Arrokoth (2014 MU69)

Most Distant Object Explored Up Close
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Introduction

The small Kuiper Belt object officially known as Arrokoth — or by its original designation (486958) 2014 MU69 — is the most distant and most primitive object ever explored by a spacecraft. It was discovered in 2014 by NASA’s New Horizons science team, using the Hubble Space Telescope.

New Horizons flew by Arrokoth on Jan. 1, 2019, snapping images that showed a double-lobed object that looked like a partially flattened snowman. It’s also very red — even redder than Pluto. The object's strange shape — unlike any ever seen — was the biggest surprise of the flyby.

Arrokoth is in a region of space beyond Neptune called the Kuiper Belt that is swarming with small, icy and ancient objects. Because they are so far from the Sun, Kuiper Belt objects have only been slightly heated since forming, and are thought to be well-preserved, frozen samples of what the outer solar system was like after its birth more than 4.5 billion years ago.

Arrokoth means means "“sky” in the Powhatan/Algonquian language.

10 Need-to-Know-Things About Arrokoth

10 Need-to-Know Things About Arrokoth

1

HELP FROM HUBBLE

NASA’s New Horizons science team member Marc Buie discovered Arrokoth on June 26, 2014, using NASA’s Hubble Space Telescope.

2

BY THE NUMBERS

MU69 is officially known as (486958) 2014 MU69. 

3

FAR OUT NICKNAME

Before its official naming in 2019, Arrokoth was nicknamed “Ultima Thule,” a mythical island beyond the borders of the known world.

Flyby

4

FAR, FAR AWAY

Arrokoth is about 4.1 billion miles (6.6 billion kilometers) from Earth.

5

THE LONG WAY AROUND

It takes Arrokoth about 293 Earth years to make one trip around the Sun.

6

TWO FOR ONE

Arrokoth is actually two objects that gently merged into one. End to end, it measures about 22 miles (35 kilometers) long. It’s about 12 miles (20 kilometers) wide and 6 miles (10 kilometers) thick.

7

SQUASHED SNOWMAN

Arrokoth is very red and it has two roundish lobes, resembling a snowman that’s been partially flattened.

8

DISTANT 'SKY'

In 2019 MU69 was officially named Arrokoth, a Native American term meaning “sky” in the Powhatan/Algonquian language. 

9

HISTORY ON ICE

Arrokoth is thought to be a well-preserved sample of what the outer solar system was like when it formed more than 4.5 billion years ago.

10

FLAWLESS FLYBY

NASA’s New Horizons spacecraft zipped by Arrokoth on Jan. 1, 2019 — coming as close as 2,198 miles (3,538 kilometers) of the object.

In Color

Did You Know?

Did You Know?

Arrokoth was discovered June 26, 2014, by NASA’s New Horizons spacecraft team using the Hubble Space Telescope.

Arrokoth is the most distant object explored by a spacecraft.

Arrokoth is even redder than Pluto. It is, in fact, the reddest outer solar system object visited by a spacecraft thus far.

Additional Resources

Additional Resources

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