It is about the size of the Colosseum in Rome (between 100 and 200 meters long) and was accidentally detected within the main asteroid belt, located between Mars and Jupiter, by a team of European astronomers. At less than a kilometer long, the asteroid (10920) 1998 BC1 is considered the smallest ever observed by NASA’s James Webb Space Telescope, and it is also one of the smallest found so far in this specific region.
“It was completely unexpected. We detected a small asteroid in publicly available Mid-Infrared Instrument (MIRI) calibration observations,” explained Thomas Müller, an astronomer at the Max Planck Institute for Extraterrestrial Physics in Germany. quoted in a NASA statement.
The discovery of asteroid (10920) 1998 BC1 was made “by chance” when the researchers focused the telescope’s MIRI on the main belt to obtain calibration images.
These calibration images did not turn out as expected, with a glitch due to “objective brightness and a telescope offset.”
However, the team of scientists used the data from asteroid (10920) 1998 BC1 to test a new technique for constraining the orbit and estimating the size of an asteroid.
While analyzing the data, the researchers found an “intruder.” According to the results, the object measured between 100 and 200 meters, occupied a very low inclination orbit, and was located in the inner region of the main asteroid belt.
“Our results showed that even ‘failed’ Webb observations can be scientifically useful if we have the right mindset and a bit of luck,” Müller said. “Our discovery is in the main asteroid belt, but Webb’s incredible sensitivity made it possible to see this roughly 100-meter object from a distance of more than 100 million kilometers.”
Observing this asteroid, which the team believes is the smallest yet detected by Webb and one of the smallest located in the main belt, could be important for understanding the formation and evolution of the solar system.
Future dedicated Webb observations will allow astronomers to study asteroids less than a kilometer in length. This result also indicates that NASA’s telescope may accidentally detect new asteroids.
“This is a fantastic result that highlights MIRI’s ability to incidentally detect an asteroid of previously undetectable size in the main belt,” concluded Bryan Holler, Webb’s support scientist at the Space Telescope Science Institute in Baltimore, Maryland.
The James Webb, the largest and most powerful telescope ever launched into space, is a $10 billion project and named after a former NASA administrator, which was sent into space in December as a European-made rocket. It is in orbit 1.5 million kilometers from Earth.
The astronomers hope with James Webb to obtain more data on the beginnings of the Universe, including the birth of the first galaxies and stars, but also on the formation of the planets.
Source: TSF
