China announces plan to build early-warning system for dangerous asteroids

China has announced that it wants to develop a "space-ground" asteroid early-warning network, while providing few details on what it could look like. But recent papers and presentations to the United Nations provide clues as to what the country has in mind for planetary defense.

The China National Space Administration (CNSA) made the announcement on June 30 — International Asteroid Day — stating plans to construct a coordinated ground-and-space monitoring system for near-Earth asteroids. Li Mingtao, chief scientist at CNSA's Asteroid Monitoring and Early Warning Research Center, told state media that China is studying the feasibility of an asteroid defense system, with the ground-space monitoring network as its core.

"No asteroid has so far been identified that will definitely collide with Earth in the foreseeable future, but concerns over impact risks are not unfounded. Many near-Earth asteroids remain undetected," the state-run media outlet Xinhua quoted Li as saying in a report by Science and Technology Daily.

Li added that China will deploy multiple large-aperture optical telescopes at carefully chosen sites in order to be able to survey the sky, while adding a space-based monitoring constellation, free from atmospheric disruption and day-night constraints, with a particular focus on threats from the sunward direction, which are, from the ground, lost in the glare of the sun. The meteor that exploded over Chelyabinsk, Russia, in 2013, approached roughly from a sunward direction and was only detected once it entered the atmosphere.

Li told Science and Technology Daily that more than 40,000 near-Earth asteroids have been discovered so far, including over 95% of asteroids at least 1 kilometer (0.6 miles) wide, which are capable of causing a globally catastrophic impact. However, only around 45% of asteroids in the 140-meter (460-foot) class have been detected, which are large enough to devastate a small country.

The June 30 reports and CNSA statements were vague on what China's actual plans for its monitoring network may be. However, recent journal papers and a 2025 presentation to the U.N.'s Committee on the Peaceful Uses of Outer Space (COPUOS) give more detail on the country's thinking.

For example, a paper published in the Journal of Deep Space Exploration in June 2026, co-authored by Wu Weiren, chief designer of China's lunar exploration program and a leading voice on the country's asteroid defense plans, lays out the options under study.

For the space-based component, the paper names four candidate orbital positions for a monitoring network: the Sun-Earth L1 Lagrange point, an Earth-leading or trailing orbit, a Venus-like heliocentric orbit, and an Earth-companion distant retrograde orbit (DRO). The paper also describes ongoing research into each option's monitoring effectiveness.

a cube-shaped spacecraft with two wing-like solar arrays flies towards two large rocks in space

In 2022, NASA's Double Asteroid Redirection Test (DART) mission slammed into the asteroid Dimorphos, which orbits a larger asteroid named Didymos, and changed the binary system's orbit around the sun. (Image credit: NASA/Johns Hopkins APL/Steve Gribben)

A similar outline was found in a 2025 technical presentation to COPUOS by Chinese researcher Chen Yongcai. A "basic model" would consist of a single satellite at Sun-Earth L1, an orbit about 1.5 million kilometers (930,000 miles) inside that of Earth, paired with northern and southern ground stations. An "extended model" includes spacecraft in the three additional orbits stated in the Wu Weiren paper. The Venus-like option in particular closely tracks an earlier proposal known as CROWN, a constellation of small satellites in Venus-like orbits designed to survey the sunward sky and use its favorable geometry to track other populations of near-Earth asteroids.

The status and timelines of these plans are unclear, but they do indicate a clear interest in and commitment to planetary defense by China. The country's 15th Five-Year Plan, approved in March, states that an asteroid defense engineering project is under study, while China is developing a kinetic-impact and observation demonstration mission, similar to NASA's DART mission and the European Space Agency's (ESA) follow-on Hera project, which is scheduled to launch in 2027.

While China's apparent plans are not unique, they could augment global efforts. Anne Virkki, an asteroid researcher at the University of Helsinki who's familiar with international monitoring efforts, noted that NASA and ESA have plans to send missions to Sun-Earth L1 to search for asteroids in infrared light — NEO Surveyor and NEOMIR respectively.

"If China launches a similar mission, hopefully it has some capability that the other two do not, and that it shares the data internationally and not only for Chinese scientists," Virkki said.

Virkki noted that asteroids approaching from the sun's direction aren't physically unusual, but they are simply harder to track, which statistically makes them more likely to produce a surprise. She also pointed to the persistent, less-discussed gap in radar tracking capacity. That capacity took a serious hit with the 2020 collapse of the Arecibo Observatory in Puerto Rico, with no U.S. successor in the works.

China has discussed building its own radar capability, which Virkki said would be a welcome addition, provided the data is shared openly. China has built the "China Compound Eye" or Fuyan project near Chongqing in the country's southwest, which can be used for near-Earth asteroid monitoring. Wu's paper also notes ground-based radar in the proposal for asteroid monitoring.

"Hopefully, as China's planetary defense plans become more specific, we'll see telescopes and space telescopes that complement the existing or planned capabilities of other countries, rather than repeat redundantly, and contribute data openly and collaboratively," Virkki said. She noted that there are likely about 100,000 near-Earth asteroids that could cause significant local damage if they hit Earth, and we know the orbits of less than half of all such space rocks.

2029 will mark the International Year of Planetary Defense, when the infamous asteroid Apophis will fly past the Earth just within the orbit of geostationary satellites. "There is a lot of work left to do, and international collaboration is crucial," said Virkki.

NASA begins funding hardware for ‘Skyfall’ Mars helicopter mission

NASA's nuclear-powered mission to Mars is taking shape with the selection of Firefly Aerospace to design and manufacture the protective aeroshell that will shield the Skyfall spacecraft's descent stage during its plummet through the Martian atmosphere.

Skyfall, slated to be NASA's first-ever nuclear powered interplanetary probe, is scheduled to launch in 2028 with three helicopters similar to the Ingenuity drone that landed on the Red Planet with the Perseverance rover. The mission is being managed by NASA's Jet Propulsion Laboratory (JPL), in California, which just awarded Firefly a $13 million subcontract for the spacecraft component.

It will be the company's first project to be developed in its expanded Texas facility, Gloworks, and will lean on engineering expertise gained from its Blue Ghost lunar lander and Firefly's Alpha and Eclipse rockets, according to a company statement.

"We've proved our ability to execute off-Earth missions at a fraction of the cost and timeline through our successful Blue Ghost lunar mission," said Ray Allensworth, Firefly's vice president of spacecraft. "Now we’re applying these lessons learned and utilizing our proven technologies to continue accelerating and lowering costs for future missions to the moon, Mars, and beyond."

Blue Ghost launched in January 2025, and successfully touched down on the moon about two months later, as only the second commercial lander to ever soft land on the lunar surface. For its Mars contract, though, Firefly will be aiming higher.

Firefly's aeroshell design will include the Skyfall capsule's heatshield and its backshell, providing the thermal protection it needs from the Martian atmosphere and the aerodynamic characteristics to guide it safely and accurately out of its exit from the vacuum of space. Unlike Blue Ghost, however, Firefly won't need to worry about an actual landing.

Instead of delivering its helicopter trio to Mars' surface, Skyfall will release them mid-descent, where they will take to immediate flight through the Martian sky to begin their resource mapping mission. NASA is calling it the "SkyFall Maneuver."

The mission aims to demonstrate the applicability of the helicopters' onboard prospecting instruments. NASA plans to use that data to scout for water ice on Mars' surface to study potential landing sites for crewed missions in the future.

Once Firefly completes aeroshell development at Gloworks, work will move to the company's Rocket Ranch in Briggs, Texas, where it will begin manufacturing and testing before being transported to JPL for spacecraft integration.

Trump gifts Artemis astronauts an American flag from the US Capitol to plant on the moon

The next American flag to be planted on the moon has been placed in the hands of one of the last astronauts to walk on the lunar surface.

Late into the night during the America 250 celebrations in Washington, D.C. on July 4, President Donald Trump delivered the keynote address from the National Mall, praising the country's history and accomplishments. The speech also acknowledged several American heroes in attendance, from military veterans, descendants of notable American historical figures like Davy Crocket, and the crew of NASA's Artemis II mission that flew around the moon in April.

Each honoree was invited briefly on stage, and recognized in front of an array of historical American flags, like the oldest known one in existence from 1777, the flag draped over the casket of Abraham Lincoln and one carried by Lewis and Clark in 1803. The Artemis crew were joined by Apollo 17 astronaut Jack Schmitt, and presented before the flag flown aboard the Wright brothers' plane on its first flight in 1903. They were also given a flag to take with them before walking off stage.

"Within 66 years of inventing the airplane, Americans planted our flag on the moon. Just three months ago, we sent American astronauts back to the far side of the moon, and this time they flew further from Earth than anyone has ever flown before," Trump said of the astronauts, and told the crowd, "I have a special gift for these patriots."

As he spoke, U.S. Air Force Maj. Kaitlyn Tinkham joined the astronauts, carrying a folded flag in her hands. "This morning, on America's 250th birthday, a new flag was flown above the United States Capitol," Trump said. "Tonight I present it to you, to soon be planted by American astronauts on their upcoming return to the moon."

Tinkham handed the flag to Schmitt. Standing next to him, Artemis II commander NASA astronaut Reid Wiseman put an arm on Schmitt's shoulder as the two stood in recognition of the symbolism of the flag being held by a member of the Apollo generation alongside the astronauts currently taking on NASA's return to the moon.

Wiseman was joined by his Artemis II crewmates, NASA astronauts Victory Glover and Christina Koch, as well as Canadian Space Agency astronaut Jeremy Hansen (who recently announced his retirement). The four-person crew launched aboard NASA's Orion spacecraft on April 1, and flew a 10-day mission around the far side of the moon. Their journey took them farther from Earth than any crewed spaceflight in history, and captivated millions of people following their mission from launch to splashdown.

It was the only flight of Orion with astronauts aboard, and the first crewed mission of NASA's Artemis program, which endeavors to return astronauts to the surface of the moon and eventually establish a permanent base. With the success of Artemis II behind it, the agency has shifted into full gear for preparations for Artemis III and Artemis IV.

NASA is currently targeting Artemis III for mid-to-late 2027, which will launch Orion into low Earth orbit for a rendezvous and docking operations validation flight with the program's two commercial lunar lander vehicles, SpaceX's Starship and Blue Origin's Blue Moon. Artemis IV is scheduled for 2028, and is slated to be the first Artemis mission to deliver astronauts to the lunar surface.

And, while we don't yet know the crew that will fly that mission, the flag they will plant on the moon once they land is now officially in the hands of NASA's astronauts.

Artemis 2’s Jeremy Hansen stepping down from active astronaut duty after epic moon mission

The first non-American to reach the moon is ready for a new mission.

Canadian Space Agency (CSA) astronaut Jeremy Hansen, best known for his flight around the moon in April on NASA's Artemis 2 mission, will step back from active astronaut duty in September.

Hansen, who's also a colonel in the Royal Canadian Air Force (RCAF), will next serve as a reservist to "enable the vital work happening in Canada with respect to space," the astronaut wrote Monday (July 6) in a statement on X.

"Our future depends on a fierce continuation of Canadian innovation and exploration in space," Hansen added. "The technological breakthroughs and economic benefits born from this sector are vital for our country and the world, and I am as determined as ever to push that work forward."

Space sovereignty has come under renewed focus in recent months in Canada. Long-standing efforts at a homegrown launch capability, for example, received a wave of Canadian defense funding in March, with $200 million CDN ($140 million) offered to an in-development spaceport in Nova Scotia over 10 years, plus additional money to eventually get Canadian-made rockets into orbit. Hansen, an astronaut for 17 years, went to the Maritime Launch Services spaceport to attend a suborbital launch last month.

But Hansen's role in recent years also includes significant strides in space diplomacy: In 2026 alone, he and his three Artemis 2 crewmates have been seen at the White House, with congressional committee representatives and at the president's State of the Union address, also making similar-tier stops in Canadian politics. Just last week, he attended both Independence Day and Canada Day national celebrations.

Part of Hansen's messaging at these events is evident in this June 11 X post: "Canada and the United States have been close collaborators in space exploration for over six decades," he stated.

A long road to space

Hansen, 50, has been flying since the age of 12, first with the Royal Canadian Air Cadets, according to his official CSA biography. He graduated quickly to gliding and private piloting before serving as a fighter pilot for the RCAF. After growing up in the London, Ontario area somewhat near Toronto, Hansen served in multiple locations across Canada, most prominently as a CF-18 fighter pilot with the 441 Tactical Fighter Squadron and 409 Tactical Fighter Squadron. Hansen also worked on NORAD (North American Air Defense) projects as combat operations officer at 4 Wing Operations.

In May 2009, at age 33, Hansen was one of two recruits for the Canadian astronaut corps selected that year, and he became fully qualified as an astronaut in 2011. To the surprise of many, he did not receive his first flight assignment for an incredible 14 years after initial selection, when the Artemis 2 crew was announced on April 3, 2023.

The wait was in part because Canada's approximately 2% contribution to the International Space Station (ISS), through robotics programs like Canadarm2, means a CSA astronaut gets to fly a long-duration mission there just every five or six years at current flight rates. (Some Canadians have also reached the station as private astronauts, or on behalf of NASA.)

For perspective: During Hansen's tenure, he was not fully qualified for a CSA mission when Robert Thirsk flew to the ISS in 2009 (before the space shuttle's retirement, when long-duration missions were allocated differently), or for most of the training that Chris Hadfield did ahead of his own 2012-13 mission to the orbiting lab.

David Saint-Jacques, Hansen's slightly older classmate from 2009, flew in 2018-19. The next ISS mission, by CSA astronaut Josh Kutryk this September, will have a longer gap because — ultimately, and very simply put — he was switched from a delayed Boeing Starliner mission to SpaceX's Crew-13.

But astronauts never sit idle. Aside from the usual mission support and background work at NASA, Hansen helped develop the tools and procedures for a complex spacewalk to repair a an instrument outside the ISS designed to hunt for elusive dark matter, which NASA once described as "four years in the making."

Hansen also served as what he called a "den mother" for NASA's 2017 astronaut class, an approximately two-year posting to be the first-ever Canadian manager of their training schedules.

"The buck stops with me," he told Space.com back then. "If we get to the end and they don't have the training they need, I'll be the one answering the questions about why was that not completed."

Moon work

Then program changes intervened. NASA's human spaceflight plans beyond the ISS sharpened in 2017 into returning humans to the moon, and luckily for Artemis (as this has not always been the case) the change has stuck through several presidential administration changes.

CSA was an early signatory to the Artemis Accords, with a commitment of hardware as well. (The initial promise was a Canadarm3 robotic arm to operate on a planned moon-orbiting space station called Gateway. However, with NASA recently deciding to build a moon base in Gateway's stead, what happens next with international partners is under negotiation, although Canadarm3's CSA contract continues with the company MDA Space.)

CSA's commitment secured two Canadian astronaut seats aboard Artemis missions, and the consortium decided to award Canada a seat on the very first crewed mission: Artemis 2. Canadian space industry representatives widely expected that would be Hansen's mission, not only due to his qualifications, but because Canada recruited Kutryk and Jenni Gibbons in 2017, who alongside Saint-Jacques were the only active astronauts at this time. Gibbons would go on to serve as CSA's backup astronaut for Artemis 2, as well as the CAPCOM (Capsule Communicator) during the mission's lunar flyby, in which she served as the direct voice link between mission control in Houston and the crew in the Orion spacecraft.

But Hansen, visited by Space.com in Houston on the day he was announced as an Artemis 2 crewmate, expressed modesty. "It really isn't about me. I feel a great sense of pride for Canada," he said, adding words he would often repeat in the following few years: "It was so awesome to see NASA, the United States, showcasing Canada as part of this mission. It's not as a gift, but because we bring real value."

A selfie of four people in a space capsule.

The Artemis 2 crew in space during their epic moon mission in April 2026. Jeremy Hansen is in the center of the back "row." (Image credit: NASA)

In between training for the first moon mission in 50 years alongside NASA astronauts Reid Wiseman, Victor Glover and Christina Koch, Hansen's message through the three years before liftoff was one of international and national collaboration. His mission patch, as the CSA noted in a description, included contributions with "elements of Anishinaabe culture" as well as from Turtle Lodge in Sagkeeng First Nation, where Hansen did a vision quest during his mission training. Numerous Canadians played front-line roles on Artemis 2, including Gibbons serving as capcom during the lunar flyby.

Artemis 2's 10-day mission included numerous scientific, historic and cultural milestones. The astronauts traveled farther from Earth than any people ever had, for example, and witnessed a unique solar eclipse not long after passing beyond the far side of the moon. They observed flashes of meteors on the lunar surface, took high-definition photos of the regolith, and spoke with politicians, reporters and school children about their experience from space.

Moreover, what we now know as "moon joy" was evident among the four astronauts. As one example, they shared an emotional group hug on camera on April 6, when the world learned a nomination would be put forward to name a lunar crater for Wiseman's late wife, Carroll.

At a NASA event shortly after the April 10 mission splashdown, Hansen said staying on the "joy train" as a crew took effort, but he added that what everyone witnessed among the crew was also possible on Earth. "We are a mirror, reflecting you," he said.

China releases 1st photo of Earth’s elusive ‘quasi-moon’ Kamo’oalewa

China's first-ever asteroid sampling mission has sent home a picture of its first target, the "quasi-moon" Kamo'oalewa.

The Tianwen-2 probe launched in 2025 and traveled 620 million miles (1 billion kilometers) to reach a safe distance about 12 miles (20 km) away from Kamo'oalewa, more formally known as asteroid 2016HO3. The spacecraft will spend nearly a year studying the asteroid with a suite of 11 different scientific instruments before attempting to collect a sample from its surface, which will be sent back to Earth.

The new photo was taken on July 2, according to China's Xinhua news outlet, and reveals the asteroid to be a small, asymmetrical rock measuring around 50–65 feet (16–20 meters) in diameter. While its origin isn't known, some scientists believe this quasi-moon could have been created when a massive impact knocked a chunk of our own moon into space between 1 million and 10 million years ago.

So-called quasi-moons (or quasi-satellites) are small bodies like Kamo'oalewa that circle the sun on orbits that keep them close to our planet. Earth has at least seven known quasi-satellites, and our planet's gravity will occasionally capture others temporarily before they are flung back out into orbit around the sun. In general, the orbits of these quasi-moons are less stable than the orbits of true moons.

Unlike most near-Earth asteroids that are thought to originate from the main asteroid belt between Mars and Jupiter, Kamo'oalewa could have come from much closer to home. A 2024 study published in Nature Astronomy proposes Kamo'oalewa could be material ejected from the moon by the impact that formed Giordano Bruno crater.

Sample of the asteroid collected by Tianwen-2 could help prove that hypothesis, if the mission is successful.

an illustration of the moon, with earth visible in the far distance, and a small grey rock in between the two

An artist's impression of Kamo'oalewa near the Earth-moon system. (Image credit: Addy Graham/University of Arizona)

Tianwen-2 launched on May 28, 2025 atop a Long March 3B rocket from Xichang spaceport in southwestern China. The appearance of the spacecraft wasn't revealed until China's space agency released an image beamed home by Tianwen-2 when it was 1.8 million miles (3 million km) away from Earth. This occurred just over a week past launch.

an octagonal solar panel on the end of a metal arm that extends outward from a metallic rectangle, just out of view on the left side of the image

The first public image of China's Tianwen 2 spacecraft, released by China's space agency well after the spacecraft was on its way to its first asteroid target. (Image credit: CNSA)

While Tianwen-2 marks China's first asteroid sample attempt, Japan and the United States have already performed successful space-rock-sample missions of their own. Japan's Hayabusa spacecraft executed the world's first asteroid sample return mission when it sent material from asteroid 25143 Itokawa back to Earth in 2010.

The United States accomplished the feat in 2023 with the OSIRIS-REx mission that snagged material from asteroid Bennu. Those samples have already produced surprising scientific data, including the fact they contain the amino acids we consider vital for life here on Earth.

Tianwen-2 is China's first-ever mission to an asteroid and its second planetary exploration mission overall. Its first interplanetary endeavor, Tianwen-1, saw an orbiter and a rover reach Mars in 2020.

More Tianwen missions are in the works. China plans to launch the Tianwen-3 Mars sample-return mission in 2028 and Tianwen 4 two years later to study Jupiter and Uranus.

‘That’s going to come back and bite us’: Former NASA chief questions Artemis moon lander plans

The former head of NASA is questioning the agency's plans to return astronauts to the moon, asking whether the crewed landers selected for the Artemis program are the right vehicles to get the job done.

Jim Bridenstine, who served as NASA administrator during President Donald Trump's first term, joined Space.com's Tariq Malik and co-host Rod Pyle on the This Week in Space podcast on June 12 to discuss his recently appointed position as CEO of Quantum Space and current events in the space industry. During the show, Bridenstine voiced skepticism about the architecture of NASA's Artemis moon landers, both of which are trailing in development compared to the Orion spacecraft with which they're being designed to fly.

"The architecture is extraordinarily complicated," Bridenstine said. He compared the Artemis plan unfavorably to NASA's approach during the Apollo program, which he argued was much less complex.

"They designed that thing to be as simple as you could possibly make it, and because of that they were able to land on the moon eight years after John F. Kennedy declared that we were doing it," Bridenstine said of the Apollo architecture.

NASA has contracted both SpaceX's Starship and Blue Origin's Blue Moon to be the crewed lunar landers for the Artemis program, and plans to use one of them to perform the first Artemis moon landing in 2028, on the Artemis 4 mission. That's a tight timeline for SpaceX and Blue Origin, whose spacecraft have faced ongoing delays in their development.

Neither lander has managed to make it to orbit yet, and both have a number of qualification tests to accomplish before NASA will certify the vehicles to fly with astronauts aboard, including uncrewed lunar landing demonstrations. For some development perspective, Bridenstine brought up NASA's Space Launch System (SLS) rocket, which, though also severely delayed for years leading up to its debut, managed a completely successful mission right out of the gate. "The first time SLS launched, it was rated for crew, and it was ready to go to the moon on the first launch. That's hard to do, and yet it did it," he said.

"This is the challenge," Bridenstine said. "We still don't have a lander, and without a lander, you can't land on the moon. It's really that simple, and I worry that over time that's going to come back and bite us."

During NASA's Apollo missions to the lunar surface in the 1960s and '70s, the Saturn V rocket launched the astronauts aboard their return capsule, with their moon landing vehicle stowed beneath. In contrast, NASA's Artemis missions, which launch Orion on SLS, require separate launches on different launch vehicles to get the moon landers off Earth.

"The genius of Apollo was its simplicity," Bridenstine said.

three moon landers stand on the lunar surface, side-by-side.

Scale renders of the Apollo Lunar Module, Blue Moon and Starship. (Image credit: NASA OIG)

The architecture for the Artemis missions is much more complex. Starship and Blue Moon will both require refueling flights in order to land astronauts on the lunar surface and then launch them back to orbit around the moon to rendezvous with Orion. The exact number of refueling flights for each lander is unknown, but a recent report from NASA's Office of Inspector General estimated Starship will need at least 15 additional launches to replenish its tanks enough for a full lunar landing mission.

Ahead of the planned Artemis 4 landing, NASA will launch a practice run with Orion and both of the two landers in low Earth orbit (LEO) in mid-to-late 2027. That mission, Artemis 3, will see the astronauts rendezvous and dock with both landers over the course of about two weeks. According to NASA's current plan, Artemis 3 astronauts will have the opportunity to board Blue Moon during their mission, but Starship will fly with a docking adapter only, and not a functional crew cabin — a likely sign of Starship's development progress, and what NASA expects of the spacecraft's capabilities within the next year.

NASA had previously tapped Starship as the lunar lander for Artemis 4, but its performance, as well as Blue Moon's, during Artemis 3 could possibly spur a change in that decision. The agency already voiced dissatisfaction with Starship's development last year, when it announced the possible reopening of the Artemis 3 lander contract due to SpaceX delays. "They're behind," Sean Duffy, who was then NASA's acting administrator, said at the time. "They've pushed their timelines out, and we're in a race against China."

Bridenstine voiced a similar sentiment. "Whatever it takes to build a lander soonest is what we ought to be doing as a country," he said.

Chinese scientists find the best way to nuke an asteroid on its way to impact Earth

How do you stop a large, threatening asteroid on its way to Earth? A new Chinese paper, investigating the issue, suggests a "pre-excavation detonation" could be the solution if there's enough warning time.

There may be millions of asteroids in our solar system, with a tiny percentage of them posing a possible, very tiny threat to our planet. NASA and many other entities keep an eye on the skies, and continue discovering new asteroids, but have found no imminent threats yet; Apophis, previously believed to be a small threat during its 2068 flyby of Earth, has now been ruled out as a problem for the foreseeable future.

But Earth has been smacked by space rocks in the past, with even the moderate-sized Chelyabinsk incident of 2013 causing reported property damage near its blast site in Russia. And as the researchers of a new paper point out, asteroids tens of meters in size and larger have been tracked flying safely, but closely, by Earth.

Assuming a theoretical space rock is on an imminent collision course and exceeds about 330 feet (100 meters) in size, simply blasting it (or even guiding it away) may not be a viable option, the researchers said in a peer-reviewed study in the journal Space: Science and Technology.

"Traditional kinetic impact, or long‑term force deflection methods, offer limited energy and cannot achieve effective deflection within short timeframes," the researchers said in a press release, adding they found few comprehensive analyses of how to do so. (NASA did successfully deflect an asteroid moonlet's orbit with the DART spacecraft in 2022, for example, but that was a unique test case in space.)

So the team, led by Xiaowei Wang from the China Academy of Launch Vehicle Technology, instead proposed using one of two "defense modes" for large incoming asteroids.

The first mode is a more simple impact detonation — simply put, smacking the asteroid's surface to create a shallow crater, in which a nuclear device is exploded. The other mode is a "pre-excavation detonation", or using a penetration device to create a deeper crater before exploding a nuclear warhead to "achieve deep detonation" in the interior of the asteroid.

The researchers' modeling included the energy of a launch vehicle, the velocity of the impact spacecraft, and changes to the velocity of the asteroid, in each of these two modes. The two modes were also tested against a "virtual threat asteroid database" assuming warning times of anywhere between one year and 20 years.

All in all, assuming enough time is available, it seems the deep-crater method wins out. "The flyby pre-excavation detonation mode, due to its ability to autonomously select the cratering location and achieve deep detonation, offers stronger energy coupling," the researchers wrote in the press release.

Such an impact could "destroy" asteroids that are roughly 330 feet (100 meters) or of that range, and push away asteroids of a size reaching about 0.6 miles (1 km) by imparting a velocity change of roughly 1 m/s in about 60 days.

a cube-shaped spacecraft with two wing-like solar arrays flies towards two large rocks in space

In 2022, NASA's Double Asteroid Redirection Test (DART) mission slammed into the asteroid Dimorphos, which orbits a larger asteroid named Didymos, and changed the binary system's orbit around the sun. (Image credit: NASA/Johns Hopkins APL/Steve Gribben)

A spacecraft with solar panels heads for an asteroid in the darkness of space

(Image credit: NASA/Johns Hopkins APL/Steve Gribben)

While a shallow-crater mission could be launched more quickly, the researchers added, "the impact location is random, energy coupling is weak, and requirements for the nuclear device's impact resistance and detonation timing are extremely stringent."

Real-world missions would also have to take into account the composition of an asteroid (as a pile of rubble would likely require a different approach than a solid rock), whether the pathways of any pieces generated by an impact pose a threat, and how to safely get the nuclear warhead into space in the first place, among many other technical issues. The researchers did not raise these considerations in the press release.

They did, however, provide "recommended solutions" for when to use each of the two options. The shallow impact might be preferable "for emergency defense" on a huge asteroid if there is an extremely short warning time, because that mission is less complex. Otherwise, the "deep impact" would be the way to go.

Even astronauts in space saw America 250 fireworks on the Fourth of July. See their ISS view of Los Angeles (video)

The U.S. just celebrated its 250th birthday, and Americans living off the planet had a great view of some of the parties down below.

"The International Space Station orbited over Los Angeles on July 4th as America marked 250 years of independence with a burst of fireworks lighting up the city below — a celebration so bright it reached all the way to space!" NASA officials said on Monday (July 6) via the agency's ISS X account.

That post featured a 15-second video captured from the orbiting lab, which showed hundreds of firework shows flickering across the L.A. area at night like cameras flashing in quick succession at a concert or a football game.

There are seven people living in Earth orbit at the moment, members of the ISS' current Expedition 74. Three are Americans: NASA astronauts Jack Hathaway, Jessica Meir and Chris Williams, all of whom serve as flight engineers.

The others are the European Space Agency's Sophie Adenot and cosmonauts Andrey Fedyaev, Sergey Kud-Sverchkov and Sergei Mikaev. Kud-Sverchkov is Expedition 74's commander, while Adenot, Fedyaev and Mikaev are flight engineers.

NASA didn't just passively observe celebrations of the United States' 250th birthday; the agency marked the occasion in multiple ways as well.

For example, NASA painted big "America 250" logos on the Space Launch System rocket that launched the Artemis 2 astronauts around the moon this past April. The four Artemis 2 crewmates also wore special patches commemorating the anniversary.

In addition, NASA conducted a series of airplane flyovers in the Washington, D.C. area over the July 4 weekend and will perform more in the coming weeks and months. You can learn more about the agency's anniversary activities in this Space.com story.

Japan’s Hayabusa2 probe captures remarkable photo of a two-headed asteroid 62 million miles away

A Japanese spacecraft has gotten up close and personal with yet another asteroid, beaming home stunning new imagery of the distant space rock.

On Sunday (July 5), the Japan Aerospace Exploration Agency (JAXA)'s Hayabusa2 probe performed a close flyby of asteroid Torifune, a 1,475-foot (450-meter) space rock currently traveling through space some 62 million miles (100 million kilometers) from Earth. It was expected to be one of the closest-ever high-speed passes a spacecraft has had with an asteroid.

During the flyby, Hayabusa2 captured this breathtaking new image of Torifune using its optical camera, and was able to transmit it back to JAXA controllers. The probe captured additional scientific data about the asteroid, but will beam those results home at a later date, according to JAXA.

Hayabusa2 also imaged asteroid Torifune using its Mid-Infrared Camera (TIR), which allows scientists to measure asteroids' surface temperatures, thermal inertia and surface roughness, according to JAXA. This mid-infrared image reveals Torifune to be much cooler in what appear to be shadowed regions seen in the optical image, and much warmer where the surface faces the sun.

a double-lobed space rock on a black background, depicted in a gradient of false colors ranging from white-yellow to deep violet

Asteroid Torifune as seen by the Hayabusa2 probe's Mid-Infrared Camera (TIR) on July 5, 2026. (Image credit: JAXA)

Torifune orbits the sun every 383 days and rotates every 5 hours. It belongs to the Apollo group, a classification of near-Earth asteroids whose orbits cross Earth's as they make their way around the sun.

Hayabusa2's flyby of Torifune was not part of its original mission, and one of the members of the probe's scientific team previously told Space.com the flyby was a "risky operation" due to the unknowns surrounding the asteroid.

These new images add to the growing list of incredible accomplishments the Hayabusa2 probe has notched on its now nearly 12-year mission.

a two panel image of a grey, boulder-covered rock

Asteroid Ryugu, also seen by JAXA's Hayabusa2 spacecraft. (Image credit: JAXA, University of Tokyo, Kochi University, Rikkyo University, Nagoya University, Chiba Institute of Technology, Meiji University, University of Aizu and AIST.)

Hayabusa2 launched in December 2014 on an ambitious mission to collect asteroid samples and return them back to Earth. The probe did just that in December 2020 when JAXA successfully landed samples of asteroid Ryugu in the Australian desert.

Since then, scientists have used the samples to peer back in cosmic time at the history of our solar system and have even discovered that Ryugu contains all five nucleobases found within DNA and RNA.

After collecting its precious samples, Hayabusa2 left Ryugu in 2019. It's ultimate goal is now to flyby asteroid 1998 KY26, which could become the smallest asteroid ever visited by a spacecraft. 1998 KY26 is just 36 feet (11 meters) across, close to the size of the asteroid that exploded above Chelyabinsk, Russia in 2013.

two lumpy grey rocks on a black background; the one on the left is hundreds of times larger than the one on the right

A size comparison between asteroid Ryugu, which was visited by Hayabusa2 in 2020, and its next target, 1998 KY26. (Image credit: ESO/M. Kornmesser. Asteroid models: T. Santana-Ros, JAXA/University of Aizu/Kobe University)

Hayabusa2 is expected to reach 1998 KY26 in the year 2031. Once there, the probe will orbit the space rock before attempting to touch down on its surface. JAXA hopes the mission will help scientists more about the structure and composition of small asteroids.

‘Rocket’s Red Glare’: How NASA’s Artemis 2 moon mission celebrated America’s 250th birthday

It doesn't get more America than giant rockets and missions to the moon.

That's why NASA painted two giant "America 250" logos on the rocket that launched the Artemis 2 astronauts around the moon earlier this year. The Space Launch System (SLS) rocket lifted off on April 1, carrying the Orion spacecraft to orbit with NASA astronauts Reid Wiseman, Victor Glover and Christina Koch, as well as the Canadian Space Agency's Jeremy Hansen.

Their 10-day mission around the moon and back to Earth began with the roaring ignition of SLS's four RS-25 engines and two massive solid rocket boosters (SRBs). Together, they produce 8.8 million pounds (4 million kilograms) of force at liftoff, and lofted the 5.75-million-pounds (2.61 million kg) SLS spaceward on what could be the brightest candle lit for America all year.

Each SRB is integrated into a sectioned stack that stands 177 feet (54 meters) tall on either side of the core SLS booster, which, itself, is supported by the SRBs. With the SRBs securely clamped to the launch pad, SLS hangs in the center between them, held up only by the strength of the interstage bolts at their connection points.

At liftoff, the strength of those bolts gets thrust in the opposite direction. SLS's four RS-25 engines aren't powerful enough to carry the rocket through its initial phase of flight, so the SRBs supply the extra force needed to lift SLS off the launch pad.

The Artemis 2 SLS spent much of 2025 under assembly inside NASA's Vehicle Assembly Building at the Kennedy Space Center in Florida. The rocket was completed and fully stacked by October last year, but the "America 250" was added later and unveiled on Dec. 2.

the back of someone's arm wearing a blue sleeve with red-outlined patch near the elbow.

A special patch worn by the Artemis 2 astronauts honors America’s 250th anniversary. (Image credit: Space.com / Josh Dinner)

The Artemis 2 crew (including Hansen) sported some America 250 swag as well. On their flight suits, each wore a red-outlined patch featuring SLS blasting off toward the moon and Mars above a United States flag and the phrase, in all caps, "THE ROCKET'S RED GLARE," quoting lyrics from the U.S. national anthem.

The patches first made an appearance in January, during the first Artemis 2 SLS rollout from the VAB, and were worn by the crew before, during and after their mission.

"America’s spirit of discovery is alive, and Artemis is carrying it to the moon and beyond," NASA said in a statement after the "America 250" SRB reveal last year.

The space agency is celebrating America in other ways this summer, as well. Check out NASA's America 250 website for a full list of events.