While observing a star, the James Webb Space Telescope accidentally discovered an asteroid the size of Rome's Colosseum. An international team of European astronomers has made an exciting discovery while using NASA's James Webb Space Telescope.
The team serendipitously detected an asteroid that is likely the smallest observed to date by the telescope and may be an example of an object measuring under 1 kilometer in length within the main asteroid belt.
This result has important implications for our understanding of the formation and evolution of the solar system.
The team was using data from the calibration of the Mid-InfraRed Instrument (MIRI) to test the performance of some of MIRI's filters. However, the calibration images were considered to have failed for technical reasons.
Despite this, the team used the data to establish and test a new technique to constrain an object's orbit and to estimate its size.
In the course of the analysis, the team found the small interloping asteroid in the same field of view.
The team's results suggest that the object measures between 100 to 200 meters, has a very low-inclination orbit, and was located in the inner main-belt region at the time of the Webb observations.
"Our detection lies in the main asteroid belt, but Webb's incredible sensitivity made it possible to see this roughly 100-meter object at a distance of more than 100 million kilometers," said Thomas Müller, an astronomer at the Max Planck Institute for Extraterrestrial Physics in Germany.
This result also suggests that Webb will be able to serendipitously contribute to the detection of new asteroids.
The team suspects that even short MIRI observations close to the plane of the solar system will always include a few asteroids, most of which will be unknown objects.
In order to confirm that the object detected is a newly discovered asteroid, more position data relative to background stars is required from follow-up studies to constrain the object's orbit.
"This is a fantastic result which highlights the capabilities of MIRI to serendipitously detect a previously undetectable size of asteroid in the main belt," said Bryan Holler, Webb support scientist at the Space Telescope Science Institute in Baltimore, Maryland.
"Repeats of these observations are in the process of being scheduled, and we are fully expecting new asteroid interlopers in those images."
The James Webb Space Telescope is the world's premier space science observatory and is an international program led by NASA with its partners, the European Space Agency (ESA) and the Canadian Space Agency.
This exciting discovery is just a small part of the many mysteries that the telescope will solve in our solar system, beyond to distant worlds around other stars, and in the structures and origins of our universe.