Viewers of the SpaceX TESS (Transiting Exoplanet Survey Satellite) livestream on Wednesday saw a little something extra slowly drift across the camera’s view. Some wondered what it could be. A piece of the satellite? Space debris? Advanced alien technology?

It wasn’t any of that. That unknown object was ice. SpaceX uses liquid oxygen — which has a very low temperature — as part of the propellant to fuel the rockets. The extra cold liquid can cause condensation to form on the outside of the rocket, which can create ice. This piece broke off at the perfect time to be captured on camera.

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A space object captured by a SpaceX camera

Wednesday’s mission by SpaceX was to launch the TESS, which will now be on the lookout for planets that exist outside of our solar system known as exoplanets. It will scan parts of the galaxy for the next two years. NASA’s goal is to have the satellite discover approximately 20,000 new exoplanets.

“Some of the most interesting work that TESS will enable centers on probing the chemistry of planets,” Patrick McCarthy, a vice president at Giant Magellan Telescope Organization, told Inverse this month. “As a planet passes in front of its star, a large telescope on the ground, like the GMT, can use spectra to search for the fingerprints of molecules in the planetary atmosphere.”

This makes eight successful missions for SpaceX in 2018. The Falcon 9 booster used to put the satellite into space successfully made its way back to Earth and landed on a drone ship in the Atlantic Ocean. Out of the 52 Falcon 9 launches, this was the 24th to successfully land.