The Snowman Of The Universe


Three images of Ultima Thule, center image is black-and-white (photos from NASA / Johns Hopkins University Applied Physics Laboratory / Southwest Research Institute)

Last week the news broke that NASA’s New Horizons spacecraft had flown by and photographed what looks like the “snowman of the universe,” two icy chunks stuck together like a snowman and spinning out there in the Kuiper Belt beyond Neptune.

Yes, this object spins. Here’s a time lapse from NASA on New Years Day 2019.

Polar view of  Ultima Thule’s rotation over 2.5 hours (animation from NASA)

The snowman is reddish and tiny, only 20 miles long, so he can’t be seen from Earth. We wouldn’t even know about him except that a few years ago the New Horizons team looked for something interesting for the spacecraft to explore after it passed Pluto. They saw him as a dot using the Hubble Space Telescope in 2014 and chose him because he’s a classical Kuiper Belt object with low inclination and low eccentricity.

How eccentric is a snowman in outer space? It depends on his orbit.

NASA named his big chunk Ultima and his small one Thule. The combo sounds like a name from science fiction but in fact Ultima Thule was the name ancient geographers gave to the northernmost land in the inhabited world. Back then it was somewhere in Iceland, Norway, or a remote Shetland Island. Now it’s beyond Neptune. (Click here to pronounce Ultima Thule. It’s not what you think.)

Ultima Thule’s real name is (486958) 2014 MU69. It’s just the right number of digits for a phone number, but don’t call it. The long distance charges are astronomical!

For more information, including a diagram showing how the snowman formed, read NASA’s New Horizons Mission Reveals Entirely New Kind of World.

p.s. I’m sure Ultima Thule is not the only snowman out there so he’s actually “A Snowman” in the universe, not “The Snowman.”

(images from NASA / Johns Hopkins University Applied Physics Laboratory / Southwest Research Institute)