Exploring the
Farthest World Yet
BY KOREY HAYNES2424 DISCOVERMAGAZINE.COMDISCOVERMAGAZINE.COM
NASA
/JHUAPL/SWRIi
On New Year’s Day 2019, the far-flung New Horizons
spacecraft, which visited Pluto in 2015, set a new
record when it buzzed by the most distant object
yet visited by humanity: a remote space rock nicknamed
Ultima Thule. The object — officially dubbed 2014 MU 69
— orbits the sun a whopping 4 billion miles from Earth,
deep within the realm of frozen rocks called the Kuiper
Belt. That distance meant it took more than six hours for
the spacecraft’s signals — traveling at light-speed — to
reach Earth. The delay will only increase as New Horizons
continues speeding deeper into space at 9 miles per second.
It won’t finish sending back data on the space rock until
summer 2020.
When the first images trickled in, they revealed UltimaThule to be a snowman-shaped world. Since then, researchers
have found it oddly flat — less a snowman and more like two
conjoined pancakes poured too closely together in the pan. Its
two lobes, now called Ultima and Thule, were likely separate
bodies that collided gently in the distant past. The region
around Ultima Thule was clear of any dust, moons or rings.
Those facts, and the asteroid’s fairly uniform makeup, make
scientists think it’s led a quiet life in the far reaches of the
solar system.
Astronomers often consider space rocks the building
blocks of the solar system, since they’ve undergone fewer
changes than the material in large, complex bodies like
planets and moons. For researchers looking for a pristine
example, lonely Ultima Thule may be exactly the right target.