Astronomers spot 'weirdo' asteroid in cold outer reaches of Solar System

Likely formed in the asteroid belt between Mars and Jupiter during the early Solar System

A team of astronomers from around the globe have discovered an asteroid that they believe to be the first of its kind sighted in the cold outer reaches of the Solar System.

Using European Southern Observatory (ESO) telescopes to investigate the relic, the team found that the asteroid, now named Object 2004 EW95, is carbon-rich and likely formed in the asteroid belt between Mars and Jupiter.

ESO is the foremost inter-governmental astronomy organisation in Europe and also claims to be the world's "most productive ground-based astronomical observatory".

Named a "weirdo" by some astronomers, the asteroid is said to have been flung billions of kilometres from its origin to its current home in the Kuiper Belt in the outer reaches of the Solar System.

Given 2004 EW95's present-day abode in the icy outer reaches of the Solar System, this implies that it has been flung out into its present orbit by a migratory planet in the early days of the Solar System

After painstaking measurements from multiple instruments at ESO's Very Large Telescope (VLT), a small team of astronomers in the UK were able to measure the composition of the anomalous asteroid, and determined that it is a carbonaceous asteroid.

This suggests that it was originally formed in the inner Solar System and must have since migrated outwards.

"The reflectance spectrum of 2004 EW95 was clearly distinct from the other observed outer Solar System objects," explained lead astronomer, Tom Seccull of Queen's University Belfast. "It looked enough of a weirdo for us to take a closer look."

However, even with the impressive light-collecting power of the VLT, 2004 EW95 was still difficult to observe. Though the object is 300 kilometres across, it is currently a colossal four billion kilometres from Earth, making gathering data from its dark, carbon-rich surface a demanding scientific challenge.

"Not only is 2004 EW95 moving, it's also very faint," said Seccull. "We had to use a pretty advanced data processing technique to get as much out of the data as possible."

The astronomers noted that two features of the object were particularly eye-catching and corresponded to the presence of ferric oxides and phyllosilicates. The presence of these materials had never before been confirmed in a Kuiper Belt object or KBO, and strongly suggested that 2004 EW95 formed in the inner Solar System.

"Given 2004 EW95's present-day abode in the icy outer reaches of the Solar System, this implies that it has been flung out into its present orbit by a migratory planet in the early days of the Solar System," added Seccull.