Look up to the stars tomorrow, because if you’re lucky, and in the right place with a telescope, you might be able to spot a spacecraft tearing past on its way to an asteroid.

That spacecraft is NASA’s OSIRIS-REx, which was launched on September 8, 2016, as it headed to asteroid 101955 Bennu. It’s scheduled to arrive in August 2018, but to get there it needs a gravitational boost from our planet. So tomorrow at 12.52pm EST (4.52pm GMT), it will fly past to get a little speed bump.

OSIRIS-REx will fly past at a distance of about 17,000 kilometers (11,000 miles). It will begin its flyby above Australia, finishing over Antarctica. You should be able to see it from nearby locations such as Japan and Chile too. You’ll need a half decent telescope, though.

The spacecraft will be busy testing out some of its instruments during the flyby, including snapping pictures of Earth and the Moon. Astronomers on the ground will also get a chance to take some images in the other direction and can submit their images online.

“The opportunity to capture images of the OSIRIS-REx spacecraft as it approaches Earth provides a unique challenge for observers to hone their skills during this historic flyby,” said Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona, Tucson, in a statement.

“As the spacecraft approaches Earth for its own imaging campaign, ground-based observers will also be looking up and taking photos from the opposite perspective.”

NASA is understandably excited about the event, so they’re asking people to “wave to OSIRIS-REx,” taking pictures of themselves and posting them on Twitter or Instagram with the hashtag #HelloOSIRISREx. Don’t forget to tag the mission accounts – @OSIRISREx on Twitter and @OSIRIS_REx on Instagram.

As it flies past, the spacecraft will be traveling at about 30,000 kilometers per hour (19,000 miles per hour). This encounter will give it an additional kick that will help it make the rest of its journey to Bennu, which is about 225 million kilometers (140 million miles) from Earth.

Once the spacecraft reaches Bennu, it will spend two years observing it from a distance. Then, in July 2020, it will approach the asteroid and attempt to grab a sample with a robotic arm. If all goes to plan, it will leave the asteroid in March 2021, returning the sample to Earth in September 2023.