This morning, the Japanese Aerospace Exploration Agency, or JAXA, confirmed that its mission to return samples of an asteroid to Earth did indeed bring home some space rocks. Engineers at the agency found black sand they believe to be from an asteroid inside the mission’s sample container.

It’s great news for the mission, known as Hayabusa2, which launched to space in 2014. The mission sent a spacecraft to an asteroid named Ryugu to collect samples of rocks from the object’s surface and then bring them back to our planet for study. Hayabusa2 wound up scooping up materials from Ryugu twice before heading back to Earth. The vehicle arrived this month, jettisoning a canister filled with the asteroid samples, which then landed in Australia with the help of a parachute on December 5th.

Up until today, JAXA engineers weren’t exactly sure if the spacecraft had grabbed any samples. While the vehicle performed all of its sampling maneuvers at Ryugu as planned, the mission team didn’t have a way to confirm that the vehicle held any asteroid materials while in space. They had to wait until today when they opened the sample container in a clean room in Japan for the first time.

“The sample container inside the re-entry capsule has been opened,” JAXA wrote in a statement. “On the 14th of March, a black sand granular sample believed to be derived from the asteroid Ryugu was confirmed inside the sample container.”

The good news doesn’t stop there, as there may be even more asteroid material that the engineers haven’t reached yet. The black sand that JAXA found was located just at the opening of the sample container. There is still a main chamber deeper inside the container that hasn’t been opened yet, which could contain the bulk of the sample. The goal of the mission was to collect up to 100 milligrams of material from Ryugu. Engineers will know if they hit their target as they dive in deeper into Haybusa2’s stores.