A tiny spacecraft is getting ready to reveal the secrets of one of Saturn's largest moons, Titan.
The Huygens probe was taken into space by another craft, called Cassini, and was released from it towards Titan.
Scientists hope that the information Huygens sends back will help them learn more about how life started on Earth.
The scientists don't even know what Huygens will land on, as a thick haze stops them from seeing if Titan's surface is liquid, solid or even ice.
The conditions on Titan are thought to be similar to how Earth was around 4.6 billion years ago.
A model of Titan shows what the probe looks like
Researchers hope Huygens will send them back photos of what it sees on its way to Titan and when it lands.
They're also hoping a special microphone on the spacecraft will transmit sounds back to them as well, perhaps even lightning.
Huygens has spent seven years attached to Cassini on the way to Saturn and its moons.
It is expected to reach Titan's atmosphere around 9am on Friday and should get to the moon's surface around 90 minutes later.