Our solar system has been visited by an interstellar traveller. First discovered late last month, the interstellar asteroid is believed to be at least ten times as long (around 400 meters) as it is wide, giving it a peculiar cigar-shaped appearance. The discovery has been met with great excitement in the scientific community as it proves long-held theories of roaming interstellar objects.
“For decades we’ve theorized that such interstellar objects are out there, and now – for the first time – we have direct evidence they exist,” said associate administrator for NASA’s Science Mission Directorate in Washington, Thomas Zurbuchen. “This history-making discovery is opening a new window to study [the] formation of solar systems beyond our own.”
The discovery was made by the University of Hawaii’s Pan-STARRS1 telescope on October 19. Part of NASA’s Near-Earth Object Observations (NEOO) programme, researchers couldn’t believe their luck having discovered our interstellar visitor purely by chance. The team of researchers that discovered the asteroid named it ‘Oumuamua (“Oh-moo-ah-moo-ah”), Hawaiian for “a messenger from afar arriving first”
Following the initial discovery of the asteroid telescopes from around the world began to collect additional data. Using the FORS instrument on ESO’s Very Large Telescope in Chile, Karen Meech of the Institute for Astronomy in Hawaii was able to determine the asteroid’s appearance in some detail.
Meech described the asteroid as being reddish in colour and elongated in shape “without the faintest hint of dust around it”. With this information, researchers have theorised that the asteroid is dense and possibly comprised of rock and metals. Additional, the reddish colour is indicative of objects found in the outer solar system and is likely the result of prolonged exposure to cosmic rays over hundreds of millions of years.
‘Oumuamua will be closely monitored until mid-December when it will be too faint to be detected.
Image Credit: European Southern Observatory/M. Kornmesser