We’ve been talking about this mission many times recently, but here’s one final reminder. On September 26, the DART spacecraft will impact the moon of asteroid Didymos at 23:14 UTC. The goal of the mission is to change the orbit of that tiny moon, Dimorphos, by an incredibly small amount, essentially by launching the spacecraft directly at the moon like a small battering ram.

There are a lot of things the spacecraft needs to do before the impact. Four hours before impact, the autonomous navigation system activates. One hour before impact, tiny moonlet Dimorphos will become visibly separate from Didymos. Four minutes from impact, the autonomous navigation system begins its final correction, completed by two minutes to impact. Three seconds before impact, DART will take nine-centimeter per pixel imagery of the asteroid before hitting Dimorphos at over six kilometers a second relative velocity.

During and after the impact, DART’s companion CubeSat, LICIACube, deployed about two weeks ago, will be capturing images of the impact event. Then, in 2024, the European Space Agency plans to launch Hera, a spacecraft that will arrive in 2026 at the Didymos system, and take observations of both asteroids. Hera will be in the company of two CubeSats to take a complete survey, focusing especially on the impact crater left behind.

NASA’s official live coverage will start two hours before impact, and Beth Johnson will be co-hosting coverage for the SETI Institute with colleague Franck Marchis and a slate of guests involved with the mission. We’ll have links to all that coverage in the show notes for this episode.

More Information

PDF: DART press kit (JHUAPL)

VIDEO: The incredible adventures of the Hera mission – Creating a crater (ESA)