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NASA says DART spacecraft successfully alters asteroid’s path

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NASA says it has succeeded in deflecting an asteroid in a historic test of humanity’s ability to stop an incoming cosmic object from devastating life on Earth.

The fridge-sized Double Asteroid Redirection Test (DART) impactor deliberately smashed into the asteroid Dimorphos on September 26, pushing it into a smaller, faster orbit around its big brother Didymos, NASA chief Bill Nelson said.

“DART shortened the 11 hour, 55 minute orbit to 11 hours and 23 minutes,” he said. Speeding up Dimorphos’ orbital period by 32 minutes exceeded NASA’s own expectation of 10 minutes.

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“We showed the world that NASA is serious as a defender of this planet,” Nelson said.

The asteroid pair loop together around the sun every 2.1 years and pose no threat to Earth, but they posed an ideal test of the “kinetic impact” method of planetary defence in case an actual approaching object is ever detected.

“There is no risk in this case because this was a deliberately chosen target to make sure that this [asteroid crashing on Earth] would not happen,” Yvette Cendes, an astronomer at Harvard University, told Al Jazeera.

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DART’s success as a proof-of-concept has made a reality of science fiction.

Astronomers rejoiced in stunning images of matter spreading out thousands of kilometres in the wake of the impact. The pictures were collected by Earth and space telescopes as well as a satellite that had travelled to the zone with DART.

“I grew up watching Armageddon and Deep Impact and all that, and it is amazing to see this stuff become a reality,” Cendes said.

Thanks to its temporary new tail, Dimorphos, which is 160 metres (530-foot) in diameter or roughly the size of a big Egyptian pyramid, has turned into a man-made comet.

But quantifying just how well the test worked required an analysis of light patterns from ground telescopes, which took a few weeks to become apparent.

The binary asteroid system, which was about 11m km (6.8m miles) from Earth at impact, is visible only as a single dot from the ground.

‘Rubbish pile’

Ahead of the test, NASA scientists said the results of the experiment would reveal whether the asteroid is a solid rock, or more like a “rubbish pile” of boulders bound by mutual gravity.

If an asteroid is more solid, the momentum imparted by a spaceship will be limited. But if it is “fluffy” and significant mass is pushed at high velocity in the opposite direction to impact, there will be an additional boost.

Never actually photographed before, Dimorphos appeared as a speck of light about an hour before impact.

Its egg-like shape and craggy, boulder-dotted surface finally came into clear view in the last few moments as DART raced towards it at roughly 23,500km/h (14,500 mph).

Very few of the billions of asteroids and comets in our solar system are considered potentially hazardous to our planet, and none is expected to hit in the next 100 years or so. But wait long enough, and it will happen.

The geological record shows, for example, that a 9.6km (6 mile) wide asteroid struck Earth 66m years ago, plunging the world into a long winter that led to the mass extinction of the dinosaurs along with 75 percent of all species.

An asteroid the size of Dimorphos, by contrast, would only cause a regional impact, such as devastating a city.

Kinetic impact with a spaceship is just one way to defend the planet, albeit the only method possible with current technology.

Should an approaching object be detected early, a spaceship could be sent to fly alongside it for long enough to divert its path by using the ship’s gravitational pull, creating a so-called gravity tractor.

Another option would be launching nuclear explosives to redirect or destroy an asteroid.

NASA believes the best way to deploy such weapons would be at a distance, to impart force without blowing the asteroid to smithereens, which could further imperil Earth.

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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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