Computer scientists at MIT have unveiled a new, soft robot fish that can independently swim alongside real fish in the ocean. They call their robot fish SoFi and described the work in an article published March 21, 2018 in the peer-reviewed journal Science Robotics. The article is online here. A statement from MIT said:
During test dives in the Rainbow Reef in Fiji, SoFi swam at depths of more than 50 feet [15 meters] for up to 40 minutes at once, nimbly handling currents and taking high-resolution photos and videos using (what else?) a fisheye lens.
Using its undulating tail and a unique ability to control its own buoyancy, SoFi can swim in a straight line, turn, or dive up or down. The team also used a waterproofed Super Nintendo controller and developed a custom acoustic communications system that enabled them to change SoFi’s speed and have it make specific moves and turns.
Robert Katzschmann is a PhD candidate at MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) and lead author of the new research. He said:
To our knowledge, this is the first robotic fish that can swim untethered in three dimensions for extended periods of time.
We are excited about the possibility of being able to use a system like this to get closer to marine life than humans can get on their own.
The research team pointed out that, even with many technological advances in recent years, documenting marine life up close remains a challenging task. They pointed to recent rare footage of an elusive Greenland shark that can live more than 400 years. It revealed how little we know about life in the coldest oceans, and in the oceans in general.
These scientists hope that SoFI can help shed light on the ocean’s mysteries.
Bottom line: MIT computer scientists have developed SoFi – a soft, robot fish made of silicone rubber – that can swim alongside real fish in the ocean.
Computer scientists at MIT have unveiled a new, soft robot fish that can independently swim alongside real fish in the ocean. They call their robot fish SoFi and described the work in an article published March 21, 2018 in the peer-reviewed journal Science Robotics. The article is online here. A statement from MIT said:
During test dives in the Rainbow Reef in Fiji, SoFi swam at depths of more than 50 feet [15 meters] for up to 40 minutes at once, nimbly handling currents and taking high-resolution photos and videos using (what else?) a fisheye lens.
Using its undulating tail and a unique ability to control its own buoyancy, SoFi can swim in a straight line, turn, or dive up or down. The team also used a waterproofed Super Nintendo controller and developed a custom acoustic communications system that enabled them to change SoFi’s speed and have it make specific moves and turns.
Robert Katzschmann is a PhD candidate at MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) and lead author of the new research. He said:
To our knowledge, this is the first robotic fish that can swim untethered in three dimensions for extended periods of time.
We are excited about the possibility of being able to use a system like this to get closer to marine life than humans can get on their own.
The research team pointed out that, even with many technological advances in recent years, documenting marine life up close remains a challenging task. They pointed to recent rare footage of an elusive Greenland shark that can live more than 400 years. It revealed how little we know about life in the coldest oceans, and in the oceans in general.
These scientists hope that SoFI can help shed light on the ocean’s mysteries.
Bottom line: MIT computer scientists have developed SoFi – a soft, robot fish made of silicone rubber – that can swim alongside real fish in the ocean.
View larger. | Big and Little Dippers at different seasons, and different times of night, as captured by Matthew Chin in Hong Kong.
A fixture of the northern sky, the Big and Little Dippers swing around the north star Polaris like riders on a Ferris wheel. They go full circle around Polaris once a day – or once every 23 hours and 56 minutes. If you live at temperate latitudes in the Northern Hemisphere, simply look northward and chances are that you’ll see the Big Dipper in your nighttime sky. It looks just like its namesake.
Once you’ve found the Big Dipper, it’s only a hop, skip and jump to Polaris and the Little Dipper.
If you’re in the northern U.S., Canada or at a similar latitude, the Big Dipper is circumpolar for you – always above the horizon. These images show the Dipper’s location at around midnight in these seasons. Just remember “spring up and fall down” for the Dipper’s appearance in our northern sky. It ascends in the northeast on spring evenings, and descends in the northwest on fall evenings. Image via burro.astr.cwru.edu
The Big Dipper seen in the midst of the northern lights, taken in by Birgit Boden in northern Sweden.
The Big Dipper as seen by John Michael Mizzi on the island of Gozo, south of Italy.
Depending upon the season of the year, the Big Dipper can be found high in the northern sky or low in the northern sky. Just remember the old saying spring up and fall down. On spring and summer evenings, the Big Dipper shine highest in the sky. On autumn and winter evenings, the Big Dipper lurks closest to the horizon.
Given an unobstructed horizon, latitudes at and north of Little Rock, Arkansas (35 degrees north) can expect to see the Big Dipper at any hour of the night for all days of the year. As for the Little Dipper, it is circumpolar – always above the horizon – as far south as the tropic of Cancer (23.5 degrees north latitude).
Stars in the Big Dipper via EarthSky Facebook friend Ken Christison. He captured this photo on September 9, 2013.
No matter what time of year you look, the two outer stars in the Big Dipper’s bowl always point to Polaris.
Notice that the Big Dipper has two parts – a bowl and a handle. Notice the two outer stars in the bowl of the Big Dipper. They are called Dubhe and Merak, and an imaginary line drawn between them goes to Polaris, the North Star. That’s why Dubhe and Merak are known in skylore as The Pointers.
In turn, Polaris marks the end of the Little Dipper’s Handle. So why isn’t the Little Dipper as easy to pick out as the Big Dipper? The answer is that, like the Big Dipper, the Little Dipper has 7 stars. But the 4 stars in between Polaris and the outer bowl stars – Kochab and Pherkad – are rather dim. You need a dark country sky to see all 7.
The Big Dipper is part of Ursa Major, the celestial Great Bear. Image via storybookipedia.
The Big Dipper is really an asterism – a star pattern that is NOT a constellation. The Big Dipper is a clipped version of the constellation Ursa Major the Big Bear, these Big Dipper stars outlining the Bear’s tail and hindquarters. In the star lore of the Micmacs in Canada, the Big Dipper is also associated with a bear but with a different twist. The Micmacs see the Big Dipper bowl as Celestial Bear, and the 3 stars of the handle as hunters chasing the Bear.
The starry sky serves as a calendar and a story book, as is beautifully illustrated by the Micmac tale of Celestial Bear. In autumn, the hunters finally catch up with the Bear, and it’s said that the blood from the Bear colors the autmn landscape. In another version of the story, Celestial bear hits its nose when coming down to Earth, with its bloody nose giving color to autumn leaves. When Celestial Bear is seen right on the northern horizon on late fall and early winter evenings, it’s a sure sign that the hibernation season is upon us.
The Little Dipper is also an asterism, these stars belonging to the constellation Ursa Minor the Little Bear. In ancient times, the Little Dipper formed the wings of the constellation Draco the Dragon. But when the seafaring Phoenicians met with the Greek astronomer Thales around 600 B.C., they showed him how to use the Little Dipper stars to navigate. Thereby, Thales clipped Draco’s wings, to create a new constellation that gave Greek sailors a new way to steer by the stars.
In Thales’s day, the stars Kochab and Pherkad (rather than Polaris) marked the approximate direction of the north celestial pole – the point in the sky that is directly above the Earth’s North Pole.
To this day, Kochab and Pherkad are still known as the Guardians of the Pole.
Astronomers have found that the stars of the Big Dipper (excepting the pointer star, Dubhe, and the handle star, Alkaid) belong to an association of stars known as the Ursa Major Moving Cluster. Here are the stars of the Big Dipper, at their various distances from Earth, via AstroPixie.
Astronomers sometimes speak of the fixed stars, but they know that the stars are not truly fixed. They move in space. Thus the star patterns that we see today will slowly but surely drift apart over the long course of time.
But even 25,000 years from now, the Big Dipper pattern will look nearly the same as its does today. Astronomers have found that the stars of the Big Dipper (excepting the pointer star, Dubhe, and the handle star, Alkaid) belong to an association of stars known as the Ursa Major Moving Cluster. These stars, loosely bound by gravity, drift in the same direction in space.
In 100,000 years, this pattern of Big Dipper stars (minus Dubhe and Alkaid) will appear much as it does today! But there will be some differences, as illustrated in the drawing below:
Stars of the Big Dipper today – 100,000 years ago – and 100,000 years from now via AstroPixie
Bottom line: All about the Big and Little Dippers. How to spot them, their mythology, plus learn how the stars of the Big Dipper are moving in space.
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View larger. | Big and Little Dippers at different seasons, and different times of night, as captured by Matthew Chin in Hong Kong.
A fixture of the northern sky, the Big and Little Dippers swing around the north star Polaris like riders on a Ferris wheel. They go full circle around Polaris once a day – or once every 23 hours and 56 minutes. If you live at temperate latitudes in the Northern Hemisphere, simply look northward and chances are that you’ll see the Big Dipper in your nighttime sky. It looks just like its namesake.
Once you’ve found the Big Dipper, it’s only a hop, skip and jump to Polaris and the Little Dipper.
If you’re in the northern U.S., Canada or at a similar latitude, the Big Dipper is circumpolar for you – always above the horizon. These images show the Dipper’s location at around midnight in these seasons. Just remember “spring up and fall down” for the Dipper’s appearance in our northern sky. It ascends in the northeast on spring evenings, and descends in the northwest on fall evenings. Image via burro.astr.cwru.edu
The Big Dipper seen in the midst of the northern lights, taken in by Birgit Boden in northern Sweden.
The Big Dipper as seen by John Michael Mizzi on the island of Gozo, south of Italy.
Depending upon the season of the year, the Big Dipper can be found high in the northern sky or low in the northern sky. Just remember the old saying spring up and fall down. On spring and summer evenings, the Big Dipper shine highest in the sky. On autumn and winter evenings, the Big Dipper lurks closest to the horizon.
Given an unobstructed horizon, latitudes at and north of Little Rock, Arkansas (35 degrees north) can expect to see the Big Dipper at any hour of the night for all days of the year. As for the Little Dipper, it is circumpolar – always above the horizon – as far south as the tropic of Cancer (23.5 degrees north latitude).
Stars in the Big Dipper via EarthSky Facebook friend Ken Christison. He captured this photo on September 9, 2013.
No matter what time of year you look, the two outer stars in the Big Dipper’s bowl always point to Polaris.
Notice that the Big Dipper has two parts – a bowl and a handle. Notice the two outer stars in the bowl of the Big Dipper. They are called Dubhe and Merak, and an imaginary line drawn between them goes to Polaris, the North Star. That’s why Dubhe and Merak are known in skylore as The Pointers.
In turn, Polaris marks the end of the Little Dipper’s Handle. So why isn’t the Little Dipper as easy to pick out as the Big Dipper? The answer is that, like the Big Dipper, the Little Dipper has 7 stars. But the 4 stars in between Polaris and the outer bowl stars – Kochab and Pherkad – are rather dim. You need a dark country sky to see all 7.
The Big Dipper is part of Ursa Major, the celestial Great Bear. Image via storybookipedia.
The Big Dipper is really an asterism – a star pattern that is NOT a constellation. The Big Dipper is a clipped version of the constellation Ursa Major the Big Bear, these Big Dipper stars outlining the Bear’s tail and hindquarters. In the star lore of the Micmacs in Canada, the Big Dipper is also associated with a bear but with a different twist. The Micmacs see the Big Dipper bowl as Celestial Bear, and the 3 stars of the handle as hunters chasing the Bear.
The starry sky serves as a calendar and a story book, as is beautifully illustrated by the Micmac tale of Celestial Bear. In autumn, the hunters finally catch up with the Bear, and it’s said that the blood from the Bear colors the autmn landscape. In another version of the story, Celestial bear hits its nose when coming down to Earth, with its bloody nose giving color to autumn leaves. When Celestial Bear is seen right on the northern horizon on late fall and early winter evenings, it’s a sure sign that the hibernation season is upon us.
The Little Dipper is also an asterism, these stars belonging to the constellation Ursa Minor the Little Bear. In ancient times, the Little Dipper formed the wings of the constellation Draco the Dragon. But when the seafaring Phoenicians met with the Greek astronomer Thales around 600 B.C., they showed him how to use the Little Dipper stars to navigate. Thereby, Thales clipped Draco’s wings, to create a new constellation that gave Greek sailors a new way to steer by the stars.
In Thales’s day, the stars Kochab and Pherkad (rather than Polaris) marked the approximate direction of the north celestial pole – the point in the sky that is directly above the Earth’s North Pole.
To this day, Kochab and Pherkad are still known as the Guardians of the Pole.
Astronomers have found that the stars of the Big Dipper (excepting the pointer star, Dubhe, and the handle star, Alkaid) belong to an association of stars known as the Ursa Major Moving Cluster. Here are the stars of the Big Dipper, at their various distances from Earth, via AstroPixie.
Astronomers sometimes speak of the fixed stars, but they know that the stars are not truly fixed. They move in space. Thus the star patterns that we see today will slowly but surely drift apart over the long course of time.
But even 25,000 years from now, the Big Dipper pattern will look nearly the same as its does today. Astronomers have found that the stars of the Big Dipper (excepting the pointer star, Dubhe, and the handle star, Alkaid) belong to an association of stars known as the Ursa Major Moving Cluster. These stars, loosely bound by gravity, drift in the same direction in space.
In 100,000 years, this pattern of Big Dipper stars (minus Dubhe and Alkaid) will appear much as it does today! But there will be some differences, as illustrated in the drawing below:
Stars of the Big Dipper today – 100,000 years ago – and 100,000 years from now via AstroPixie
Bottom line: All about the Big and Little Dippers. How to spot them, their mythology, plus learn how the stars of the Big Dipper are moving in space.
Nima Asadzadeh at Lake Urmia, Iran composed this beautiful composite image of 33 vertical shots acquired March 26, 2018, around 3:30 a.m. The brightest starlike object in this image is Jupiter (on the far right). Below and to the left of Jupiter – below the little arc of three stars – is the bright red star Antares in the constellation Scorpius. Two more planets, Mars (right) and Saturn (left) are the bright starlike objects above the left side of the boat. Here are some details on the shot:
Nikon D7200 – Nikkor 18-140@18mm. Exif Of each shot: Shutter Speed 20″ – ISO 3200 – Aperture f/4.5. Photos were stitched in PTGui and entire photo processed in Adobe ACR and Adobe Photoshop.
Thank you, Nima!
This is a good week to look for Jupiter, Mars and Saturn. See Jupiter near the moon from late night April 2 and 3 to dawn April 3 and 4. See Mars and Saturn are in conjunction April 2 and are together before dawn – in a single binocular field – all week. Plus Saturn and Mars are very near the moon on the morning of April 7.
Nima Asadzadeh at Lake Urmia, Iran composed this beautiful composite image of 33 vertical shots acquired March 26, 2018, around 3:30 a.m. The brightest starlike object in this image is Jupiter (on the far right). Below and to the left of Jupiter – below the little arc of three stars – is the bright red star Antares in the constellation Scorpius. Two more planets, Mars (right) and Saturn (left) are the bright starlike objects above the left side of the boat. Here are some details on the shot:
Nikon D7200 – Nikkor 18-140@18mm. Exif Of each shot: Shutter Speed 20″ – ISO 3200 – Aperture f/4.5. Photos were stitched in PTGui and entire photo processed in Adobe ACR and Adobe Photoshop.
Thank you, Nima!
This is a good week to look for Jupiter, Mars and Saturn. See Jupiter near the moon from late night April 2 and 3 to dawn April 3 and 4. See Mars and Saturn are in conjunction April 2 and are together before dawn – in a single binocular field – all week. Plus Saturn and Mars are very near the moon on the morning of April 7.
The US air force has confirmed the reentry of the Tiangong-1 spacecraft at about 02:16 CEST this morning over the southern Pacific Ocean. The location of the reentry was, by chance, not too far from the so-called South Pacific Ocean Unpopulated Area. The SPOUA has long been used by many space agencies including ESA, to dispose of end-of-life spacecraft through controlled reentries.
The air force wrote:
The JFSCC used the Space Surveillance Network sensors and their orbital analysis system to confirm Tiangong-1’s reentry, and to refine its prediction and ultimately provide more fidelity as the reentry time approached. This information is publicly-available on USSTRATCOM’s website www.Space-Track.org. The JFSCC also confirmed reentry through coordination with counterparts in Australia, Canada, France, Germany, Italy, Japan, South Korea, and the United Kingdom.
VANDENBERG AIR FORCE BASE, Calif. — U.S. Strategic Command’s (USSTRATCOM) Joint Force Space Component Command (JFSCC), through the Joint Space Operations Center (JSpOC), confirmed Tiangong-1 reentered the Earth’s atmosphere over the southern Pacific Ocean at approximately 5:16 p.m. (PST) April 1, 2018.
The US air force has confirmed the reentry of the Tiangong-1 spacecraft at about 02:16 CEST this morning over the southern Pacific Ocean. The location of the reentry was, by chance, not too far from the so-called South Pacific Ocean Unpopulated Area. The SPOUA has long been used by many space agencies including ESA, to dispose of end-of-life spacecraft through controlled reentries.
The air force wrote:
The JFSCC used the Space Surveillance Network sensors and their orbital analysis system to confirm Tiangong-1’s reentry, and to refine its prediction and ultimately provide more fidelity as the reentry time approached. This information is publicly-available on USSTRATCOM’s website www.Space-Track.org. The JFSCC also confirmed reentry through coordination with counterparts in Australia, Canada, France, Germany, Italy, Japan, South Korea, and the United Kingdom.
VANDENBERG AIR FORCE BASE, Calif. — U.S. Strategic Command’s (USSTRATCOM) Joint Force Space Component Command (JFSCC), through the Joint Space Operations Center (JSpOC), confirmed Tiangong-1 reentered the Earth’s atmosphere over the southern Pacific Ocean at approximately 5:16 p.m. (PST) April 1, 2018.
Main Control Room at ESA’s European Space Operations Centre, Darmstadt, Germany. Credit: ESA/P. Shlyaev
With the reentry of Tiangong-1 now forecast to happen within a few hours, ESA’s formal role in the tracking campaign is winding down.
To recall, here’s what’s been happening.
Each year, about 100 tonnes of defunct satellites, uncontrolled spacecraft, spent upper stages and discarded items like instrument covers are dragged down by Earth’s upper atmosphere, ending their lives in flaming arcs across the sky.
While still in orbit, these and many other objects are tracked by a US military radar network, which shares the data with ESA, since Europe has no such capability of its own.
IADC campaign
Around once a year, ESA takes part in a joint tracking campaign run by the Inter Agency Space Debris Coordination Committee, which consists of experts from 13 space organisations such as NASA, Roscosmos, CNSA and European and other national agencies.
During the campaign, participants have been pooling their predictions of the time window, as well as their respective tracking datasets obtained from radar and other sources, with the aim of cross-verifying, cross-analysing and improving the prediction accuracy for all members.
ESA has been acting as host and administrator for the campaign, as it has done for the twenty previous IADC test campaigns since 1998. A special case for ESA was the campaign in 2013 during the uncontrolled reentry of ESA’s own GOCE satellite.
In addition to IADC campaigns, it is the task of ESA’s Space Debris team to generate its own independent predictions to ESA Member States and partner civil authorities around the globe.
The team mix in additional tracking information gleaned from European sources, such as Germany’s Fraunhofer research radar near Bonn or telescopes and other detectors run by a mix of institutional and private researchers, to generate reentry forecasts – a challenging and imprecise art.
We’ve been posting ESA’s reentry forecasts regularly here in the blog, and sharing the link via social media.
Getting close
In just a few hours, we’ll be well within the uncertainty window associated with this reentry, and we don’t expect any more forecast updates with any higher accuracy. In other words, we’re at the limit of what we can forecast.
Just over an hour ago, ESA’s space debris team provided their final estimate for reentry, forecasting a window of about four hours and centred on 01:07 UTC (03:07 CEST) on 2 April.
Final Tiangong-1 reentry window forecast for 18:00 CEST 1 April Credit: ESA
Final Tiangong-1 altitude decay forecast as of 18:00 CEST, 1 April Credit: ESA
“With our current understanding of the dynamics of the upper atmosphere and Europe’s limited sensors, we are not able to make very precise predictions,” says Holger Krag, head of ESA’s Space Debris Office.
Holger says that there will always be an uncertainty of a few hours in all predictions, and that even just a day or so before any reentry, like now, the uncertainty window can be very large.
“The high speeds of returning satellites mean they can travel thousands of kilometres during that time window, and that makes it very hard to predict a precise location of reentry.”
Spotting reentry
It is likely that the pending reentry of Tiangong-1 will occur over water, probably unseen by anyone (although possibly detected by radar or other sensors).
Tiangong-1 seen at an altitude of about 161 km by the powerful TIRA research radar operated by the Fraunhofer Institute for High Frequency Physics and Radar Techniques (FHR) near Bonn, Germany. Image acquired on the morning of 1 April 2018, during one of the craft’s final orbits. Credit: Fraunhofer FHR
Our planet is a big place, mostly covered by water, and if any pieces survive the fiery reentry, these are unlikely to be found by anyone, sinking instead to the bottom of some ocean, or landing far from human habitation.
If you do witness the event, we’d certainly like to see any images you get.
These will help ESA’s debris team conduct their post-reentry analysis, and improve models and forecasts for future.
We need the time, your location (GPS coordinates fine) and – ideally – the direction in which you were facing when you saw any arc across the sky.
In the unlikely case that you find a piece of debris on ground, leave it alone and inform your local authorities.
Our final word comes from last week’s web article, which closed with an observation worth repeating:
Since 2009, ESA has been developing software, technologies and precursor systems to test a fully European network that would provide independent data on the risks from spaceflight.
“Today, everyone in Europe relies on the US military for space debris orbit data – we lack the radar network and other detectors needed to perform independent tracking and monitoring of objects in space,” says Holger Krag.
“This is needed to allow meaningful European participation in the global efforts for space safety.”
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Main Control Room at ESA’s European Space Operations Centre, Darmstadt, Germany. Credit: ESA/P. Shlyaev
With the reentry of Tiangong-1 now forecast to happen within a few hours, ESA’s formal role in the tracking campaign is winding down.
To recall, here’s what’s been happening.
Each year, about 100 tonnes of defunct satellites, uncontrolled spacecraft, spent upper stages and discarded items like instrument covers are dragged down by Earth’s upper atmosphere, ending their lives in flaming arcs across the sky.
While still in orbit, these and many other objects are tracked by a US military radar network, which shares the data with ESA, since Europe has no such capability of its own.
IADC campaign
Around once a year, ESA takes part in a joint tracking campaign run by the Inter Agency Space Debris Coordination Committee, which consists of experts from 13 space organisations such as NASA, Roscosmos, CNSA and European and other national agencies.
During the campaign, participants have been pooling their predictions of the time window, as well as their respective tracking datasets obtained from radar and other sources, with the aim of cross-verifying, cross-analysing and improving the prediction accuracy for all members.
ESA has been acting as host and administrator for the campaign, as it has done for the twenty previous IADC test campaigns since 1998. A special case for ESA was the campaign in 2013 during the uncontrolled reentry of ESA’s own GOCE satellite.
In addition to IADC campaigns, it is the task of ESA’s Space Debris team to generate its own independent predictions to ESA Member States and partner civil authorities around the globe.
The team mix in additional tracking information gleaned from European sources, such as Germany’s Fraunhofer research radar near Bonn or telescopes and other detectors run by a mix of institutional and private researchers, to generate reentry forecasts – a challenging and imprecise art.
We’ve been posting ESA’s reentry forecasts regularly here in the blog, and sharing the link via social media.
Getting close
In just a few hours, we’ll be well within the uncertainty window associated with this reentry, and we don’t expect any more forecast updates with any higher accuracy. In other words, we’re at the limit of what we can forecast.
Just over an hour ago, ESA’s space debris team provided their final estimate for reentry, forecasting a window of about four hours and centred on 01:07 UTC (03:07 CEST) on 2 April.
Final Tiangong-1 reentry window forecast for 18:00 CEST 1 April Credit: ESA
Final Tiangong-1 altitude decay forecast as of 18:00 CEST, 1 April Credit: ESA
“With our current understanding of the dynamics of the upper atmosphere and Europe’s limited sensors, we are not able to make very precise predictions,” says Holger Krag, head of ESA’s Space Debris Office.
Holger says that there will always be an uncertainty of a few hours in all predictions, and that even just a day or so before any reentry, like now, the uncertainty window can be very large.
“The high speeds of returning satellites mean they can travel thousands of kilometres during that time window, and that makes it very hard to predict a precise location of reentry.”
Spotting reentry
It is likely that the pending reentry of Tiangong-1 will occur over water, probably unseen by anyone (although possibly detected by radar or other sensors).
Tiangong-1 seen at an altitude of about 161 km by the powerful TIRA research radar operated by the Fraunhofer Institute for High Frequency Physics and Radar Techniques (FHR) near Bonn, Germany. Image acquired on the morning of 1 April 2018, during one of the craft’s final orbits. Credit: Fraunhofer FHR
Our planet is a big place, mostly covered by water, and if any pieces survive the fiery reentry, these are unlikely to be found by anyone, sinking instead to the bottom of some ocean, or landing far from human habitation.
If you do witness the event, we’d certainly like to see any images you get.
These will help ESA’s debris team conduct their post-reentry analysis, and improve models and forecasts for future.
We need the time, your location (GPS coordinates fine) and – ideally – the direction in which you were facing when you saw any arc across the sky.
In the unlikely case that you find a piece of debris on ground, leave it alone and inform your local authorities.
Our final word comes from last week’s web article, which closed with an observation worth repeating:
Since 2009, ESA has been developing software, technologies and precursor systems to test a fully European network that would provide independent data on the risks from spaceflight.
“Today, everyone in Europe relies on the US military for space debris orbit data – we lack the radar network and other detectors needed to perform independent tracking and monitoring of objects in space,” says Holger Krag.
“This is needed to allow meaningful European participation in the global efforts for space safety.”
What do birds and aerospace engineers have in common? Both have invented incredibly dark, “super-black” surfaces that absorb almost every last bit of light that strikes them.
These are resplendent birds native to Papua New Guinea and surrounding areas. Males are brilliantly colored, with complicated mating dances. Females, who are drab and brown in comparison, carefully inspect the ornaments and dances of males before choosing their mate.
We wanted to know more about these birds’ super-black plumage and how it works. What mechanism do these feathers employ to be so effective at absorbing light?
Super-black feathers on these guys are like looking into a dark cave. Image via Natasha Baucas/Flickr.
Fanciest feathers, under the microscope
The Birds of Paradise have evolved many remarkable traits, but none are more mysterious than the males’ velvety black plumage.
This black is so dark that your eyes cannot focus on its surface; it looks like a cave, or a fuzzy black hole in space. Using optical measurements, we found that these feather patches absorb up to 99.95 percent of directly incident light. That’s comparable to human-made very black materials such as solar panels, the lining of space telescopes, and even the “blackest black” material: Vantablack, which absorbs 99.96 percent of light.
On the left, a normal black feather from a Lesser Melampitta. On the right, a super-black feather from the Paradise Riflebird. Image via Dakota McCoy.
Normal feathers are flat, and look like fractals; when you zoom in using a microscope, each branch of the feather looks like a tiny, flat feather. Under a powerful scanning electron microscope, we were surprised to see that the super-black feathers look like miniature coral reefs, bottle brushes or trees with tightly packed leaves.
These tiny, specially shaped bits stick up to form a jagged, complex surface; together they act as microscopic light traps. When light rays strike these surface microstructures, they repeatedly scatter around the shapes and are absorbed, rather than being reflected back to an observer. It’s an iterative process: Each time a scattering event occurs, a portion of the light is absorbed until it’s almost completely absorbed.
Human-made super-black materials such as “black silicon” also rely on what materials scientists call structural absorption. Like the super-black feathers, their microscopic “light traps” are due to a rough surface that scatters light repeatedly, but the actual surface shapes they use are different. Rather than the feathers’ bottle brush shapes, human engineers designed regularly spaced microscopic cones and pits. With almost no exposed flat surface, these structurally black materials are the opposite of a mirror.
Due to its unusual microstructure, the feather from the Paradise Riflebird (on the right) still appears super-black when coated with gold, as compared to a regular black feather (on the left). Image via Dakota McCoy.
The Birds of Paradise’s super-black feathers are so good at absorbing light that even when we coated them in gold, a shiny metal, they still looked black. That’s because it’s not the inside of the feather making the color via pigment or ordered nanostructures; instead, just as with human-made black silicon, the super black comes from the physical surface structure. Evolution and human ingenuity arrived at the same solution.
Advantages of super-black feathers
But why do these birds have such incredibly dark black patches? What selective advantage caused this trait to evolve? It’s tempting to think that super black somehow helps with camouflage, to keep predators away. In fact, some snakes have super-black scales that mimic shadows between leaves, helping them blend into the forest floor. The snake example illustrates evolution by natural selection – “survival of the fittest.”
But other factors can also influence evolution’s course, including random chance or sexual selection. As my colleague Rick Prum points out in his new book “The Evolution of Beauty: How Darwin’s Forgotten Theory of Mate Choice Shapes the Animal World – and Us,” mate choice is a powerful force driving evolution. In Birds of Paradise, super-black feathers help male birds look more beautiful to a female’s eye.
A male Superb Bird of Paradise displays his super-black and brilliant blue plumage to an onlooking female. Image via Ed Scholes.
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To understand how, it helps to look at Bird of Paradise mating dances. Males vigorously display their super-black patches to females, making sure that females can’t get a view from the side. This is because these feathers are highly directional, and they look darkest from straight ahead.
And super-black patches always sit around or next to brilliant color patches. A super-black, anti-reflective frame makes nearby colors appear brighter, almost glow. In other words, super black is an evolved optical illusion that relies on the way animal eyes and brains adjust our perceptions based on ambient light.
In the high-stakes game of choosing a mate, a single feather that isn’t quite blue enough could be enough to turn off a female Bird of Paradise. Clearly, female Birds of Paradise prefer males with super-black plumage. As females pick the most impressive males to mate with, those dazzling feather genes are passed on to future generations while the genes of less splendid males, overlooked by females, are not. Sexual selection drove evolution toward super-black plumage.
Evolution is not an orderly, coherent process; evolutionary arms races can produce great innovation. Perhaps these super-black feathers with their unique microscopic structure could eventually inspire better solar panels, or new textiles; super-black butterfly wings already have. Evolution has had millions of years to tinker; we still have much to learn from its solutions.
What do birds and aerospace engineers have in common? Both have invented incredibly dark, “super-black” surfaces that absorb almost every last bit of light that strikes them.
These are resplendent birds native to Papua New Guinea and surrounding areas. Males are brilliantly colored, with complicated mating dances. Females, who are drab and brown in comparison, carefully inspect the ornaments and dances of males before choosing their mate.
We wanted to know more about these birds’ super-black plumage and how it works. What mechanism do these feathers employ to be so effective at absorbing light?
Super-black feathers on these guys are like looking into a dark cave. Image via Natasha Baucas/Flickr.
Fanciest feathers, under the microscope
The Birds of Paradise have evolved many remarkable traits, but none are more mysterious than the males’ velvety black plumage.
This black is so dark that your eyes cannot focus on its surface; it looks like a cave, or a fuzzy black hole in space. Using optical measurements, we found that these feather patches absorb up to 99.95 percent of directly incident light. That’s comparable to human-made very black materials such as solar panels, the lining of space telescopes, and even the “blackest black” material: Vantablack, which absorbs 99.96 percent of light.
On the left, a normal black feather from a Lesser Melampitta. On the right, a super-black feather from the Paradise Riflebird. Image via Dakota McCoy.
Normal feathers are flat, and look like fractals; when you zoom in using a microscope, each branch of the feather looks like a tiny, flat feather. Under a powerful scanning electron microscope, we were surprised to see that the super-black feathers look like miniature coral reefs, bottle brushes or trees with tightly packed leaves.
These tiny, specially shaped bits stick up to form a jagged, complex surface; together they act as microscopic light traps. When light rays strike these surface microstructures, they repeatedly scatter around the shapes and are absorbed, rather than being reflected back to an observer. It’s an iterative process: Each time a scattering event occurs, a portion of the light is absorbed until it’s almost completely absorbed.
Human-made super-black materials such as “black silicon” also rely on what materials scientists call structural absorption. Like the super-black feathers, their microscopic “light traps” are due to a rough surface that scatters light repeatedly, but the actual surface shapes they use are different. Rather than the feathers’ bottle brush shapes, human engineers designed regularly spaced microscopic cones and pits. With almost no exposed flat surface, these structurally black materials are the opposite of a mirror.
Due to its unusual microstructure, the feather from the Paradise Riflebird (on the right) still appears super-black when coated with gold, as compared to a regular black feather (on the left). Image via Dakota McCoy.
The Birds of Paradise’s super-black feathers are so good at absorbing light that even when we coated them in gold, a shiny metal, they still looked black. That’s because it’s not the inside of the feather making the color via pigment or ordered nanostructures; instead, just as with human-made black silicon, the super black comes from the physical surface structure. Evolution and human ingenuity arrived at the same solution.
Advantages of super-black feathers
But why do these birds have such incredibly dark black patches? What selective advantage caused this trait to evolve? It’s tempting to think that super black somehow helps with camouflage, to keep predators away. In fact, some snakes have super-black scales that mimic shadows between leaves, helping them blend into the forest floor. The snake example illustrates evolution by natural selection – “survival of the fittest.”
But other factors can also influence evolution’s course, including random chance or sexual selection. As my colleague Rick Prum points out in his new book “The Evolution of Beauty: How Darwin’s Forgotten Theory of Mate Choice Shapes the Animal World – and Us,” mate choice is a powerful force driving evolution. In Birds of Paradise, super-black feathers help male birds look more beautiful to a female’s eye.
A male Superb Bird of Paradise displays his super-black and brilliant blue plumage to an onlooking female. Image via Ed Scholes.
\
To understand how, it helps to look at Bird of Paradise mating dances. Males vigorously display their super-black patches to females, making sure that females can’t get a view from the side. This is because these feathers are highly directional, and they look darkest from straight ahead.
And super-black patches always sit around or next to brilliant color patches. A super-black, anti-reflective frame makes nearby colors appear brighter, almost glow. In other words, super black is an evolved optical illusion that relies on the way animal eyes and brains adjust our perceptions based on ambient light.
In the high-stakes game of choosing a mate, a single feather that isn’t quite blue enough could be enough to turn off a female Bird of Paradise. Clearly, female Birds of Paradise prefer males with super-black plumage. As females pick the most impressive males to mate with, those dazzling feather genes are passed on to future generations while the genes of less splendid males, overlooked by females, are not. Sexual selection drove evolution toward super-black plumage.
Evolution is not an orderly, coherent process; evolutionary arms races can produce great innovation. Perhaps these super-black feathers with their unique microscopic structure could eventually inspire better solar panels, or new textiles; super-black butterfly wings already have. Evolution has had millions of years to tinker; we still have much to learn from its solutions.
Red Mars and golden Saturn have been edging toward each other – day by day – and their conjunction comes on April 2, 2018. You might be able to recognize them just by looking outside before dawn for two similarly bright objects, very near each other. Plus … Jupiter, a very bright planet, is near the moon late at night on April 1 or early in the morning April 2. The moon and Jupiter can also help you find Mars and Saturn!
At mid-northern latitudes, Mars and Saturn rise around one and one-half hours after midnight; from temperate latitudes in the Southern Hemisphere, these two worlds climb over the southeast horizon about one hour before the midnight hour.
Victor C. Rogus in Arcadia, Florida caught Saturn (left) and Mars before dawn on the morning of March 30, 2018. He wrote they … “were glowing just 2° apart, above the Sagittarius Teapot. A beautiful conjunction of the angry Red Planet, Mars and the ringed wonder, Saturn, as the sun rose.” Cannon 80d camera with 50mm Carl Zeiss manual focus lens at f1,4 camera on tripod.
The moon and Jupiter come up earlier. From northerly latitudes, Jupiter follows the moon into the eastern sky around mid-to-late evening; whereas at southerly latitudes in the Southern Hemisphere, the moon and Jupiter are up by early-to-mid evening.
By the predawn hours on April 2, the moon and Jupiter will have moved over into the western half of sky. If you’re up at that early hour, draw an imaginary line from the moon through Jupiter to locate Mars and Saturn. It’s a long jump from the moon and Jupiter to Mars and Saturn, but you should be able to pick them out, because Mars and Saturn are bright and close together on the sky’s dome. Just don’t let the star Antares fool you. It’s about the same brightness and redness as Mars now!
Mars and Saturn are located in a rich region of the sky, above the famous Teapot of the constellation Sagittarius. If you see them in a dark sky, you’ll find the edgewise view of our Milky Way galaxy broadening and brightening in this direction, which is toward the galaxy’s center.
Planets Saturn (left) and Mars over 3 different days in March 2018, as seen by Shobhit Tiwari in Kanpur, India. He wrote: “Getting closer day by day … “
From anywhere worldwide, get up about 90 minutes (or sooner) before sunrise to view Mars and Saturn in the predawn/dawn sky. At conjunction on April 2, Mars passes a rather scant 1.3o south of Saturn. (For some perspective, 1.3o on the sky’s dome is approximately equal to the width of your little finger at an arm’s length. These two colorful celestial gems will easily fit within the same binocular field for another week or so.
Mars, the 4th planet from the sun, goes eastward in front of all the constellations of the zodiac in nearly two years, while Saturn, the 6th planet outward, takes nearly 30 years to go full circle through the zodiac. So that means Mars laps Saturn, or has a conjunction with Saturn, in periods of roughly two years.
The last conjunction of Mars and Saturn happened on August 25, 2016, and the next one will be March 31, 2020.
The moon will be edging toward Mars and Saturn over the coming week, and the pair will still be close when the moon slides by them on the morning of April 7. From North America, you have a good chance of viewing the threesome – the moon, Mars and Saturn – in a single binocular field. Circle April 7 on your calendar and think photo opportunity.
From North America, you have a good chance of viewing three worlds – the moon, Mars and Saturn – in a single binocular field on April 7.
Bottom line: Enjoy the close pairing of ruddy Mars and golden Saturn before dawn on April 2, 2018. The moon and bright Jupiter will be nearby.
from EarthSky https://ift.tt/2GpFIOJ
Red Mars and golden Saturn have been edging toward each other – day by day – and their conjunction comes on April 2, 2018. You might be able to recognize them just by looking outside before dawn for two similarly bright objects, very near each other. Plus … Jupiter, a very bright planet, is near the moon late at night on April 1 or early in the morning April 2. The moon and Jupiter can also help you find Mars and Saturn!
At mid-northern latitudes, Mars and Saturn rise around one and one-half hours after midnight; from temperate latitudes in the Southern Hemisphere, these two worlds climb over the southeast horizon about one hour before the midnight hour.
Victor C. Rogus in Arcadia, Florida caught Saturn (left) and Mars before dawn on the morning of March 30, 2018. He wrote they … “were glowing just 2° apart, above the Sagittarius Teapot. A beautiful conjunction of the angry Red Planet, Mars and the ringed wonder, Saturn, as the sun rose.” Cannon 80d camera with 50mm Carl Zeiss manual focus lens at f1,4 camera on tripod.
The moon and Jupiter come up earlier. From northerly latitudes, Jupiter follows the moon into the eastern sky around mid-to-late evening; whereas at southerly latitudes in the Southern Hemisphere, the moon and Jupiter are up by early-to-mid evening.
By the predawn hours on April 2, the moon and Jupiter will have moved over into the western half of sky. If you’re up at that early hour, draw an imaginary line from the moon through Jupiter to locate Mars and Saturn. It’s a long jump from the moon and Jupiter to Mars and Saturn, but you should be able to pick them out, because Mars and Saturn are bright and close together on the sky’s dome. Just don’t let the star Antares fool you. It’s about the same brightness and redness as Mars now!
Mars and Saturn are located in a rich region of the sky, above the famous Teapot of the constellation Sagittarius. If you see them in a dark sky, you’ll find the edgewise view of our Milky Way galaxy broadening and brightening in this direction, which is toward the galaxy’s center.
Planets Saturn (left) and Mars over 3 different days in March 2018, as seen by Shobhit Tiwari in Kanpur, India. He wrote: “Getting closer day by day … “
From anywhere worldwide, get up about 90 minutes (or sooner) before sunrise to view Mars and Saturn in the predawn/dawn sky. At conjunction on April 2, Mars passes a rather scant 1.3o south of Saturn. (For some perspective, 1.3o on the sky’s dome is approximately equal to the width of your little finger at an arm’s length. These two colorful celestial gems will easily fit within the same binocular field for another week or so.
Mars, the 4th planet from the sun, goes eastward in front of all the constellations of the zodiac in nearly two years, while Saturn, the 6th planet outward, takes nearly 30 years to go full circle through the zodiac. So that means Mars laps Saturn, or has a conjunction with Saturn, in periods of roughly two years.
The last conjunction of Mars and Saturn happened on August 25, 2016, and the next one will be March 31, 2020.
The moon will be edging toward Mars and Saturn over the coming week, and the pair will still be close when the moon slides by them on the morning of April 7. From North America, you have a good chance of viewing the threesome – the moon, Mars and Saturn – in a single binocular field. Circle April 7 on your calendar and think photo opportunity.
From North America, you have a good chance of viewing three worlds – the moon, Mars and Saturn – in a single binocular field on April 7.
Bottom line: Enjoy the close pairing of ruddy Mars and golden Saturn before dawn on April 2, 2018. The moon and bright Jupiter will be nearby.
Evolution is not an orderly, coherent process; evolutionary arms races can produce great innovation. Perhaps these super-black feathers with their unique microscopic structure could eventually inspire better solar panels, or new textiles; super-black butterfly wings 
