Science
Astronomers look to preserve the night sky as thousands of satellites set to launch
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The potential launch of tens of thousands of satellites is a serious threat to astronomy, according to the International Astronomical Union (IAU). Now, it’s trying to find solutions.
The announcement came just days before SpaceX launched an additional 60 of its Starlink satellites.
Such “constellations” — any collection of artificial satellites — are already in wide use, powering the GPS in our cars and cellphones, for instance. But it’s the massive number yet to come that has astronomers around the world deeply concerned.
“We are used to some satellites crossing the night sky, but now we’re talking about thousands, some that would be bright enough to see with the human eye,” said Piero Benvenuti, an adviser at the executive committee of the IAU, which has more than 13,000 members worldwide.
In all, SpaceX plans to launch as many as 42,000 satellites, and it’s not the only one. Amazon plans to launch roughly 3,200 satellites, and OneWeb’s 650 satellites. Canada also plans to launch 300 Telesat satellites.
The goal of Starlink is to bring internet connectivity to every part of the world, a goal similar to OneWeb’s.
And while astronomers agree that goal is a practical one, they are concerned over not only the loss of the night sky, which is already under threat due to light pollution, but also to large-scale and very expensive observatories, like the $1 billion US, 8.4-metre, ground-based Large Synoptic Survey Telescope.
There are more and more of these all-sky surveys being put into place. Instead of looking at a small patch of sky, they scan large swaths. But moving satellites create long streaks of light in the images collected.
“Apart from their naked-eye visibility, it is estimated that the trails of the constellation satellites will be bright enough to saturate modern detectors on large telescopes,” the IAU statement said. “Wide-field scientific astronomical observations will therefore be severely affected.”
‘Pristine’ night sky
Reports of the visibility of a “train” of Starlink satellites began last May, shortly after the first batch of 60 were launched. Astronomers, both professional and amateur, posted videos and photos of the long streak of satellites dotting the night sky.
Then, in December, more satellites were launched.
We hate you, <a href=”https://twitter.com/hashtag/Starlink?src=hash&ref_src=twsrc%5Etfw”>#Starlink</a> <a href=”https://twitter.com/hashtag/Starlinked?src=hash&ref_src=twsrc%5Etfw”>#Starlinked</a> <a href=”https://t.co/S97N7fyELC”>pic.twitter.com/S97N7fyELC</a>
—@SuperASASSN
But while the threat may be most felt by professionals, the IAU statement noted, “The appearance of the pristine night sky, particularly when observed from dark sites, will nevertheless be altered, because the new satellites could be significantly brighter than existing orbiting man-made objects.”
As a result, the IAU, as well as other organizations like the American Astronomical Society, sought out professional astronomers to run simulations showing what would happen with tens of thousands of satellites in orbit around Earth. The hope was to not only better understand the consequences but also head toward some solutions.
Preliminary findings
They found that, using an example of 25,000 satellites in low-Earth orbit — which ranges from 160 to 2,000 kilometres above Earth and with orbits between 84 and 127 minutes — at any given point, satellites above the horizon could number from 1,500 to a few thousand.
Some other notable findings:
- While most would lie near the horizon, roughly 250 to 300 of those would appear in a part of the sky where most of astronomical observations are conducted (roughly 30 degrees above the horizon).
- When the night sky is darkest, there could be 1,000 satellites visible at once, until they enter Earth’s shadow and become less visible.
- The trains of satellites are most visible shortly after initial launch.
- While the IAU’s focus is on optical telescopes, radio telescopes are also in jeopardy.
Benvenuti is keen for more research in order to better understand what the effects of tens of thousands of satellites could be. Right now, he said, astronomers are working with SpaceX in an effort to reduce their reflectivity — called albedo — and trying to work with other companies as well.
Agreed, sent a note to Starlink team last week specifically regarding albedo reduction. We’ll get a better sense of value of this when satellites have raised orbits & arrays are tracking to sun.
—@elonmusk
Connie Walker, an astronomer and president of the Commission B7, which is involved in the IAU constellation analysis, said the idea is to find a solution suitable for everyone.
“It’s going to be a long process, and I think to some extent, the various companies producing these satellite constellations are willing to try to come up with some solutions,” she said. Some of the ideas being examined, she said, are changes to the coatings of the satellites and changes to software to help observatories avoid, or compensate for, albedo.
But, she said, there is unlikely to be one quick-fix that will check off all the boxes.
Moving forward
The launch of satellite constellations and their consequences have largely taken the astronomical community by surprise. One of the problems is that there is no regulation surrounding the albedo of an object in orbit.
But that might change.
The IAU plans to bring the issue to the UN Committee on the Peaceful Uses of Outer Space (COPUOS) in the coming months. They also plan to include the issue of constellations and their threat to science in the program of the Conference on Dark and Quiet Skies for Science and Society, held by the IAU, the United Nations Office for Outer Space Affairs and the Government of Spain in October.
“We don’t want to stop the progress of having this G5 interconnectivity,” Benvenuti said. “But one has to consider the implications that you’re creating on the environment, and in particular the night sky.”
And, he added, “We don’t want to cry wolf and say it’s a disaster and you can’t do astronomy anymore.”
But astronomy is more than just looking up at the night sky, admiring the stars or photographing them. It’s about advancing knowledge and even technologies.
“The progress that we’ve made in the last 100 years … It’s absolutely astonishing how much we’ve learned because of astronomical observations,” he said. “When you use your GPS, you apply Einstein’s relativity, otherwise you wouldn’t know where you are. People tend to forget about this.”
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SASKATOON – Saskatchewan engineering students will have their eyes on the sky as the province’s first homegrown satellite is to be launched on board a SpaceX rocket headed for the International Space Station.
“I am so excited about it,” said Rylee Moody, a third-year student at the University of Saskatchewan.
“It’s something I would never have dreamed of doing.”
Engineering students at the University of Saskatchewan spent five years developing the cube satellite called RADSAT-SK. It is set to be launched into space Saturday.
RADSAT-SK will be sent into its own orbit for a year, where it will collect radiation data that will be analyzed at a ground station located near the university’s campus.
The project was part of a Canadian Space Agency project that saw 15 universities get grants to build CubeSats — cubical, standard-sized miniature satellites that generally weigh about a kilogram.
Sean Maw, a principal investigator and chair in innovative teaching at the College of Engineering, said Saskatchewan’s project began in 2018 with about 20 engineering undergraduate students. Since then, hundreds of students have put in tens of thousands of hours to ensure ideas became reality.
It was no easy task to get from a satellite concocted in a Saskatchewan university to infinity and beyond. Students designed, built, tested and integrated the satellite.
They also navigated the complicated international regulatory environment to get it approved for launch. A global pandemic certainly didn’t make it easier, Maw added.
“Students persevered through the whole COVID crisis to get this project done,” Maw said. “Especially in the last 12 months or so they fought tooth and nail to get RADSAT-SK to the finish line.”
The team came up with a motto to get through the tough times: fail hard, fail fast, recover.
The satellite’s payload, what it carries as it orbits earth, is focused on radiation research. A Saskatchewan-made dosimeter board will measure radiation from space and a fungal melanin coating on board will test the feasibility of the polymer to shield space radiation.
Arliss Sidlowksi, a fourth-year student, said it has been an incredible and challenging experience getting the satellite ready for orbit.
“I am so proud of our team for their resilience,” she said.
“We experienced numerous challenges over the years. Our members viewed each setback as an opportunity to learn, adapt and proving time and time again their perseverance and intelligence.”
Sidlowksi said she hopes it will inspire other students to see themselves working in the space industry while also showing the rest of the country what Saskatchewan has to offer.
“I think it’s really opening up Saskatchewan to the space sector.”
It’s very important students have the support to dream for the stars, Maw added. Decades ago when he was getting his undergraduate degree at the University of Waterloo he brought a group of students together to build a satellite.
The project wasn’t supported. And the satellite never got off ground.
“I wasn’t going to let that happen to these guys,” Maw said.
“Their efforts were truly remarkable.”
This report by The Canadian Press was first published May 29, 2023.
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A flat, rounded shell. A tail that’s folded under the body. This is what a crab looks like, and apparently what peak performance might look like — at least according to evolution. A crab-like body plan has evolved at least five separate times among decapod crustaceans, a group that includes crabs, lobsters and shrimp. In fact, it’s happened so often that there’s a name for it: carcinization.
So why do animals keep evolving into crab-like forms? Scientists don’t know for sure, but they have lots of ideas.
Carcinization is an example of a phenomenon called convergent evolution, which is when different groups independently evolve the same traits. It’s the same reason both bats and birds have wings. But intriguingly, the crab-like body plan has emerged many times among very closely related animals.
The fact that it’s happening at such a fine scale “means that evolution is flexible and dynamic,” Javier Luque, a senior research associate in the Department of Zoology at the University of Cambridge, told Live Science.
Related: Does evolution ever go backward?
Crustaceans have repeatedly gone from having a cylindrical body plan with a big tail — characteristic of a shrimp or a lobster — to a flatter, rounder, crabbier look, with a much less prominent tail. The result is that many crustaceans that resemble crabs, like the tasty king crab that’s coveted as a seafood delicacy, aren’t even technically “true crabs.” They’ve adopted a crab-like body plan, but actually belong to a closely related group of crustaceans called “false crabs.”
When a trait appears in an animal and sticks around through generations, it’s a sign that the trait is advantageous for the species — that’s the basic principle of natural selection. Animals with crabby forms come in many sizes and thrive in a wide array of habitats, from mountains to the deep sea. Their diversity makes it tricky to pin down a single common benefit for their body plan, said Joanna Wolfe, a research associate in organismic and evolutionary biology at Harvard University.
Wolfe and colleagues laid out a few possibilities in a 2021 paper in the journal BioEssays. For example, crabs’ tucked-in tail, versus the lobster’s much more prominent one, could reduce the amount of vulnerable flesh that’s accessible to predators. And the flat, rounded shell could help a crab scuttle sideways more effectively than a cylindrical lobster body would allow.
But more research is needed to test those hypotheses, Wolfe said. She is also trying to use genetic data to better understand the relationships among different decapod crustaceans, to more accurately pinpoint when various “crabby” lineages evolved, and pick apart the factors driving carcinization.
There’s another possible explanation: “It’s possible that having a crab body isn’t necessarily advantageous, and maybe it’s a consequence of something else in the organism,” Wolfe said. For example, the crab body plan might be so successful not because of the shell or tail shape itself, but because of the possibilities that this shape opens up for other parts of the body, said Luque, who is a co-author of the 2021 paper with Wolfe.
For example, a lobster’s giant tail can propel the animal through the water and help it crush prey. But it can also get in the way and constrain other features, Luque said. The crab body shape might leave more flexibility for animals to evolve specialized roles for their legs beyond walking, allowing crabs to easily adapt to new habitats. Some crabs have adapted their legs for digging under sediment or paddling through water.
“We think that the crab body plan has evolved so many times independently because of the versatility that the animals have,” Luque said. “That allows them to go places that no other crustaceans have been able to go.”
The crab-like body plan also has been lost multiple times over evolutionary time — a process known as decarcinization.
“Crabs are flexible and versatile,” Luque explained. “They can do a lot of things back and forth.”
Wolfe thinks of crabs and other crustaceans like Lego creations: They have many different components that can be swapped out without dramatically changing other features. So it’s relatively straightforward for a cylindrical body to flatten out, or vice versa. But for better or worse, humans won’t be turning into crabs anytime soon. “Our body isn’t modular like that,” Wolfe said. “[Crustaceans] already have the right building blocks.”
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Ibadan, 29 May 2023. – Rocket Lab USA, Inc. has successfully completed the second of two dedicated Electron launches to deploy a constellation of tropical cyclone monitoring satellites for NASA. The “Coming To A Storm Near You” launch lifted off on May 26 at 15:46 NZST (03:46 UTC) from Rocket Lab Launch Complex 1 on New Zealand’s Mahia Peninsula, deploying the final two CubeSats of NASA’s TROPICS constellation to orbit.
“Coming To A Storm Near You” is Rocket Lab’s second of two TROPICS launches for NASA, following the first launch on May 8th NZST. Like the previous launch, “Coming To A Storm Near You” deployed a pair of shoebox-sized satellites to low Earth orbit to collect tropical storm data more frequently than other weather satellites. The constellation aims to help increase understanding of deadly storms and improve tropical cyclone forecasts.
Rocket Lab has now launched all four satellites across two dedicated launches within 18 days, enabling the TROPICS satellites to settle into their orbits and begin commissioning ahead of the 2023 North American storm season, which begins in June.
“Electron was for exactly these kinds of missions – to deploy spacecraft reliably and on rapid timelines to precise and bespoke orbits, so we’re proud to have delivered that for NASA across both TROPICS launches and meet the deadline for getting TROPICS to orbit in time for the 2023 storm season,” said Rocket Lab founder and CEO Peter Beck. “Thank you to the team at NASA for entrusting us with such an important science mission, we’re grateful to be your mission launch providers once again.”
‘Coming To A Storm Near You’ was Rocket Lab’s fifth mission for 2023 and the Company’s 37th Electron mission overall. It brings the total number of satellites launched into orbit by Rocket Lab to 163.
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