Arc to Arcturus, and speed on to Spica. Scouts learn this phrase. Grandparents teach it to kids. It’s one of the first sky tools many learn to use in astronomy.
This mnemonic directs you to two stars that are bright enough to shine even through the light pollution of suburbs and small cities. In fact, Spica is a prime example of a 1st-magnitude star. This means that, according to a brightness scale first used by the early astronomers Hipparchus (c.190-c.120 BCE) and Ptolemy (c.100-c.170 CE), it is one of our sky’s brightest stars.
And the star Arcturus beams brighter yet, shining one magnitude (2.5 times) more brightly than Spica.
Find the asterism of the Big Dipper high in the northeastern sky in the evenings this month. You can’t miss the distinctive kitchen ladle-like arrangement of its seven bright stars. Notice it has two parts: a bowl and a handle. Extend the curve of the handle until you come to a bright orange star: Arcturus! It shines at -0.04 magnitude.
Arcturus is a giant star, located an estimated 36.7 light-years from Earth. It is the third brightest individual star in the night sky, and the brightest star in the constellation Boötes the Herdsman. Its name derives from the Ancient Greek for ‘Guardian of the Bear’ due to its proximity to Ursa Major, the Great Bear, and some still refer to it as the Bear Guard.
Speed on to Spica
Once you’ve followed the curve of the Big Dipper’s handle to Arcturus, you’re on your way to your next target. Just extend that same curve and speed on to the bright, blue-white star Spica! It shines at +1.04 magnitude.
Spica is the brightest light in Virgo the Maiden, a large, rambling constellation. Spica’s name derives from the Latin word for ‘ear’, referring to an ear of wheat held by the maiden. Greek astronomers associated the star and its constellation with the goddess of the harvest, Demeter, though it has also been associated with Demeter’s daughter, Persephone.
Today we know Spica as a tight double star. The two stars are indistinguishable from a single point of light in ordinary telescopes. Spica’s dual nature was revealed only by analyzing its light with a spectroscope: an instrument that splits light into its component colors. Separated by just less than 11 million miles (18 million km), Spica’s two stars orbit a common center of gravity in only four days. They’re collectively more than 2,000 times brighter than our sun, and are estimated to be 7.8 and 4 times larger!
Bottom line: If you only ever learn one star mnemonic, make it this one! Arc to Arcturus and speed on to Spica to identify two of the sky’s brightest stars.
Arc to Arcturus, and speed on to Spica. Scouts learn this phrase. Grandparents teach it to kids. It’s one of the first sky tools many learn to use in astronomy.
This mnemonic directs you to two stars that are bright enough to shine even through the light pollution of suburbs and small cities. In fact, Spica is a prime example of a 1st-magnitude star. This means that, according to a brightness scale first used by the early astronomers Hipparchus (c.190-c.120 BCE) and Ptolemy (c.100-c.170 CE), it is one of our sky’s brightest stars.
And the star Arcturus beams brighter yet, shining one magnitude (2.5 times) more brightly than Spica.
Find the asterism of the Big Dipper high in the northeastern sky in the evenings this month. You can’t miss the distinctive kitchen ladle-like arrangement of its seven bright stars. Notice it has two parts: a bowl and a handle. Extend the curve of the handle until you come to a bright orange star: Arcturus! It shines at -0.04 magnitude.
Arcturus is a giant star, located an estimated 36.7 light-years from Earth. It is the third brightest individual star in the night sky, and the brightest star in the constellation Boötes the Herdsman. Its name derives from the Ancient Greek for ‘Guardian of the Bear’ due to its proximity to Ursa Major, the Great Bear, and some still refer to it as the Bear Guard.
Speed on to Spica
Once you’ve followed the curve of the Big Dipper’s handle to Arcturus, you’re on your way to your next target. Just extend that same curve and speed on to the bright, blue-white star Spica! It shines at +1.04 magnitude.
Spica is the brightest light in Virgo the Maiden, a large, rambling constellation. Spica’s name derives from the Latin word for ‘ear’, referring to an ear of wheat held by the maiden. Greek astronomers associated the star and its constellation with the goddess of the harvest, Demeter, though it has also been associated with Demeter’s daughter, Persephone.
Today we know Spica as a tight double star. The two stars are indistinguishable from a single point of light in ordinary telescopes. Spica’s dual nature was revealed only by analyzing its light with a spectroscope: an instrument that splits light into its component colors. Separated by just less than 11 million miles (18 million km), Spica’s two stars orbit a common center of gravity in only four days. They’re collectively more than 2,000 times brighter than our sun, and are estimated to be 7.8 and 4 times larger!
Bottom line: If you only ever learn one star mnemonic, make it this one! Arc to Arcturus and speed on to Spica to identify two of the sky’s brightest stars.
When you deliver a university course that makes students happier, everybody wants to know what the secret is. What are your tips? What are your top ten recommendations? These are the most asked questions, as if there is some quick, surefire path to happiness.
The problem is that there are no life-transforming discoveries, because most of what works has already been talked about. Social connection, mindfulness, gratitude letters, acts of kindness, going for a walk in nature, sleep hygiene, limiting social media use. These are some of the 80 or so psychological interventions which have been shown to work to improve our wellbeing (to a lesser or greater extent).
But if we already know so much about what works, then why are we still fielding requests for top happiness tips?
The data tells us that students and young people today are increasingly unhappy. National surveys find wellbeing is lowest among the young in the U.K. and the U.S. compared to other age groups.
It was for this reason we began teaching the science of happiness course at the University of Bristol in 2019, to counter some worrying downward trends. During the course, we teach lessons from positive psychology and create opportunities for students to put these lessons into practice.
Learning the science of happiness
We award credit based on engagement – an important component of not only education, but also getting the most out of life – rather than graded assessments. It would be ironic to talk about the problems of performance anxiety and student perfectionism only to then give our students a graded exam.
Course credit without examination? That must be a breeze, you might say. However, for many students, turning up on time to over 80% of lectures and tutorials, completing journal entries on a weekly basis and submitting a final group project turned out to be more of a challenge than they predicted.
Around 5% of students fail to meet the course demands each year and have to complete a reassessment in the summer. Creating consistent positive habits in the face of all of life’s other demands is not a trivial request.
Nevertheless, the science of happiness course is extraordinarily popular. It also appears to be effective. Every year we find increases of around 10 to 15% on measures of students’ mental wellbeing at the end of the course, compared to a waiting-list control group.
Life after the course
However, we recently published the findings from a study that followed up with students one to two years after they had taken the science of happiness course, before they graduated. When we looked at the overall trends, students’ initially elevated scores of happiness had largely returned to their original levels.
We were not dejected, though. One of the mechanisms we teach on the course is hedonic adaptation: we get used to both good and bad things. Humans have a brain wired to pay extra attention to problems. So it comes as no surprise that the initial wellbeing boost we created in the course disappeared as students returned to focusing on life’s hassles.
However, we observed that not all students followed this pattern. Approximately half the cohort reported that they continued to regularly practice some of the things they had learned many months or years after completing the course. Those included such things as gratitude or mindfulness.
Although the students who no longer practiced the activities returned to their happiness baselines, on average, those who did keep up with at least some of the recommended activities showed no such drop. They maintained their elevated levels of wellbeing up to two years later.
Use science for mental and physical health
In many ways, mental health is no different from physical health. Few people expect to see long-lasting muscle gains after one trip to the gym. For the most part, we are begrudgingly aware that there are no shortcuts if you want to remain fit and healthy. You have to stick with the program.
The same applies to our happiness. Unless we keep working at it, the improvements are temporary. Indeed, if we did have to focus on just one top tip it might be to learn how to harness lessons from psychology to build the better habits we need for lasting change. For example, aiming for small incremental changes rather than an unsustainable overhaul of your whole life.
One thing we question is whether the self-care industry may be sending out the wrong message by telling people happiness is all about making yourself feel better. One of us – Bruce Hood – writes in his new book that becoming a happier person in the long term is less to do with focusing on ourselves, and much more to do with focusing on others.
Self-care may bring some short-term benefits, but enriching the lives of others can offer wellbeing effects that are less susceptible to adaptation over time.
Ultimately, whatever methods or activities we choose to improve our wellbeing, we would do well to remember that happiness is always a work in progress.
Bottom line: Mental wellness is much like physical fitness. If you want to see any consistent, positive change in your happiness level, you have to continue to “work out” by keeping up good happiness habits.
When you deliver a university course that makes students happier, everybody wants to know what the secret is. What are your tips? What are your top ten recommendations? These are the most asked questions, as if there is some quick, surefire path to happiness.
The problem is that there are no life-transforming discoveries, because most of what works has already been talked about. Social connection, mindfulness, gratitude letters, acts of kindness, going for a walk in nature, sleep hygiene, limiting social media use. These are some of the 80 or so psychological interventions which have been shown to work to improve our wellbeing (to a lesser or greater extent).
But if we already know so much about what works, then why are we still fielding requests for top happiness tips?
The data tells us that students and young people today are increasingly unhappy. National surveys find wellbeing is lowest among the young in the U.K. and the U.S. compared to other age groups.
It was for this reason we began teaching the science of happiness course at the University of Bristol in 2019, to counter some worrying downward trends. During the course, we teach lessons from positive psychology and create opportunities for students to put these lessons into practice.
Learning the science of happiness
We award credit based on engagement – an important component of not only education, but also getting the most out of life – rather than graded assessments. It would be ironic to talk about the problems of performance anxiety and student perfectionism only to then give our students a graded exam.
Course credit without examination? That must be a breeze, you might say. However, for many students, turning up on time to over 80% of lectures and tutorials, completing journal entries on a weekly basis and submitting a final group project turned out to be more of a challenge than they predicted.
Around 5% of students fail to meet the course demands each year and have to complete a reassessment in the summer. Creating consistent positive habits in the face of all of life’s other demands is not a trivial request.
Nevertheless, the science of happiness course is extraordinarily popular. It also appears to be effective. Every year we find increases of around 10 to 15% on measures of students’ mental wellbeing at the end of the course, compared to a waiting-list control group.
Life after the course
However, we recently published the findings from a study that followed up with students one to two years after they had taken the science of happiness course, before they graduated. When we looked at the overall trends, students’ initially elevated scores of happiness had largely returned to their original levels.
We were not dejected, though. One of the mechanisms we teach on the course is hedonic adaptation: we get used to both good and bad things. Humans have a brain wired to pay extra attention to problems. So it comes as no surprise that the initial wellbeing boost we created in the course disappeared as students returned to focusing on life’s hassles.
However, we observed that not all students followed this pattern. Approximately half the cohort reported that they continued to regularly practice some of the things they had learned many months or years after completing the course. Those included such things as gratitude or mindfulness.
Although the students who no longer practiced the activities returned to their happiness baselines, on average, those who did keep up with at least some of the recommended activities showed no such drop. They maintained their elevated levels of wellbeing up to two years later.
Use science for mental and physical health
In many ways, mental health is no different from physical health. Few people expect to see long-lasting muscle gains after one trip to the gym. For the most part, we are begrudgingly aware that there are no shortcuts if you want to remain fit and healthy. You have to stick with the program.
The same applies to our happiness. Unless we keep working at it, the improvements are temporary. Indeed, if we did have to focus on just one top tip it might be to learn how to harness lessons from psychology to build the better habits we need for lasting change. For example, aiming for small incremental changes rather than an unsustainable overhaul of your whole life.
One thing we question is whether the self-care industry may be sending out the wrong message by telling people happiness is all about making yourself feel better. One of us – Bruce Hood – writes in his new book that becoming a happier person in the long term is less to do with focusing on ourselves, and much more to do with focusing on others.
Self-care may bring some short-term benefits, but enriching the lives of others can offer wellbeing effects that are less susceptible to adaptation over time.
Ultimately, whatever methods or activities we choose to improve our wellbeing, we would do well to remember that happiness is always a work in progress.
Bottom line: Mental wellness is much like physical fitness. If you want to see any consistent, positive change in your happiness level, you have to continue to “work out” by keeping up good happiness habits.
View larger. | Artist’s concept of a brown dwarf. It’s an object that’s too massive enough to be an ordinary planet, but not massive enough to shine as a star. Many brown dwarfs come in binary pairs, where two orbit one another. But a new study shows the less massive and older a brown dwarf is, the more likely it is to be alone. Image via NASA/ ESA, Joseph Olmsted (STScI)/ Hubblesite.
Brown dwarfs are star-planet hybrid objects, with a mass in between that of stars and planets.
The older and less massive a brown dwarf is, the less likely it is to have a companion brown dwarf.
Over time, it appears the brown dwarf companions just drift apart.
Older brown dwarfs are more likely to be lonely
Most stars come in pairs, or binary systems. Brown dwarfs – objects more massive than Jupiter but less massive than the smallest stars – can come in binary pairs, too. But a new study with the Hubble Space Telescope has found older brown dwarfs are less likely to have companions. On March 21, 2024, an international team of scientists said the older and less massive a brown dwarf is, the more likely it is to wander through space alone. It appears that many binary brown dwarfs drift apart over timescales of millions of years.
The researchers first published their peer-reviewed paper in the Monthly Notices of the Royal Astronomical Society on September 22, 2023.
Older and lower-mass brown dwarfs unlikely to have companions
Hubble found that it’s rare for a lower-mass, cooler brown dwarf to have a binary companion. The researchers studied a sampling of 33 older and cooler brown dwarfs in our local galactic neighborhood. The team used two different near-infrared filters on Hubble, one in which a cold brown dwarf will appear bright, and another covering specific wavelengths where it will look very faint due to water absorption in its atmosphere.
NASA’s Wide-Field Infrared Survey Explorer (WISE) had previously found these brown dwarfs. Most of them are only a few hundred degrees warmer than Jupiter. None of them had binary companions, even though Hubble can detect binary companions as close as 300 million miles (480 million km) to each other. That’s about the same distance from the sun to the asteroid belt in our solar system.
Astronomers have previously found that younger brown dwarfs often do have companions, however. Lead author Clémence Fontanive of the Trottier Institute for Research on Exoplanets at the University of Montréal, Canada, said:
Our survey confirms that widely separated companions are extremely rare among the lowest-mass and coldest isolated brown dwarfs, even though binary brown dwarfs are observed at younger ages. This suggests that such systems do not survive over time.
What does this mean? It suggests younger brown dwarfs generally aren’t massive enough to have sufficient gravity to keep the pair together. Instead, they gradually drift apart over hundreds of millions of years.
Born the same way as stars
The findings not only provide new information about brown dwarf binaries but how a brown dwarf itself forms and evolves. And the results support previous theories that brown dwarfs form the same way stars do. This involves both of them forming from the gravitational collapse of a cloud of molecular hydrogen. But then why do brown dwarfs end up so different from stars?
Essentially, brown dwarfs are not massive enough for the nuclear fusion of hydrogen to occur.
More than half the stars in our galaxy have a binary companion. And, similar to brown dwarfs, it’s more massive stars that are typically in those binary systems. That prompted the researchers to compare them to brown dwarf binaries and look for similar trends, as Fontanive noted:
The motivation for the study was really to see how low in mass the trends seen among multiple stars systems hold up.
Our Hubble survey offers direct evidence that these binaries that we observe when they’re young are unlikely to survive to old ages; they’re likely going to get disrupted. When they’re young, they’re part of a molecular cloud, and then as they age the cloud disperses. As that happens, things start moving around and stars pass by each other. Because brown dwarfs are so light, the gravitational hold tying wide binary pairs is very weak, and bypassing stars can easily tear these binaries apart.
The new data from Hubble is the best ever obtained so far regarding brown dwarf pairs. Fontanive said:
This is the best observational evidence to date that brown dwarf pairs drift apart over time. We could not have done this kind of survey and confirmed earlier models without Hubble’s sharp vision and sensitivity.
Bottom line: NASA’s Hubble Space Telescope has found that older and less massive brown dwarfs tend to be alone with no companions, unlike brown dwarfs that are younger and larger.
View larger. | Artist’s concept of a brown dwarf. It’s an object that’s too massive enough to be an ordinary planet, but not massive enough to shine as a star. Many brown dwarfs come in binary pairs, where two orbit one another. But a new study shows the less massive and older a brown dwarf is, the more likely it is to be alone. Image via NASA/ ESA, Joseph Olmsted (STScI)/ Hubblesite.
Brown dwarfs are star-planet hybrid objects, with a mass in between that of stars and planets.
The older and less massive a brown dwarf is, the less likely it is to have a companion brown dwarf.
Over time, it appears the brown dwarf companions just drift apart.
Older brown dwarfs are more likely to be lonely
Most stars come in pairs, or binary systems. Brown dwarfs – objects more massive than Jupiter but less massive than the smallest stars – can come in binary pairs, too. But a new study with the Hubble Space Telescope has found older brown dwarfs are less likely to have companions. On March 21, 2024, an international team of scientists said the older and less massive a brown dwarf is, the more likely it is to wander through space alone. It appears that many binary brown dwarfs drift apart over timescales of millions of years.
The researchers first published their peer-reviewed paper in the Monthly Notices of the Royal Astronomical Society on September 22, 2023.
Older and lower-mass brown dwarfs unlikely to have companions
Hubble found that it’s rare for a lower-mass, cooler brown dwarf to have a binary companion. The researchers studied a sampling of 33 older and cooler brown dwarfs in our local galactic neighborhood. The team used two different near-infrared filters on Hubble, one in which a cold brown dwarf will appear bright, and another covering specific wavelengths where it will look very faint due to water absorption in its atmosphere.
NASA’s Wide-Field Infrared Survey Explorer (WISE) had previously found these brown dwarfs. Most of them are only a few hundred degrees warmer than Jupiter. None of them had binary companions, even though Hubble can detect binary companions as close as 300 million miles (480 million km) to each other. That’s about the same distance from the sun to the asteroid belt in our solar system.
Astronomers have previously found that younger brown dwarfs often do have companions, however. Lead author Clémence Fontanive of the Trottier Institute for Research on Exoplanets at the University of Montréal, Canada, said:
Our survey confirms that widely separated companions are extremely rare among the lowest-mass and coldest isolated brown dwarfs, even though binary brown dwarfs are observed at younger ages. This suggests that such systems do not survive over time.
What does this mean? It suggests younger brown dwarfs generally aren’t massive enough to have sufficient gravity to keep the pair together. Instead, they gradually drift apart over hundreds of millions of years.
Born the same way as stars
The findings not only provide new information about brown dwarf binaries but how a brown dwarf itself forms and evolves. And the results support previous theories that brown dwarfs form the same way stars do. This involves both of them forming from the gravitational collapse of a cloud of molecular hydrogen. But then why do brown dwarfs end up so different from stars?
Essentially, brown dwarfs are not massive enough for the nuclear fusion of hydrogen to occur.
More than half the stars in our galaxy have a binary companion. And, similar to brown dwarfs, it’s more massive stars that are typically in those binary systems. That prompted the researchers to compare them to brown dwarf binaries and look for similar trends, as Fontanive noted:
The motivation for the study was really to see how low in mass the trends seen among multiple stars systems hold up.
Our Hubble survey offers direct evidence that these binaries that we observe when they’re young are unlikely to survive to old ages; they’re likely going to get disrupted. When they’re young, they’re part of a molecular cloud, and then as they age the cloud disperses. As that happens, things start moving around and stars pass by each other. Because brown dwarfs are so light, the gravitational hold tying wide binary pairs is very weak, and bypassing stars can easily tear these binaries apart.
The new data from Hubble is the best ever obtained so far regarding brown dwarf pairs. Fontanive said:
This is the best observational evidence to date that brown dwarf pairs drift apart over time. We could not have done this kind of survey and confirmed earlier models without Hubble’s sharp vision and sensitivity.
Bottom line: NASA’s Hubble Space Telescope has found that older and less massive brown dwarfs tend to be alone with no companions, unlike brown dwarfs that are younger and larger.
On March 31, 2024, around midnight, SpaceX launched more Starlink satellites from Florida. Image via SpaceX.
Upcoming Starlink launches in April 2024
Starlink Group 8-1: April 4, 2024, Time TBD
Falcon 9 Block 5 | Vandenberg Space Force Station, California | DATE/TIME MAY CHANGE
Starlink Group 6-47: April 5, 2024, Time TBD
Falcon 9 Block 5 | Cape Canaveral Space Force Station, Florida | DATE/TIME MAY CHANGE
Starlink Group 7-29: April 2024, Time & Date TBD
Falcon 9 Block 5 | Cape Canaveral Space Force Station, Florida | DATE/TIME MAY CHANGE
Starlink Group 8-2: April 2024, Time & Date TBD
Falcon 9 Block 5 | Vandenberg Space Force Station, California | DATE/TIME MAY CHANGE
Starlink Group 8-3: April 2024, Time & Date TBD
Falcon 9 Block 5 | Vandenberg Space Force Station, California | DATE/TIME MAY CHANGE
Starlink Group 8-4: April 2024, Time & Date TBD
Falcon 9 Block 5 | Cape Canaveral Space Force Station, Florida | DATE/TIME MAY CHANGE
Starlink Group 8-5: April 2024, Time & Date TBD
Falcon 9 Block 5 | Cape Canaveral Space Force Station, Florida | DATE/TIME MAY CHANGE
Starlink Group 7-30: April 2024, Time & Date TBD
Falcon 9 Block 5 | Cape Canaveral Space Force Station, Florida | DATE/TIME MAY CHANGE
You can watch a livestream of the Starlink launches on SpaceX’s X account.
Watch this space for updates!
After launch, look for a train of lights
Following every Starlink launch, the internet buzzes with people asking:
What’s that long line of lights in the sky that looks like a train?
What you’re seeing is the Starlink satellites moving into a higher orbit. You can check to see if they will pass over your area using the Find Starlink website.
Growing numbers amid controversy
According to Wikipedia, as of January 2024, Starlink consists of over 5,275 mass-produced small satellites in low Earth orbit that communicate with designated ground transceivers. They provide internet access to more than 2 million subscribers.
Love ’em or hate ’em, these Starlink satellites are part of SpaceX’s vision for a global internet communication satellite constellation. They deliver high-speed internet service worldwide, mainly to locations where ground-based internet is unreliable, unavailable or expensive. The private company is well-known for launching batches back-to-back, several times a month, regularly lofting 60 satellites at a time. And SpaceX plans to build up to perhaps as many as 30,000 eventually.
Most thought it was exciting to see the first few Starlink satellites traveling together in the night sky. But then more were launched, and then more. And astronomers began to worry.
Because Starlinks are bright, astronomers say they’re photobombing astronomical images. Therefore, they have the potential to interfere with the professional astronomical observations that have brought us our modern-day view of the cosmos. And although SpaceX has tried to address the issue, they remain far from what astronomers say is acceptable.
Bottom line: Get a list of all the SpaceX Starlink launches for April 2024 from both the West and East Coasts!
On March 31, 2024, around midnight, SpaceX launched more Starlink satellites from Florida. Image via SpaceX.
Upcoming Starlink launches in April 2024
Starlink Group 8-1: April 4, 2024, Time TBD
Falcon 9 Block 5 | Vandenberg Space Force Station, California | DATE/TIME MAY CHANGE
Starlink Group 6-47: April 5, 2024, Time TBD
Falcon 9 Block 5 | Cape Canaveral Space Force Station, Florida | DATE/TIME MAY CHANGE
Starlink Group 7-29: April 2024, Time & Date TBD
Falcon 9 Block 5 | Cape Canaveral Space Force Station, Florida | DATE/TIME MAY CHANGE
Starlink Group 8-2: April 2024, Time & Date TBD
Falcon 9 Block 5 | Vandenberg Space Force Station, California | DATE/TIME MAY CHANGE
Starlink Group 8-3: April 2024, Time & Date TBD
Falcon 9 Block 5 | Vandenberg Space Force Station, California | DATE/TIME MAY CHANGE
Starlink Group 8-4: April 2024, Time & Date TBD
Falcon 9 Block 5 | Cape Canaveral Space Force Station, Florida | DATE/TIME MAY CHANGE
Starlink Group 8-5: April 2024, Time & Date TBD
Falcon 9 Block 5 | Cape Canaveral Space Force Station, Florida | DATE/TIME MAY CHANGE
Starlink Group 7-30: April 2024, Time & Date TBD
Falcon 9 Block 5 | Cape Canaveral Space Force Station, Florida | DATE/TIME MAY CHANGE
You can watch a livestream of the Starlink launches on SpaceX’s X account.
Watch this space for updates!
After launch, look for a train of lights
Following every Starlink launch, the internet buzzes with people asking:
What’s that long line of lights in the sky that looks like a train?
What you’re seeing is the Starlink satellites moving into a higher orbit. You can check to see if they will pass over your area using the Find Starlink website.
Growing numbers amid controversy
According to Wikipedia, as of January 2024, Starlink consists of over 5,275 mass-produced small satellites in low Earth orbit that communicate with designated ground transceivers. They provide internet access to more than 2 million subscribers.
Love ’em or hate ’em, these Starlink satellites are part of SpaceX’s vision for a global internet communication satellite constellation. They deliver high-speed internet service worldwide, mainly to locations where ground-based internet is unreliable, unavailable or expensive. The private company is well-known for launching batches back-to-back, several times a month, regularly lofting 60 satellites at a time. And SpaceX plans to build up to perhaps as many as 30,000 eventually.
Most thought it was exciting to see the first few Starlink satellites traveling together in the night sky. But then more were launched, and then more. And astronomers began to worry.
Because Starlinks are bright, astronomers say they’re photobombing astronomical images. Therefore, they have the potential to interfere with the professional astronomical observations that have brought us our modern-day view of the cosmos. And although SpaceX has tried to address the issue, they remain far from what astronomers say is acceptable.
Bottom line: Get a list of all the SpaceX Starlink launches for April 2024 from both the West and East Coasts!
Last night, we received a response from #SLIM, confirming that the spacecraft made it through the lunar night for the second time! Since the sun was still high and the equipment was still hot, we only took some shots of the usual scenery with the navigation camera. #GoodAfterMoonpic.twitter.com/5BjIr7vxMG
Japanese moon lander SLIM set down on the moon’s surface on January 20. The landing was less than ideal (SLIM is upside-down on the lunar surface), but it was alive and communicating. Japan thus became the 5th earthly nation to reach the moon.
SLIM wasn’t designed to withstand the freezing cold of lunar night. But, as the moon rotated, carrying the craft into night for two weeks, then back to day again, SLIM did withstand its first lunar night, JAXA said on February 26.
Now SLIM has emerged again, from its 2nd lunar night, JAXA said on March 27.
Japan Aerospace Exploration Agency (JAXA) said in a tweet on March 27, 2024, that its lunar lander SLIM has survived a second two-week-long lunar night. Night on the moon is harsh, with temperatures falling to -202 degrees F (-130 degrees C). And SLIM is not in an ideal position on the moon. Its landing on January appeared flawed from the first, and it was realized some days after landing that the craft had ended up upside-down on the moon’s surface. But, SLIM did survive its first lunar night as announced by JAXA on February 26, 2024. And now it has survived a second.
That earlier conversation with SLIM was quick, as harsh sunlight drove the probe to another thermal extreme (in full daylight, the temps on the lunar surface can reach a scorching 260 degrees F, or 127 C). We haven’t seen any information about the exact level of communicaiton during this second wake-up period.
On February 26, JAXA officials had written in English:
Last night, I sent a command and got a response from SLIM. SLIM successfully survived the night on the lunar surface while maintaining communication capabilities! Last night, as it was still midday on the moon, the temperature of the communication equipment was extremely high, so communication was terminated after only a short period of time. From now on, preparations will be made so that observations can be resumed once the temperature has cooled sufficiently.
The Japanese lunar lander SLIM set down on the moon on January 19, 2024. Five days later, NASA’s Lunar Reconnaissance Orbiter (LRO) spacecraft passed over the landing site and photographed SLIM. LRO acquired the image at an altitude of about 50 miles (80 km). Bright streaks on the left side of the image are rocky material ejected from the nearby, relatively young Shioli crater. Japan is the 5th nation to complete a soft landing on the moon. Image via NASA.
Why upside-down?
SpaceNews.com described how the lander came to rest wrong way up:
Shinichiro Sakai, SLIM project manager, reiterated that the landing was hampered by the failure of one of two engines with around 50 meters of descent remaining. This resulted in uncontrolled lateral movement and the lander ending up on its nose, and the main engine pointing upward.
Japan’s SLIM lunar lander set down on the moon in Mare Nectaris, the Sea of Nectar. Specifically, it landed near the small impact crater Shioli.
Japanese moon lander made soft landing on the moon
JAXA’s Smart Lander for Investigating the Moon – aka SLIM – has been on the lunar surface since its awkward landing on January 20. Japan thus became the 5th earthly nation to reach the moon. So, Japan achieved its main objective, landing softly on the lunar surface. But all was not well with the uncrewed craft.
Because the craft did not land in the orientation planned for, its solar panels were not facing the right way. But as the moon moves in its orbit, the solar panels were able to get some energy and carry out some science before the two-week lunar night approached.
Images from the moon
Despite the lander being upside down, it has still been able to take and send back images of the lunar surface. The caption on the post below says:
Believing in Koshiya’s success, the MBC (Multi-Band Camera) team created a new command to image the area inside the red frame, which was not visible last time!
I’m excited about the possibilities for further observations!
SLIM’s mission objectives were simple but not easy
SLIM had basically two tasks to accomplish at the moon, and the first one was just making it to the lunar surface. But not just anywhere on the moon. SLIM’s navigation systems were designed to put the craft within 100 meters (330 feet) of its intended target in Mare Nectaris, the Sea of Nectar. Specifically, it landed near the small impact crater Shioli.
Previous landers were considered on target if they touched down within a few kilometers of their landing zone. JAXA’s SLIM aimed to bull’s-eye the moon using “vision-based navigation” and “navigation, guidance and control.” JAXA designed a three-step process:
1. Initiate the landing descent from lunar orbit and perform precise vision-based navigation to accurately estimate its own position. Utilizing navigation, guidance and control, it will approach the target location above the lunar surface.
2. From above the target location, precise measurements of altitude and terrain-relative velocity will be conducted using the landing radar, which will be integrated into the navigation and guidance system.
3. During the final approach, autonomous image-based obstacle detection and avoidance will be employed to ensure a safe landing, avoiding hazardous rocks and other obstacles.
The second objective was more of a proof-of-concept for SLIM’s small, lightweight design. It’s a compact vehicle, only about 6.5 feet (2 meters) tall and 5 feet (1.5 meters) wide, and weighing just 250 pounds (120 kg). The design is intended to allow more frequent landings on the moon and other planets. So far, the high-performance chemical propulsion system has worked perfectly, nudging SLIM along its way on this shakedown cruise.
Artist’s concept shows the steps of JAXA’s SLIM landing on the surface of the moon. The small craft was meant to land on a slope, intentionally tipping over. Image via JAXA.
JAXA lander planned to tip over
SLIM has a unique approach to landing. It was planned to tip itself onto its side in what JAXA calls a two-step landing. The craft hovered toward the lunar surface, tipping itself to about a 45-degree angle before its main leg touched down. The craft then pitched forward onto its “front” leg, located at what was moments earlier the top of the craft.
But this maneuver did not go exactly as planned.
Bottom line: The Japanese moon lander SLIM – which set down sideways onthe moon on January 20 – has survived its 2nd night of freezing cold and dark on the moon. It has awoken and is transmitting data, JAXA said on March 27.
Last night, we received a response from #SLIM, confirming that the spacecraft made it through the lunar night for the second time! Since the sun was still high and the equipment was still hot, we only took some shots of the usual scenery with the navigation camera. #GoodAfterMoonpic.twitter.com/5BjIr7vxMG
Japanese moon lander SLIM set down on the moon’s surface on January 20. The landing was less than ideal (SLIM is upside-down on the lunar surface), but it was alive and communicating. Japan thus became the 5th earthly nation to reach the moon.
SLIM wasn’t designed to withstand the freezing cold of lunar night. But, as the moon rotated, carrying the craft into night for two weeks, then back to day again, SLIM did withstand its first lunar night, JAXA said on February 26.
Now SLIM has emerged again, from its 2nd lunar night, JAXA said on March 27.
Japan Aerospace Exploration Agency (JAXA) said in a tweet on March 27, 2024, that its lunar lander SLIM has survived a second two-week-long lunar night. Night on the moon is harsh, with temperatures falling to -202 degrees F (-130 degrees C). And SLIM is not in an ideal position on the moon. Its landing on January appeared flawed from the first, and it was realized some days after landing that the craft had ended up upside-down on the moon’s surface. But, SLIM did survive its first lunar night as announced by JAXA on February 26, 2024. And now it has survived a second.
That earlier conversation with SLIM was quick, as harsh sunlight drove the probe to another thermal extreme (in full daylight, the temps on the lunar surface can reach a scorching 260 degrees F, or 127 C). We haven’t seen any information about the exact level of communicaiton during this second wake-up period.
On February 26, JAXA officials had written in English:
Last night, I sent a command and got a response from SLIM. SLIM successfully survived the night on the lunar surface while maintaining communication capabilities! Last night, as it was still midday on the moon, the temperature of the communication equipment was extremely high, so communication was terminated after only a short period of time. From now on, preparations will be made so that observations can be resumed once the temperature has cooled sufficiently.
The Japanese lunar lander SLIM set down on the moon on January 19, 2024. Five days later, NASA’s Lunar Reconnaissance Orbiter (LRO) spacecraft passed over the landing site and photographed SLIM. LRO acquired the image at an altitude of about 50 miles (80 km). Bright streaks on the left side of the image are rocky material ejected from the nearby, relatively young Shioli crater. Japan is the 5th nation to complete a soft landing on the moon. Image via NASA.
Why upside-down?
SpaceNews.com described how the lander came to rest wrong way up:
Shinichiro Sakai, SLIM project manager, reiterated that the landing was hampered by the failure of one of two engines with around 50 meters of descent remaining. This resulted in uncontrolled lateral movement and the lander ending up on its nose, and the main engine pointing upward.
Japan’s SLIM lunar lander set down on the moon in Mare Nectaris, the Sea of Nectar. Specifically, it landed near the small impact crater Shioli.
Japanese moon lander made soft landing on the moon
JAXA’s Smart Lander for Investigating the Moon – aka SLIM – has been on the lunar surface since its awkward landing on January 20. Japan thus became the 5th earthly nation to reach the moon. So, Japan achieved its main objective, landing softly on the lunar surface. But all was not well with the uncrewed craft.
Because the craft did not land in the orientation planned for, its solar panels were not facing the right way. But as the moon moves in its orbit, the solar panels were able to get some energy and carry out some science before the two-week lunar night approached.
Images from the moon
Despite the lander being upside down, it has still been able to take and send back images of the lunar surface. The caption on the post below says:
Believing in Koshiya’s success, the MBC (Multi-Band Camera) team created a new command to image the area inside the red frame, which was not visible last time!
I’m excited about the possibilities for further observations!
SLIM’s mission objectives were simple but not easy
SLIM had basically two tasks to accomplish at the moon, and the first one was just making it to the lunar surface. But not just anywhere on the moon. SLIM’s navigation systems were designed to put the craft within 100 meters (330 feet) of its intended target in Mare Nectaris, the Sea of Nectar. Specifically, it landed near the small impact crater Shioli.
Previous landers were considered on target if they touched down within a few kilometers of their landing zone. JAXA’s SLIM aimed to bull’s-eye the moon using “vision-based navigation” and “navigation, guidance and control.” JAXA designed a three-step process:
1. Initiate the landing descent from lunar orbit and perform precise vision-based navigation to accurately estimate its own position. Utilizing navigation, guidance and control, it will approach the target location above the lunar surface.
2. From above the target location, precise measurements of altitude and terrain-relative velocity will be conducted using the landing radar, which will be integrated into the navigation and guidance system.
3. During the final approach, autonomous image-based obstacle detection and avoidance will be employed to ensure a safe landing, avoiding hazardous rocks and other obstacles.
The second objective was more of a proof-of-concept for SLIM’s small, lightweight design. It’s a compact vehicle, only about 6.5 feet (2 meters) tall and 5 feet (1.5 meters) wide, and weighing just 250 pounds (120 kg). The design is intended to allow more frequent landings on the moon and other planets. So far, the high-performance chemical propulsion system has worked perfectly, nudging SLIM along its way on this shakedown cruise.
Artist’s concept shows the steps of JAXA’s SLIM landing on the surface of the moon. The small craft was meant to land on a slope, intentionally tipping over. Image via JAXA.
JAXA lander planned to tip over
SLIM has a unique approach to landing. It was planned to tip itself onto its side in what JAXA calls a two-step landing. The craft hovered toward the lunar surface, tipping itself to about a 45-degree angle before its main leg touched down. The craft then pitched forward onto its “front” leg, located at what was moments earlier the top of the craft.
But this maneuver did not go exactly as planned.
Bottom line: The Japanese moon lander SLIM – which set down sideways onthe moon on January 20 – has survived its 2nd night of freezing cold and dark on the moon. It has awoken and is transmitting data, JAXA said on March 27.
The total solar eclipse crossing America on April 8, 2024, will be the last visible total solar eclipse visible to cross the contiguous U.S. until the year 2045. This astronomical event is a unique opportunity for scientists studying the shadow of the moon, but it’s also a perfect opportunity to capture unforgettable images. Whether you’re an amateur photographer or a selfie master, try out these tips for photographing the eclipse.
To take images as the sun is being eclipsed, you’ll need to use a special solar filter to protect your camera, just as you’ll need a pair of eclipse glasses to protect your own eyes. However, at totality, when the moon completely blocks the sun, make sure to remove the filter so you can see the sun’s outer atmosphere, the corona.
Having a few other pieces of equipment can also come in handy during the eclipse. Using a tripod can help you stabilize the camera and avoid taking blurry images during the low lighting. Additionally, using a delayed shutter release timer will allow you to snap shots without jiggling the camera.
2. Any camera is a good camera
Taking a stunning photo has more to do with the photographer than the camera. Whether you have a high-end DLSR, or a camera phone, you can take great photos during the eclipse; after all, the best piece of equipment you can have is a good eye and a vision for the image you want to create.
If you don’t have a telephoto zoom lens, focus on taking landscape shots, which capture the changing environment.
During totality, when the moon completely covers the sun, if you do have a telephoto lens with a solar filter, you’ll be able to see and photograph the structures in the sun’s corona.
View larger. | Shaun Tarpley from Shawnee National Forest, Illinois, wrote: “I created this using a 9-image bracket series I took during the 2017 total solar eclipse and overlaid frames indicating the relative field-of-view of common focal lengths to help photographers planning to photograph the 2024 eclipse to visualize what focal length is optimum for their imaging goals. It is a quick way to visualize the differences.” Thank you, Shaun!
While the sun is the most commanding element of an eclipse, remember to look around you. As the moon slips in front of the sun, the landscape will be bathed in long shadows, creating eerie lighting across the landscape. Light filtering through the overlapping leaves of trees, creating natural pinholes, which will also create mini eclipse replicas on the ground. Everywhere you can point your camera can yield exceptional imagery, so be sure to compose some wide-angle photos that can capture your eclipse experience.
NASA photographer Bill Ingalls recommends focusing on the human experience of watching the eclipse. He said:
The real pictures are going to be of the people around you pointing, gawking and watching it. Those are going to be some great moments to capture to show the emotion of the whole thing.
4. Practice
Be sure you know the capabilities of your camera before eclipse day. Most cameras, and even many camera phones, have adjustable exposures, which can help you darken or lighten your image during the tricky eclipse lighting. Make sure you know how to manually focus the camera for crisp shots.
For DSLR cameras, the best way to determine the correct exposure is to test settings on the uneclipsed sun beforehand. Using a fixed aperture of f/8 to f/16, try shutter speeds between 1/1000 to 1/4 second to find the optimal setting, which you can then use to take images during the partial stages of the eclipse. During totality, the corona has a wide range of brightness so it’s best to use a fixed aperture and a range of exposures from approximately 1/1000 to 1 second.
5. Share!
Share your eclipse experience with friends and family afterwards. Use the hashtag #Eclipse2024 on your favorite social media sites.
Share your pics with us at EarthSky here and see more images at our social media: Facebook, Instagram, X, or Threads.
While you’re out perfecting your perfect eclipse shot, don’t forget to stop and look at the eclipse with your own eyes. Just remember to wear your eclipse glasses for all stages of the eclipse before and after totality!
Bottom line: Five tips for photographing the April 8, 2024, total solar eclipse.
The total solar eclipse crossing America on April 8, 2024, will be the last visible total solar eclipse visible to cross the contiguous U.S. until the year 2045. This astronomical event is a unique opportunity for scientists studying the shadow of the moon, but it’s also a perfect opportunity to capture unforgettable images. Whether you’re an amateur photographer or a selfie master, try out these tips for photographing the eclipse.
To take images as the sun is being eclipsed, you’ll need to use a special solar filter to protect your camera, just as you’ll need a pair of eclipse glasses to protect your own eyes. However, at totality, when the moon completely blocks the sun, make sure to remove the filter so you can see the sun’s outer atmosphere, the corona.
Having a few other pieces of equipment can also come in handy during the eclipse. Using a tripod can help you stabilize the camera and avoid taking blurry images during the low lighting. Additionally, using a delayed shutter release timer will allow you to snap shots without jiggling the camera.
2. Any camera is a good camera
Taking a stunning photo has more to do with the photographer than the camera. Whether you have a high-end DLSR, or a camera phone, you can take great photos during the eclipse; after all, the best piece of equipment you can have is a good eye and a vision for the image you want to create.
If you don’t have a telephoto zoom lens, focus on taking landscape shots, which capture the changing environment.
During totality, when the moon completely covers the sun, if you do have a telephoto lens with a solar filter, you’ll be able to see and photograph the structures in the sun’s corona.
View larger. | Shaun Tarpley from Shawnee National Forest, Illinois, wrote: “I created this using a 9-image bracket series I took during the 2017 total solar eclipse and overlaid frames indicating the relative field-of-view of common focal lengths to help photographers planning to photograph the 2024 eclipse to visualize what focal length is optimum for their imaging goals. It is a quick way to visualize the differences.” Thank you, Shaun!
While the sun is the most commanding element of an eclipse, remember to look around you. As the moon slips in front of the sun, the landscape will be bathed in long shadows, creating eerie lighting across the landscape. Light filtering through the overlapping leaves of trees, creating natural pinholes, which will also create mini eclipse replicas on the ground. Everywhere you can point your camera can yield exceptional imagery, so be sure to compose some wide-angle photos that can capture your eclipse experience.
NASA photographer Bill Ingalls recommends focusing on the human experience of watching the eclipse. He said:
The real pictures are going to be of the people around you pointing, gawking and watching it. Those are going to be some great moments to capture to show the emotion of the whole thing.
4. Practice
Be sure you know the capabilities of your camera before eclipse day. Most cameras, and even many camera phones, have adjustable exposures, which can help you darken or lighten your image during the tricky eclipse lighting. Make sure you know how to manually focus the camera for crisp shots.
For DSLR cameras, the best way to determine the correct exposure is to test settings on the uneclipsed sun beforehand. Using a fixed aperture of f/8 to f/16, try shutter speeds between 1/1000 to 1/4 second to find the optimal setting, which you can then use to take images during the partial stages of the eclipse. During totality, the corona has a wide range of brightness so it’s best to use a fixed aperture and a range of exposures from approximately 1/1000 to 1 second.
5. Share!
Share your eclipse experience with friends and family afterwards. Use the hashtag #Eclipse2024 on your favorite social media sites.
Share your pics with us at EarthSky here and see more images at our social media: Facebook, Instagram, X, or Threads.
While you’re out perfecting your perfect eclipse shot, don’t forget to stop and look at the eclipse with your own eyes. Just remember to wear your eclipse glasses for all stages of the eclipse before and after totality!
Bottom line: Five tips for photographing the April 8, 2024, total solar eclipse.
This is the Corinto crater in Elysium Planitia on Mars. A new study using data from Mars Reconnaissance Orbiter (MRO) shows the single asteroid impact that created Corinto also created about 2 billion much smaller secondary craters on Mars, up to 1,200 miles (2,000 km) away. Image via NASA/ JPL/ M. Golombek et al.
About 2 million years ago, an asteroid hit Mars and created Corinto crater. A massive amount of smaller debris from the impact formed nearly 2 billion other, smaller craters on Mars.
The debris created new, small craters as far as 1,200 miles (2,000 km) from the original asteroid impact site.
Scientists determined the number of craters using imaging data from Mars Reconnaissance Orbiter.
1 asteroid = 2 billion craters
Some 2.3 million years ago – relatively recent in geologic time – a space rock careened toward Mars. It smashed into the Red Planet, hurling massive amounts of ejecta out of its newly formed crater. With no plate tectonics and little weathering, Mars still bears the scars of that impact today. Researchers counted the secondary craters formed from flying Martian rocks and dirt. Did they find hundreds? Thousands? Nope, the researchers found nearly two billion smaller craters! These craters are a minimum of 32 feet (10 meters) in size, lying up to 1,200 miles (2,000 km) from the main crater. The researchers presented their findings at the Lunar and Planetary Science Conference (LPSC 2024) in The Woodlands, Texas, in March.
You can read the new paper on the Universities Space Research Association (USRA) website.
The international team of researchers focused on a crater called Corinto, just north of the Martian equator in Elysium Planitia. Corinto is fairly large, about nine miles (14 km) across and 0.6 miles (one km) deep. So, when its parent asteroid hit Mars, it produced a lot of debris called ejecta. Secondary impacts created smaller craters both inside and outside the main crater.
The researchers used imaging data from the HiRISE and Context Camera (CTX) on the Mars Reconnaissance Orbiter (MRO) to study Corinto. The paper stated:
Orbital thermal and visible imaging datasets are used to describe the crater, ejecta blanket, four facies of rays and secondary craters, and to estimate the age of the impact and the total number of secondary craters.
The researchers examined five different kinds of craters around Corinto. Those five groups are what’s known as facies. Each group is distinct in appearance, largely due to how far away they are from Corinto crater. The craters closest to Corinto are semi-circular and have no ejecta of their own. They also have distinct rims. But some of the craters farther away are long and narrow looking.
Studies of the main crater also showed the ground was likely saturated with water ice. As a result, the superheated ice degassed during the impact.
View larger. | This image from the HiRISE camera on Mars Reconnaissance Orbiter (MRO), taken January 13, 2018, shows a field of small craters just outside of Corinto crater (out of view). They are just some of the 2 billion small craters created by secondary impacts. The crater with the colorful ejecta is actually a much more recent one. Image via NASA/ JPL-Caltech/ UArizona/ HiRISE.
Craters on Mars
Scientists calculated the angle of impact was about 30-45 degrees, with the asteroid coming from the north. Coming in from that northerly angle, most of the debris fell back to the surface to the south of the crater.
Consider the great distance from the main impact to the furthest craters, an incredible 1,200 miles (2,000 km) apart. It would be like an asteroid hitting Los Angeles and the debris reaching halfway across the United States to Dallas. What might it have been like to witness that impact and massive debris shower?
Bottom line: An asteroid created a large Martian crater called Corinto, about 2 million years ago. Debris from the impact also created 2 billion smaller craters on Mars.
This is the Corinto crater in Elysium Planitia on Mars. A new study using data from Mars Reconnaissance Orbiter (MRO) shows the single asteroid impact that created Corinto also created about 2 billion much smaller secondary craters on Mars, up to 1,200 miles (2,000 km) away. Image via NASA/ JPL/ M. Golombek et al.
About 2 million years ago, an asteroid hit Mars and created Corinto crater. A massive amount of smaller debris from the impact formed nearly 2 billion other, smaller craters on Mars.
The debris created new, small craters as far as 1,200 miles (2,000 km) from the original asteroid impact site.
Scientists determined the number of craters using imaging data from Mars Reconnaissance Orbiter.
1 asteroid = 2 billion craters
Some 2.3 million years ago – relatively recent in geologic time – a space rock careened toward Mars. It smashed into the Red Planet, hurling massive amounts of ejecta out of its newly formed crater. With no plate tectonics and little weathering, Mars still bears the scars of that impact today. Researchers counted the secondary craters formed from flying Martian rocks and dirt. Did they find hundreds? Thousands? Nope, the researchers found nearly two billion smaller craters! These craters are a minimum of 32 feet (10 meters) in size, lying up to 1,200 miles (2,000 km) from the main crater. The researchers presented their findings at the Lunar and Planetary Science Conference (LPSC 2024) in The Woodlands, Texas, in March.
You can read the new paper on the Universities Space Research Association (USRA) website.
The international team of researchers focused on a crater called Corinto, just north of the Martian equator in Elysium Planitia. Corinto is fairly large, about nine miles (14 km) across and 0.6 miles (one km) deep. So, when its parent asteroid hit Mars, it produced a lot of debris called ejecta. Secondary impacts created smaller craters both inside and outside the main crater.
The researchers used imaging data from the HiRISE and Context Camera (CTX) on the Mars Reconnaissance Orbiter (MRO) to study Corinto. The paper stated:
Orbital thermal and visible imaging datasets are used to describe the crater, ejecta blanket, four facies of rays and secondary craters, and to estimate the age of the impact and the total number of secondary craters.
The researchers examined five different kinds of craters around Corinto. Those five groups are what’s known as facies. Each group is distinct in appearance, largely due to how far away they are from Corinto crater. The craters closest to Corinto are semi-circular and have no ejecta of their own. They also have distinct rims. But some of the craters farther away are long and narrow looking.
Studies of the main crater also showed the ground was likely saturated with water ice. As a result, the superheated ice degassed during the impact.
View larger. | This image from the HiRISE camera on Mars Reconnaissance Orbiter (MRO), taken January 13, 2018, shows a field of small craters just outside of Corinto crater (out of view). They are just some of the 2 billion small craters created by secondary impacts. The crater with the colorful ejecta is actually a much more recent one. Image via NASA/ JPL-Caltech/ UArizona/ HiRISE.
Craters on Mars
Scientists calculated the angle of impact was about 30-45 degrees, with the asteroid coming from the north. Coming in from that northerly angle, most of the debris fell back to the surface to the south of the crater.
Consider the great distance from the main impact to the furthest craters, an incredible 1,200 miles (2,000 km) apart. It would be like an asteroid hitting Los Angeles and the debris reaching halfway across the United States to Dallas. What might it have been like to witness that impact and massive debris shower?
Bottom line: An asteroid created a large Martian crater called Corinto, about 2 million years ago. Debris from the impact also created 2 billion smaller craters on Mars.
