SpaceX Falcon 9 rocket stage expected to crash into the Moon

A 4-ton piece of a SpaceX Falcon 9 rocket that had been drifting through space since early 2025 was expected to slam into the Moon early Wednesday, creating an unusual collision that could give scientists a closer look at what happens when space debris hits the lunar surface.

The school-bus-size rocket stage, left over from a mission carrying a Firefly Aerospace lunar lander, was expected to strike the Moon at about 2:35 a.m. ET (0635 GMT) at roughly 5,400 miles per hour (8,690 kph).

The impact was not intentional, and scientists did not expect spacecraft orbiting the Moon to be positioned to photograph the collision in real time. Confirmation was expected to take several hours, with researchers relying on telescopes and later observations.

The unusual event has also revived questions about what happens to space junk left in deep space, particularly as NASA and private companies prepare for a much busier future around the Moon.

The object was the second stage of a SpaceX Falcon 9 rocket launched in January 2025. The rocket had helped send a lunar lander built by Firefly Aerospace toward the Moon.

Normally, rocket stages used for missions closer to Earth eventually re-enter the atmosphere and burn up, or fall into the ocean.

This mission was different.

Because sending a spacecraft toward the Moon requires considerably more energy than placing a payload into a nearby Earth orbit, the Falcon 9's upper stage was left traveling through space after completing its primary job.

The stage had also dumped its remaining fuel, meaning it could no longer be controlled. For months, it effectively became another piece of human-made material drifting through space.

Astronomers did not immediately know that the Falcon 9 stage was destined for the lunar surface.

It was only earlier this year that researchers determined its trajectory would eventually intersect with the Moon.

The explanation was a combination of gravity and solar activity gradually changing the object's path.

"What has happened is essentially a mixture of solar activity and gravity forces have put it on a path toward the moon," Julianna Scheiman, SpaceX director of NASA science and Dragon programs, told reporters on Monday.

The trajectory was expected to take the rocket stage into Einstein Crater, located near the Moon's western limb.

That location is particularly challenging to observe from Earth.

The impact was expected to happen at an extraordinary speed of approximately 5,400 mph.

A collision involving thousands of kilograms of metal would likely blast lunar material from the surface and create a plume of dust and debris.

Scientists expected sunlight to illuminate some of that material, but the event would still be extremely difficult to observe from Earth.

There was another problem: none of the spacecraft currently orbiting the Moon were expected to have a suitable position to capture the collision as it happened.

That meant researchers would likely need to compare telescope observations taken before and after the predicted impact.

The crater and surrounding area could potentially provide scientists with information about how high-speed impacts disturb the Moon's surface.

Although the collision was accidental, astronomers said it could still have some scientific value.

"This may be of some — probably minor — scientific interest, and we may learn some things from it," said Bill Gray, creator of widely used astronomy software who published a report on the stage's impact in April.

Gray also noted that the event was not a danger to people on Earth, while raising concerns about how leftover hardware is handled.

"It doesn't present any danger to anyone, though it does highlight a certain carelessness about how leftover space hardware (space junk) is disposed of."

Human-made objects have collided with the Moon before, although such events remain relatively uncommon.

In March 2022, a Chinese rocket stage crashed into the lunar surface after completing a lunar test mission.

NASA has also deliberately sent rocket hardware crashing into the Moon.

In 2009, NASA intentionally crashed a rocket stage into the lunar surface to study the plume of material produced by the collision.

The agency also deliberately crashed stages from the Saturn V rockets into the Moon during the 1970s, using the impacts to study the Moon's seismic response.

The accidental SpaceX rocket impact is part of a longer history of human-made spacecraft hitting the Moon unintentionally.

Russia's Luna-25 mission crashed into the lunar surface in 2023 after the spacecraft spun out of control during its attempted landing.

India's Chandrayaan-2 lander crashed in 2019 after losing contact during its descent.

That same year, Israel's Beresheet lunar lander also crashed.

Beresheet carried an unusual biological payload: tiny tardigrades, microscopic creatures famous for their ability to survive extreme conditions, including radiation and harsh environments. They may still be present on the lunar surface.

The timing of the incident is particularly significant because the Moon is about to become much busier.

NASA's Artemis program aims to return astronauts to the lunar surface and establish a more sustained human presence there later this decade.

That means the space around the Moon will increasingly contain spacecraft, landers, scientific instruments and other hardware.

NASA and SpaceX are already discussing ways to prevent similar impacts in the future, according to Scheiman.

The concern is not that this particular rocket stage posed a threat to people. Rather, as lunar exploration accelerates, uncontrolled objects could become a bigger operational problem.

For decades, discussions about space junk have largely focused on Earth's orbit, where thousands of inactive satellites, rocket stages and fragments travel at enormous speeds.

But the growing number of missions to the Moon is creating another question: What happens to spacecraft and rocket stages after they finish their jobs in deep space?

A rocket stage that cannot be controlled does not simply disappear. Its trajectory can continue to evolve under the influence of gravity from the Earth, Moon and Sun.

In this case, those forces ultimately placed a piece of SpaceX hardware on a collision course with the lunar surface.

The incident highlights a challenge that could become increasingly important as the United States, China, India and private space companies send more missions toward the Moon.

The Moon is no longer simply a distant destination for occasional government missions.

NASA's Artemis program is designed to support recurring human missions, while commercial companies are developing lunar landers and other spacecraft.

As lunar traffic increases, lunar space junk and spacecraft disposal could become an increasingly important part of mission planning.

The accidental Falcon 9 impact therefore represents more than a strange piece of space debris finally reaching the Moon. It offers an early reminder that future lunar missions may need to consider what happens to hardware after its mission ends.