FAQs:

When will we get the first pictures?:

Due to the small size of Ultima (30km), the spacecraft's cameras can only resolve it just as a couple of pixels until a few hours right before the flyby. Since it takes 6 hours for a signal from the spacecraft to reach Earth, this means the first detailed pictures won't be released until January 2nd.

So the pictures shown today will be the clearest we've ever seen Ultima, but it'll only appear a few pixels across. That's still enough to make scientific discoveries, however- such as Ultima's rotation rate, hints at its shape, whether it has any moons, etc

Why is this flyby important?:

This will be the furthest world ever explored by a spacecraft, we've never been to anything like it before. Ultima is a small frozen asteroid that's sitting at the edge of our solar system. It's important because scientists hope that this asteroid is a remnant of the early system, preserved in a kind of deep-freeze. We suspect it's asteroids like these that delivered to Earth the 'seeds of life' billions of years ago- compounds crucial to the development of life.

What will Ultima Thule look like?:

We've never been to anything like Ultima so we don't know! We’ve never gone to a target in the solar system we knew less about. Ultima Thule will probably be made from exotic material like methane ice, stained a deep red colour by billions of years of exposure to solar & galactic radiation. Its surface will likely be heavily cratered, unlike Pluto.

There's some limited evidence that Ultima may be elongated or peanut-shaped, but the mysterious lack of a light curve has made determining Ultima's shape particularly difficult.

During the Jupiter flyby in February 2007, New Horizons sent data home at about 38 kilobits per second (kbps), which is slightly slower than the transmission speed was for acoustic computer modems which operated over telephone lines. The average downlink rate after New Horizons passed Pluto (and sent the bulk of its encounter data back to Earth) was approximately 2,000 bits per second, a rate the spacecraft achieved by downlinking with both of its transmitters through NASA's largest antennas. Even then, it took until late 2016 to bring down all the encounter data stored on the spacecraft's recorders.