Tomorrow's a big day at the European Space Agency: Officials are getting ready to land a probe on Comet 67P/Churyumov-Gerasimenko, Space.com reports. The Philae robot will have to navigate a "very, very rough" surface, and officials won't know whether things have worked out until after what NASA has dubbed "seven hours of terror." Parent spacecraft Rosetta is due to release Philae at 3:35am EST tomorrow, and they'll know whether all went well by 11:02am. Prior to that little stretch of suspense comes four hours of sending directions to the probe. "We have four hours to put them together, check to verify they are consistent, uplink to the spacecraft ... and double-check they are OK," says a mission head.
The team announced a landing spot in September; getting there will require a harpoon due to low gravity. A successful landing would mark the first time a probe has landed on a comet, a process that's taken years of preparation. Officials began work on Rosetta in the 1990s, and the mission was launched in 2004. And that probe, by the way, has "less computer processing power than your iPhone," VentureBeat reports. Experts aim to find out whether comets, which have been around for 4.6 billion years, might have delivered water to Earth, helping life to emerge, the Wall Street Journal reports. "Sometimes, we wake up and wonder if this dream is going to be true," says an official. "But we are ready for every option and are still very confident we can make it." (Join in the terror via webcast here.)