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'This is uncomfortably close': 2 defunct satellites orbiting Earth at risk of colliding – CBC.ca

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Two defunct satellites orbiting Earth are at risk of colliding on Wednesday, according to private satellite-tracking company LeoLabs, though they may just simply pass dangerously close to each other.

Should the pair collide, they could potentially create hundreds of pieces of space debris that would threaten other satellites in a similar orbit.

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The first satellite, the Infrared Astronomical Satellite (IRAS), a joint venture between NASA and the Netherlands Agency for Aerospace Programmes, was launched in 1983 and is roughly 954 kilograms. The second, smaller GGSE-4 (also known as POPPY 5B) was launched by the U.S. Naval Research Laboratory in 1967 and weighs about 85 kilograms. 

Both are now inoperative.

Alan DeClerck, vice-president of business development and strategy for LeoLabs, told CBC News the satellites could miss one another by roughly 15 to 30 metres and that there is a 1 in 100 chance of a collision at a breakneck speed of 14.7 km/s. It would occur 900 kilometres above Pittsburgh at 6:59 p.m. ET.

“In terms of normal operations satellites, one in 10,000 is considered something that you want to take a very close look at. One in 1,000 is considered an emergency,” said DeClerck​​​​​​​. “One in 100 is something that any operator would certainly want to do manoeuvre around.” 

LeoLabs is a private company with radar in Alaska, Texas and New Zealand capable of tracking satellites and space debris roughly 10 centimetres in diameter. It has plans to track debris as small as about two centimetres in diameter.

In an email statement from a NASA spokesperson to CBC News, the U.S. air force’s Combined Space Operations Center, which is responsible for tracking satellites, has yet to inform the space agency of any pending collision.

However, DeClerck​​​​​​​, said the air force doesn’t track satellite debris, which is what the two defunct satellites would be considered.

And according to Jonathan McDowell, an astronomer at Harvard-Smithsonian Center for Astrophysics, who has been closely monitoring the situation, that might be because there are some uncertainties and that not all models will produce the same result.

“The uncertainty on the miss distance is greater than the miss distance,” McDowell said. “We’re in an era now where there are several independent companies as well as the Air Force that track satellites, and their solutions often don’t quite agree at the kilometre level.”

Using what McDowell said is the less reliable public data supplied by the Air Force on satellite orbits, he made his own calculations and got a miss distance of one-and-a-half kilometres, plus-or-minus two kilometres. 

“The best thing to say is that this is uncomfortably close,” he said. “It’s more likely there not to be a collision than there will be, but at the same time, a collision wouldn’t be astonishing. So we’ve got to watch it very closely and see if we see any debris afterwards or change in the satellites’ orbits.”

McDowell said there’s one other thing to take into account.

GGSE-4 has 18-metre-long protruding booms, which he doesn’t think are factored into the calculations. Even if those booms do strike the larger IRAS, it’s unclear what that would even do.

DeClerck said LeoLabs will continue to monitor the orbits in the coming hours of the time of closest approach (TCA), and there could be revisions to the orbits. And after the TCA, they will likely know within hours what actually occurred.

If the satellites do collide and produce debris, it won’t be a major addition to the 18,000 pieces of debris currently being tracked, McDowell said, but it could generate about 1,000 more. 

But what it does is up the chance of further collisions for satellites in the popular type of orbit called sun-synchronous.

If you’re concerned about pieces falling out of the sky, you needn’t worry: the threat is only to satellites. 

“It’s not a things-falling-out-of-the-sky-on-our-heads situation,” McDowell said. “It’s just an increase-in-the-amount-of-ambient-space-debris-in-a-particularly-valuable-orbit kind of thing.”

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Marine plankton could act as alert in mass extinction event: UVic researcher – Langley Advance Times

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A University of Victoria micropaleontologist found that marine plankton may act as an early alert system before a mass extinction occurs.

With help from collaborators at the University of Bristol and Harvard, Andy Fraass’ newest paper in the Nature journal shows that after an analysis of fossil records showed that plankton community structures change before a mass extinction event.

“One of the major findings of the paper was how communities respond to climate events in the past depends on the previous climate,” Fraass said in a news release. “That means that we need to spend a lot more effort understanding recent communities, prior to industrialization. We need to work out what community structure looked like before human-caused climate change, and what has happened since, to do a better job at predicting what will happen in the future.”

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According to the release, the fossil record is the most complete and extensive archive of biological changes available to science and by applying advanced computational analyses to the archive, researchers were able to detail the global community structure of the oceans dating back millions of years.

A key finding of the study was that during the “early eocene climatic optimum,” a geological era with sustained high global temperatures equivalent to today’s worst case global warming scenarios, marine plankton communities moved to higher latitudes and only the most specialized plankton remained near the equator, suggesting that the tropical temperatures prevented higher amounts of biodiversity.

“Considering that three billion people live in the tropics, the lack of biodiversity at higher temperatures is not great news,” paper co-leader Adam Woodhouse said in the release.

Next, the team plans to apply similar research methods to other marine plankton groups.

Read More: Global study, UVic researcher analyze how mammals responded during pandemic

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Scientists Say They Have Found New Evidence Of An Unknown Planet… – 2oceansvibe News

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In the new work, scientists looked at a set of trans-Neptunian objects, or TNOs, which is the technical term for those objects that sit out at the edge of the solar system, beyond Neptune

The new work looked at those objects that have their movement made unstable because they interact with the orbit of Neptune. That instability meant they were harder to understand, so typically astronomers looking at a possible Planet Nine have avoided using them in their analysis.

Researchers instead looked towards those objects and tried to understand their movements. And, Dr Bogytin claimed, the best explanation is that they result from another, undiscovered planet.

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The team carried out a host of simulations to understand how those objects’ orbits were affected by a variety of things, including the giant planets around them such as Neptune, the “Galactic tide” that comes from the Milky Way, and passing stars.

The best explanation was from the model that included Planet 9, however, Dr Bogytin said. They noted that there were other explanations for the behaviour of those objects – including the suggestion that other planets once influenced their orbit, but have since been removed – but claim that the theory of Planet 9 remains the best explanation.

A better understanding of the existence or not of Planet 9 will come when the Vera C Rubin Observatory is turned on, the authors note. The observatory is currently being built in Chile, and when it is turned on it will be able to scan the sky to understand the behaviour of those distant objects.

Planet Nine is theorised to have a mass about 10 times that of Earth and orbit about 20 times farther from the Sun on average than Neptune. It may take between 10,000 and 20,000 Earth years to make one full orbit around the Sun.

You may be tempted to ask how an entire planet could ‘hide’ in our solar system when we have zooming capabilities such as the new iPhone 15 has, but consider this: If Earth was the size of a marble, the edge of our solar system would be 11 kilometres away. That’s a lot of space to hide a planet.

[source:independent]

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Dragonfly: NASA Just Confirmed The Most Exciting Space Mission Of Your Lifetime – Forbes

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NASA has confirmed that its exciting Dragonfly mission, which will fly a drone-like craft around Saturn’s largest moon, Titan, will cost $3.35 billion and launch in July 2028.

Titan is the only other world in the solar system other than Earth that has weather and liquid on the surface. It has an atmosphere, rain, lakes, oceans, shorelines, valleys, mountain ridges, mesas and dunes—and possibly the building blocks of life itself. It’s been described as both a utopia and as deranged because of its weird chemistry.

Set to reach Titan in 2034, the Dragonfly mission will last for two years once its lander arrives on the surface. During the mission, a rotorcraft will fly to a new location every Titan day (16 Earth days) to take samples of the giant moon’s prebiotic chemistry. Here’s what else it will do:

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  • Search for chemical biosignatures, past or present, from water-based life to that which might use liquid hydrocarbons.
  • Investigate the moon’s active methane cycle.
  • Explore the prebiotic chemistry in the atmosphere and on the surface.

Spectacular Mission

“Dragonfly is a spectacular science mission with broad community interest, and we are excited to take the next steps on this mission,” said Nicky Fox, associate administrator of the Science Mission Directorate at NASA Headquarters in Washington. “Exploring Titan will push the boundaries of what we can do with rotorcraft outside of Earth.”

It comes in the wake of the Mars Helicopter, nicknamed Ingenuity, which flew 72 times between April 2021 and its final flight in January 2023 despite only being expected to make up to five experimental test flights over 30 days. It just made its final downlink of data this week.

Dense Atmosphere

However, Titan is a completely different environment to Mars. Titan has a dense atmosphere on Titan, which will make buoyancy simple. Gravity on Titan is just 14% of the Earth’s. It sees just 1% of the sunlight received by Earth.

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The atmosphere is 98% nitrogen and 2% methane. Its seas and lakes are not water but liquid ethane and methane. The latter is gas in Titan’s atmosphere, but on its surface, it exists as a liquid in rain, snow, lakes, and ice on its surface.

COVID-Affected

Dragonfly was a victim of the pandemic. Slated to cost $1 billion when it was selected in 2019, it was meant to launch in 2026 and arrive in 2034 after an eight-year cruise phase. However, after delays due to COVID, NASA decided to compensate for the inevitable delayed launch by funding a heavy-lift launch vehicle to massively shorten the mission’s cruise phase.

The end result is that Dragonfly will take off two years later but arrive on schedule.

Previous Visit

Dragonfly won’t be the first time a robotic probe has visited Titan. As part of NASA’s landmark Cassini mission to Saturn between 2004 and 2017, a small probe called Huygens was despatched into Titan’s clouds on January 14, 2005. The resulting timelapse movie of its 2.5 hours descent—which heralded humanity’s first-ever (and only) views of Titan’s surface—is a must-see for space fans. It landed in an area of rounded blocks of ice, but on the way down, it saw ancient dry shorelines reminiscent of Earth as well as rivers of methane.

The announcement by NASA makes July 2028 a month worth circling for space fans, with a long-duration total solar eclipse set for July 22, 2028, in Australia and New Zealand.

Wishing you clear skies and wide eyes.

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