A DISTANT space rock shaped like a snowman that formed 4.6billion years ago may have sparked life on Earth.
The peanut-like object Arrokoth is the most distant object we've ever explored, at 4.1billion miles from our home planet.
Arrokoth, previously named Ultima Thule, was pictured early last year by Nasa's New Horizons spacecraft.
Images of the "snowman" released in January 2019 wowed the world – and space scientists have been investigating the data ever since.
The rock sits in the Kuiper Belt, a mysterious region of the Solar System beyond the eight major planets.
And now scientists have detailed the objects true nature and history in three separate studies.
"Arrokoth is the most distant, most primitive and most pristine object ever explored by spacecraft," said Alan Stern, who works on the New Horizons project.
"So we knew it would have a unique story to tell. It's teaching us how planetesimals formed.
"We believe the result marks a significant advance in understanding overall planetesimal and planet formation."
Arrokoth is now believed to have been two separate objects that eventually fused into a single entity.
It's around 22 miles long and 12 miles wide, and marked with several craters.
The space rock is also very cold, and is covered with methanol ice.
Importantly, it has a distinctive reddish colour – which could link it to the presence of life on Earth.
Scientists think that it's likely evidence of organic molecules on Arrokoth.
Organic molecules are carbon-based. And carbon is a primary component of all known life on Earth.
It proves that the building blocks of life can occur even at very distant reaches of space.
Arrokoth itself – or debris from Arrokoth – could potentially be responsible for delivering these key materials to Earth.
"That these complex organics are so ubiquitous in colder parts of the universe means they are readily available to lead to formation of life," said Dr Will Grundy, of the University of Arizona, speaking to .
Dr Grundy, who has been analysing the New Horizons data, said: "Objects like Arrokoth certainly could have delivered them to early Earth from the far edge of the Solar System, but that's not the only possible source.
"Organics would have been abundant in the nearer part of the outer Solar System, too, such as at Jupiter's distance from the Sun.
"And they could even have been produced directly on the early Earth, after it had cooled down somewhat from the great heat of its formation and the Moon-forming impact."
New Horizons is now millions of miles beyond Ultima Thule, also known as 2014 MU69.
During its flyby on January 1 it spent several hours collecting data which scientists will unravel over the next 20 months.
NASA released its first images of Ultima, the most distant object ever visited, on January 3.
The pictures revealed the 21-mile long frozen object is red and "looks like a snowman".
It is formed of two spheres - named Ultima and Thule - which have combined to form one snowman-esque rock.
Dr Stern said: "It is only really the size of something like Washington DC and it is about as reflective as garden variety dirt.
"It's a snowman if it's anything at all."
A video was released later in January 2019, showing the rock tumbling through space.
Arrokoth – The most distant world we've ever explored
Here's what you need to know...
- Ultima Thule, now known as Arrokoth, is a snowman-shaped object in deep space
- It sits in the Solar System about 4billion miles from Earth
- That's well beyond Pluto in a mysterious region known as the Kuiper belt
- Arrokoth was visited by Nasa's New Horizons space probe in January 2019
- It is the most distant world ever explored by humanity
- Horizons spent several hours collecting data which scientists are still unravelling
- So far, we know it's about 21 miles long and is mostly made of ice
Ultima, one of the oldest known objects in our star system, orbits around 4billion miles from Earth in a mysterious region known as the Kuiper Belt.
New Horizons' close approach came five hours into 2019, and three years after New Horizons' historic flyby of Pluto.
The spacecraft will continue downloading images and other data in the days and months ahead.
At its closest approach, the probe brushed within 2,200 miles of Ultima – meaning there are far more detailed images still to come.
Officially known as 2014 MU69, experts believe Ultima Thule is two space rocks fused together.
They were likely created by an ancient planetary collision billions of years ago, and gently came together due to their gravitational pulls.
The latest research on Arrokoth was published in the journal Science.
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