A skyscraper-sized space rock which floated into our solar system has withstood the intense heat of the sun because it is coated in a special crust, research suggests.
The cigar-shaped object, known as Oumuamua, was heated to more than 300C as it passed by, but it is thought a half-metre thick coating prevented it from being vaporised.
It is likely to be the size and shape of London’s Gherkin, according to research involving astronomers at Queen’s University in Belfast.
Loading article content
Dr Michele Bannister said the rock “looks so much like a tiny world from our own home system”.
She likened the effect of the sun on the greyish-red object to an oven baking a cake.
She said: “This object went past the sun and it was only heated like a good oven cooking a cake. It wasn’t actually particularly hot. The surface composition is consistent of a layer of insulating material, so something along the lines of dust and grit, maybe organic compounds.
“We don’t know that the interior does contain ice but if it did contain ice it would have been insulated by the layer on the surface.”
Oumuamua is thought to be an asteroid, but its elongated cigar shape, hundreds of metres long but only a tenth as wide, is highly unusual for a space rock. Findings are to be published in Astrophysical Journal Letters.