Falcon 9 rocket booster could collide with the moon in coming weeks

A drifting rocket booster could collide with the Moon in the coming weeks, space experts say, an event that could leave a crater on the far side of the Moon.

The chunk of SpaceX’s Falcon rocket was used in 2015 to launch the US Deep Space Climate Observatory (DSCOVR) and has been floating on the outside of the Earth-Moon system ever since.

Bill Gray, an independent researcher with a focus on orbital dynamics who was the first to publicize the impending collision, said that, according to his calculations, the rocket chunk would hit the Moon a little north of its equator “about a minute away.” ” from 07:26 a.m. Eastern Time (09:26 GMT) on March 4. The way the object is moving makes it difficult to pinpoint the exact location, he added, although it is likely to change only by a few kilometers.

“Right now, we can’t get any more data because the object is very close to the sun in the sky. On the 7th and 8th of February, we will have a brief opportunity to observe it and obtain more data, so the date and location previously reported can be better determined,” Gray wrote in an email.

While spacecraft sometimes intentionally hit the Moon at the end of a lunar mission, for example, space debris randomly hitting the Moon is not common, said Holger Krag, head of the Space Debris Office at the European Space Agency.

It’s safer for the 50-foot-long chunk of the rocket to crash into the Moon than it is to make an uncontrolled entry into Earth’s atmosphere, Krag said. The rocket booster weighs about 3 to 4 tons.

“The piece would be permanently discarded. From a security point of view, this is really the safest way to dispose of it. Leaving it adrift in an orbit around the Sun does not guarantee that it will not be captured again by Earth one day.”

“Managing the return of the part to re-enter the atmosphere in a controlled and safe way is extremely complex. Disposal on the lunar surface is still the safest.”

deep space objects

There are about 30 to 50 stray objects in deep space, like the chunk of the Falcon rocket, that have been missing for years, but no space agency has systematically tracked these space debris so far from Earth, said Jonathan McDowell, an astronomer at the Center for Astrophysics. Harvard and Smithsonian.

“This is the first time something not aimed at the Moon has been noticed accidentally hitting it, but that’s mainly because we weren’t paying attention until recently,” he wrote via email.

Unintentional collisions of rocket parts with the Moon could occur more frequently in the future, Krag said, with more missions making use of Lagrange points — equilibrium points more than a million kilometers from Earth where the sun’s gravitational forces and of the Earth are more or less balanced. Space vehicles such as the Newly Launched James Webb Telescope, are usually launched at these points, where they don’t need much thrust to stay in orbit.

McDowell said on your blog that the rocket booster’s orbit was “somewhat chaotic” as it was affected over time by lunar and solar gravity, as well as Earth’s gravity as well.

Both Krag and McDowell said there are no clear guidelines for space agencies and companies to deal with these situations, and disposing of these launchers, space vehicles and satellites is difficult.

“Deep space traffic is increasing,” McDowell said. “And it’s not just the US and [Rússia] that are sending things into space, there are several countries and even commercial companies like SpaceX. So I think it’s time for the world to get more serious about regulating and cataloging deep space activity.”

“That’s not ‘SpaceX did something bad’” — it’s perfectly common practice to drop things in deep orbit,” he added.

SpaceX did not immediately respond to the email asking for comment.

Krag said the collision could be a scientific opportunity.

Dust clouds resulting from an impact can be analyzed for clues about the composition of the lunar surface. Gray said orbiters such as India’s Chandrayaan-2 rover could also capture images of the crater that will form, giving a glimpse of newly exposed lunar soil from a meter or two deep — a rare chance to look beneath the surface. from the moon.