On New Year’s Day, a spacecraft will zoom by the most distant object humanity has ever visited

The Verge ^ | Dec 27, 2018, 10:37am EST | Loren Grush

[BenLurkin]

This remote interplanetary flyby will be over in a blink. But if successful, the event could tell us a whole lot about the objects that dominate the far reaches of our cosmic neighborhood.

The robotic spacecraft making this daring visit is called New Horizons, and it’s been traveling through space for the last 13 years. You may remember this famous bot: it was the first human-made object to ever visit Pluto in the summer of 2015. Ever since that flyby, New Horizons has been plunging farther into the Solar System. Three years later, it’s ready to meet up with another faraway target, a rock nicknamed Ultima Thule located 1 billion miles beyond Pluto. That’s 4.1 billion miles from Earth.

It’s a tiny frigid object about the size of New York City, orbiting in an area of the Solar System known as the Kuiper Belt. This region of space, located beyond the orbit of Neptune, is filled with possibly millions of small frozen objects. It’s a bit like a super distant Asteroid Belt. Except the bodies in the Kuiper Belt are thought to be incredibly primitive — leftover remnants from the birth of the Solar System. When the planets first formed 4.5 billion years ago, the materials in the Kuiper Belt region didn’t join together to form new worlds but instead remained as tiny fragments.

Kuiper Belt objects are incredibly cold — just 35 degrees Kelvin above absolute zero. At this temperature, the objects don’t change very much on the surface. They’ve essentially been frozen in time over billions of years.

[Campion]

Not following you. The trajectory to the moon is a (very eccentric) orbit around the earth, which is why Apollo 13 could just whip around the moon and come straight back home. Apollo flights were actually in "earth orbit" for the entire trip, including the time they were also orbiting the moon, and the time they spent *on* the lunar surface, the moon itself being in earth orbit.

Although man's machines have left earth orbit, man himself regrettably has not. So far.

[ThornJ56]

Ah I must simply be uninformed. Thanks for the lesson, always neat to learn something new.

[sparklite2]

Put them in a class that includes the Lewis and Clark expedition. Only the astronauts knew what was out there. Lewis and Clark didn’t know what they would find.