Hayabusa Asteroid Landing: Why Researchers Shot an Asteroid With a Bullet

A Japanese-made spacecraft named Hayabusa2 landed on the Ryugu asteroid. Its mission? Shoot it with a bullet, for science.

This is according to a report from Japan’s space agency JAXA. No, this wasn’t a recreation of Obi-Wan’s dogfight with Jango Fett in Star Wars: Episode II – Attack of the Clones (though that would be cool, tbh). It was the first step in part of a bigger effort to understand exactly how planets formed in the fledgling solar system billions of year ago.

Hayabusa2 has been eyeing Ryugu since mid-2018 when it first began creeping up on the asteroid that floats between Earth and Mars in an elliptical orbit. The craft finally touched down on the roughly 3,168-feet in diameter space rock on Friday morning Japanese time and fired a bullet-like device into its surface to collect asteroid samples. But like any remote space mission, everything didn’t go according to plan.

During Hayabusa2’s approach, JAXA scientists noticed that it was covered in large hunks of gravel instead of the chalky dust coating that they expected. They even had to conduct an impromptu test at the University of Tokyo on December 28 to see if the probe’s sampling gun would even still function as intended, given the drastically different surface. Fortunately, it did and Hayabusa2 was able to go on to collect its first-ever asteroid sample.

The sampling device that Hayabusa2 fired into Ryugu inside of its barrel.


JAXA is planning two more sampling shots in the next few weeks. After it’s collected enough particles of Ryugu, Hayabusa2 will leave the asteroid in December 2019 and is expected to return to Earth by the end of 2020. If it makes it back in one piece, scientists will begin examining its bounty of space rocks that will hopefully help unlock the secrets of how life began to develop in earliest days of the solar system.

What’s So Special About Ryugu?

Asteroids are relics of the ancient universe. The solar system was born out of a spiraling ring of dust and gas circling around the juvenile sun, which went on to form rocky and gaseous planets. All the leftover debris eventually turned into what we’ve now named asteroids, and as a result they may still house compounds that served as the building blocks of life 4.5 billion years ago.

Hayabusa2 approaching Ryugu.


Ryugu is a particularly rare breed of space rock. It’s considered a “Type-Cg” asteroid, meaning one that is rich in carbon molecules, are the basic compounds that make up amino acids and proteins. Studying its shrapnel will give scientists a glimpse of what the solar system was like when it was just forming.

The floating rock was originally discovered in 1999 by astronomers at the Lincoln Laboratory Experimental Test Site in New Mexico, but it was eventually given a proper name in 2015 by Japanese scientists. The name refers to a Japanese folktale about a fisherman that travels to a dragon’s palace — or Ryugu-jo — and returns with a mysterious box.

Hayabusa2 is close to doing the same.

Related Tags