The Chinese Tianwen-2 mission has captured the first imagery of a space object that some astronomers are calling Earth’s “quasi-moon.”

The object was captured in images released by the China National Space Administration (CNSA), after its Tianwen-2 spacecraft reached the tiny asteroid 469219 Kamoʻoalewa. Initially discovered in 2016, the asteroid became the target of a sample return mission launched by China on 28 May 2025.

Officially the CNSA’s second mission under its Planetary Exploration of China Program, Tianwen-2 aims to return close to 100 grams of samples from the surface of the small object.

Earth’s Mysterious Quasi-Moons

Quasi-moons are the name astronomers have for small, very distant objects that do not impact our planet’s tides or possess other characteristics associated with our primary moon.

These objects are nonetheless considered moon-like because they remain in our celestial neighborhood for extended periods, providing unique opportunities for studying near-Earth objects (NEOs) like asteroids, and the impact things like solar radiation and gravity have on them.

Although Kamoʻoalewa (also known as asteroid 2016 HO3) is the most well-known of Earth’s quasi-moons, it is one of seven that are currently known to astronomers. Kamoʻoalewa’s orbit is technically also around the Sun, rather than Earth, although its synchronized path keeps it locked closely to Earth’s orbit, thereby justifying its recognition as a “quasi-satellite.”

The object’s size and distance make it an ideal target for studying NEOs, and China leaped at the opportunity with the CNSA’s Tianwen-2 mission.

Approaching a Quasi-Moon

The Tianwen-2 spacecraft is currently nearing 20 kilometers from the 130 to 330-foot space rock, according to a statement CNSA released on Monday.

Along with a mission update, the CNSA also released new images, which are the first to officially document the object’s appearance. According to current mission timelines, Tianwen-2 will remain in the vicinity of 469219 Kamoʻoalewa until next April, and by sometime in November 2027, its return capsule is expected to reach Earth.

After its study of 469219 Kamoʻoalewa, Tianwen-2 will then make its way with the aid of a gravity assist in the direction of the comet 311P/PANSTARRS, arriving in its vicinity by January 2035.

“Going forward, the probe will gradually conduct more detailed scientific explorations to obtain information on the asteroid’s shape, material composition, and internal structure,” read the CNSA’s statement on Monday.

The agency said its ongoing collection of information will help to provide “support for preparations for sampling,” and the spacecraft will spend the next several months conducting reconnaissance of the asteroid before its sample collection begins, which will combine high-speed maneuvers with the deployment of a specialized robotic arm.

Following their collection, the samples will be delivered to a recovery site in the Gobi Desert after dropping into Earth’s atmosphere in November 2027.

Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. A longtime reporter on science, defense, and technology with a focus on space and astronomy, he can be reached at micah@thedebrief.org. Follow him on X @MicahHanks, and at micahhanks.com.

As the United States of America celebrated its 250th birthday on terra firma with fireworks displays this weekend, two Asian countries made some splashes of their own farther from Earth.

On Sunday, an aging Japanese spacecraft named Hayabusa2, which completed its initial sample-return objective more than half a decade ago, found success with an extended mission that saw the vehicle fly by a peanut-shaped asteroid named Torifune.

Hours later, the Chinese space agency released images from a spacecraft, Tianwen-2, arriving at its target asteroid following a journey of 1 billion km. At this small asteroid, the Chinese spacecraft will attempt to retrieve samples and return them to Earth late next year.

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The Hayabusa2 spacecraft completed its flyby of the asteroid Torifune over the weekend, according to a statement issued by Japan’s space agency.

The intrepid Japan Aerospace Exploration Agency (JAXA) probe’s visit marks one of the closest approaches a spacecraft has ever made to a distant asteroid, and follows Hayabusa2’s successful 2020 mission to return samples from the asteroid Ryugu.

Information obtained during the flyby, which occurred on Sunday, may help to provide new insights into both the composition of these ancient space rocks drifting through our solar system, as well as how to defend our planet if one large enough to pose a significant risk were ever to make its way here.

Hayabusa2 completes a Historic Close Encounter

At approximately 6:30 p.m. Japan Standard Time on Sunday, Hayabusa2 passed the asteroid while traveling at speeds approaching 5 kilometers per second.

The recent achievement comprises part of the probe’s extended mission, which will include a future visit to the small asteroid 1998 KY26, which is expected to occur in 2031.

Over the weekend, the spacecraft’s flyby of Torifune helped to showcase Hayabusa2’s orbital guidance systems, as well as its ability to monitor asteroids and collect data to aid in the protection against potentially dangerous near-Earth objects (NEOs) before they become a threat, the Japanese Times reported.

Fortunately, asteroids with life-threatening potential only reach the Earth every few hundred years on average, and none currently being monitored by space agencies around the world are believed to represent any imminent threat.

Close Approach, not a Collision

One of the most difficult aspects of flybys like the one on Sunday involves the speeds at which spacecraft are moving, which can make avoiding a collision with the asteroid complicated. This is partly because of their dark coloration, which prevents visual confirmation of their location until just days before the flyby occurs, leaving only a small window for planning and preparation.

In a statement, Japan’s space agency said that these difficulties mean “that the flyby operation is similar to orbit-inducing technologies used to collide a spacecraft with an asteroid.”

If such technologies were to be used for planetary defense in the future, such a direct collision would be the goal, thereby aiming to set any potentially dangerous NEOs off course and keep Earth out of their line of fire.

Future Opportunities

In addition to the probe’s 2031 visit to 1998 KY26, JAXA officials say that additional opportunities for future reconnaissance will be likely, and that Sunday’s flyby served as an important dress rehearsal in that regard.

Additionally, data obtained from the flyby will be useful in helping JAXA officials and other space agencies around the world to know what to expect should a planetary defense effort become a requirement at any time in the future.

Once Hayabusa2 reaches 1998 KY26 in the early 2030s, it will mark the first time a spacecraft has engaged in close-range explorations of such an asteroid, which is currently estimated to be approximately 30 meters in diameter.

Additional details about the Hayabusa2 mission can be found at JAXA’s website.

Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. A longtime reporter on science, defense, and technology with a focus on space and astronomy, he can be reached at micah@thedebrief.org. Follow him on X @MicahHanks, and at micahhanks.com.

When you think of an asteroid impact, you’re probably imagining something like the cataclysmic event that nearly wiped out the dinosaurs. In an astonishingly rare event, a rock the size of the island of Manhattan could come hurtling from deep space towards Earth and destroy the world.

On the contrary, asteroids are generally leftover debris from the primordial solar system that didn’t become part of a larger body, like a planet or moon, and they’re not particularly rare. Scientists estimate that there are about 1 billion asteroids and comets classified as near-Earth objects, or NEOs. NEOs are generally much smaller than the asteroid that killed the dinosaurs. They range from weakly held-together piles of rubble 200 meters (700 feet) across, to the minuscule 2024 BX1, approximately 44 centimeters (17 inches) across. 

For several decades, astronomical surveys of the sky have looked for these asteroids. NASA’s Center for Near-Earth Object Studies (CNEOS) Fireball and Bolide Database has records of over 1,000 incidents of objects colliding with our planet since the mid-1990s. Among these is a set of 11 objects that scientists detected before they hit Earth, known as imminent impactors. Finding imminent impactors allows scientists unique opportunities to study the smallest building blocks of the solar system, enabling them to learn more about asteroid composition, structure, and history.

A team of scientists recently conducted a study on how the newly built Vera Rubin Observatory could detect more imminent impactors before they strike Earth. They examined the CNEOS Fireball and Bolide Database impact records spanning February 1, 1994, to January 1, 2026, for records of the asteroids’ coordinates, velocities, and the energy they released at the time of collision. 

They found that 343 NEOs met this criterion, including 5 known imminent impactors. Using these recorded data, they reconstructed the objects’ pre-impact characteristics. The team predicted the asteroids’ orbital paths from the recorded coordinates and velocity. Assuming the objects were spherical, they estimated the size from velocity and impact energy. From this information about the asteroids’ state before impact, the team could then simulate whether the Rubin Observatory would have detected them. 

When small asteroids hit Earth, they mostly burn up in the atmosphere, producing a bright flash that is relatively easy to spot compared to when they are in space. The Rubin Observatory can see objects up to 10 billion times dimmer than the brightest star in the night sky, Sirius. To predict if the Rubin Observatory can detect dim NEOs, the team used the solar system simulator SORCHA. SORCHA takes an observatory’s specifications and the physical properties of the NEOs and uses these to determine whether the observatory could detect them. It also estimates the measured sizes and speeds of the NEOs, and predicts when the observatory would have seen them. 

At the Rubin Observatory, an imminent impactor is considered discovered if it’s observed at least 3 separate times over 15 days before hitting Earth. So this team applied this same criterion to their simulation. They found that of their 343 impactors, SORCHA estimated that the Rubin Observatory would have discovered 14 of them before impact. 

They also found that SORCHA predicted 4 additional impactors that could have been observed at least once, potentially allowing scientists to search other telescope data for evidence of their existence in pre-collision images. Based on these results, the team estimated that the Rubin Observatory could find 4% of all objects longer than 1 meter (3 feet) before they hit Earth. This percentage of discovery translates to 1 to 2 imminent impactors detected every year, at least double their current discovery rate.

The ability to more consistently find imminent impactors would allow researchers to study the smallest pieces of the solar system in detail and to draw general conclusions about the properties of objects that could potentially collide with Earth. This would also allow scientists to more accurately calculate the orbits of imminent impactors, determine where more meteorites land to recover them, and keep tabs on the extremely rare but more hazardous large impactors for planetary defense initiatives. So, humanity can learn more about the ancient solar system, and hopefully avoid going the way of the dinosaurs while doing so!

The post How many asteroids can we detect before they hit Earth? appeared first on Sciworthy.

More than two decades have passed since geologists first identified an unusual circular structure buried beneath the North Sea, and now scientists say new evidence could finally solve the mystery.

New research has confirmed that the feature, known as the Silverpit Crater, was likely formed by an asteroid impact as much as 46 million years ago. The discovery ends years of speculation about the mysterious feature’s origins, much of which debated whether the circular structure had been caused by volcanic activity or shifting underground salt deposits.

The research was led by researchers at Heriot-Watt University in Edinburgh and published in Nature Communications.

Combining high-resolution seismic imaging, microscopic analysis of rock samples, and computer simulations, the team behind the new study says their assessment offers the strongest evidence yet that Silverpit represents one of Earth’s relatively rare ancient impact features that have survived throughout time.

The Silverpit Enigma

The three-kilometer feature, which lies approximately 700 meters (2,300 feet) beneath the floor of the southern North Sea, and close to 80 miles off the Yorkshire coast, has long perplexed geologists. Several larger concentric ringlike structures encircle the primary feature, comprising about 12 miles, and since its discovery in 2002, geologists have remained divided over what might have caused it.

Some argued that the weird feature possesses the unmistakable hallmarks of a hypervelocity impact; others maintained that more conventional geological explanations could better account for the circular structure.

Now, after nearly a quarter of a century of debate, the new research appears to finally put the debate over this North Sea enigma to rest.

New Data Sheds Light on the Mystery

“New seismic imaging has given us an unprecedented look at the crater,” said lead author Dr. Uisdean Nicholson, a seismologist with Heriot-Watt University. Of even greater intrigue, the researchers identified microscopic “shocked” quartz and feldspar crystals recovered from an oil exploration well at the same depth as the crater floor.

“We were exceptionally lucky to find these,” according to Nicholson, who called the team’s work “a real ‘needle-in-a-haystack’ effort.”

“These prove the impact crater hypothesis beyond doubt, because they have a fabric that can only be created by extreme shock pressures,” Nicholson said, making them among the strongest lines of evidence available to researchers for confirming ancient impact sites.

Reconstructing an Ancient Impact

By reconstructing the ancient impact event that shaped the Silverpit feature, the team now believes that an asteroid roughly 160 meters wide struck the North Sea at a low angle after approaching from the west. The resulting collision produced the main crater, while launching massive volumes of stone and seawater to levels of up to 1.5 kilometers—the resulting tsunami would have exceeded 100 meters in height.

This ancient impact is still dwarfed when compared to the likes of Mexico’s Chicxulub Crater, which was created by an asteroid that struck our planet 66 million years ago, now widely believed to be responsible for the extinction of the dinosaurs. While smaller by comparison, the Silverpit impact would still have unleashed enormous destructive energy across the surrounding region.

The team’s work also adds to the accumulation of impact features known to scientists, which are relatively rare, despite thousands of asteroids reaching the surface of our world over the last several billion years. However, over such long periods, other geological processes such as erosion, plate tectonics, and volcanic activity have erased most of the remaining evidence of these collisions.

Presently, there are only around 200 impact craters that are known to exist on land, and another few dozen that have been detected beneath Earth’s oceans.

Altogether, while the mystery of Silverpit has now been solved, the new research does more than merely settle a debate: it allows seismologists a deeper look at how asteroid impacts reshape planetary surfaces.

Such knowledge, while improving scientists’ understanding of Earth’s past, could also help provide potentially crucial data for future planetary defense efforts by helping scientists refine models of future impact hazards.

The team’s recent study, “Multiple lines of evidence for a hypervelocity impact origin for the Silverpit Crater,” appeared in Nature Communications.

Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. A longtime reporter on science, defense, and technology with a focus on space and astronomy, he can be reached at micah@thedebrief.org. Follow him on X @MicahHanks, and at micahhanks.com.