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Here's What Really Happened to Those 2 Satellites Projected to Crash in Earth Orbit – ScienceAlert

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It appears we have missed another close call between two satellites – but how close did we really come to a catastrophic event in space?

It all began with a series of tweets from LeoLabs, a company that uses radar to track satellites and debris in space. It predicted that two obsolete satellites orbiting Earth had a 1 in 100 chance of an almost direct head-on collision at 9:39am AEST on 30 January (23:39 UTC, January 29) with potentially devastating consequences.

LeoLabs estimated that the satellites could pass within 15-30 meters (50-100 feet) of one another. Neither satellite could be controlled or moved. All we could do was watch whatever unfolded above us.

Collisions in space can be disastrous and can send high-speed debris in all directions. This endangers other satellites, future launches, and especially crewed space missions.

As a point of reference, NASA often moves the International Space Station when the risk of collision is just 1 in 100,000. Last year the European Space Agency moved one of its satellites when the likelihood of collision with a SpaceX satellite was estimated at 1 in 50,000.

However, this increased to 1 in 1,000 when the US Air Force, which maintains perhaps the most comprehensive catalogue of satellites, provided more detailed information.

Following LeoLabs’ warning, other organisations such as the Aerospace Corporation began to provide similarly worrying predictions. In contrast, calculations based on publicly available data were far more optimistic. Neither the US Air Force nor NASA issued any warning.

This was notable, as the United States had a role in the launch of both satellites involved in the near-miss. The first is the Infrared Astronomical Satellite (IRAS), a large space telescope weighing around a tonne and launched in 1983.

It successfully completed its mission later that year and has floated dormant ever since.

The second satellite has a slightly more intriguing story. Known as GGSE-4, it is a formerly secret government satellite launched in 1967. It was part of a much larger project to capture radar emissions from the Soviet Union. This particular satellite also contained an experiment to explore ways to stabilise satellites using gravity.

Weighing in at 83 kilograms (182 pounds), it is much smaller than IRAS, but it has a very unusual and unfortunate shape. It has an 18 meter (60 foot) protruding arm with a weight on the end, thus making it a much larger target.

Almost 24 hours later, LeoLabs tweeted again. It downgraded the chance of a collision to 1 in 1,000, and revised the predicted passing distance between the satellites to 13-87 meters (43-285 feet). Although still closer than usual, this was a decidedly smaller risk.

But less than 15 hours after that, the company tweeted yet again, raising the probability of collision back to 1 in 100, and then to a very alarming 1 in 20 after learning about the shape of GGSE-4.

The good news is that the two satellites appear to have missed one another. Although there were a handful of eyewitness accounts of the IRAS satellite appearing to pass unharmed through the predicted point of impact, it can still take a few hours for scientists to confirm that a collision did not take place.

LeoLabs has since confirmed it has not detected any new space debris.

But why did the predictions change so dramatically and so often? What happened?

Tricky situation

The real problem is that we don’t really know precisely where these satellites are. That requires us to be extremely conservative, especially given the cost and importance of most active satellites, and the dramatic consequences of high-speed collisions.

The tracking of objects in space is often called Space Situational Awareness, and it is a very difficult task. One of the best methods is radar, which is expensive to build and operate. Visual observation with telescopes is much cheaper but comes with other complications, such as weather and lots of moving parts that can break down.

Another difficulty is that our models for predicting satellites’ orbits don’t work well in lower orbits, where drag from Earth’s atmosphere can become a factor.

There is yet another problem. Whereas it is in the best interest of commercial satellites for everyone to know exactly where they are, this is not the case for military and spy satellites. Defence organisations do not share the full list of objects they are tracking.

This potential collision involved an ancient spy satellite from 1967. It is at least one that we can see. Given the difficulty of just tracking the satellites that we know about, how will we avoid satellites that are trying their hardest not to be seen?

In fact, much research has gone into building stealth satellites that are invisible from Earth. Even commercial industry is considering making satellites that are harder to see, partly in response to astronomers’ own concerns about objects blotting out their view of the heavens.

SpaceX is considering building “dark satellites” the reflect less light into telescopes on Earth, which will only make them harder to track.

What should we do?

The solution starts with developing better ways to track satellites and space debris. Removing the junk is an important next step, but we can only do that if we know exactly where it is.

Western Sydney University is developing biology-inspired cameras that can see satellites during the day, allowing them to work when other telescopes cannot. These sensors can also see satellites when they move in front of bright objects like the Moon.

There is also no clear international space law or policy, but a strong need for one. Unfortunately, such laws will be impossible to enforce if we cannot do a better job of figuring out what is happening in orbit around our planet.

Gregory Cohen, Associate Professor, Western Sydney University.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Full buck moon with a lunar eclipse visible this weekend – BC News – Castanet.net

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British Columbians were treated to a glorious full Strawberry Moon this June, but they’ll have the opportunity to view a magnificent full Buck Moon this July in addition to a lunar eclipse. 

Named after the time of year when young bucks begin to grow new antlers from their foreheads, the July full moon marks a time of renewal. The full Buck Moon will be at its fullest on July 4.

As the full moon increases in fullness, British Columbians will also be able to view a “penumbral lunar eclipse.” Timeanddate.com explains is set to begin July 4 at 8:07 p.m. but that it won’t be directly visible at that time.

At 9:22 p.m., “it will be rising but the the combination of a very low moon and the total eclipse phase will make the moon so dim that it will be extremely difficult to view until moon gets higher in the sky or the total phase ends.” 

The moon will be closest to the centre of shadow at 9:29 p.m. (-0.644 Magnitude). It will end at 10:52 p.m.

During this penumbral lunar eclipse, the Earth’s main shadow does not cover the Moon. 

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How to watch the Fourth of July weekend's "buck moon" lunar eclipse – CBS News

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Fourth of July celebrations look a little bit different this year due to the coronavirus pandemic, but skywatchers are still in for a special Independence Day treat. The weekend brings not only a full moon, but also a lunar eclipse.  

The “buck moon” lunar eclipse will be visible the night of July 4 into the morning of July 5. Viewers across most of North and South America, as well as parts of southwestern Europe and Africa, will be able to spot the celestial phenomenon. 

The event will be a penumbral eclipse, not a total lunar eclipse, meaning part of the moon will pass through the outer part of Earth’s shadow. 

According to The Old Farmer’s Almanac, July’s full moon is called the “buck moon,” because early summer is when male deer grow new antlers. It’s also called the thunder moon — because of summer storms that occur in July — the guru moon and the hay moon. 

The Full Moon Rises in New York City on the 50th Anniversary of the Launch of Apollo 11
On the 50th anniversary of the launch of Apollo 11, the full buck moon rises above the skyline of lower Manhattan and One World Trade Center in New York City on July 16, 2019 as seen from Kearney, New Jersey.

Gary Hershorn / Getty Images


According to NASA, the full moon will peak early Sunday morning, at 12:30 a.m. EDT. At that time, about 35% of the moon will be in the partial shadow. 

The full moon peaks just a few minutes later, appearing opposite the sun at 12:44 a.m. EDT. However, it will appear full all weekend, from Friday evening into Monday morning. 

Clear skies will reveal the moon in all its glory, but moon gazers may need the help of a telescope or binoculars for the full effect. It’s also possible the events could be overshadowed by Fourth of July fireworks across the U.S. — despite warnings from officials. 

Not only does the Fourth of July weekend mark a full moon and lunar eclipse, it also highlights the closest grouping of Saturn, Jupiter and the moon, forming a triangle of celestial celebration. 


Full Moon: July Full Buck Moon by
Old Farmer’s Almanac on
YouTube

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Industry, mild winters clear way for white-tailed deer 'invasion' in Alberta's boreal forest – CBC.ca

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Herds of invasive white-tailed deer continue to migrate north in Alberta’s boreal forest — bolstered by milder winters and human development that cuts through the vast wilderness, a new study suggests. 

The survey, recently published in the journal Nature, used 62 trail cameras to track the movements of white-tailed deer near Fort McMurray, Alta., over three years.

It’s a “deer invasion,” said Jason Fisher, study author and wildlife ecologist at the University of Victoria.

“They’re all over the landscape,” Fisher said. “They’re expanding their range. And because they’re having these negative effects on the ecosystem, they could definitely be considered invasive.” 

The cameras captured more than 141,000 images, and white-tailed deer appeared in 80 per cent of them. The survey makes clear that deer are now, by far, the most prevalent large mammal in the habitat, Fisher said.

“We’re kind of feeling around in the dark. But them being there in the numbers they currently are is definitely new, it’s definitely increased, and it’s gotten a lot worse over the last decade.” 

‘Deer don’t really belong in that landscape’

Deer are not native to the boreal forest and their populations are thriving, often at the expense of other species, including fragile populations of woodland caribou, Fisher said. 

The deer create imbalances in the natural food chain. The herds compete with other animals, devouring the boreal forest’s limited grazing lands. Their presence also draws more predators such as wolves to the area.

It’s like a caribou, white-tailed deer teeter-totter with wolves as the fulcrum.– Jason Fisher

“The deer don’t really belong in that landscape,” Fisher said. “They’re not evolved to move quickly over snow the way that caribou are, and so they’re easy targets for wolves. 

“With all these white-tailed deer around, that’s pushing wolf numbers up. With more wolves around, they’re hitting caribou harder.

“It’s like a caribou, white-tailed deer teeter-totter with wolves as the fulcrum. And that’s the big problem.” 

Higher numbers of white-tailed deer are attracting wolves to the area, putting increased pressure on fragile populations of woodland caribou. (Supplied by Jason Fisher)

Historically confined to the Eastern Seaboard, deer have been expanding their territory across the continent since European colonization. First they followed farmers, occupying open areas created when land was cleared of trees.

In their move north, they followed humans again, taking advantage of open grazing areas created by seismic lines and other industrial developments that cut through the thick bush.

“As agriculture swept across North America, white-tailed deer have come with it,” Fisher said. “The increase we’re seeing here in Alberta now is basically the continuation of that process. Alberta has had deer in the south ever since we’ve had agriculture. But the move north is a pretty recent phenomenon.” 

Local populations of deer have been able to rebound after even the harshest winters. (Supplied by Jason Fisher)

The study area — 3,000 square kilometres of white and black spruce, aspen, Jack pine and muskeg — is marked by extensive oil and gas development, logging roads, off-road trails and seismic lines. Deer have only been in the area for a couple of decades, Fisher said. 

Aerial surveys done by the province provide some information on local populations, Fisher said, but his team wanted to better understand the animals in relation to the weather and the landscape. 

According to the thousands of images captured by their cameras, deer were most numerous in areas touched by human development, he said. 

During the three-year study, the severity of winter fluctuated. Populations would soar after a mild winter, but even after a “biblical” second winter, herd numbers appeared relatively untouched, he said. 

‘This isn’t fully a climate-change problem’

Climate change and landscape change are working in tandem to drive the deer invasion, Fisher said. But the loss of mature forest to oil and gas development in the area is the biggest driver, he said.

The altered landscape has given the animals access to new foraging grounds, allowing them to withstand harsh seasons when they might normally starve, Fisher said. 

In an ongoing follow-up study he is overseeing in the Richardson Backcountry, an untouched swath of wilderness north of Fort McMurray, deer numbers are sparse. 

With milder winters expected and more development encroaching into the boreal habitat every year, white-tailed deer territory will only continue to grow, Fisher said.

“This isn’t fully a climate-change problem,” he said. “As long as there is ongoing disturbance in the landscape without restoration, then the white-tailed deer are going to be there.” 

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