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‘Apocalyptic’ skies across U.S. West this week

The video above is from an article at CBS News, updated on the evening of September 9, 2020. It reported:

Record-breaking wildfires in the western U.S. have turned skies shocking shades of bright red and orange this week, thanks to a relentless and unprecedented fire season across multiple states. Social media users are sharing ‘apocalyptic’ photos and videos of the hazy sky, comparing it to the planet Mars, the film Blade Runner 2049 and the show Stranger Things.

Parts of Washington, Oregon, California, Idaho, Nevada, Arizona and Utah are currently under critical and elevated risk of fire weather, according to the National Weather Service. Air quality in some regions has reached hazardous levels, and tens of thousands of firefighters are battling day and night to contain the thousands of fires.

The New York Times reported on the fires, too:

In Oregon, wildfires have this week, and thousands of people have evacuated their homes. In Washington State, a fire hit the town of Malden so quickly that deputies drove through the streets screaming for residents to leave. In Colorado, a 100,000-acre blaze was slowed only by a rare September snowstorm.

And in California, residents are coping with the worst wildfires on record. Smoke blotted out the sun yesterday in San Francisco, and ash fluttered down from the sky. ‘The sky had a faint orange glow that some said evoked a nuclear winter,’ Thomas Fuller, The Times’s San Francisco bureau chief, told us. Jill Cowan, a Times reporter in Los Angeles, said, ‘The smoke and the poor air quality are just oppressive.’

Bottom line: Video of weirdly red and orange skies across U.S. West, early September 2020.



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The video above is from an article at CBS News, updated on the evening of September 9, 2020. It reported:

Record-breaking wildfires in the western U.S. have turned skies shocking shades of bright red and orange this week, thanks to a relentless and unprecedented fire season across multiple states. Social media users are sharing ‘apocalyptic’ photos and videos of the hazy sky, comparing it to the planet Mars, the film Blade Runner 2049 and the show Stranger Things.

Parts of Washington, Oregon, California, Idaho, Nevada, Arizona and Utah are currently under critical and elevated risk of fire weather, according to the National Weather Service. Air quality in some regions has reached hazardous levels, and tens of thousands of firefighters are battling day and night to contain the thousands of fires.

The New York Times reported on the fires, too:

In Oregon, wildfires have this week, and thousands of people have evacuated their homes. In Washington State, a fire hit the town of Malden so quickly that deputies drove through the streets screaming for residents to leave. In Colorado, a 100,000-acre blaze was slowed only by a rare September snowstorm.

And in California, residents are coping with the worst wildfires on record. Smoke blotted out the sun yesterday in San Francisco, and ash fluttered down from the sky. ‘The sky had a faint orange glow that some said evoked a nuclear winter,’ Thomas Fuller, The Times’s San Francisco bureau chief, told us. Jill Cowan, a Times reporter in Los Angeles, said, ‘The smoke and the poor air quality are just oppressive.’

Bottom line: Video of weirdly red and orange skies across U.S. West, early September 2020.



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Every visible star is within Milky Way

The image at top, showing a campfire under the Milky Way, is a classic, from 2014. It’s by Ben Coffman Photography in Oregon. He had written:

These good folks – co-workers from one of the resorts on Mt. Hood, if I remember correctly – let me take their photo on the beach near Cape Kiwanda [a state natural area near in Pacific City, Oregon]. They looked like they were having fun.

And so they do. What could be better than a beautiful night under the Milky Way? But did you know that every night of your life is a night under the Milky Way? By that we mean … every individual star you can see with the unaided eye, in all parts of the sky, lies within the confines of our Milky Way galaxy.

Our galaxy – seen in Ben’s photo above as a bright and hazy band of stars – is estimated to be some 100,000 light-years wide and only about 1,000 light-years thick. That’s why the starlit band of the Milky Way, which is still visible in the evening this month but will soon be less so, appears so well-defined in our sky.

Gazing into it, we’re really looking edgewise into the thin plane of our own galaxy:

This image is mosaic of multiple shots on large-format film. It comprises all 360 degrees of the galaxy from our earthly vantage point. Photography was done in Ft. Davis, Texas for the northern hemisphere shots and from Broken Hill, New South Wales, Australia, for the southern portions. Note the dust lanes, which obscure our view of some features beyond them. Image via Digital Sky LLC

In the image directly above – comprising all 360 degrees of the galaxy as seen from our earthly vantage point – note that the galaxy is brightest at its center, where most of the stars and a 4-million-solar-mass black hole reside. This image shows stars down to 11th magnitude – fainter than the eye alone can see.

If you’re standing under a clear, dark night sky, you’ll see the Milky Way clearly as a band of stars stretched across the sky on late summer evenings.

The band of the Milky Way is tough to see unless you’re far from the artificial lights of the city and you’re looking on a night when the moon is down.

If you do look in a dark country sky, you’ll easily spot the Milky Way. And, assuming you’re looking from the Northern Hemisphere, you’ll notice that it gets broader and richer in the southern part of the sky, in the direction of the constellations Scorpius and Sagittarius. This is the direction toward the galaxy’s center.

If you’re in the Southern Hemisphere, the galactic center is still in the direction of Sagittarius. But from the southern part of Earth’s globe, this constellation is closer to overhead.

The image below gives you an idea of the awesome beauty of our Milky Way galaxy in the night sky.

Bottom line: If you look in a dark country sky, you’ll easily spot the starlit band of our huge, flat Milky Way galaxy. Every star in our night sky that’s visible to the unaided eye lies inside this galaxy.

A planisphere is virtually indispensable for beginning stargazers. Order your EarthSky planisphere from our store.

Enjoying EarthSky so far? Sign up for our free daily newsletter today!

Donate: Your support means the world to us



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The image at top, showing a campfire under the Milky Way, is a classic, from 2014. It’s by Ben Coffman Photography in Oregon. He had written:

These good folks – co-workers from one of the resorts on Mt. Hood, if I remember correctly – let me take their photo on the beach near Cape Kiwanda [a state natural area near in Pacific City, Oregon]. They looked like they were having fun.

And so they do. What could be better than a beautiful night under the Milky Way? But did you know that every night of your life is a night under the Milky Way? By that we mean … every individual star you can see with the unaided eye, in all parts of the sky, lies within the confines of our Milky Way galaxy.

Our galaxy – seen in Ben’s photo above as a bright and hazy band of stars – is estimated to be some 100,000 light-years wide and only about 1,000 light-years thick. That’s why the starlit band of the Milky Way, which is still visible in the evening this month but will soon be less so, appears so well-defined in our sky.

Gazing into it, we’re really looking edgewise into the thin plane of our own galaxy:

This image is mosaic of multiple shots on large-format film. It comprises all 360 degrees of the galaxy from our earthly vantage point. Photography was done in Ft. Davis, Texas for the northern hemisphere shots and from Broken Hill, New South Wales, Australia, for the southern portions. Note the dust lanes, which obscure our view of some features beyond them. Image via Digital Sky LLC

In the image directly above – comprising all 360 degrees of the galaxy as seen from our earthly vantage point – note that the galaxy is brightest at its center, where most of the stars and a 4-million-solar-mass black hole reside. This image shows stars down to 11th magnitude – fainter than the eye alone can see.

If you’re standing under a clear, dark night sky, you’ll see the Milky Way clearly as a band of stars stretched across the sky on late summer evenings.

The band of the Milky Way is tough to see unless you’re far from the artificial lights of the city and you’re looking on a night when the moon is down.

If you do look in a dark country sky, you’ll easily spot the Milky Way. And, assuming you’re looking from the Northern Hemisphere, you’ll notice that it gets broader and richer in the southern part of the sky, in the direction of the constellations Scorpius and Sagittarius. This is the direction toward the galaxy’s center.

If you’re in the Southern Hemisphere, the galactic center is still in the direction of Sagittarius. But from the southern part of Earth’s globe, this constellation is closer to overhead.

The image below gives you an idea of the awesome beauty of our Milky Way galaxy in the night sky.

Bottom line: If you look in a dark country sky, you’ll easily spot the starlit band of our huge, flat Milky Way galaxy. Every star in our night sky that’s visible to the unaided eye lies inside this galaxy.

A planisphere is virtually indispensable for beginning stargazers. Order your EarthSky planisphere from our store.

Enjoying EarthSky so far? Sign up for our free daily newsletter today!

Donate: Your support means the world to us



from EarthSky https://ift.tt/2m2Eobw

The launch and landing of China’s reusable spacecraft

A daytime rocket launch.

No images have yet been released of China’s September 4, 2020 rocket launch. This image shows a launch in October 2016 of a Chinese Long March 2F rocket, the same rocket model that launched a new, experimental, reusable spacecraft. Image via China Aerospace Science and Technology Corporation.

China is widely believed to have launched and landed a reusable spacecraft late last week, which might have deployed a satellite while in orbit. Chinese media outlet Xinhua News reported on September 6, 2020 that a Long March-2F rocket sent the experimental spacecraft into orbit on September 4 from the Gobi Desert Jiuquan Satellite Launch Center, and that the craft touched down as scheduled after a two-day in-orbit operation. The Xinhau report provided no information about exact launch time, landing location, or what technologies the spacecraft tested. It said:

The reusable spacecraft successfully launched by my country at the Jiuquan Satellite Launch Center successfully returned to the scheduled landing site on September 6, after flying in orbit for 2 days.

The successful flight marked the country’s important breakthrough in reusable spacecraft research, and is expected to offer convenient and low-cost round-trip transport for the peaceful use of the space.

The new spacecraft may be linked with China’s plans to build and operate a reusable space plane by the year 2020, although that connection has not been confirmed.

China calls the new spacecraft Chongfu Shiyong Shiyan Hangtian Qi, which translates as Repeat-Use Test Spacecraft (or, more loosely, Reusable Test Spacecraft).

Analysis by space experts show a object in space that wasn’t there before the September 4 launch. The analysis suggests that the Chinese spacecraft released a satellite while in orbit, although the satellite’s purpose is pure speculation, as neither Chinese nor United States space-tracking organizations have released details.

Likewise, China has not so far released images of the spacecraft or the launch; an apparent higher-than-usual level of security surrounding the mission also prevented bystander images from appearing on social media. These precautions are widely said in the west to be “unusual,” given China’s assurance that the intention of the mission is peaceful.

Xinhua had reported in 2017 that China was planning a reusable space vehicle that would take off and land horizontally, like an airplane. In fact, officials from the China Aerospace Science and Industry Corporation added in 2017 that it had already fulfilled several ground tests for engines and other components, for such a craft. But Harvard-Smithsonian Center for Astrophysics astronomer Jonathan McDowell (@planet4589 on Twitter) – who comments frequently on the spacecraft program – has stressed that we cannot assume the spacecraft launched September 4 is a space plane, with wings.

Other winged vehicles have made it to orbit previously. For example, NASA’s now-retired space shuttle program flew 135 missions with astronauts onboard between 1981 and 2011. A similarly reusable Soviet Union vehicle called Buran flew a single uncrewed mission in 1988 before the program was canceled in 1993, shortly after the Soviet Union collapsed.

In the present era, in the U.S., private companies are working hard to develop and test space planes and reusable rocketry. Virgin Galactic’s suborbital SpaceShipTwo has flown into space during test missions, which aims to fly customers and cargo aboard in the coming years. Similarly, the Sierra Nevada Corporation plans to fly NASA cargo to the International Space Station on its Dream Chaser spacecraft. Competitors like SpaceX and Blue Origin are making headlines every week for their record-setting accomplishments with fully reusable space vehicles.

Meanwhile, there’s already a rocket graveyard at the bottom of Earth’s ocean, littered with the exhausted shells of thousands of rockets used to send satellites and people to space. It’s humbling to contemplate these relics of a past age, but also important to notice that the lack of reusable rocket technology restricts space flight to the richest nations only.

Now, with the evolution of reusable rockets through such commercial companies, the price tag on space exploration and utilization is decreasing. The recent milestones of the U.S. private space companies – perhaps in conjunction with China’s Reusable Test Spacecraft – may be acting as a gateway of opportunity for interplanetary transport and the first manned mission to Mars.

Bottom line: Although few details are known, and no images have been released, the Chinese did apparently launch a reusable spacecraft on September 4, 2020. It appears to have deployed a satellite to orbit and then returned to Earth safely 2 days later.

Read more from Space News: Chinese Reusable Experimental Spacecraft Releases Object Before Returning to Earth

Read more from Discovery.com: Reusable Rockets: Expanding Space Exploration Possibilities with Retrievable Spacecraft.

Read more from Cosmos Magazine: Reusable Rockets Explained



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A daytime rocket launch.

No images have yet been released of China’s September 4, 2020 rocket launch. This image shows a launch in October 2016 of a Chinese Long March 2F rocket, the same rocket model that launched a new, experimental, reusable spacecraft. Image via China Aerospace Science and Technology Corporation.

China is widely believed to have launched and landed a reusable spacecraft late last week, which might have deployed a satellite while in orbit. Chinese media outlet Xinhua News reported on September 6, 2020 that a Long March-2F rocket sent the experimental spacecraft into orbit on September 4 from the Gobi Desert Jiuquan Satellite Launch Center, and that the craft touched down as scheduled after a two-day in-orbit operation. The Xinhau report provided no information about exact launch time, landing location, or what technologies the spacecraft tested. It said:

The reusable spacecraft successfully launched by my country at the Jiuquan Satellite Launch Center successfully returned to the scheduled landing site on September 6, after flying in orbit for 2 days.

The successful flight marked the country’s important breakthrough in reusable spacecraft research, and is expected to offer convenient and low-cost round-trip transport for the peaceful use of the space.

The new spacecraft may be linked with China’s plans to build and operate a reusable space plane by the year 2020, although that connection has not been confirmed.

China calls the new spacecraft Chongfu Shiyong Shiyan Hangtian Qi, which translates as Repeat-Use Test Spacecraft (or, more loosely, Reusable Test Spacecraft).

Analysis by space experts show a object in space that wasn’t there before the September 4 launch. The analysis suggests that the Chinese spacecraft released a satellite while in orbit, although the satellite’s purpose is pure speculation, as neither Chinese nor United States space-tracking organizations have released details.

Likewise, China has not so far released images of the spacecraft or the launch; an apparent higher-than-usual level of security surrounding the mission also prevented bystander images from appearing on social media. These precautions are widely said in the west to be “unusual,” given China’s assurance that the intention of the mission is peaceful.

Xinhua had reported in 2017 that China was planning a reusable space vehicle that would take off and land horizontally, like an airplane. In fact, officials from the China Aerospace Science and Industry Corporation added in 2017 that it had already fulfilled several ground tests for engines and other components, for such a craft. But Harvard-Smithsonian Center for Astrophysics astronomer Jonathan McDowell (@planet4589 on Twitter) – who comments frequently on the spacecraft program – has stressed that we cannot assume the spacecraft launched September 4 is a space plane, with wings.

Other winged vehicles have made it to orbit previously. For example, NASA’s now-retired space shuttle program flew 135 missions with astronauts onboard between 1981 and 2011. A similarly reusable Soviet Union vehicle called Buran flew a single uncrewed mission in 1988 before the program was canceled in 1993, shortly after the Soviet Union collapsed.

In the present era, in the U.S., private companies are working hard to develop and test space planes and reusable rocketry. Virgin Galactic’s suborbital SpaceShipTwo has flown into space during test missions, which aims to fly customers and cargo aboard in the coming years. Similarly, the Sierra Nevada Corporation plans to fly NASA cargo to the International Space Station on its Dream Chaser spacecraft. Competitors like SpaceX and Blue Origin are making headlines every week for their record-setting accomplishments with fully reusable space vehicles.

Meanwhile, there’s already a rocket graveyard at the bottom of Earth’s ocean, littered with the exhausted shells of thousands of rockets used to send satellites and people to space. It’s humbling to contemplate these relics of a past age, but also important to notice that the lack of reusable rocket technology restricts space flight to the richest nations only.

Now, with the evolution of reusable rockets through such commercial companies, the price tag on space exploration and utilization is decreasing. The recent milestones of the U.S. private space companies – perhaps in conjunction with China’s Reusable Test Spacecraft – may be acting as a gateway of opportunity for interplanetary transport and the first manned mission to Mars.

Bottom line: Although few details are known, and no images have been released, the Chinese did apparently launch a reusable spacecraft on September 4, 2020. It appears to have deployed a satellite to orbit and then returned to Earth safely 2 days later.

Read more from Space News: Chinese Reusable Experimental Spacecraft Releases Object Before Returning to Earth

Read more from Discovery.com: Reusable Rockets: Expanding Space Exploration Possibilities with Retrievable Spacecraft.

Read more from Cosmos Magazine: Reusable Rockets Explained



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2020 is your year to see Capricornus

Chart showing Jupiter and Saturn between triangular Capricornus and Sagittarius.

This chart works for September 9 or 10, 2020 … and for lots of nights after that, approximately through late September. Chart via Guy Ottewell’s blog.

Originally published at Guy Ottewell’s blog. Reprinted here with permission.

Above is a chart showing the night sky on Wednesday, September 9, 2020. See how Jupiter and Saturn are pointing to the constellation Capricornus the Sea Goat? You need a dark sky to see this constellation, but Jupiter and Saturn are very bright. If you have that dark sky, and have never seen this faint constellation, now is the time to look.

Below you’ll find is an example of the unhelpful sky charts generally used in the astronomy columns of newspapers and popular magazines.

It’s from Sunday’s Guardian. The article rightly says that Capricornus is an important constellation because it is part of the ancient zodiac, but it is inconspicuous, and you can at present use Jupiter and Saturn as pointers to it.

A chart with a scattering of equally bright stars and constellations outlined, plus text.

Chart via The Guardian.

Fair enough. But the chart doesn’t do Capricornus justice. Perhaps you, sage reader, can with effort decipher the Guardian’s chart because you know the sky. But, if you were a beginner, could you use this maze of dots and lines to find anything as you gaze at the sky? I don’t think so.

I think the way of connecting dots is derived from H.A. Rey’s ingenious but doomed method as described in his book “The Stars: A New Way to See Them.” It tries to make Capricornus look like a goat. But Capricornus doesn’t look like a goat; it looks like a boat, or – as the Americans prefer – an arrowhead.

I hope my way of rendering this part of the sky – as seen on the chart at the top of the post – is more helpful.

Read more about the constellation Capricornus

Cartoon showing a line of stars, with the ancient stargazers saying 'ah yes, a goat.'

Chart via Posts That Look Like Science. Thanks for pointing it out, David Terry Dorais!

Bottom line: In 2020, the bright planets Jupiter and Saturn can help you find the faint constellation Capricornus the Sea Goat.



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Chart showing Jupiter and Saturn between triangular Capricornus and Sagittarius.

This chart works for September 9 or 10, 2020 … and for lots of nights after that, approximately through late September. Chart via Guy Ottewell’s blog.

Originally published at Guy Ottewell’s blog. Reprinted here with permission.

Above is a chart showing the night sky on Wednesday, September 9, 2020. See how Jupiter and Saturn are pointing to the constellation Capricornus the Sea Goat? You need a dark sky to see this constellation, but Jupiter and Saturn are very bright. If you have that dark sky, and have never seen this faint constellation, now is the time to look.

Below you’ll find is an example of the unhelpful sky charts generally used in the astronomy columns of newspapers and popular magazines.

It’s from Sunday’s Guardian. The article rightly says that Capricornus is an important constellation because it is part of the ancient zodiac, but it is inconspicuous, and you can at present use Jupiter and Saturn as pointers to it.

A chart with a scattering of equally bright stars and constellations outlined, plus text.

Chart via The Guardian.

Fair enough. But the chart doesn’t do Capricornus justice. Perhaps you, sage reader, can with effort decipher the Guardian’s chart because you know the sky. But, if you were a beginner, could you use this maze of dots and lines to find anything as you gaze at the sky? I don’t think so.

I think the way of connecting dots is derived from H.A. Rey’s ingenious but doomed method as described in his book “The Stars: A New Way to See Them.” It tries to make Capricornus look like a goat. But Capricornus doesn’t look like a goat; it looks like a boat, or – as the Americans prefer – an arrowhead.

I hope my way of rendering this part of the sky – as seen on the chart at the top of the post – is more helpful.

Read more about the constellation Capricornus

Cartoon showing a line of stars, with the ancient stargazers saying 'ah yes, a goat.'

Chart via Posts That Look Like Science. Thanks for pointing it out, David Terry Dorais!

Bottom line: In 2020, the bright planets Jupiter and Saturn can help you find the faint constellation Capricornus the Sea Goat.



from EarthSky https://ift.tt/2ZktSg2

See Messier 20, the Trifid Nebula

Visible light pictures show the nebula divided into 3 parts by dark, obscuring dust lanes, but this penetrating infrared image by the Spitzer Space Telescope reveals filaments of luminous gas and newborn stars. Image via APOD/ JPL-Caltech/ J. Rho (SSC/Caltech)

The Trifid Nebula (Messier 20 or M20) is one of the many binocular treasures in the direction of the center of our Milky Way galaxy. Its name means divided into three lobes, although you’ll likely need a telescope to see why. On a dark, moonless night – from a rural location – you can star-hop upward from the spout of the Teapot in Sagittarius to another famous nebula, the Lagoon, also known as Messier 8. In the same binocular field, look for the smaller and fainter Trifid Nebula as a fuzzy patch above the Lagoon.

To locate this nebula, first find the famous Teapot asterism in the western half of Sagittarius. The Teapot is just a star pattern, not an entire constellation. Nonetheless, most people have an easier time envisioning the Teapot than the Centaur that Sagittarius is supposed to represent. How can you find it? First, be sure you’re looking on a dark night, from a rural location.

Then, look for southward in the evening from Earth’s Northern Hemisphere. If you’re in Earth’s Southern Hemisphere, look northward, closer to overhead, and turn the charts below upside-down. Want a more exact location for the Teapot in Sagittarius? We hear good things about Stellarium, which will let you set a date and time from your exact location on the globe.

Chart showing location of M8 and M20 with respect to the Teapot in the constellation Sagittarius.

You’ll find M20 in a dark sky near the spout of the Teapot in Sagittarius. Notice the 3 westernmost (right-hand) stars of the Teapot spout … then get ready to star-hop! Use binoculars and go about twice the spout’s distance upward until a bright hazy object glares at you in your binoculars. That’s the Lagoon Nebula (Messier 8), which is actually visible to the unaided eye on a dark, moonless night. Once you locate the Lagoon Nebula, look for the smaller Trifid Nebula as a hazy object some 2 degrees above the Lagoon. For reference, keep in mind that a binocular field commonly spans 5 to 6 degrees of sky. Here’s more about the Teapot.

Chart showing one of the most star-rich regions of the Milky Way galaxy, toward the galaxy's center, in the direction of the constellation Sagittarius. Chart via astronomy.com

Chart showing one of the most star-rich regions of the Milky Way galaxy, toward the galaxy’s center, in the direction of the constellation Sagittarius. If you look closely, you can pick out M20 on this chart. Chart via astronomy.com.

Whether the close-knit nebulosity of the Trifid and the Lagoon represents a chance alignment or an actual kinship between the two nebulae is open to question. Both the Trifid and Lagoon are thought to reside about 5,000 light-years away, suggesting the possibility of a common origin. But these distances are not known with precision, and may be subject to revision.

Both the Trifid and Lagoon are vast cocoons of interstellar dust and gas. These are stellar nurseries, actively giving birth to new stars. The Trifid and Lagoon Nebulae are a counterpart to another star-forming region on the opposite side of the sky: the Great Orion Nebula.

Trifid Nebula via the Hubble Space Telescope. Image via NASA/ESA.

The Trifid Nebula (M20) is at RA: 18h 02.6s; Dec: -23o 02′

Bottom line: The Trifid nebula (M20) is located in the direction of the center of the Milky Way galaxy. If you have an extremely dark sky, you can see the nebula on a moonless night as a fuzzy patch in the Milky Way. Binoculars show more … and a telescope still more.

Read more: Find the Teapot, and look toward the galaxy’s center

Read more: M8 is the Lagoon Nebula

Read more: Exploring the Trifid Nebula



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Visible light pictures show the nebula divided into 3 parts by dark, obscuring dust lanes, but this penetrating infrared image by the Spitzer Space Telescope reveals filaments of luminous gas and newborn stars. Image via APOD/ JPL-Caltech/ J. Rho (SSC/Caltech)

The Trifid Nebula (Messier 20 or M20) is one of the many binocular treasures in the direction of the center of our Milky Way galaxy. Its name means divided into three lobes, although you’ll likely need a telescope to see why. On a dark, moonless night – from a rural location – you can star-hop upward from the spout of the Teapot in Sagittarius to another famous nebula, the Lagoon, also known as Messier 8. In the same binocular field, look for the smaller and fainter Trifid Nebula as a fuzzy patch above the Lagoon.

To locate this nebula, first find the famous Teapot asterism in the western half of Sagittarius. The Teapot is just a star pattern, not an entire constellation. Nonetheless, most people have an easier time envisioning the Teapot than the Centaur that Sagittarius is supposed to represent. How can you find it? First, be sure you’re looking on a dark night, from a rural location.

Then, look for southward in the evening from Earth’s Northern Hemisphere. If you’re in Earth’s Southern Hemisphere, look northward, closer to overhead, and turn the charts below upside-down. Want a more exact location for the Teapot in Sagittarius? We hear good things about Stellarium, which will let you set a date and time from your exact location on the globe.

Chart showing location of M8 and M20 with respect to the Teapot in the constellation Sagittarius.

You’ll find M20 in a dark sky near the spout of the Teapot in Sagittarius. Notice the 3 westernmost (right-hand) stars of the Teapot spout … then get ready to star-hop! Use binoculars and go about twice the spout’s distance upward until a bright hazy object glares at you in your binoculars. That’s the Lagoon Nebula (Messier 8), which is actually visible to the unaided eye on a dark, moonless night. Once you locate the Lagoon Nebula, look for the smaller Trifid Nebula as a hazy object some 2 degrees above the Lagoon. For reference, keep in mind that a binocular field commonly spans 5 to 6 degrees of sky. Here’s more about the Teapot.

Chart showing one of the most star-rich regions of the Milky Way galaxy, toward the galaxy's center, in the direction of the constellation Sagittarius. Chart via astronomy.com

Chart showing one of the most star-rich regions of the Milky Way galaxy, toward the galaxy’s center, in the direction of the constellation Sagittarius. If you look closely, you can pick out M20 on this chart. Chart via astronomy.com.

Whether the close-knit nebulosity of the Trifid and the Lagoon represents a chance alignment or an actual kinship between the two nebulae is open to question. Both the Trifid and Lagoon are thought to reside about 5,000 light-years away, suggesting the possibility of a common origin. But these distances are not known with precision, and may be subject to revision.

Both the Trifid and Lagoon are vast cocoons of interstellar dust and gas. These are stellar nurseries, actively giving birth to new stars. The Trifid and Lagoon Nebulae are a counterpart to another star-forming region on the opposite side of the sky: the Great Orion Nebula.

Trifid Nebula via the Hubble Space Telescope. Image via NASA/ESA.

The Trifid Nebula (M20) is at RA: 18h 02.6s; Dec: -23o 02′

Bottom line: The Trifid nebula (M20) is located in the direction of the center of the Milky Way galaxy. If you have an extremely dark sky, you can see the nebula on a moonless night as a fuzzy patch in the Milky Way. Binoculars show more … and a telescope still more.

Read more: Find the Teapot, and look toward the galaxy’s center

Read more: M8 is the Lagoon Nebula

Read more: Exploring the Trifid Nebula



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Use the Big Dipper to find the North Star

Tonight’s chart shows Polaris and the Big and Little Dippers for a September evening. You can use the Big Dipper to find Polaris, which is also known as the North Star. Notice that a line from the two outermost stars in the bowl of the Big Dipper points to Polaris. And notice that Polaris marks the tip of the handle of the Little Dipper.

The northern sky is a large clock, with Polaris at its center. The hour hand is a line drawn through Dubhe and Merak, the two pointer stars of the Big Dipper. Because the stars make a full circle in 23 hours 56 minutes instead of exactly 24 hours, this star clock is not exactly the same as the one on the wall, but with a little practice you can learn to read it well.

The Big Dipper swings full circle – 360 degrees – around Polaris in about 23 hours and 56 minutes. In 24 hours, the Big Dipper actually swings more than a full circle, or 361 degrees. Does that make a difference? Yes! It means that – if you look at the same time each evening – the Big Dipper will appear just a little bit lower in the northwestern evening sky.

Diagram: White sky with four black Big Dippers in a circle around Polaris.

If you’re in the northern U.S., Canada or at a similar latitude, the Big Dipper is circumpolar for you – always above the horizon. Image via burro.astr.cwru.edu

A month from now at mid-evening, the Big Dipper will be noticeably lower in the northwest. It’ll be actually beneath the horizon as seen from the southern latitudes in the United States – although it’s circumpolar, or always above the northern horizon, as seen from the northern U.S., Canada and similarly northern latitudes.

The constant motion from night to night of these stars circling Polaris is a bit like a bear circling its prey, looking for a way to attack. Several ancient cultures from the Greeks and Romans to the Mi?kmaq Indians likened these stars to a bear.

In Greek mythology, the Big Dipper asterism represents the hindquarters and tail of the constellation Ursa Major, the Great Bear. The Mi?kmaq saw the three stars of the Big Dipper handle as hunters chasing the bear.

Watch the Big and Little Dippers circle around Polaris tonight!

Bottom line: To locate Polaris, the North Star, just draw a line between the two outer stars in the bowl of the Big Dipper.

The Big and Little Dippers: All you need to know

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Tonight’s chart shows Polaris and the Big and Little Dippers for a September evening. You can use the Big Dipper to find Polaris, which is also known as the North Star. Notice that a line from the two outermost stars in the bowl of the Big Dipper points to Polaris. And notice that Polaris marks the tip of the handle of the Little Dipper.

The northern sky is a large clock, with Polaris at its center. The hour hand is a line drawn through Dubhe and Merak, the two pointer stars of the Big Dipper. Because the stars make a full circle in 23 hours 56 minutes instead of exactly 24 hours, this star clock is not exactly the same as the one on the wall, but with a little practice you can learn to read it well.

The Big Dipper swings full circle – 360 degrees – around Polaris in about 23 hours and 56 minutes. In 24 hours, the Big Dipper actually swings more than a full circle, or 361 degrees. Does that make a difference? Yes! It means that – if you look at the same time each evening – the Big Dipper will appear just a little bit lower in the northwestern evening sky.

Diagram: White sky with four black Big Dippers in a circle around Polaris.

If you’re in the northern U.S., Canada or at a similar latitude, the Big Dipper is circumpolar for you – always above the horizon. Image via burro.astr.cwru.edu

A month from now at mid-evening, the Big Dipper will be noticeably lower in the northwest. It’ll be actually beneath the horizon as seen from the southern latitudes in the United States – although it’s circumpolar, or always above the northern horizon, as seen from the northern U.S., Canada and similarly northern latitudes.

The constant motion from night to night of these stars circling Polaris is a bit like a bear circling its prey, looking for a way to attack. Several ancient cultures from the Greeks and Romans to the Mi?kmaq Indians likened these stars to a bear.

In Greek mythology, the Big Dipper asterism represents the hindquarters and tail of the constellation Ursa Major, the Great Bear. The Mi?kmaq saw the three stars of the Big Dipper handle as hunters chasing the bear.

Watch the Big and Little Dippers circle around Polaris tonight!

Bottom line: To locate Polaris, the North Star, just draw a line between the two outer stars in the bowl of the Big Dipper.

The Big and Little Dippers: All you need to know

EarthSky astronomy kits are perfect for beginners. Order today from the EarthSky store

Enjoying EarthSky so far? Sign up for our free daily newsletter today!



from EarthSky https://ift.tt/34O5RPB

Last quarter moon is September 10

One half the moon's face in sunlight, lighted portion facing downward, left side marked N for north.

View at EarthSky Community Photos. | Dr Ski in Valencia, Philippines, caught the last quarter moon shortly after it rose around midnight on the morning of September 22, 2019. This moon phase is perfect for helping you envision the location of the sun … below your feet. Thanks, Dr Ski!

September’s last quarter moon falls on Thursday, September 10, at 09:25 UTC (4:25 a.m. CDT). Translate UTC to your time.

A last quarter moon appears half-lit by sunshine and half-immersed in its own shadow. It rises in the middle of the night, appears at its highest in the sky around dawn, and sets around midday.

A last quarter moon provides a great opportunity to think of yourself on a three-dimensional world in space. Watch for this moon just after moonrise, shortly after midnight. Then the lighted portion points downward, to the sun below your feet. Think of the last quarter moon as a mirror to the world you’re standing on. Think of yourself standing in the midst of Earth’s nightside, on the midnight portion of Earth.

Half-lit Earth from north, and half-lit moon with divisions between dark and light sides lined up.

Click here to see animation. As seen from the north side of the moon’s orbital plane, the Earth rotates counterclockwise on its rotational axis, and the moon revolves counterclockwise around Earth. The terminators of the Earth and moon align at first and last quarter moons, and only the near half of the moon’s day side is visible from Earth.

On a last quarter moon, the lunar terminator – the shadow line dividing day and night – shows you where it’s sunset on the moon.

Craters and other features, including a short straight white line on a dark flat mare floor.

View at EarthSky Community Photos. | September 22, 2019, photo by Dr Ski. He wrote: “The moon’s southern limb at last quarter. The Straight Wall is either black or white depending on the angle of the sun’s rays. At lunar sunset (now), it’s white. Around full moon, Tycho is one of the easiest craters to find due to the impact rays emanating from it. It’s like the hub of a spoked wheel! At last quarter, Tycho becomes unremarkable. Clavius, on the other hand, becomes remarkable at high magnification.”

Labeled craters and mountain ranges at the edge between dark and light.

View at EarthSky Community Photos. | September 22, 2019, photo by Dr Ski. He wrote: “The Sea of Rains at last quarter. The lunar Alps and Apennines are bisected by the moon’s meridian. You can get an idea of the height of these mountains by how far they extend into the dark side of the terminator. At an elevation of over 5,000 meters [16,000 feet], the Apennines are twice as tall as the Alps.”

Also, a last quarter moon can be used as a guidepost to Earth’s direction of motion in orbit around the sun.

In other words, when you look toward a last quarter moon high in the predawn sky, for example, you’re gazing out approximately along the path of Earth’s orbit, in a forward direction. The moon is moving in orbit around the sun with the Earth and never holds still. But, if we could somehow anchor the moon in space … tie it down, keep it still … Earth’s orbital speed of 18 miles per second (29 km/sec) would carry us across the space between us and the moon in only a few hours.

Want to read more about the last quarter moon as a guidepost for Earth’s motion? Astronomer Guy Ottewell talks about it here.

A great thing about using the moon as a guidepost to Earth’s motion is that you can do it anywhere … as, for example, in the photo below, from large cities.

Daytime sky. High small moon, left half visible, above conical-top water tower and tall tan brick chimney.

Ben Orlove wrote from New York City: “I was sitting in the roof garden of my building, and there was the moon, right in front of me. You were right, this is a perfect time to visualize … the Earth’s motion.”

As the moon orbits Earth, it changes phase in an orderly way. Read more: 4 keys to understanding moon phases

Bottom line: The moon reaches its last quarter phase on September 10, 2020, at 09:25 UTC. In the coming week, watch for the moon to rise in the east in the hours after midnight, waning thinner each morning.



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One half the moon's face in sunlight, lighted portion facing downward, left side marked N for north.

View at EarthSky Community Photos. | Dr Ski in Valencia, Philippines, caught the last quarter moon shortly after it rose around midnight on the morning of September 22, 2019. This moon phase is perfect for helping you envision the location of the sun … below your feet. Thanks, Dr Ski!

September’s last quarter moon falls on Thursday, September 10, at 09:25 UTC (4:25 a.m. CDT). Translate UTC to your time.

A last quarter moon appears half-lit by sunshine and half-immersed in its own shadow. It rises in the middle of the night, appears at its highest in the sky around dawn, and sets around midday.

A last quarter moon provides a great opportunity to think of yourself on a three-dimensional world in space. Watch for this moon just after moonrise, shortly after midnight. Then the lighted portion points downward, to the sun below your feet. Think of the last quarter moon as a mirror to the world you’re standing on. Think of yourself standing in the midst of Earth’s nightside, on the midnight portion of Earth.

Half-lit Earth from north, and half-lit moon with divisions between dark and light sides lined up.

Click here to see animation. As seen from the north side of the moon’s orbital plane, the Earth rotates counterclockwise on its rotational axis, and the moon revolves counterclockwise around Earth. The terminators of the Earth and moon align at first and last quarter moons, and only the near half of the moon’s day side is visible from Earth.

On a last quarter moon, the lunar terminator – the shadow line dividing day and night – shows you where it’s sunset on the moon.

Craters and other features, including a short straight white line on a dark flat mare floor.

View at EarthSky Community Photos. | September 22, 2019, photo by Dr Ski. He wrote: “The moon’s southern limb at last quarter. The Straight Wall is either black or white depending on the angle of the sun’s rays. At lunar sunset (now), it’s white. Around full moon, Tycho is one of the easiest craters to find due to the impact rays emanating from it. It’s like the hub of a spoked wheel! At last quarter, Tycho becomes unremarkable. Clavius, on the other hand, becomes remarkable at high magnification.”

Labeled craters and mountain ranges at the edge between dark and light.

View at EarthSky Community Photos. | September 22, 2019, photo by Dr Ski. He wrote: “The Sea of Rains at last quarter. The lunar Alps and Apennines are bisected by the moon’s meridian. You can get an idea of the height of these mountains by how far they extend into the dark side of the terminator. At an elevation of over 5,000 meters [16,000 feet], the Apennines are twice as tall as the Alps.”

Also, a last quarter moon can be used as a guidepost to Earth’s direction of motion in orbit around the sun.

In other words, when you look toward a last quarter moon high in the predawn sky, for example, you’re gazing out approximately along the path of Earth’s orbit, in a forward direction. The moon is moving in orbit around the sun with the Earth and never holds still. But, if we could somehow anchor the moon in space … tie it down, keep it still … Earth’s orbital speed of 18 miles per second (29 km/sec) would carry us across the space between us and the moon in only a few hours.

Want to read more about the last quarter moon as a guidepost for Earth’s motion? Astronomer Guy Ottewell talks about it here.

A great thing about using the moon as a guidepost to Earth’s motion is that you can do it anywhere … as, for example, in the photo below, from large cities.

Daytime sky. High small moon, left half visible, above conical-top water tower and tall tan brick chimney.

Ben Orlove wrote from New York City: “I was sitting in the roof garden of my building, and there was the moon, right in front of me. You were right, this is a perfect time to visualize … the Earth’s motion.”

As the moon orbits Earth, it changes phase in an orderly way. Read more: 4 keys to understanding moon phases

Bottom line: The moon reaches its last quarter phase on September 10, 2020, at 09:25 UTC. In the coming week, watch for the moon to rise in the east in the hours after midnight, waning thinner each morning.



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