NASA: Icy object past Pluto looks like reddish snowman

A NASA spacecraft travelling 4 billion miles from Earth has sent back its first close-up pictures of the most distant celestial object ever explored, and it looks like a reddish snowman.

Ultima Thule, as the small, icy object has been dubbed, is an elongated body about 20 miles long, consisting of two fused-together spheres.

NASA's New Horizons, the spacecraft that sent back pictures of Pluto 3 1/2 years ago, swept past the ancient, mysterious object early on New Year's Day. 

It is a billion miles past Pluto.

The pictures from Ultima Thule were revealed Wednesday.

Scientist Jeff Moore says that the two spheres formed when small, icy pieces coalesced in space billions of years ago. Then the spheres slowly spiraled closer to each other and stuck together.

Ultima Thule has a mottled appearance the colour of light brick. Scientists say no impact craters could be seen in the latest photos.