Will you see Comet SWAN?

Twilight sky with a few stars and a long arrow pointing at a dot.

View at EarthSky Community Photos. | Dr Ski in Valencia, Philippines (latitude 9 degrees north), caught this image of the comet on May 2, 2020, and wrote, “Comet C/2020 F8 (SWAN) was discovered in March by NASA’s SOHO imaging. At magnitude +5, it was easy to spot through binoculars in nautical twilight when this image was captured.” Thank you, Dr Ski! Has the comet continued to brighten? Not as much as hoped so far, but you never know. Read on …

Earlier this spring, bright Comet ATLAS was brightening steadily, on a course that might have brought it into visibility with the unaided eye. That was before it broke our hearts by fracturing into multiple pieces. Then, surprisingly, a second comet – recently discovered and initially visible only from Earth’s Southern Hemisphere – began brightening and creating a buzz among those who watch the skies. Comet C/2020 F8 (SWAN) is now visible with good binoculars in Northern Hemisphere skies, too, although finding it requires skill, with only a small window for locating it each day. That’s because the comet is rising only shortly before the sun, and can be found near the horizon when dawn breaks.

This comet has already come closest to Earth (on May 12-13, 2020), at a distance of 51.7 million miles (83.2 million km).

It’s now heading toward its perihelion, or closest point to the sun, on May 27, 2020.

Amateur astronomer Michael Mattiazzo in Australia discovered comet C/2020 F8 (SWAN) on April 11, 2020. Mattiazzo was not looking at the sky when he made his discovery. Instead, he saw the possible – and then confirmed – comet while reviewing images captured by the Solar Wind ANisotropies (SWAN) instrument aboard the Solar and Heliospheric Observatory (SOHO) spacecraft overseen by NASA and the European Space Agency. This is Mattiazzo’s 8th comet discovery; like comet C/2020 F8 (SWAN), his others were found via inspection of SOHO images. It is the SWAN instrument’s 12th comet discovery. And it’s SOHO’s 3,932nd comet discovery!

Read more: Here’s how SOHO and a skywatcher discovered Comet SWAN

Comet C/2020 F8 (SWAN) was ejecting huge amounts of water vapor, which showed as hydrogen on SOHO’s instrument, according to the European Space Agency. Michael Combi from the University of Michigan estimated that, by April 15, the comet was ejecting about 2,866 pounds (1,300 kg) of water vapor every second.

Thus, during the month of April, Comet SWAN showed a trend of increasing brightness – likely due to that temporary outburst in activity – but then that trend stopped. As of early and mid May, the comet is not getting brighter, although it might (or not) get somewhat brighter in the days during which it’s approaching the sun for its May 27 perihelium.

That previous apparent outburst was enough to let experienced observers at southerly latitudes view the comet without optical aid, barely, using peripheral or averted vision.

Some experienced astrophotographers have been able to capture amazing long-exposure images of Comet SWAN, some of which show that the comet’s tail is extremely long, as long as 20 times the apparent diameter of the full moon! Those observers were lucky to image Comet SWAN when it was high in the sky from their perspective. As stated above, though, this comet appears low in the sky as viewed in Northern Hemisphere skies. Its nearness to the horizon might subtract a little brightness of this (already not-so-bright) celestial visitor.

Check out the tweets below:

Visible to the unaided eye? Probably not, but with comets, you never know.

Of course, the question on everyone’s mind is, will Comet SWAN become visible to the unaided eye? And the answer is, probably not.

It’s important to note that the photographs above are made by experienced photographers using telescopes and other special equipment. They do not mean that Comet SWAN is or was clearly visible to the unaided eye for most observers.

Observers at latitudes like those in the southern U.S. (say, 30 degrees north latitude) and locations in both hemispheres close to the equator have the best chance – still only a slight chance – to view or capture this horizon-grazing comet. Your location on the globe will be key here. Also, sky conditions for observing Comet SWAN are quite challenging. Observers equipped with binoculars or a small telescope will have a small window – only a few minutes, just before dawn – to spot it. Seeing it will, of course, also require a clear sky and, in that sense, the ongoing Covid-19 pandemic appears to have provided many parts of Earth with clearer skies, especially toward your horizons, than usual.

If you have a camera capable of taking long-exposure photos (which provide far more sensitivity than the human eye), a good option would be to point the camera at the approximate area where the comet is located (even if you don’t see the comet; charts provided below), and take several images at different exposures (30, 45, 60 seconds, or more), as well as diverse zoom settings. Then review those images, as some may reveal the comet with its greenish color, and perhaps even a hint of its long tail.

And, of course – as usual with comets – the unpredictability factor has to weigh in. We just don’t know what comets will do, until they do it.

One thing is certain. Sky enthusiasts will continue to monitor the comet using binoculars, small telescopes and cameras. Just don’t be fooled by claims that Comet SWAN will provide an “amazing and spectacular show” to the unaided eye. If you do see the comet with binoculars or a small telescope, your view – at best – might be more like this:

You might catch it using binoculars or a small telescope, but with the caveat that it’s very, very close to the horizon, not to mention that it’s in our sky only shortly before dawn each day, as the comet approaches its closest point to the sun on May 27. Although any improvement in the comet’s visibility cannot be ruled out, it appears to be remaining just a binocular or camera target.

You’ll be looking toward your northeastern horizon, before sunup. See the charts at the bottom of this post.

Some charts to help you locate Comet SWAN in the sky

These charts are set for the latitude of the southern U.S. If you are elsewhere on the globe, the comet will be up at or around this same time of day, in front of these same constellations and near these same stars. But the comet, and the stars, will be oriented differently with respect to different horizons around the globe. Or they might not be above your horizon at all. Stellarium-Web is tracking Comet SWAN. Set your individual location on the globe, set the time for before dawn, face the program toward the northeast, and see the comet’s whereabouts each day.

Chart with stars labeled and comet location marked with red lines.

May 17, 2020, just before dawn. Facing northeast, as seen from southern U.S. For an individualized view, try Stellarium. Illustration by Eddie Irizarry using Stellarium.

Chart with stars labeled including Algol and comet location marked with red lines.

Location of Comet C/2020 F8 (SWAN) on May 19, 2020, shortly before dawn. Facing northeast, as seen from southern U.S. For an individualized view, try Stellarium. Illustration by Eddie Irizarry using Stellarium.

Chart with stars labeled and comet location marked with red lines.

May 21, 2020, a few minutes before dawn. Facing northeast, as seen from southern U.S. For an individualized view, try Stellarium. Illustration by Eddie Irizarry using Stellarium.

Chart with stars labeled and comet location marked with red lines.

By May 24, 2020, Comet SWAN will become increasingly closer to the horizon, making observations even more difficult, perhaps allowing only long-exposure photography. This chart faces northeast just before dawn, as seen from southern U.S. For an individualized view, try Stellarium. Illustration by Eddie Irizarry using Stellarium.

Chart with stars labeled and comet location marked with red lines.

May 27, 2020. This is the date of the comet’s perihelion, or closest approach to the sun. At this point, Comet SWAN will be located extremely close to your sunrise horizon. This chart faces northeast just before dawn, as seen from southern U.S. For an individualized view, try Stellarium. Illustration by Eddie Irizarry using Stellarium.

Chart with stars labeled and comet location marked with red lines.

May 31 – June 1, 2020. After passing close to the sun, Comet SWAN will reappear early in the evening sky, and pass close to star Capella. This chart faces northwest during evening dusk, as seen from southern U.S. For an individualized view, try Stellarium. Illustration by Eddie Irizarry using Stellarium.

A large glowing fuzzy dot with a long tail.

Comet C/2020 F8 (SWAN). Image via Ezequiel Benitez, from Isabela, Puerto Rico.

Bottom line: Comet C/2020 F8 (SWAN) has provided experienced astrophotographers with some amazing captures. Now, for Northern Hemisphere observers, it appears very close to the northeastern horizon before sunup; we don’t expect this comet to be widely seen, or to become easily visible to the eye. It likely won’t be a great comet visually, but amateur astronomers will be keeping an eye on Comet SWAN, just in case.



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Twilight sky with a few stars and a long arrow pointing at a dot.

View at EarthSky Community Photos. | Dr Ski in Valencia, Philippines (latitude 9 degrees north), caught this image of the comet on May 2, 2020, and wrote, “Comet C/2020 F8 (SWAN) was discovered in March by NASA’s SOHO imaging. At magnitude +5, it was easy to spot through binoculars in nautical twilight when this image was captured.” Thank you, Dr Ski! Has the comet continued to brighten? Not as much as hoped so far, but you never know. Read on …

Earlier this spring, bright Comet ATLAS was brightening steadily, on a course that might have brought it into visibility with the unaided eye. That was before it broke our hearts by fracturing into multiple pieces. Then, surprisingly, a second comet – recently discovered and initially visible only from Earth’s Southern Hemisphere – began brightening and creating a buzz among those who watch the skies. Comet C/2020 F8 (SWAN) is now visible with good binoculars in Northern Hemisphere skies, too, although finding it requires skill, with only a small window for locating it each day. That’s because the comet is rising only shortly before the sun, and can be found near the horizon when dawn breaks.

This comet has already come closest to Earth (on May 12-13, 2020), at a distance of 51.7 million miles (83.2 million km).

It’s now heading toward its perihelion, or closest point to the sun, on May 27, 2020.

Amateur astronomer Michael Mattiazzo in Australia discovered comet C/2020 F8 (SWAN) on April 11, 2020. Mattiazzo was not looking at the sky when he made his discovery. Instead, he saw the possible – and then confirmed – comet while reviewing images captured by the Solar Wind ANisotropies (SWAN) instrument aboard the Solar and Heliospheric Observatory (SOHO) spacecraft overseen by NASA and the European Space Agency. This is Mattiazzo’s 8th comet discovery; like comet C/2020 F8 (SWAN), his others were found via inspection of SOHO images. It is the SWAN instrument’s 12th comet discovery. And it’s SOHO’s 3,932nd comet discovery!

Read more: Here’s how SOHO and a skywatcher discovered Comet SWAN

Comet C/2020 F8 (SWAN) was ejecting huge amounts of water vapor, which showed as hydrogen on SOHO’s instrument, according to the European Space Agency. Michael Combi from the University of Michigan estimated that, by April 15, the comet was ejecting about 2,866 pounds (1,300 kg) of water vapor every second.

Thus, during the month of April, Comet SWAN showed a trend of increasing brightness – likely due to that temporary outburst in activity – but then that trend stopped. As of early and mid May, the comet is not getting brighter, although it might (or not) get somewhat brighter in the days during which it’s approaching the sun for its May 27 perihelium.

That previous apparent outburst was enough to let experienced observers at southerly latitudes view the comet without optical aid, barely, using peripheral or averted vision.

Some experienced astrophotographers have been able to capture amazing long-exposure images of Comet SWAN, some of which show that the comet’s tail is extremely long, as long as 20 times the apparent diameter of the full moon! Those observers were lucky to image Comet SWAN when it was high in the sky from their perspective. As stated above, though, this comet appears low in the sky as viewed in Northern Hemisphere skies. Its nearness to the horizon might subtract a little brightness of this (already not-so-bright) celestial visitor.

Check out the tweets below:

Visible to the unaided eye? Probably not, but with comets, you never know.

Of course, the question on everyone’s mind is, will Comet SWAN become visible to the unaided eye? And the answer is, probably not.

It’s important to note that the photographs above are made by experienced photographers using telescopes and other special equipment. They do not mean that Comet SWAN is or was clearly visible to the unaided eye for most observers.

Observers at latitudes like those in the southern U.S. (say, 30 degrees north latitude) and locations in both hemispheres close to the equator have the best chance – still only a slight chance – to view or capture this horizon-grazing comet. Your location on the globe will be key here. Also, sky conditions for observing Comet SWAN are quite challenging. Observers equipped with binoculars or a small telescope will have a small window – only a few minutes, just before dawn – to spot it. Seeing it will, of course, also require a clear sky and, in that sense, the ongoing Covid-19 pandemic appears to have provided many parts of Earth with clearer skies, especially toward your horizons, than usual.

If you have a camera capable of taking long-exposure photos (which provide far more sensitivity than the human eye), a good option would be to point the camera at the approximate area where the comet is located (even if you don’t see the comet; charts provided below), and take several images at different exposures (30, 45, 60 seconds, or more), as well as diverse zoom settings. Then review those images, as some may reveal the comet with its greenish color, and perhaps even a hint of its long tail.

And, of course – as usual with comets – the unpredictability factor has to weigh in. We just don’t know what comets will do, until they do it.

One thing is certain. Sky enthusiasts will continue to monitor the comet using binoculars, small telescopes and cameras. Just don’t be fooled by claims that Comet SWAN will provide an “amazing and spectacular show” to the unaided eye. If you do see the comet with binoculars or a small telescope, your view – at best – might be more like this:

You might catch it using binoculars or a small telescope, but with the caveat that it’s very, very close to the horizon, not to mention that it’s in our sky only shortly before dawn each day, as the comet approaches its closest point to the sun on May 27. Although any improvement in the comet’s visibility cannot be ruled out, it appears to be remaining just a binocular or camera target.

You’ll be looking toward your northeastern horizon, before sunup. See the charts at the bottom of this post.

Some charts to help you locate Comet SWAN in the sky

These charts are set for the latitude of the southern U.S. If you are elsewhere on the globe, the comet will be up at or around this same time of day, in front of these same constellations and near these same stars. But the comet, and the stars, will be oriented differently with respect to different horizons around the globe. Or they might not be above your horizon at all. Stellarium-Web is tracking Comet SWAN. Set your individual location on the globe, set the time for before dawn, face the program toward the northeast, and see the comet’s whereabouts each day.

Chart with stars labeled and comet location marked with red lines.

May 17, 2020, just before dawn. Facing northeast, as seen from southern U.S. For an individualized view, try Stellarium. Illustration by Eddie Irizarry using Stellarium.

Chart with stars labeled including Algol and comet location marked with red lines.

Location of Comet C/2020 F8 (SWAN) on May 19, 2020, shortly before dawn. Facing northeast, as seen from southern U.S. For an individualized view, try Stellarium. Illustration by Eddie Irizarry using Stellarium.

Chart with stars labeled and comet location marked with red lines.

May 21, 2020, a few minutes before dawn. Facing northeast, as seen from southern U.S. For an individualized view, try Stellarium. Illustration by Eddie Irizarry using Stellarium.

Chart with stars labeled and comet location marked with red lines.

By May 24, 2020, Comet SWAN will become increasingly closer to the horizon, making observations even more difficult, perhaps allowing only long-exposure photography. This chart faces northeast just before dawn, as seen from southern U.S. For an individualized view, try Stellarium. Illustration by Eddie Irizarry using Stellarium.

Chart with stars labeled and comet location marked with red lines.

May 27, 2020. This is the date of the comet’s perihelion, or closest approach to the sun. At this point, Comet SWAN will be located extremely close to your sunrise horizon. This chart faces northeast just before dawn, as seen from southern U.S. For an individualized view, try Stellarium. Illustration by Eddie Irizarry using Stellarium.

Chart with stars labeled and comet location marked with red lines.

May 31 – June 1, 2020. After passing close to the sun, Comet SWAN will reappear early in the evening sky, and pass close to star Capella. This chart faces northwest during evening dusk, as seen from southern U.S. For an individualized view, try Stellarium. Illustration by Eddie Irizarry using Stellarium.

A large glowing fuzzy dot with a long tail.

Comet C/2020 F8 (SWAN). Image via Ezequiel Benitez, from Isabela, Puerto Rico.

Bottom line: Comet C/2020 F8 (SWAN) has provided experienced astrophotographers with some amazing captures. Now, for Northern Hemisphere observers, it appears very close to the northeastern horizon before sunup; we don’t expect this comet to be widely seen, or to become easily visible to the eye. It likely won’t be a great comet visually, but amateur astronomers will be keeping an eye on Comet SWAN, just in case.



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2 views from space: San Francisco Bay

Satellite image of San Francisco Bay.

View larger. | In the larger view, you can see Golden Gate Bridge, 1.7 miles long (2.7 km long). It’s visible crossing the opening of the bay into the Pacific Ocean between Marin County and the city of San Francisco (at the tip of the southern peninsula in the center of the image). Image via ESA.

We thought many of you would enjoy these two images from space of one of Earth’s most captivating places: San Francisco Bay.

The European Space Agency (ESA) shared the image above on May 15, 2020. It’s a view of San Francisco Bay from the Copernicus Sentinel-2 mission, which consists of twin Earth-observing satellites, launched in 2015. They routinely acquire beautiful optical imagery of Earth; see more here. In describing the image above, ESA wrote that San Francisco Bay is:

… almost 100 km [60 miles] in length – a shallow estuary surrounded by the San Francisco Bay Area – an extensive metropolitan region that is dominated by large cities such as San Francisco, Oakland and San Jose. The densely populated urban areas around the bay contrast strongly with the surrounding green forest and park areas.

In the upper right of the image, the delta of the Sacramento and San Joaquin rivers is visible – with the brown, sediment-filled water flowing down into San Pablo Bay. Here, the murky waters mix before flowing into the larger bay area, which is connected to the Pacific Ocean via the Golden Gate strait. A large sediment plume can be seen traveling westward into the Pacific in the left of the image.

The Golden Gate Bridge, around 2.7 km long [1.7 miles], is visible crossing the opening of the bay into the Pacific Ocean between Marin County and the city of San Francisco – which can be seen at the tip of the southern peninsula in the center of the image. Treasure, Angel and Alcatraz islands can be seen sticking out of the waters of the bay, with several bridges connecting its east and west shores. Several boats are also visible …

Read more about this image from ESA.

Since some of its earliest missions, astronauts traveling aboard the International Space Station (ISS) have also been tempted to capture the beauty of San Francisco Bay. The image below is from ISS Expedition 4 (December 2001 to June 2002; the current mission is Expedition 63). NASA wrote of the image below:

This view featuring the San Francisco Bay Area was photographed by an Expedition 4 crewmember onboard the International Space Station. The gray urban footprint of San Francisco, Oakland, San Jose, and their surrounding suburbs contrasts strongly with the green hillsides. Pacific Ocean water patterns are highlighted in the sun glint. Sets of internal waves traveling east impinge on the coastline south of San Francisco. At the same time, fresher bay water flows out from the bay beneath the Golden Gate Bridge, creating a large plume traveling westward. Tidal current channels suggest the tidal flow deep in the bay.

San Francisco Bay, captured by an astronaut in an early ISS mission, Expedition 4.

View larger. | San Francisco Bay via Expedition 4 of the International Space Station (December 2001 to June 2002). Image via NASA.

Bottom line: A beautiful image of San Francisco Bay via ESA’s Copernicus Sentinel-2 mission.



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Satellite image of San Francisco Bay.

View larger. | In the larger view, you can see Golden Gate Bridge, 1.7 miles long (2.7 km long). It’s visible crossing the opening of the bay into the Pacific Ocean between Marin County and the city of San Francisco (at the tip of the southern peninsula in the center of the image). Image via ESA.

We thought many of you would enjoy these two images from space of one of Earth’s most captivating places: San Francisco Bay.

The European Space Agency (ESA) shared the image above on May 15, 2020. It’s a view of San Francisco Bay from the Copernicus Sentinel-2 mission, which consists of twin Earth-observing satellites, launched in 2015. They routinely acquire beautiful optical imagery of Earth; see more here. In describing the image above, ESA wrote that San Francisco Bay is:

… almost 100 km [60 miles] in length – a shallow estuary surrounded by the San Francisco Bay Area – an extensive metropolitan region that is dominated by large cities such as San Francisco, Oakland and San Jose. The densely populated urban areas around the bay contrast strongly with the surrounding green forest and park areas.

In the upper right of the image, the delta of the Sacramento and San Joaquin rivers is visible – with the brown, sediment-filled water flowing down into San Pablo Bay. Here, the murky waters mix before flowing into the larger bay area, which is connected to the Pacific Ocean via the Golden Gate strait. A large sediment plume can be seen traveling westward into the Pacific in the left of the image.

The Golden Gate Bridge, around 2.7 km long [1.7 miles], is visible crossing the opening of the bay into the Pacific Ocean between Marin County and the city of San Francisco – which can be seen at the tip of the southern peninsula in the center of the image. Treasure, Angel and Alcatraz islands can be seen sticking out of the waters of the bay, with several bridges connecting its east and west shores. Several boats are also visible …

Read more about this image from ESA.

Since some of its earliest missions, astronauts traveling aboard the International Space Station (ISS) have also been tempted to capture the beauty of San Francisco Bay. The image below is from ISS Expedition 4 (December 2001 to June 2002; the current mission is Expedition 63). NASA wrote of the image below:

This view featuring the San Francisco Bay Area was photographed by an Expedition 4 crewmember onboard the International Space Station. The gray urban footprint of San Francisco, Oakland, San Jose, and their surrounding suburbs contrasts strongly with the green hillsides. Pacific Ocean water patterns are highlighted in the sun glint. Sets of internal waves traveling east impinge on the coastline south of San Francisco. At the same time, fresher bay water flows out from the bay beneath the Golden Gate Bridge, creating a large plume traveling westward. Tidal current channels suggest the tidal flow deep in the bay.

San Francisco Bay, captured by an astronaut in an early ISS mission, Expedition 4.

View larger. | San Francisco Bay via Expedition 4 of the International Space Station (December 2001 to June 2002). Image via NASA.

Bottom line: A beautiful image of San Francisco Bay via ESA’s Copernicus Sentinel-2 mission.



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News digest – 15-minute prostate test, COVID-19 AI database, CAR T cell therapy and cancer ancestry links

Test for prostate cancer ‘in under 15 minutes’ 

A new ‘prostogram’ test has been developed in the UK, which uses MRI to detect cancer. Science Focus covered early results from a trial involving 400 men aged 50–69 suggest the scan was better at detecting aggressive cancers than the current test. It’s hoped that the new, non-invasive testing method will encourage more men to get checked for prostate cancer. The 15 minute scan is not the only way MRI is being used to help improve prostate cancer diagnosis, as our blog post explains.  

Cancer drug database adapted for COVID-19  

CanSar, a powerful database used to collate cancer research and drug discovery, is being adapted by a team at The Institute of Cancer Research to help accelerate the search for COVID-19 treatments. The new knowledgebase, Coronavirus-CanSar, will draw on worldwide data for COVID-19 and related diseases such as SARS and MERS. By creating a one-stop resource, the hope is researchers may be able to rapidly repurpose drugs to combat the disease. Engineering and Technology and our blog post have the full story.  

Study suggest more people with lymphoma could benefit from CAR T cell therapy 

News Medical reports that immune-boosting CAR T cell therapy has the potential to treat a wider group of patients with lymphoma than trials suggested. In a study involving 298 people who were treated in hospitals across the US, the treatment was shown to be tolerated by patients who wouldn’t have been eligible for the treatment in the original trials because of their comorbidities. 

And finally… 

Scientists at the NCI Cancer Genome Analysis Network in the US have been researching the connection between ancestry and the molecular makeup of cancers. By studying databases including over 10,500 patients and 33 cancer types, the group concluded that ancestry is linked to variations in hundreds of genes, but most were specific to a particular cancer type. Find out more at Cosmos.

Scarlett Sangster is a writer for PA Media Group



from Cancer Research UK – Science blog https://ift.tt/364RCqB

Test for prostate cancer ‘in under 15 minutes’ 

A new ‘prostogram’ test has been developed in the UK, which uses MRI to detect cancer. Science Focus covered early results from a trial involving 400 men aged 50–69 suggest the scan was better at detecting aggressive cancers than the current test. It’s hoped that the new, non-invasive testing method will encourage more men to get checked for prostate cancer. The 15 minute scan is not the only way MRI is being used to help improve prostate cancer diagnosis, as our blog post explains.  

Cancer drug database adapted for COVID-19  

CanSar, a powerful database used to collate cancer research and drug discovery, is being adapted by a team at The Institute of Cancer Research to help accelerate the search for COVID-19 treatments. The new knowledgebase, Coronavirus-CanSar, will draw on worldwide data for COVID-19 and related diseases such as SARS and MERS. By creating a one-stop resource, the hope is researchers may be able to rapidly repurpose drugs to combat the disease. Engineering and Technology and our blog post have the full story.  

Study suggest more people with lymphoma could benefit from CAR T cell therapy 

News Medical reports that immune-boosting CAR T cell therapy has the potential to treat a wider group of patients with lymphoma than trials suggested. In a study involving 298 people who were treated in hospitals across the US, the treatment was shown to be tolerated by patients who wouldn’t have been eligible for the treatment in the original trials because of their comorbidities. 

And finally… 

Scientists at the NCI Cancer Genome Analysis Network in the US have been researching the connection between ancestry and the molecular makeup of cancers. By studying databases including over 10,500 patients and 33 cancer types, the group concluded that ancestry is linked to variations in hundreds of genes, but most were specific to a particular cancer type. Find out more at Cosmos.

Scarlett Sangster is a writer for PA Media Group



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Bright star Vega on May evenings

Vega is a lovely star to come to know. When I was first learning the night sky, more than 40 years ago, I spent hours, days, weeks, months poring over charts and books. So I sometimes came to know the names and whereabouts of certain stars before seeing them in the night sky. One soft May evening, I happened to glance toward the northeast. I was thrilled at the sight of Vega – gleaming sapphire-blue – and surprisingly bright for being so low in the sky.

Look for this star tonight. It’s the fifth brightest star in our sky. If you’re in the Northern Hemisphere, you’ll find beautiful, bluish Vega easily, simply by looking northeastward at mid-evening in May. Vega is so bright that you can see it on a moonlit night.

From far south in the Southern Hemisphere, you can’t see Vega until late at night in May. That’s because Vega is located so far north on the sky’s dome. Vega will reach its high point for the night around three to four hours after midnight, at which time people in the Southern Hemisphere can see this star in their northern sky. As seen from mid-northern latitudes, the star shines high overhead at this early morning hour.

Because it’s the brightest star in the constellation Lyra the Harp, Vega is sometimes called the Harp Star. Like all stars, Vega rises some four minutes earlier each day as Earth moves around the sun. So Vega will ornament our evening sky throughout the summer and fall.

Although Vega is considered a late spring or summer star, it’s actually so far north on the sky’s dome that – from mid-latitudes in the Northern Hemisphere – you can find it at some time during the night, nearly every night of the year.

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Constellation Lyra with bright blue-white star Vega, and other interesting objects in Lyra marked.

View at EarthSky Community Photos. | Here’s Vega as seen around 3 a.m. from Valencia, Philippines, on May 10, 2019, from our friend Dr Ski. See Vega’s beautiful blue color? Notice the star near Vega, marked the Greek letter Epsilon. This star is Epsilon Lyrae, a famous double-double star.

Bottom line: It’s easy to identify the star Vega in the constellation Lyra at this time of year. From the Northern Hemisphere, look northeast in the evening for a bright, bluish star above the northeastern horizon.

A planisphere is virtually indispensable for beginning stargazers. Order your EarthSky planisphere today.



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Vega is a lovely star to come to know. When I was first learning the night sky, more than 40 years ago, I spent hours, days, weeks, months poring over charts and books. So I sometimes came to know the names and whereabouts of certain stars before seeing them in the night sky. One soft May evening, I happened to glance toward the northeast. I was thrilled at the sight of Vega – gleaming sapphire-blue – and surprisingly bright for being so low in the sky.

Look for this star tonight. It’s the fifth brightest star in our sky. If you’re in the Northern Hemisphere, you’ll find beautiful, bluish Vega easily, simply by looking northeastward at mid-evening in May. Vega is so bright that you can see it on a moonlit night.

From far south in the Southern Hemisphere, you can’t see Vega until late at night in May. That’s because Vega is located so far north on the sky’s dome. Vega will reach its high point for the night around three to four hours after midnight, at which time people in the Southern Hemisphere can see this star in their northern sky. As seen from mid-northern latitudes, the star shines high overhead at this early morning hour.

Because it’s the brightest star in the constellation Lyra the Harp, Vega is sometimes called the Harp Star. Like all stars, Vega rises some four minutes earlier each day as Earth moves around the sun. So Vega will ornament our evening sky throughout the summer and fall.

Although Vega is considered a late spring or summer star, it’s actually so far north on the sky’s dome that – from mid-latitudes in the Northern Hemisphere – you can find it at some time during the night, nearly every night of the year.

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

Constellation Lyra with bright blue-white star Vega, and other interesting objects in Lyra marked.

View at EarthSky Community Photos. | Here’s Vega as seen around 3 a.m. from Valencia, Philippines, on May 10, 2019, from our friend Dr Ski. See Vega’s beautiful blue color? Notice the star near Vega, marked the Greek letter Epsilon. This star is Epsilon Lyrae, a famous double-double star.

Bottom line: It’s easy to identify the star Vega in the constellation Lyra at this time of year. From the Northern Hemisphere, look northeast in the evening for a bright, bluish star above the northeastern horizon.

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Vega: Brilliant blue-white star in the Summer Triangle

Image via Fred Espanak. Used with permission.

The blue-white star Vega via Fred Espenak. Used with permission.

The beautiful blue-white star Vega has a special place in the hearts of skywatchers around the world. Come to know it, and you will see.

How to see Vega. Observers in the Northern Hemisphere typically begin noticing Vega in the evening around May, when this star comes into view in the northeast in mid-evening. You can see Vega in very early evening by June – and high in the east by August evenings – high overhead on autumn evenings – in the northwestern quadrant of the sky on December evenings.

Vega is easily recognizable for its brilliance and blue-white color. You can also easily pick out its constellation Lyra, which is small and compact, and consists primarily of Vega and four fainter stars in the form of a parallelogram.

The little constellation Lyra has some interesting features. Near Vega is Epsilon Lyrae, the famed “double-double” star. Between the Gamma and Beta stars is the famous Ring Nebula, visible in small telescopes.

Vega is one of three stars in an asterism – or noticeable star pattern – called the Summer Triangle in the early evening sky. The other two stars in the Triangle are Deneb and Altair. You can see the Summer Triangle in the evening beginning around June, through the end of each year.

The constellation Lyra the Harp and its brightest star Vega.

Vega in history and myth. In western skylore, Vega’s constellation Lyra is said to be the harp played by the legendary Greek musician Orpheus. It’s said that when Orpheus played this harp, neither god nor mortal could turn away.

In western culture, Vega is often called the Harp Star.

Star-crossed lovers Zhinu – represented by the star Vega in the constellation Lyra – and a humble farm boy, Niulang, represented by the star Altair in Aquila. Image via The NewsTalkers.

Matthew Chin wrote: Happy Chinese Valentine's Day The Qixi Festival. Photo taken in Yuen Long, Hong Kong.

Here are the stars depicted in the illustration above, from Matthew Chin in Yuen Long, Hong Kong.

But the most beautiful story relating to Vega comes from Asia. There are many variations. In China, the legend speaks of a forbidden romance between the goddess Zhinu – represented by Vega – and a humble farm boy, Niulang – represented by the star Altair. Separated in the night sky by the Milky Way, or Celestial River, the two lovers are allowed to meet only once a year. It’s said that meeting comes on the 7th night of the 7th moon, when a bridge of magpies forms across the Celestial River, and the two lovers are reunited.

Their reunion marks the time of the Qixi Festival.

Tanabata and her lover meet on a bridge of magpies across the Celestial River, each year on the 7th night of the 7th moon. Image by Anhellica via Lilliacerise's blog

In Japan, the festival is called Tanabata. Orihime and her lover Hikoboshi meet on a bridge of magpies across the Celestial River, each year on the 7th night of the 7th moon. Image via Anhellica/Lilliacerise’s blog.

In Japan, Vega is called Orihime, a celestial princess or goddess. She falls in love with a mortal, Hikoboshi, represented by the star Altair. But when Orihime’s father finds out, he is enraged and forbids her to see this mere mortal. Then … you know the story. The two lovers are placed in the sky, separated by the Celestial River or Milky Way. Yet the sky gods are kind, and they reunite on the 7th night of the 7th moon each year. Sometimes Hikoboshi’s annual trip across the Celestial River is treacherous, though, and he doesn’t make it. In that case, Orihime’s tears form raindrops that fall over Japan.

Many Japanese celebrations of Tanabata are held in July, but sometimes they are held in August. If it rains, the raindrops are thought to be Orihime’s tears because Hikoboshi could not meet her. Sometimes, the Perseid meteor shower is said to represent Orihime’s tears.

Vega science. Vega is the 5th brightest star visible from Earth, and the 3rd brightest easily visible from mid-northern latitudes, after Sirius and Arcturus. At about 25 light-years in distance, it is the 6th closest of all the bright stars, or 5th if you exclude Alpha Centauri, which is not easily visible from most of the Northern Hemisphere.

Size of the star Vega in contrast to our sun. Image via RJHall/ Wikimedia Commons

Vega’s distinctly blue color indicates a surface temperature of nearly 17,000 degrees Fahrenheit (9,400 Celsius), making it about 7,000 degrees F (4,000 C) hotter than our sun. Roughly 2.5 times the diameter of the sun, and just less than that in mass, Vega’s internal pressures and temperatures are far greater than our sun, making it burn its fuel faster. This causes Vega to produce 35 to 40 times the energy of the sun, which in turn shortens its lifetime. At about 500 million years, Vega is already middle-aged. Currently it is only about a tenth the age of our sun, and will run out of fuel in another half-billion years.

In astronomer-speak, Vega is an “A0V main sequence star.” The “A0” signifies its temperature, whereas the “V” is a measure of energy output (luminosity), indicating that Vega is a normal star (not a giant). “Main sequence” again testifies to the fact that it belongs in the category of normal stars, and that it produces energy through stable fusion of hydrogen into helium. With a visual magnitude (apparent brightness) of 0.03, Vega is only marginally dimmer than Arcturus, but with a distinctly different, cool-blue color.

Vega’s position is RA: 18h 36m 56.3s, dec: +38° 47′ 1.3″.

Bottom line: The star Vega in the constellation Lyra is one of the sky’s most beloved stars, for people around the world.



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Image via Fred Espanak. Used with permission.

The blue-white star Vega via Fred Espenak. Used with permission.

The beautiful blue-white star Vega has a special place in the hearts of skywatchers around the world. Come to know it, and you will see.

How to see Vega. Observers in the Northern Hemisphere typically begin noticing Vega in the evening around May, when this star comes into view in the northeast in mid-evening. You can see Vega in very early evening by June – and high in the east by August evenings – high overhead on autumn evenings – in the northwestern quadrant of the sky on December evenings.

Vega is easily recognizable for its brilliance and blue-white color. You can also easily pick out its constellation Lyra, which is small and compact, and consists primarily of Vega and four fainter stars in the form of a parallelogram.

The little constellation Lyra has some interesting features. Near Vega is Epsilon Lyrae, the famed “double-double” star. Between the Gamma and Beta stars is the famous Ring Nebula, visible in small telescopes.

Vega is one of three stars in an asterism – or noticeable star pattern – called the Summer Triangle in the early evening sky. The other two stars in the Triangle are Deneb and Altair. You can see the Summer Triangle in the evening beginning around June, through the end of each year.

The constellation Lyra the Harp and its brightest star Vega.

Vega in history and myth. In western skylore, Vega’s constellation Lyra is said to be the harp played by the legendary Greek musician Orpheus. It’s said that when Orpheus played this harp, neither god nor mortal could turn away.

In western culture, Vega is often called the Harp Star.

Star-crossed lovers Zhinu – represented by the star Vega in the constellation Lyra – and a humble farm boy, Niulang, represented by the star Altair in Aquila. Image via The NewsTalkers.

Matthew Chin wrote: Happy Chinese Valentine's Day The Qixi Festival. Photo taken in Yuen Long, Hong Kong.

Here are the stars depicted in the illustration above, from Matthew Chin in Yuen Long, Hong Kong.

But the most beautiful story relating to Vega comes from Asia. There are many variations. In China, the legend speaks of a forbidden romance between the goddess Zhinu – represented by Vega – and a humble farm boy, Niulang – represented by the star Altair. Separated in the night sky by the Milky Way, or Celestial River, the two lovers are allowed to meet only once a year. It’s said that meeting comes on the 7th night of the 7th moon, when a bridge of magpies forms across the Celestial River, and the two lovers are reunited.

Their reunion marks the time of the Qixi Festival.

Tanabata and her lover meet on a bridge of magpies across the Celestial River, each year on the 7th night of the 7th moon. Image by Anhellica via Lilliacerise's blog

In Japan, the festival is called Tanabata. Orihime and her lover Hikoboshi meet on a bridge of magpies across the Celestial River, each year on the 7th night of the 7th moon. Image via Anhellica/Lilliacerise’s blog.

In Japan, Vega is called Orihime, a celestial princess or goddess. She falls in love with a mortal, Hikoboshi, represented by the star Altair. But when Orihime’s father finds out, he is enraged and forbids her to see this mere mortal. Then … you know the story. The two lovers are placed in the sky, separated by the Celestial River or Milky Way. Yet the sky gods are kind, and they reunite on the 7th night of the 7th moon each year. Sometimes Hikoboshi’s annual trip across the Celestial River is treacherous, though, and he doesn’t make it. In that case, Orihime’s tears form raindrops that fall over Japan.

Many Japanese celebrations of Tanabata are held in July, but sometimes they are held in August. If it rains, the raindrops are thought to be Orihime’s tears because Hikoboshi could not meet her. Sometimes, the Perseid meteor shower is said to represent Orihime’s tears.

Vega science. Vega is the 5th brightest star visible from Earth, and the 3rd brightest easily visible from mid-northern latitudes, after Sirius and Arcturus. At about 25 light-years in distance, it is the 6th closest of all the bright stars, or 5th if you exclude Alpha Centauri, which is not easily visible from most of the Northern Hemisphere.

Size of the star Vega in contrast to our sun. Image via RJHall/ Wikimedia Commons

Vega’s distinctly blue color indicates a surface temperature of nearly 17,000 degrees Fahrenheit (9,400 Celsius), making it about 7,000 degrees F (4,000 C) hotter than our sun. Roughly 2.5 times the diameter of the sun, and just less than that in mass, Vega’s internal pressures and temperatures are far greater than our sun, making it burn its fuel faster. This causes Vega to produce 35 to 40 times the energy of the sun, which in turn shortens its lifetime. At about 500 million years, Vega is already middle-aged. Currently it is only about a tenth the age of our sun, and will run out of fuel in another half-billion years.

In astronomer-speak, Vega is an “A0V main sequence star.” The “A0” signifies its temperature, whereas the “V” is a measure of energy output (luminosity), indicating that Vega is a normal star (not a giant). “Main sequence” again testifies to the fact that it belongs in the category of normal stars, and that it produces energy through stable fusion of hydrogen into helium. With a visual magnitude (apparent brightness) of 0.03, Vega is only marginally dimmer than Arcturus, but with a distinctly different, cool-blue color.

Vega’s position is RA: 18h 36m 56.3s, dec: +38° 47′ 1.3″.

Bottom line: The star Vega in the constellation Lyra is one of the sky’s most beloved stars, for people around the world.



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Saturn’s bizarre polar hexagon is really hazy

Gray globe with hexagon on top and arc of many fine lines above it, on black background.

A view of Saturn, its rings and its north polar hexagon, as captured by Cassini on November 27, 2013. Image via NASA/ JPL/ SSI/ Lights in the Dark.

Did you know that Saturn has a huge, persistent, hexagonal (six-sided) cloud formation at its north pole? Saturn’s hexagon is one of the most unusual and easily recognized features in the solar system. Now, a new study from researchers at the University of the Basque Country in Spain has revealed details about a multi-layered, sandwich-like haze that hangs above the hexagon itself. The findings come from an examination of images taken by the Hubble Space Telescope as well as those sent back by the Cassini spacecraft, which orbited Saturn from 2004 to 2017.

The results were published in a new peer-reviewed paper in Nature Communications on May 8, 2020.

The hazes above Saturn’s hexagon were first seen by Cassini in June 2015 in high-resolution images of the planet’s limb taken by the spacecraft’s main camera. Those images captured details as small as 0.6 to 1.2 miles (1-2 km) in size. Cassini was able to see the hazes as well as analyze their composition, using color filters from ultraviolet to near-infrared.

The hazes are above the clouds that form the hexagon. The scientists identified at least seven distinct haze layers.

Hexagon shape with inset boxes showing parallel layers, with text annotations.

A closer look at Saturn’s north polar hexagon, captured by Cassini; the inset shows a closeup of the haze layers above the hexagon. Image via UPV/ EHU/ EurekAlert!.

Agustín Sánchez-Lavega, who led the study, stated:

The Cassini images have enabled us to discover that, just as if a sandwich had been formed, the hexagon has a multi-layered system of at least seven mists that extend from the summit of its clouds to an altitude of more than 300 km (186 miles) above them. Other cold worlds, such as Saturn’s satellite Titan or the dwarf planet Pluto, also have layers of hazes, but not in such numbers nor as regularly spaced out.

From the paper:

In June 2015, Cassini high-resolution images of Saturn’s limb southwards of the planet’s hexagonal wave revealed a system of at least six stacked haze layers above the upper cloud deck. Here, we characterize those haze layers and discuss their nature. Vertical thickness of layers ranged from 7 to 18 km [4-11 mi], and they extended in altitude about 130 km [80 mi], from pressure level 0.5 bar to 0.01 bar. Above them, a thin but extended aerosol layer reached altitude about 340 km [211 mi] (0.4 mbar). Radiative transfer modeling of spectral reflectivity shows that haze properties are consistent with particles of diameter 0.07–1.4 um and number density 100–500 cm-3. The nature of the hazes is compatible with their formation by condensation of hydrocarbon ices, including acetylene and benzene at higher altitudes. Their vertical distribution could be due to upward propagating gravity waves generated by dynamical forcing by the hexagon and its associated eastward jet.

Various colored layers in vertical rectangle with text annotations.

Illustration of the layers in Saturn’s atmosphere, including haze on top. Image via KHadley.com.

Hubble was also able to see the hexagon from above, not just on the limb of Saturn, as with Cassini.

The new study of the hexagon and its hazes shows just how complex this weather system and other meteorological phenomena are in Saturn’s deep and turbulent hydrogen atmosphere.

Each haze layer is between 4.3 to 11 miles (seven to 18 kilometers) thick and composed of very tiny particles about one micrometer (one-millionth of a meter) in size. Based on the Cassini data, the particles are composed of hydrocarbon ice crystallites, such as acetylene, propyne, propane, diacetylene and perhaps butane. This is like nothing found on Earth, but that isn’t too surprising, since Saturn’s atmosphere is mostly hydrogen and is much colder than Earth’s, between minus 184 and minus 292 Fahrenheit (minus 120 and minus 180 degrees Celsius).

The researchers also found that the hazes have a regular vertical distribution, thought to be caused by the vertical propagation of gravity waves that produce oscillations in the density and temperature of the atmosphere. This is common, and has been observed on other planets as well, including Earth. According to the researchers, the gravity waves may be caused by the hexagon itself and the powerful jet stream that races around it. Even on Earth, such gravity waves have been seen, produced by jet streams that travel at 62 miles per hour (100 kilometers per hour), from west to east in the mid-latitudes. On giant Saturn, though, the gravity waves and jet streams are much faster and more powerful.

Rotating blue hexagon with other bright spots, on black background.

High-resolution overhead view from Cassini of Saturn’s hexagon in motion. A massive hurricane is in the center of the hexagon and many other smaller storms can also be seen. The colors are from different wavelengths, from ultraviolet to visible light, combined to make the movie. Image via NASA Science.

The hexagon was a surprising and fascinating discovery by Cassini. When viewed directly from above, it looks almost perfect, like a giant piece of artwork floating over Saturn’s north pole. At the center of the hexagon is a massive churning hurricane, with an eye 50 times larger than the average hurricane’s eye on Earth. Many other smaller vortices are also seen within the hexagon, some of which are swept along with the jet stream.

You can see the movement of the features within the hexagon in this high-resolution movie. While hurricanes on Earth generally last about a week or so, this hexagon and central hurricane are thought to have been there for at least decades, if not centuries. As Andrew Ingersoll from the former Cassini imaging team said:

The hexagon is just a current of air, and weather features out there that share similarities to this are notoriously turbulent and unstable. A hurricane on Earth typically lasts a week, but this has been here for decades – and who knows – maybe centuries.

Three men and one woman in jackets, standing with trees in background.

Santiago Pérez-Hoyos, Agustín Sánchez-Lavega, Teresa del Río-Gaztelurrutia and Ricardo Hueso, who were involved in the new study. Image via UPV/ EHU/ Campusa.

The stunning beauty of the hexagon, and the intricacy of the layers above it, show how complex Saturn’s atmosphere and weather systems are. In some ways they are reminiscent of storms and weather on Earth, but on a much larger scale, and manifesting in ways unlike anything seen on our own planet.

Bottom line: A new study reveals details of a multi-layered, sandwich-like haze that hangs above the huge hexagon cloud pattern at Saturn’s north pole.

Source: Multilayer hazes over Saturn’s hexagon from Cassini ISS limb images

Via Campusa



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Gray globe with hexagon on top and arc of many fine lines above it, on black background.

A view of Saturn, its rings and its north polar hexagon, as captured by Cassini on November 27, 2013. Image via NASA/ JPL/ SSI/ Lights in the Dark.

Did you know that Saturn has a huge, persistent, hexagonal (six-sided) cloud formation at its north pole? Saturn’s hexagon is one of the most unusual and easily recognized features in the solar system. Now, a new study from researchers at the University of the Basque Country in Spain has revealed details about a multi-layered, sandwich-like haze that hangs above the hexagon itself. The findings come from an examination of images taken by the Hubble Space Telescope as well as those sent back by the Cassini spacecraft, which orbited Saturn from 2004 to 2017.

The results were published in a new peer-reviewed paper in Nature Communications on May 8, 2020.

The hazes above Saturn’s hexagon were first seen by Cassini in June 2015 in high-resolution images of the planet’s limb taken by the spacecraft’s main camera. Those images captured details as small as 0.6 to 1.2 miles (1-2 km) in size. Cassini was able to see the hazes as well as analyze their composition, using color filters from ultraviolet to near-infrared.

The hazes are above the clouds that form the hexagon. The scientists identified at least seven distinct haze layers.

Hexagon shape with inset boxes showing parallel layers, with text annotations.

A closer look at Saturn’s north polar hexagon, captured by Cassini; the inset shows a closeup of the haze layers above the hexagon. Image via UPV/ EHU/ EurekAlert!.

Agustín Sánchez-Lavega, who led the study, stated:

The Cassini images have enabled us to discover that, just as if a sandwich had been formed, the hexagon has a multi-layered system of at least seven mists that extend from the summit of its clouds to an altitude of more than 300 km (186 miles) above them. Other cold worlds, such as Saturn’s satellite Titan or the dwarf planet Pluto, also have layers of hazes, but not in such numbers nor as regularly spaced out.

From the paper:

In June 2015, Cassini high-resolution images of Saturn’s limb southwards of the planet’s hexagonal wave revealed a system of at least six stacked haze layers above the upper cloud deck. Here, we characterize those haze layers and discuss their nature. Vertical thickness of layers ranged from 7 to 18 km [4-11 mi], and they extended in altitude about 130 km [80 mi], from pressure level 0.5 bar to 0.01 bar. Above them, a thin but extended aerosol layer reached altitude about 340 km [211 mi] (0.4 mbar). Radiative transfer modeling of spectral reflectivity shows that haze properties are consistent with particles of diameter 0.07–1.4 um and number density 100–500 cm-3. The nature of the hazes is compatible with their formation by condensation of hydrocarbon ices, including acetylene and benzene at higher altitudes. Their vertical distribution could be due to upward propagating gravity waves generated by dynamical forcing by the hexagon and its associated eastward jet.

Various colored layers in vertical rectangle with text annotations.

Illustration of the layers in Saturn’s atmosphere, including haze on top. Image via KHadley.com.

Hubble was also able to see the hexagon from above, not just on the limb of Saturn, as with Cassini.

The new study of the hexagon and its hazes shows just how complex this weather system and other meteorological phenomena are in Saturn’s deep and turbulent hydrogen atmosphere.

Each haze layer is between 4.3 to 11 miles (seven to 18 kilometers) thick and composed of very tiny particles about one micrometer (one-millionth of a meter) in size. Based on the Cassini data, the particles are composed of hydrocarbon ice crystallites, such as acetylene, propyne, propane, diacetylene and perhaps butane. This is like nothing found on Earth, but that isn’t too surprising, since Saturn’s atmosphere is mostly hydrogen and is much colder than Earth’s, between minus 184 and minus 292 Fahrenheit (minus 120 and minus 180 degrees Celsius).

The researchers also found that the hazes have a regular vertical distribution, thought to be caused by the vertical propagation of gravity waves that produce oscillations in the density and temperature of the atmosphere. This is common, and has been observed on other planets as well, including Earth. According to the researchers, the gravity waves may be caused by the hexagon itself and the powerful jet stream that races around it. Even on Earth, such gravity waves have been seen, produced by jet streams that travel at 62 miles per hour (100 kilometers per hour), from west to east in the mid-latitudes. On giant Saturn, though, the gravity waves and jet streams are much faster and more powerful.

Rotating blue hexagon with other bright spots, on black background.

High-resolution overhead view from Cassini of Saturn’s hexagon in motion. A massive hurricane is in the center of the hexagon and many other smaller storms can also be seen. The colors are from different wavelengths, from ultraviolet to visible light, combined to make the movie. Image via NASA Science.

The hexagon was a surprising and fascinating discovery by Cassini. When viewed directly from above, it looks almost perfect, like a giant piece of artwork floating over Saturn’s north pole. At the center of the hexagon is a massive churning hurricane, with an eye 50 times larger than the average hurricane’s eye on Earth. Many other smaller vortices are also seen within the hexagon, some of which are swept along with the jet stream.

You can see the movement of the features within the hexagon in this high-resolution movie. While hurricanes on Earth generally last about a week or so, this hexagon and central hurricane are thought to have been there for at least decades, if not centuries. As Andrew Ingersoll from the former Cassini imaging team said:

The hexagon is just a current of air, and weather features out there that share similarities to this are notoriously turbulent and unstable. A hurricane on Earth typically lasts a week, but this has been here for decades – and who knows – maybe centuries.

Three men and one woman in jackets, standing with trees in background.

Santiago Pérez-Hoyos, Agustín Sánchez-Lavega, Teresa del Río-Gaztelurrutia and Ricardo Hueso, who were involved in the new study. Image via UPV/ EHU/ Campusa.

The stunning beauty of the hexagon, and the intricacy of the layers above it, show how complex Saturn’s atmosphere and weather systems are. In some ways they are reminiscent of storms and weather on Earth, but on a much larger scale, and manifesting in ways unlike anything seen on our own planet.

Bottom line: A new study reveals details of a multi-layered, sandwich-like haze that hangs above the huge hexagon cloud pattern at Saturn’s north pole.

Source: Multilayer hazes over Saturn’s hexagon from Cassini ISS limb images

Via Campusa



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A famous Mars meteorite, now with nitrogen

A dark-colored, rough-surfaced potato-shaped rock with a small black cube beside it.

Martian meteorite ALH 84001 at Johnson Space Center, shortly after being returned from Antarctica. For scale, the black cube is 1 cm (about .4 inch) on a side. The outside of ALH 84001 is partly coated with black fusion crust, typical of freshly fallen meteorites. The interior is a uniform greenish gray. Image via NASA Johnson Space Center/ LPI.

For decades, scientists have been searching for evidence of organic compounds – the building blocks of life – on Mars. The Mars rover Curiosity first confirmed organics in Martian rocks a few years ago. Then, in late April 2020, more exciting news … researchers at the Earth-Life Science Institute in Japan said they have detected 4-billion-year-old nitrogen-containing organic molecules in a famous Martian meteorite, a rock ejected from Mars, likely via an impact event, which traversed interplanetary space and ultimately landed on Earth. The meteorite is none other than Allan Hills 84001 (ALH 84001), a famous Mars meteorite picked up in the snow fields of Antarctica in 1984. This new work – and the discovery of nitrogen in this meteorite – may be a key to understanding how organics originated on Mars and whether any of them might be life-related.

The new peer-reviewed findings were published in Nature Communications on April 24, 2020.

The research team, including scientist Atsuko Kobayashi from the Earth-Life Science Institute (ELSI) at Tokyo Institute of Technology and research scientist Mizuho Koike from the Institute of Space and Astronautical Science at Japan Aerospace Exploration Agency (JAXA), found nitrogen-bearing organic material within carbonate minerals inside the meteorite. The organics are estimated to be 4 billion years old. From the paper:

Understanding the origin of organic material on Mars is a major issue in modern planetary science. Recent robotic exploration of Martian sedimentary rocks and laboratory analyses of Martian meteorites have both reported plausible indigenous organic components. However, little is known about their origin, evolution, and preservation. Here we report that 4-billion-year-old (Ga) carbonates in Martian meteorite, Allan Hills 84001, preserve indigenous nitrogen(N)-bearing organics by developing a new technique for high-spatial resolution in situ N-chemical speciation. The organic materials were synthesized locally and/ or delivered meteoritically on Mars during the Noachian age. The carbonates, alteration minerals from the Martian near-surface aqueous fluid, trapped and kept the organic materials intact over long geological times. This presence of N-bearing compounds requires abiotic or possibly biotic N-fixation and ammonia storage, suggesting that early Mars had a less oxidizing environment than today.

Two images: rough, chunky dark rock on left and lighter-colored rocky texture on right.

A fragment of the Martian meteorite ALH 84001 (left). Enlarged area showing the orange-colored carbonate grains (right). Image via Koike et al. (2020)/ Nature Communications/ ELSI.

Small square photo of rock and two large graphs with many wavy lines and blue bars.

Analysis of carbonates in Martian meteorite ALH 84001, which contain the nitrogen-bearing organics (blue bars). Image via Koike et al. (2020)/ Nature Communications/ ELSI.

Colored illustrations of rock, ocean and volcano, with text annotations.

Possible abiotic ways that nitrogen-containing organics could be created on ancient Mars. Image via Koike et al. (2020)/ Nature Communications/ ELSI.

The carbonate minerals themselves are significant, since they typically precipitate from groundwater on Earth. This adds even more evidence, along with all of the data from various Mars rovers and orbiters, that Mars was once much wetter than it is now, with plentiful organics. Such an environment could have been ideal for life to get a start on the planet.

The researchers used state-of-the-art analytical techniques to determine the nitrogen content inside the carbonates.

So why is the nitrogen important?

First, the team found that the amount of nitrogen in the form of nitrate was insignificant, meaning that early Mars had a much less oxidizing environment than it does today. (Oxidizing is when a substance combines chemically with oxygen or another oxidizing agent. A good example is iron or steel metal rusting in the presence of oxygen and water.) That’s good news for the possible emergence of life, since nitrate is a very strong oxidant. Also, as noted in the paper, these nitrogen-bearing compounds require either abiotic (non-biological) or biotic (biological) fixation. The paper discusses various possible abiotic sources, but unfortunately not the biotic ones.

Mechanical rover sitting on red terrain with inset graphic of a molecule in thought bubble shape.

The Curiosity rover has also found organics in Martian rocks. Image via NASA/ Mars Exploration Program.

While the findings show even more evidence for organics on early Mars, scientists still don’t known exactly how those organics were created. They could be either abiotic, biotic, or both. Meteorites and comets are thought to have delivered at least some of them to the surface of ancient Mars, but other organics are thought to have formed directly on the planet itself.

The researchers also had to make sure that the organics were truly Martian and not terrestrial contamination. To do this, they used silver tape in an ELSI clean lab to pluck off the tiny carbonate grains, which are about the width of a human hair, from the host meteorite. The grains were then prepared to further remove any possible surface contaminants with a scanning electron microscope-focused ion beam instrument at JAXA. In addition, they used a technique called Nitrogen K-edge micro X-ray Absorption Near Edge Structure (µ-XANES) spectroscopy, which allowed them to detect nitrogen present in very small amounts and to determine what chemical form that nitrogen was in. As a comparison, control samples from nearby igneous minerals in the meteorites showed no detectable nitrogen, indicating that the organic molecules were only in the carbonate.

Surface conditions on current Mars are extremely hostile to the preservation of organics, but as this study, and ones based on findings from Curiosity, have shown, organics can still be preserved quite well inside rocks. There also might be plenty of organic compounds in the near-surface of Mars, still waiting to be found. The organics found by Curiosity are in mudstones – composed of clay and silt-sized particles of ancient mud – that used to be at the bottom of lakes in Gale Crater. Future missions, such as the upcoming Perseverance rover, will be able to further determine the abundance of organics still on Mars now.

Smiling woman with trees in background.

Atsuko Kobayashi at ELSI, one of the researchers involved in the new study. Image via ELSI.

From the paper:

Whatever the origin, the presence of the organic and reduced nitrogen on early/ middle Noachian Mars indicates the importance of Martian nitrogen cycle. If considerable amounts and variations of organic matter were produced and/or delivered and preserved at the Martian near-surface system over geological time scales, these compounds have a chance to evolve into more complicated forms. It is expected that additional hidden records of the Martian nitrogen cycle will be acquired by future investigations, including a sample return mission from the Martian Moons eXploration (MMX), Mars Sample Return missions, and exploration of the Martian subsurface, as well as further advanced studies of Martian meteorites.

The discovery of nitrogen in some Martian organics is another significant step toward understanding how organic compounds formed on ancient Mars, how abundant they might be and whether any of them could be evidence of life itself.

Bottom line: Researchers have discovered 4-billion-year-old nitrogen-containing organic molecules in Martian meteorites.

Source: In-situ preservation of nitrogen-bearing organics in Noachian Martian carbonates

Via ELSI



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A dark-colored, rough-surfaced potato-shaped rock with a small black cube beside it.

Martian meteorite ALH 84001 at Johnson Space Center, shortly after being returned from Antarctica. For scale, the black cube is 1 cm (about .4 inch) on a side. The outside of ALH 84001 is partly coated with black fusion crust, typical of freshly fallen meteorites. The interior is a uniform greenish gray. Image via NASA Johnson Space Center/ LPI.

For decades, scientists have been searching for evidence of organic compounds – the building blocks of life – on Mars. The Mars rover Curiosity first confirmed organics in Martian rocks a few years ago. Then, in late April 2020, more exciting news … researchers at the Earth-Life Science Institute in Japan said they have detected 4-billion-year-old nitrogen-containing organic molecules in a famous Martian meteorite, a rock ejected from Mars, likely via an impact event, which traversed interplanetary space and ultimately landed on Earth. The meteorite is none other than Allan Hills 84001 (ALH 84001), a famous Mars meteorite picked up in the snow fields of Antarctica in 1984. This new work – and the discovery of nitrogen in this meteorite – may be a key to understanding how organics originated on Mars and whether any of them might be life-related.

The new peer-reviewed findings were published in Nature Communications on April 24, 2020.

The research team, including scientist Atsuko Kobayashi from the Earth-Life Science Institute (ELSI) at Tokyo Institute of Technology and research scientist Mizuho Koike from the Institute of Space and Astronautical Science at Japan Aerospace Exploration Agency (JAXA), found nitrogen-bearing organic material within carbonate minerals inside the meteorite. The organics are estimated to be 4 billion years old. From the paper:

Understanding the origin of organic material on Mars is a major issue in modern planetary science. Recent robotic exploration of Martian sedimentary rocks and laboratory analyses of Martian meteorites have both reported plausible indigenous organic components. However, little is known about their origin, evolution, and preservation. Here we report that 4-billion-year-old (Ga) carbonates in Martian meteorite, Allan Hills 84001, preserve indigenous nitrogen(N)-bearing organics by developing a new technique for high-spatial resolution in situ N-chemical speciation. The organic materials were synthesized locally and/ or delivered meteoritically on Mars during the Noachian age. The carbonates, alteration minerals from the Martian near-surface aqueous fluid, trapped and kept the organic materials intact over long geological times. This presence of N-bearing compounds requires abiotic or possibly biotic N-fixation and ammonia storage, suggesting that early Mars had a less oxidizing environment than today.

Two images: rough, chunky dark rock on left and lighter-colored rocky texture on right.

A fragment of the Martian meteorite ALH 84001 (left). Enlarged area showing the orange-colored carbonate grains (right). Image via Koike et al. (2020)/ Nature Communications/ ELSI.

Small square photo of rock and two large graphs with many wavy lines and blue bars.

Analysis of carbonates in Martian meteorite ALH 84001, which contain the nitrogen-bearing organics (blue bars). Image via Koike et al. (2020)/ Nature Communications/ ELSI.

Colored illustrations of rock, ocean and volcano, with text annotations.

Possible abiotic ways that nitrogen-containing organics could be created on ancient Mars. Image via Koike et al. (2020)/ Nature Communications/ ELSI.

The carbonate minerals themselves are significant, since they typically precipitate from groundwater on Earth. This adds even more evidence, along with all of the data from various Mars rovers and orbiters, that Mars was once much wetter than it is now, with plentiful organics. Such an environment could have been ideal for life to get a start on the planet.

The researchers used state-of-the-art analytical techniques to determine the nitrogen content inside the carbonates.

So why is the nitrogen important?

First, the team found that the amount of nitrogen in the form of nitrate was insignificant, meaning that early Mars had a much less oxidizing environment than it does today. (Oxidizing is when a substance combines chemically with oxygen or another oxidizing agent. A good example is iron or steel metal rusting in the presence of oxygen and water.) That’s good news for the possible emergence of life, since nitrate is a very strong oxidant. Also, as noted in the paper, these nitrogen-bearing compounds require either abiotic (non-biological) or biotic (biological) fixation. The paper discusses various possible abiotic sources, but unfortunately not the biotic ones.

Mechanical rover sitting on red terrain with inset graphic of a molecule in thought bubble shape.

The Curiosity rover has also found organics in Martian rocks. Image via NASA/ Mars Exploration Program.

While the findings show even more evidence for organics on early Mars, scientists still don’t known exactly how those organics were created. They could be either abiotic, biotic, or both. Meteorites and comets are thought to have delivered at least some of them to the surface of ancient Mars, but other organics are thought to have formed directly on the planet itself.

The researchers also had to make sure that the organics were truly Martian and not terrestrial contamination. To do this, they used silver tape in an ELSI clean lab to pluck off the tiny carbonate grains, which are about the width of a human hair, from the host meteorite. The grains were then prepared to further remove any possible surface contaminants with a scanning electron microscope-focused ion beam instrument at JAXA. In addition, they used a technique called Nitrogen K-edge micro X-ray Absorption Near Edge Structure (µ-XANES) spectroscopy, which allowed them to detect nitrogen present in very small amounts and to determine what chemical form that nitrogen was in. As a comparison, control samples from nearby igneous minerals in the meteorites showed no detectable nitrogen, indicating that the organic molecules were only in the carbonate.

Surface conditions on current Mars are extremely hostile to the preservation of organics, but as this study, and ones based on findings from Curiosity, have shown, organics can still be preserved quite well inside rocks. There also might be plenty of organic compounds in the near-surface of Mars, still waiting to be found. The organics found by Curiosity are in mudstones – composed of clay and silt-sized particles of ancient mud – that used to be at the bottom of lakes in Gale Crater. Future missions, such as the upcoming Perseverance rover, will be able to further determine the abundance of organics still on Mars now.

Smiling woman with trees in background.

Atsuko Kobayashi at ELSI, one of the researchers involved in the new study. Image via ELSI.

From the paper:

Whatever the origin, the presence of the organic and reduced nitrogen on early/ middle Noachian Mars indicates the importance of Martian nitrogen cycle. If considerable amounts and variations of organic matter were produced and/or delivered and preserved at the Martian near-surface system over geological time scales, these compounds have a chance to evolve into more complicated forms. It is expected that additional hidden records of the Martian nitrogen cycle will be acquired by future investigations, including a sample return mission from the Martian Moons eXploration (MMX), Mars Sample Return missions, and exploration of the Martian subsurface, as well as further advanced studies of Martian meteorites.

The discovery of nitrogen in some Martian organics is another significant step toward understanding how organic compounds formed on ancient Mars, how abundant they might be and whether any of them could be evidence of life itself.

Bottom line: Researchers have discovered 4-billion-year-old nitrogen-containing organic molecules in Martian meteorites.

Source: In-situ preservation of nitrogen-bearing organics in Noachian Martian carbonates

Via ELSI



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