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NASA on Tuesday celebrated exceeding expectations during a mission to deflect a distant asteroid, in a sci-fi like 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 moonlet asteroid Dimorphos on September 26, pushing it into a smaller, faster orbit around its big brother Didymos, NASA chief Bill Nelson announced.

That changed its orbital period by four percent, or 32 minutes — from 11 hour 55 minutes to 11 hours 23 minutes, bettering an expectation of 10 minutes.

“At some point in the future, if we find an asteroid that is threatening to hit Earth, and would be large enough to really do some damage, thank goodness that we will have had this successful test,” Nelson told AFP.

The asteroid pair loop together around our Sun every 2.1 years, and pose no threat to our planet.

But they are ideal for studying the “kinetic impact” method of planetary defense.

DART’s success as a proof-of-concept has made a reality what was once science fiction — notably films such as “Armageddon,” “Deep Impact,” and “Don’t Look Up.”

Never actually photographed before, Dimorphos, which is 530 feet (160 meters) in diameter or roughly the size of a big Egyptian pyramid, appeared as a speck of light around 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 toward it at roughly 14,500 miles (23,500 kilometres) per hour.

Pseudo-comet 

In the days that followed, astronomers rejoiced in stunning images of matter spreading out thousands of miles — pictures collected by Earth and space telescopes, as well as a tiny companion satellite that traveled to the zone with DART.

Thanks to its temporary new tail, Dimorphos 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 around 6.8 million miles (11 million kilometres) from Earth at impact, is visible only as a single dot from the ground.

The dot’s brightness changes as Dimorphos passes in front of Didymos, which is significantly bigger at half-a-mile wide.

Four optical telescopes were involved in measuring the orbital period — all in Chile and South Africa — while two US-based radar telescopes helped confirm the finding, said NASA planetary scientist Nancy Chabot.

The test also showed scientists that the asteroid is less like a solid rock, and 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 significant mass is pushed at high velocity in the opposite direction to impact, there will be an additional boost.

“It looks like the recoil from the ejecta blast off the surface was a substantial contributor to the overall push given to the asteroid,” said NASA scientist Tom Statler at a briefing.

The test will serve as an “anchor point” for simulations and calculations about the outcome of future impacts, he added.

Mass extinction

No known asteroid larger than 140 meters (460 feet) in size — big enough to devastate a city — has a significant chance to hit Earth for the next 100 years, according to NASA.

But wait long enough, and it will happen.

The geological record shows, for example, that a six-mile wide asteroid struck Earth 66 million 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.

The agency plans to launch in 2026 a telescope called the Near-Earth Object (NEO) Surveyor to better characterize potentially hazardous 140-meter asteroids and comets that come within 30 million miles.

So far, less than half of the estimated 25,000 NEOs of 140 meters have been discovered.

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 via 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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Voyager 2’s Flyby Sheds Light on Uranus’s Magnetic Mystery

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Voyager 2's Flyby Sheds Light on Uranus's Magnetic Mystery

A recent analysis of 38-year-old data from NASA’s Voyager 2 spacecraft has provided fresh insights into the unique magnetosphere of Uranus, according to a study published on November 11 in Nature Astronomy. During Voyager 2’s 1986 flyby, Uranus’ magnetosphere was found to be unexpectedly distorted by a blast of solar wind. The findings suggest that the planet’s magnetic field behaves unlike any other in the solar system.

Findings Highlight Unusual Magnetic Structures

Jamie Jasinski, a planetary scientist at NASA’s Jet Propulsion Laboratory and California Institute of Technology, and lead author of the study, noted that Voyager 2’s timing happened to coincide with an intense solar wind event, a rare occurrence near Uranus. This compression of Uranus’s magnetosphere, seen only around 4% of the time, is thought to be responsible for the unique measurements Voyager captured. Had the spacecraft arrived even a week earlier, Jasinski observed, these conditions would likely have been different, possibly leading to alternative conclusions about Uranus’s magnetic characteristics.

Unlike Earth, Uranus exhibits a complex “open-closed” magnetic process, influenced by its extreme axial tilt. This tilt subjects Uranus to highly variable solar wind effects, resulting in a magnetosphere that opens and closes cyclically.

Implications for Future Uranus Exploration

The study’s conclusions go beyond Uranus itself, offering insights into the magnetic behaviours of its outermost moons, including Titania and Oberon. These moons, it turns out, lie within Uranus’s magnetosphere rather than outside it, making them candidates for investigations into subsurface oceans through magnetic field detection. As Jasinski highlighted, these conditions would simplify detecting any magnetic signatures that suggest liquid beneath the moons’ icy surfaces.

While Voyager 2 remains the only mission to visit Uranus, the study’s findings underscore a growing interest in exploring the ice giant in greater detail.

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Tajikistan rock shelter reveals ancient human migration routes

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Tajikistan rock shelter reveals ancient human migration routes

Archaeologists have uncovered a rock shelter in Tajikistan’s Zeravshan Valley that was occupied by multiple human species, including Neanderthals, Denisovans, and Homo sapiens, for over 130,000 years. Discovered along the Zeravshan River in the Inner Asian Mountain Corridor (IAMC), this site, known as Soii Havzak, provides new insight into the migration patterns of ancient humans. Researchers believe the IAMC may have facilitated interactions between these groups, offering clues about how they lived and possibly coexisted in Central Asia.

Discovery Along the Zeravshan River

A team led by Dr Yossi Zaidner, senior lecturer at the Institute of Archaeology at the Hebrew University of Jerusalem, recently excavated the site. Evidence of various human occupations was found, including stone tools and animal bones dating from 150,000 to 20,000 years ago. Zaidner noted that Central Asia’s IAMC could have served as a natural migration route, allowing distinct human populations to cross paths. “This discovery is crucial for understanding ancient human presence in Central Asia and how different human species may have interacted here,” he stated in a press release.

Significance for Human Migration and Interaction

Artifacts from Soii Havzak, including stone blades, rock flakes, crafted flints, and signs of fire use, suggest repeated use of the shelter by different human groups. The find highlights Central Asia’s significance in ancient migration routes, with the Zeravshan River likely serving as a pathway for early humans as they dispersed across continents.

A Pathway for Ancient Civilisations

Beyond its prehistoric importance, the Zeravshan Valley later became a key route on the Silk Road, linking distant civilisations such as China and Rome. Researchers expect further studies at Soii Havzak to shed light on the broader implications of this region in ancient human migration and cross-cultural interactions, aiming to deepen understanding of human history and evolution during the Middle Paleolithic era.

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NASA’s Juno shows Jupiter’s storms and moon Amalthea up close

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NASA’s Juno shows Jupiter’s storms and moon Amalthea up close

NASA’s Juno spacecraft has delivered breathtaking images of Jupiter, highlighting the planet’s swirling, multicoloured storms and unique moons. During Juno’s 66th close flyby on October 23, the spacecraft approached the planet’s polar regions and captured close-up views of its fifth-largest moon, Amalthea. The raw images collected by JunoCam have since been processed by citizen scientists, who enhanced colours and contrasts to reveal Jupiter’s atmospheric details in a new light.

Spectacular Details of Jupiter’s Storms Revealed

Citizen scientist Jackie Branc processed one of Juno’s most striking images, showcasing a region on Jupiter called a Folded Filamentary Region (FFR), located near the planet’s subpolar areas. FFRs are known for their complex cloud patterns, which include white billows and fine, thread-like filaments. This recent image captures Jupiter’s stormy atmosphere with an emphasis on these fine details, giving scientists and the public alike a vivid view of the planet’s dynamic weather systems.

Juno’s data, available to the public online, allows enthusiasts and researchers to adjust image features such as contrast and colour balance. This collaborative effort has enabled a range of perspectives on Jupiter’s atmospheric bands, turbulent clouds, and powerful vortices.

Amalthea: A Close-Up of Jupiter’s Unique Moon

Juno also captured images of Amalthea, a small, potato-shaped moon only 84 kilometres in radius. In images processed by Gerald Eichstädt, the white balance was adjusted to distinguish Amalthea from the blackness of space, presenting the moon in stark relief. This view of Amalthea, with its rugged, irregular shape, adds to our understanding of Jupiter’s complex satellite system.

Launched in 2016, the Juno mission was originally planned to conclude in 2021, but its mission has been extended, with plans to end in September 2025. When its mission concludes, Juno will plunge into Jupiter’s atmosphere, marking the end of its successful exploration journey.

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