi. Binoculars reveal that Zubenelgenubi is double star – two stars in one. It is believed that these two stars are physically related, so Zubenelgenubi is probably a binary star – two stars revolving around a common center of mass.

Sky chart of the constellation Libra via IAU (International Astronomical Union). Each year, the sun passes in front of Libra from October 31 to November 23, and the sun has its annual conjunction with Zubenelgenubi on or near November 7. Zubenelgenubi is only about 1/3rd of a degree north of the ecliptic – the Earth’s orbital plane projected onto the constellations of the zodiac.

Want a sky chart showing the present position of Mars upon the zodiac? Click on this interactive sky chart via Heavens-Above.

Mars travels eastward in front of the constellation Libra the Scales all through December 2019. On December 10, 2019, Mars is heading in the direction of Zubenelgenubi; by December 14, 2019, Mars is definitely moving away from Zubenelgenubi. Midway between these dates – on or near December 12, 2019 – Mars passes a scant 1/5th of one degree to the north of Zubenelgenubi. (For reference, the width of your little finger at arm’s length spans about one degree of sky.)

This next week, before dawn, watch as the red planet Mars sweeps by Zubenelgenubi, the constellation Libra’s alpha star.

from EarthSky https://ift.tt/2LzIz88

Hefty black hole holds new record for most mass

This galaxy cluster – Abell 85 – consists of more than 500 individual galaxies. The bright one in the center is called Holm 15A. Astronomers peered into its heart to measure the mass of a black hole 40 billion times more massive than our sun. Image via Matthias Kluge/ USM Wendelstein observatory/ MPE.

The Max Planck Institute for Extraterrestrial Physics (MPE) near Munich, Germany said on December 3, 2019 that astronomers have set a new record for finding the most massive black hole in the universe. They found it not because it’s doing something exotic or noticeable. On the contrary, they noticed this black hole because it caused the center of its galaxy to be peculiarly fainter than it would be otherwise, given the galaxy’s huge mass of stars.

Holmberg 15A is a supergiant elliptical galaxy, some 700 million light-years from Earth. It’s the central galaxy of the Abell 85 galaxy cluster. In contrast to our Milky Way’s central black hole of about 4 million solar masses, the new record-holding central black hole in the galaxy Holm 15A is 40 billion times more massive than our sun.

The astronomers’ statement explained:

Even though the central galaxy of the cluster Abell 85 has the enormous visible mass of about 2 trillion (10¹²) solar masses in stars, the center of the galaxy is extremely diffuse and faint. This is why a joint group of astronomers at MPE and the University Observatory Munich got interested in the galaxy.

This central diffuse region in the galaxy is almost as large as the Large Magellanic Cloud, and this was a suspicious clue for the presence of a black hole with a very high mass.

Astronomers measured and evaluated the light coming from this region, using the Wendelstein Observatory in in the Bavarian Alps. They also obtained spectrographic data using the Very Large Telescope in Chile. The work let the team perform a mass estimate that was based directly on the stellar motions around the core of the galaxy. Measuring the motions of stars around a central black hole gives you a direct measurement of the black hole’s mass. Astronomer Jens Thomas of MPE, who led the study, said:

There are only a few dozen direct mass measurements of supermassive black holes, and never before has it been attempted at such a distance [700 million light-years, or twice the distance for previous direct black hole mass measurements].

But we already had some idea of the size of the black hole in this particular galaxy, so we tried it.

Read more via Max Planck Institute for Extraterrestrial Physics

This is the Large Magellanic Cloud, a nearby satellite galaxy to our Milky Way. It’s about 14,000 light-years in diameter. The central region of the galaxy Holmberg 15A – where the new record-holding black hole resides – is nearly as large. This beautiful image comes from astrophotographer Justin Ng of Singapore.

Bottom line: The mass of the new record-holding back hole – in the center of the galaxy Holmberg 15A, the central galaxy of the Abell 85 cluster – is 40 billion times more massive than our sun. That’s in contrast to our Milky Way’s central black hole at 4 million times our sun’s mass.

Source: A 40-billion solar mass black hole in the extreme core of Holm 15A, the central galaxy of Abell 85

from EarthSky https://ift.tt/2qws5pY

This galaxy cluster – Abell 85 – consists of more than 500 individual galaxies. The bright one in the center is called Holm 15A. Astronomers peered into its heart to measure the mass of a black hole 40 billion times more massive than our sun. Image via Matthias Kluge/ USM Wendelstein observatory/ MPE.

The Max Planck Institute for Extraterrestrial Physics (MPE) near Munich, Germany said on December 3, 2019 that astronomers have set a new record for finding the most massive black hole in the universe. They found it not because it’s doing something exotic or noticeable. On the contrary, they noticed this black hole because it caused the center of its galaxy to be peculiarly fainter than it would be otherwise, given the galaxy’s huge mass of stars.

Holmberg 15A is a supergiant elliptical galaxy, some 700 million light-years from Earth. It’s the central galaxy of the Abell 85 galaxy cluster. In contrast to our Milky Way’s central black hole of about 4 million solar masses, the new record-holding central black hole in the galaxy Holm 15A is 40 billion times more massive than our sun.

The astronomers’ statement explained:

Even though the central galaxy of the cluster Abell 85 has the enormous visible mass of about 2 trillion (10¹²) solar masses in stars, the center of the galaxy is extremely diffuse and faint. This is why a joint group of astronomers at MPE and the University Observatory Munich got interested in the galaxy.

This central diffuse region in the galaxy is almost as large as the Large Magellanic Cloud, and this was a suspicious clue for the presence of a black hole with a very high mass.

Astronomers measured and evaluated the light coming from this region, using the Wendelstein Observatory in in the Bavarian Alps. They also obtained spectrographic data using the Very Large Telescope in Chile. The work let the team perform a mass estimate that was based directly on the stellar motions around the core of the galaxy. Measuring the motions of stars around a central black hole gives you a direct measurement of the black hole’s mass. Astronomer Jens Thomas of MPE, who led the study, said:

There are only a few dozen direct mass measurements of supermassive black holes, and never before has it been attempted at such a distance [700 million light-years, or twice the distance for previous direct black hole mass measurements].

But we already had some idea of the size of the black hole in this particular galaxy, so we tried it.

Read more via Max Planck Institute for Extraterrestrial Physics

This is the Large Magellanic Cloud, a nearby satellite galaxy to our Milky Way. It’s about 14,000 light-years in diameter. The central region of the galaxy Holmberg 15A – where the new record-holding black hole resides – is nearly as large. This beautiful image comes from astrophotographer Justin Ng of Singapore.

Bottom line: The mass of the new record-holding back hole – in the center of the galaxy Holmberg 15A, the central galaxy of the Abell 85 cluster – is 40 billion times more massive than our sun. That’s in contrast to our Milky Way’s central black hole at 4 million times our sun’s mass.

Source: A 40-billion solar mass black hole in the extreme core of Holm 15A, the central galaxy of Abell 85

from EarthSky https://ift.tt/2qws5pY

New biomass map takes stock of Earth’s carbon

View larger. | Satellite data was used to create a map of above-ground biomass for 2017-2018. The new map uses optical, lidar and radar data acquired in 2017 and 2018 from multiple Earth observation satellites. Image via ESA.

The first of a series of global maps aimed at quantifying change in carbon stored as biomass across the world’s forests and shrublands was released Friday (December 6, 2019) by ESA’s Climate Change Initiative at the United Nation Climate Change Conference that took place in Madrid, Spain last week.

As plants grow, they remove carbon dioxide from the atmosphere and store it as biomass – the mass of living biological organisms in a given area or ecosystem at a given time. The CO2 is then released back to the atmosphere through processes such as deforestation, or wildfires. Scientists assess these dynamic changes in order to better is understanding the cycling of carbon, as well as to inform global climate models that help predict future change.

Richard Lucas, of University of New South Wales, managed the research project team that developed the map. He said in a statement:

Much of the carbon in forests is stored in the rainforests of the wet tropics but the new map shows that biomass is widely distributed across other biomes, particularly the dry tropics, subtropics and boreal zones.

All of these biomes are experiencing unprecedented changes associated with human activities, which are being exacerbated by climate change. Knowing how much carbon these forests hold and how this has changed – and is changing – is a major step towards ensuring their long-term future and addressing climate change.

According to a statement from ESA’s Climate Change Initiative, tracking biomass change is becoming increasingly important as decision-makers work towards the Global Stocktake – an aspect of the global Paris Agreement climate deal – that will periodically check international progress towards meeting emissions reduction commitments to limit global warming.

The next step for the research team is to develop a map covering the 2018-19 period and to quantify changes between years.

The UN COP25 Climate Change Conference, which took place last week in Madrid, Spain, focused on encouraging governments to increase their commitments to combatting climate change.

Source: ESA Biomass Climate Change Initiative (Biomass_cci): Global datasets of forest above-ground biomass for the year 2017, v1

Via ESA

from EarthSky https://ift.tt/36dv0De

View larger. | Satellite data was used to create a map of above-ground biomass for 2017-2018. The new map uses optical, lidar and radar data acquired in 2017 and 2018 from multiple Earth observation satellites. Image via ESA.

The first of a series of global maps aimed at quantifying change in carbon stored as biomass across the world’s forests and shrublands was released Friday (December 6, 2019) by ESA’s Climate Change Initiative at the United Nation Climate Change Conference that took place in Madrid, Spain last week.

As plants grow, they remove carbon dioxide from the atmosphere and store it as biomass – the mass of living biological organisms in a given area or ecosystem at a given time. The CO2 is then released back to the atmosphere through processes such as deforestation, or wildfires. Scientists assess these dynamic changes in order to better is understanding the cycling of carbon, as well as to inform global climate models that help predict future change.

Richard Lucas, of University of New South Wales, managed the research project team that developed the map. He said in a statement:

Much of the carbon in forests is stored in the rainforests of the wet tropics but the new map shows that biomass is widely distributed across other biomes, particularly the dry tropics, subtropics and boreal zones.

All of these biomes are experiencing unprecedented changes associated with human activities, which are being exacerbated by climate change. Knowing how much carbon these forests hold and how this has changed – and is changing – is a major step towards ensuring their long-term future and addressing climate change.

According to a statement from ESA’s Climate Change Initiative, tracking biomass change is becoming increasingly important as decision-makers work towards the Global Stocktake – an aspect of the global Paris Agreement climate deal – that will periodically check international progress towards meeting emissions reduction commitments to limit global warming.

The next step for the research team is to develop a map covering the 2018-19 period and to quantify changes between years.

The UN COP25 Climate Change Conference, which took place last week in Madrid, Spain, focused on encouraging governments to increase their commitments to combatting climate change.

Source: ESA Biomass Climate Change Initiative (Biomass_cci): Global datasets of forest above-ground biomass for the year 2017, v1

Via ESA

from EarthSky https://ift.tt/36dv0De

Interstellar object closest to the sun today

2I/Borisov’s orbit. The “2I” stands for “2nd interstellar.” In other words, this is only the 2nd object from a distant solar system known to have swept past our sun. Its perihelion – or closest point to the sun – is just outside the orbit of Mars. Image via Wikimedia Commons user Drbogdan/ NASA.

The 2nd-known interstellar object – identified as a comet and labeled 2I/Borisov – reaches its perihelion, or closest point to the sun, on December 8, 2019. It is about twice Earth’s distance from the sun, or just outside the orbit of Mars. Comets tend to be most active when they’re nearest the sun. Although this isn’t a particularly close approach for a comet, it’s the closest this interstellar comet has come to our sun.

And so the eyes of the world are upon it. Astronomers are hoping to see an outburst or other unexpected behavior.

Four Yale astronomers – Pieter van Dokkum, Cheng-Han Hsieh, Shany Danieli, and Gregory Laughlin – captured this image of 2I/Borisov on November 24, 2019. The size of Earth using the W.M. Keck Observatory’s Low-Resolution Imaging Spectrometer in Hawaii. The comet’s icy core or nucleus is only about a mile wide. But – as is usual for comets – it’s surrounded by a cloud of gas and dust is many times larger than Earth. Image via Geek.com.

As it has swept in closer to the sun, this object has gotten brighter than it was when Gennady Borisov, a comet hunter in Crimea, first spotted it on August 30. Only experienced amateur astronomers with telescopes or good binoculars – and professional astronomers using their powerful telescopes – are likely to see it in the sky.

If you want to try spotting this object, here’s a page from TheSkyLive.com that might help.

Or try this page from the the astronomy app Star Walk 2.

Astronomers say that our solar system should be visited by interstellar objects on a fairly regular basis. They estimate that several probably pass inside Earth’s orbit each year. By one estimate, 10,000 interstellar objects pass inside the orbit of Neptune on any given day! They all passed unseen, for billions of years, until recently. Astronomers in Hawaii happened upon the first interstellar object – now officially called 1I/’Oumuamua (‘Scout’) – in late 2017.

Thus 2I/Borisov may be only the second interstellar object known. But it’s surely not the second object to visit us from another solar system.

As it sweeps near the sun, 2I/Borisov’s orbit will be bent by the sun’s gravity, but the sun won’t capture it. It’ll continue to brighten – making its closest approach to Earth on December 28 – as it flees outward.

Ultimately, 2I/Borisov will return to the space between the stars once more.

The Hubble Space Telescope captured this image of the 2nd known interstellar object – called comet 2I/Borisov by earthly astronomers – on October 12, 2019, when the object was about 260 million miles (420 million km) from Earth. This object is believed to have arrived here from another planetary system elsewhere in our galaxy. Image via NASA/ESA/D. Jewitt/SpaceTelescope.org.

Bottom line: 2I/Borisov – the second-known interstellar object – has been steadily brightening since its discovery on August 30, 2019. It passes closest to the sun on December 8. It passes closest to Earth on December 28.

from EarthSky https://ift.tt/33WILop

2I/Borisov’s orbit. The “2I” stands for “2nd interstellar.” In other words, this is only the 2nd object from a distant solar system known to have swept past our sun. Its perihelion – or closest point to the sun – is just outside the orbit of Mars. Image via Wikimedia Commons user Drbogdan/ NASA.

The 2nd-known interstellar object – identified as a comet and labeled 2I/Borisov – reaches its perihelion, or closest point to the sun, on December 8, 2019. It is about twice Earth’s distance from the sun, or just outside the orbit of Mars. Comets tend to be most active when they’re nearest the sun. Although this isn’t a particularly close approach for a comet, it’s the closest this interstellar comet has come to our sun.

And so the eyes of the world are upon it. Astronomers are hoping to see an outburst or other unexpected behavior.

Four Yale astronomers – Pieter van Dokkum, Cheng-Han Hsieh, Shany Danieli, and Gregory Laughlin – captured this image of 2I/Borisov on November 24, 2019. The size of Earth using the W.M. Keck Observatory’s Low-Resolution Imaging Spectrometer in Hawaii. The comet’s icy core or nucleus is only about a mile wide. But – as is usual for comets – it’s surrounded by a cloud of gas and dust is many times larger than Earth. Image via Geek.com.

As it has swept in closer to the sun, this object has gotten brighter than it was when Gennady Borisov, a comet hunter in Crimea, first spotted it on August 30. Only experienced amateur astronomers with telescopes or good binoculars – and professional astronomers using their powerful telescopes – are likely to see it in the sky.

If you want to try spotting this object, here’s a page from TheSkyLive.com that might help.

Or try this page from the the astronomy app Star Walk 2.

Astronomers say that our solar system should be visited by interstellar objects on a fairly regular basis. They estimate that several probably pass inside Earth’s orbit each year. By one estimate, 10,000 interstellar objects pass inside the orbit of Neptune on any given day! They all passed unseen, for billions of years, until recently. Astronomers in Hawaii happened upon the first interstellar object – now officially called 1I/’Oumuamua (‘Scout’) – in late 2017.

Thus 2I/Borisov may be only the second interstellar object known. But it’s surely not the second object to visit us from another solar system.

As it sweeps near the sun, 2I/Borisov’s orbit will be bent by the sun’s gravity, but the sun won’t capture it. It’ll continue to brighten – making its closest approach to Earth on December 28 – as it flees outward.

Ultimately, 2I/Borisov will return to the space between the stars once more.

The Hubble Space Telescope captured this image of the 2nd known interstellar object – called comet 2I/Borisov by earthly astronomers – on October 12, 2019, when the object was about 260 million miles (420 million km) from Earth. This object is believed to have arrived here from another planetary system elsewhere in our galaxy. Image via NASA/ESA/D. Jewitt/SpaceTelescope.org.

Bottom line: 2I/Borisov – the second-known interstellar object – has been steadily brightening since its discovery on August 30, 2019. It passes closest to the sun on December 8. It passes closest to Earth on December 28.

from EarthSky https://ift.tt/33WILop

Hubble spots galaxy’s dramatic details

View larger. | Image via ESA/Hubble & NASA, W. Li et al.

On December 6, 2019, NASA released this Hubble Space Telescope image of galaxy NGC 5468 – located in the constellation Virgo, just over 130 million light-years away – showing the galaxy’s loose, open spiral pattern in beautiful detail.

NASA said in a statement about this image:

Some of the most dramatic events in the universe occur when certain stars die — and explode catastrophically in the process.

Such explosions, known as supernovae, mainly occur in a couple of ways. In one scenario, a massive star depletes its fuel at the end of its life, becoming dynamically unstable and unable to support its bulk, causing it to collapse inward and violently explode. In another outcome, a white dwarf (the dense remnant of a once-normal star) in an orbiting stellar couple siphons more mass off its companion than it is able to support, igniting runaway nuclear fusion in its core and beginning the supernova process. Both types result in an intensely bright object in the sky that can rival the light of a whole galaxy.

In the last 20 years, galaxy NGC 5468 hosted a number of observed supernovae of both the aforementioned types: SN 1999cp, SN 2002cr, SN2002ed, SN2005P and SN2018dfg. The orientation of the galaxy with respect to us – we see NGC 5468 face on – makes it easier to spot these new “stars” as they appear.

Via NASA

from EarthSky https://ift.tt/34YUd4c

View larger. | Image via ESA/Hubble & NASA, W. Li et al.

On December 6, 2019, NASA released this Hubble Space Telescope image of galaxy NGC 5468 – located in the constellation Virgo, just over 130 million light-years away – showing the galaxy’s loose, open spiral pattern in beautiful detail.

NASA said in a statement about this image:

Some of the most dramatic events in the universe occur when certain stars die — and explode catastrophically in the process.

Such explosions, known as supernovae, mainly occur in a couple of ways. In one scenario, a massive star depletes its fuel at the end of its life, becoming dynamically unstable and unable to support its bulk, causing it to collapse inward and violently explode. In another outcome, a white dwarf (the dense remnant of a once-normal star) in an orbiting stellar couple siphons more mass off its companion than it is able to support, igniting runaway nuclear fusion in its core and beginning the supernova process. Both types result in an intensely bright object in the sky that can rival the light of a whole galaxy.

In the last 20 years, galaxy NGC 5468 hosted a number of observed supernovae of both the aforementioned types: SN 1999cp, SN 2002cr, SN2002ed, SN2005P and SN2018dfg. The orientation of the galaxy with respect to us – we see NGC 5468 face on – makes it easier to spot these new “stars” as they appear.

Via NASA

from EarthSky https://ift.tt/34YUd4c

News digest – NHS avoidable delays, sugary festive drinks, hair dye and mistletoe

A quarter of cancer patients experience avoidable delay to diagnosis

Our new research showing 1 in 4 cancer patients in the UK are waiting longer to be diagnosed because of avoidable delays was widely reported. These avoidable delays included delays in seeking help, long waiting times for tests and a shortage of diagnostic staff in hospitals. Read our press release for the details.

Variation in NHS weight management programmes

There’s wide variation in NHS weight management programmes across the UK, ITV News reports. A study by the University of Glasgow found there was variation in who can access the programme and how they’re referred, as well as what the treatment involves and how much it costs. Because of these differences, it’s hard to measure how effective these programmes are and find the best way to help patients reach a healthy weight.

Study suggests exercise reduces risk of prostate cancer

New research exploring the link between genetics, exercise and prostate cancer risk was reported in the Telegraph. The study, mainly involving men over the age of 50, found that those who had genes that mean they’re more likely to be physically active, had a decreased risk of prostate cancer. But even though genetics may indicate who is more likely to work out, in reality they might not be more physically active, and a similar link hasn’t been seen in other studies. There’s still lots we need to learn about to what extent physical activity affects prostate cancer risk.

Headlines claim hair dye causes cancer

The Sun says that using permanent hair dye or chemical straighteners can increase a person’s risk of developing breast cancer. These headlines may seem concerning, but so far research on whether these products cause cancer has been inconsistent. This US study also focused on people with a family connection to breast cancer, which might also impact their risk. There are also strict regulations for toiletries and cosmetics in the UK.

Potential new migration policies could worsen NHS workforce issues

Experts have warned that both the Conservative and Labour migration policies could worsen NHS staffing issues. A new report, covered by the Guardian, has shown that almost 1 in 4 hospital staff are born outside of the UK, so getting the new immigration system right is vital to avoid adding to workforce strains.

Festive hot drinks high in sugar

Some hot drinks sold by high street coffee chains to celebrate the winter season may come with a heavy dose of sugar, according to the BBC. New research by Action on Sugar shows that some seasonal lattes and hot chocolates can have up to 23 teaspoons of sugar per serving. Sweetened milk-based drinks are currently not covered by the sugar tax.

And finally

A woman with breast cancer, who also has multiple sclerosis, has told the Mail Online that mistletoe injections are keeping her disease at bay. The NHS doesn’t recommend this alternative therapy as a treatment for breast cancer, as there’s no evidence that shows it can treat the disease. We’ve got more about the safety and potential harms of alternative therapies on our website.

Gabi

from Cancer Research UK – Science blog https://ift.tt/2LxM5zI

A quarter of cancer patients experience avoidable delay to diagnosis

Our new research showing 1 in 4 cancer patients in the UK are waiting longer to be diagnosed because of avoidable delays was widely reported. These avoidable delays included delays in seeking help, long waiting times for tests and a shortage of diagnostic staff in hospitals. Read our press release for the details.

Variation in NHS weight management programmes

There’s wide variation in NHS weight management programmes across the UK, ITV News reports. A study by the University of Glasgow found there was variation in who can access the programme and how they’re referred, as well as what the treatment involves and how much it costs. Because of these differences, it’s hard to measure how effective these programmes are and find the best way to help patients reach a healthy weight.

Study suggests exercise reduces risk of prostate cancer

New research exploring the link between genetics, exercise and prostate cancer risk was reported in the Telegraph. The study, mainly involving men over the age of 50, found that those who had genes that mean they’re more likely to be physically active, had a decreased risk of prostate cancer. But even though genetics may indicate who is more likely to work out, in reality they might not be more physically active, and a similar link hasn’t been seen in other studies. There’s still lots we need to learn about to what extent physical activity affects prostate cancer risk.

Headlines claim hair dye causes cancer

The Sun says that using permanent hair dye or chemical straighteners can increase a person’s risk of developing breast cancer. These headlines may seem concerning, but so far research on whether these products cause cancer has been inconsistent. This US study also focused on people with a family connection to breast cancer, which might also impact their risk. There are also strict regulations for toiletries and cosmetics in the UK.

Potential new migration policies could worsen NHS workforce issues

Experts have warned that both the Conservative and Labour migration policies could worsen NHS staffing issues. A new report, covered by the Guardian, has shown that almost 1 in 4 hospital staff are born outside of the UK, so getting the new immigration system right is vital to avoid adding to workforce strains.

Festive hot drinks high in sugar

Some hot drinks sold by high street coffee chains to celebrate the winter season may come with a heavy dose of sugar, according to the BBC. New research by Action on Sugar shows that some seasonal lattes and hot chocolates can have up to 23 teaspoons of sugar per serving. Sweetened milk-based drinks are currently not covered by the sugar tax.

And finally

A woman with breast cancer, who also has multiple sclerosis, has told the Mail Online that mistletoe injections are keeping her disease at bay. The NHS doesn’t recommend this alternative therapy as a treatment for breast cancer, as there’s no evidence that shows it can treat the disease. We’ve got more about the safety and potential harms of alternative therapies on our website.

Gabi

from Cancer Research UK – Science blog https://ift.tt/2LxM5zI