New discovery of the James Webb Space Telescope of NASA / ESA / CSA. An international team of European astronomers has indeed identified a previously unknown 100-200 meter asteroid, roughly the size of Rome’s Colosseum. The project used data from the Mid-InfraRed Instrument (MIRI) calibration, in which the team randomly detected an interlocutory asteroid. The object is probably the smallest observed to date by Webb and could be an example of an object measuring less than 1 kilometer in length within the main asteroid belt, located between Mars and Jupiter.
More than 1.1 million asteroids are known in the solar system
Further observations will now be needed to better characterize the nature and properties of this object. The Solar System teems with asteroids and small rocky bodies: astronomers currently know more than 1.1 million of these rocky remnants from the early days of its formation. The detection of this asteroid – which the team suspects is the smallest observed to date by Webb and one of the smallest detected in the main belt – would, if confirmed, have important implications for understanding the formation and evolution of the Solar System.
Discovered by accident by the team of astronomers
The Webb images that revealed this small rocky body weren’t originally designed to search for new asteroids. These were, in fact, calibration images of main-belt asteroid (10920) 1998 BC1, which astronomers discovered in 1998, although the calibration team found them non-compliant for technical reasons due to the brightness of the target and the offset pointing of the telescope. Despite this, data from asteroid 10920 was used by the team to establish and test a new technique for limiting an object’s orbit and estimating its size.