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

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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).

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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.

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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.

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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.”

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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.”

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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.

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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.”

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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.”

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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.”

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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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