adplus-dvertising
Connect with us

Science

Two Satellites Could Smash Into Each Other Over the U.S. Tonight – Gizmodo

Published

 on


Artist’s conception of the decommissioned IRAS satellite.
Image: NASA

A pair of decommissioned satellites are at risk of colliding later today, potentially producing hundreds if not thousands of new pieces of space debris. Regardless of what happens, however, this incident illustrates our dire need for sensible space management practices.

Normally, operators on the ground can adjust the orbital inclination of their satellites in the event of a potential collision, but neither of these satellites is functional. One of the two, the joint NASA-Netherlands Infrared Astronomical Satellite (IRAS), weighs around 1,073 kilograms (2,366 pounds) and has been in space since 1983. The other, GGSE-4 (also known as Poppy 5B), was launched in the late 1960s by the U.S. Naval Research Laboratory and weighs 83 kg (183 lbs).

300x250x1
Advertisement

At a relative velocity of 14.7 kilometers (9.1 miles) per second, a collision between these two satellites would generate a tremendous amount of space debris, increasing the odds of yet another collision at some point in the future. The decommissioned satellites will experience their closest approach at 6:39 p.m. ET Wednesday (January 29, 2020) in the skies above eastern North America—but don’t worry, the debris would stay in low Earth orbit (LEO).

The potential collision was detected by LeoLabs, a private company that tracks satellites and debris in low Earth orbit. The company operates three radar stations, two in the U.S. and one in New Zealand, and it can track objects as small as 10 centimeters (3.9 inches) in diameter.

Advertisement

In a recent update, LeoLabs tweeted their latest assessment of the situation. The odds of a collision are back to 1 in 100, after the company had briefly assigned a 1 in 1,000 chance earlier today. The satellites will swing past each other at a distance of around 12 meters (39.5 feet)—an extremely close shave by any measure. The closest approach will happen at an altitude of 900 kilometers (560 miles) above Earth’s surface.

An even more alarming calculation from LeoLabs takes into account the 18-meter-long (59-foot) booms attached to GGSE-4. With those taken into consideration, the odds of a collision jump to 1 in 20, according to LeoLabs.

Advertisement

Conceptual image of an earlier model, the Poppy 4D, with its long booms extended.
Image: NRO/USN

These odds may seem (relatively) low, but satellite operators ring the alarm bells when the odds approach 1 in 10,000. So while the chance of a collision seems slim, this is a matter of serious concern. In an email to Gizmodo, McDowell said two satellites coming this close together “is still rare” but is becoming “more frequent as LEO gets more crowded.”

Advertisement

The current situation with IRAS and GGSE-4 stems from their immobile status, but McDowell said this problem will eventually extend to live satellites. Operators will have to move an increasing number of satellites to avoid collisions, which could potentially put them in the paths of other satellites “depending on the accuracy of predictions,” he said, adding that another issue will be the ability to perform one-day-ahead satellite predictions. Ideally, he hopes that satellite operators will eventually work at 10-meter (33-foot) resolutions, instead of the current 100-meter (328foot) level of accuracy. That “would help,” said McDowell, “but we don’t know how to get there.”

“There have always been close calls in space—not to mention accidental collisions—but we are certainly becoming more aware of them as our ability to identify and monitor objects in space through space situational awareness improves,” Jessica West, a program officer at Project Ploughshares and the managing editor of its Space Security Index, wrote in an email to Gizmodo. “For active satellites, this means that there is more opportunity to maneuver to avoid a close call. But for dead satellites, we are still stuck waiting and watching with our fingers crossed.”

Advertisement

Chart showing unintentional collisions between space objects.
Image: Space Security Index/Jessica West

That LEO is becoming overcrowded is no secret. Figures from the U.S. Space Surveillance network shows that roughly 29,000 objects larger than 10 centimeters (3.9 inches) are currently in LEO, many of which are zipping around at speeds reaching 10 kilometers (6 miles) per second. This figure is set to increase due to the lower costs of launching objects into space and the trend toward more compact satellites. The rise of megaconstellations, such as SpaceX’s Starlink, will result in thousands more satellites.

Advertisement

Sure, LEO seems vast, but the amount of space in space is somewhat of an illusion. Space and time shrink owing to the tremendous speeds involved. Space traffic is not like it is on Earth’s surface, where velocities are measured in terms of distance per hour rather than per second. Satellite motions in space are akin to watching movies in fast-forward.

McDowell described it as an n-squared problem. A 10-fold increase in the number of satellites results in a 100-fold increase in the number of close misses and actual collisions, he said, “adding that “we’re about due for one.”

Advertisement

Even one collision would be bad. If IRAS and GGSE-4 smash into each other tonight, the resulting kinetic energy would blow debris into neighboring orbits, further heightening the odds of another collision. This could result in a hypothetical cascade known as a Kessler Syndrome, in which an ever-growing cloud of space debris eventually makes LEO inaccessible.

In terms of technical solutions to the problem, West says we could reduce the amount of defunct satellites in orbit by “designing them with the ability and intention to de-orbit at the end of their service lifespan.” Satellites in LEO, namely those below 600 kilometers (370 miles), will “naturally be dragged down into Earth’s atmosphere and disintegrate within 25 years,” West told Gizmodo, but “25 years is a long time—too long given the intensity to which we are using this orbit and the tens of thousands of new satellites potentially being launched.”

Advertisement

That said, IRAS and GGSE-4 are much higher, around 800 kilometers (500 miles), an altitude in which objects “will remain in orbit for decades unless intentionally de-orbited, which is not the norm,” said West.

Several initiatives are currently underway to devise ways of decluttering LEO, but these solutions come with their own drawbacks, including tremendous costs and numerous safety considerations. Ultimately, West says this latest incident “points to the need for better, global governance of activities in outer space.”

Advertisement

Let’s block ads! (Why?)

728x90x4

Source link

Continue Reading

Science

New AI algorithm helps find 8 radio signals from space

Published

 on

A new artificial intelligence algorithm created by a Toronto student is helping researchers search the stars for signs of life.

Peter Xiangyuan Ma, a University of Toronto undergraduate student and researcher, said he started working on the algorithm while he was in Grade 12 during the pandemic.

“I was just looking for projects and I was interested in astronomy,” he told CTV News Toronto.

The idea was to help distinguish between technological radio signals created by human technologies and signals that were potentially coming from other forms of life in space.

300x250x1

“What we’re looking for is signs of technology that signifies if the sender is intelligent or not. And so unsurprised to us, we keep on finding ourselves,” Ma explained. “We don’t want to be looking at our own noisy signals.”

Using this algorithm, Ma said researchers were able to discover eight new radio signals being emitted from five different stars about 30 to 90 light years away from the Earth.

These signals, Ma said, would disappear when researchers looked away from it, which rules out, for the most part, interference from a signal originating from Earth. When they returned to the area, the signal was still there.

“We’re all very suspicious and scratching our heads,” he said. “We proved that we found things that we wanted to find … now, what do we do with all these? That’s another separate issue.”

Steve Croft, Project Scientist for Breakthrough Listen on the Green Bank Telescope, the institute whose open source data was the inspiration for Ma’s algorithm, said that finding radio signals in space is like trying to find a needle in a haystack.

“You’ve got to recognize the haystack itself and make sure that you don’t throw the needle away as you’re looking at the individual pieces of hay,” Croft, who collaborated on Ma’s research, told CTV News Toronto.

Croft said algorithms being used to discover these signals have to account for multiple characteristics, including the position they are coming from in the sky and whether or not the transmission changes over time, which could indicate if it’s coming from a rotating planet or star.

“The algorithm that Peter developed has enabled us to do this more efficiently,” he said.

The challenge, Croft says, is recognizing that false positives may exist despite a signal meeting this criteria. What could be signs of extraterrestrial life may also just be a “weirdly shaped bit of a haystack,” he added.

“And so that’s why we have to go back and look again and see if the signal still there. And with these particular examples that Peter found with his algorithm, the signal was not there when we pointed the telescope back again. And so we sort of can’t say one way or another, is this genuine?”

Researchers have been searching the sky for technologically-generated signals since the 1960s, searching thousands of stars and galaxies for signs of intelligent life. The process is called “SETI,” or “the Search for Extraterrestrial Intelligence.”

But interference from our own radio signals has always proven to be a challenge. Croft says most pieces of technology have some kind of Bluetooth or wireless wave element that creates static, resulting in larger amounts of data needed to be collected.

“That’s a challenge but also computing provides the solution,” he said.

“So the computing and particularly the machine-learning algorithms gives us the power to search through this big haystack, looking for the needle of an interesting signal.”

Ma said that while we may not have found a “technosignal” just yet, we shouldn’t give up. The next step would be to employ multiple kinds of search algorithms to find more and more signals to study.

Peter Ma

While the “dream” is to find evidence of life, Ma says he is more focused on the scientific efforts of actively looking for it.

This sentiment is echoed by Croft, who said he is most fascinating in working towards answering the question of whether humans are alone in this universe.

“I don’t show up to work every day, thinking I’m going to find aliens, but I do show up for work. So you know, I’ve got sort of some optimism.”

728x90x4

Source link

Continue Reading

Science

How to spot the green comet in Manitoba

Published

 on

Space enthusiasts in the province will get the chance to potentially see a rare green comet over the next couple of days.

The comet was discovered by astronomers in southern California last year and it was determined the last time it passed Earth was around 50,000 years ago.

Mike Jensen, the planetarium and science gallery program supervisor at the Manitoba Museum, said the time between appearances and the colour of the comet makes this unique compared to others.

“The last time it would have appeared anywhere within the region of visibility to Earth, we’re talking primitive humans walking the Earth,” said Jensen. “And then yes, its colour. Most people associate comets, they’re often referred to as ghosts of the night sky because they often have a bit of a whitish-blue appearance. This one’s got a bit of green to it. Comets are all made up of different types of material, this just happens to have a bit more of some carbon elements in it.”

300x250x1

Jensen notes the green tint on the comet will be subtle, comparing it to the subtle red that surrounds Mars in the night sky.

Wednesday and Thursday are the best days to see the comet as Jensen said that’s when it will be closest to Earth – 42 million kilometres away.

“That proximity to us means it does get to its best visibility for us. The added advantage is it’s also appearing sort of high up in the northern sky, which puts it amongst the circumpolar stars of our night sky. In other words, the stars that are circling around the North Star.”

Now, just because the comet is close enough to be visible doesn’t mean it will be the easiest to see in the night sky according to Jensen. He said there are a few factors that play into having a successful sighting.

First, he suggests getting out of the city and away from the lights, noting, the darker it is, the better. If people head outside city limits, Jensen recommends people dress warmly, saying comet watching in the winter is not for the “faint of heart.”

Secondly, he said even though it might be possible to see the comet with the naked eye, he still suggests bringing binoculars to improve people’s chances. He also recommends checking star maps before leaving to get the most accurate location of where the comet may be.

Lastly, even if all of that is achieved, Jensen notes people will have to battle with the light of the moon, as it is close to a full moon.

“I’m not trying to dissuade anybody from going out to see it, but certainly, there’s going to be some hurdles to overcome in order to be able to spot it on your own.”

If people don’t want to go outside to see it, he said there are plenty of resources online to find digital views.

 – With files from CTV News’ Michael Lee

728x90x4

Source link

Continue Reading

Science

Is there life on Mars? Maybe, and it could have dropped its teddy

Published

 on

Larger than the average bear: there’s a 2-kilometer-wide bear’s face on the surface of Mars, space scientists say.

Yogi, Paddington and Winnie the Pooh, move over. There’s a new bear in town. Or on Mars, anyway.

The beaming face of a cute-looking teddy bear appears to have been carved into the surface of our nearest planetary neighbor, waiting for a passing satellite to discover it.

And when the Mars Reconnaissance Orbiter passed over last month, carrying aboard the most powerful camera ever to venture into the Solar System, that’s exactly what happened.

Scientists operating the HiRISE (High Resolution Imaging Science Experiment), which has been circling Mars since 2006, crunched the data that made it back to Earth, and have now published a picture of the face.

300x250x1

“There’s a hill with a V-shaped collapse structure (the nose), two craters (the eyes), and a circular fracture pattern (the head),” said scientists at the University of Arizona, which operates the kit.

Each one of the features in the 2,000-meter (1.25-mile)-wide face has a possible explanation that hints at just how active the surface of the planet is.

“The circular fracture pattern might be due to the settling of a deposit over a buried impact crater,” the scientists said.

“Maybe the nose is a volcanic or mud vent and the deposit could be lava or mud flows?”

HiRISE, one of six instruments aboard the Orbiter, snaps super-detailed pictures of the Red Planet helping to map the surface for possible future missions, either by humans or robots.

Over the last ten years the team has managed to capture images of avalanches as they happened, and discovered dark flows that could be some kind of liquid.

They’ve also found twirling across the Martian surface, as well as a feature that some people thought looked a lot like Star Trek’s Starfleet logo.

One thing they have not found, however, is the little green men who were once popularly believed to inhabit the planet.

© 2023 AFP

Citation:
Is there life on Mars? Maybe, and it could have dropped its teddy (2023, January 31)
retrieved 31 January 2023
from https://phys.org/news/2023-01-life-mars-teddy.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.

728x90x4

Source link

Continue Reading

Trending