Scientists Find Small Asteroid in James Webb Calibration Data

The James Webb Space Telescope was designed to provide more detailed data and images of distant objects and structures. However, it’s still possible for the occasional photobomb to happen.

In this case, scientists found evidence that a small asteroid wandered into the field of view of one of James Webb’s instruments during calibration. Technicians were using a previously discovered asteroid in the main asteroid belt to calibrate the MIRI instrument. The technicians ruled that the asteroid was too bright to be useful for testing its filters. However, scientists could use the data they got to test a new technique for estimating an asteroid’s size and orbit by comparing it with data from other telescopes.

While working with the data, scientists discovered the photobomb: an asteroid that isn’t much larger than Rome’s Colosseum. They estimate that it is between 100 and 200 meters in length, making it one of the smallest objects found using the James Webb Space Telescope to date.

“Our results show that even ‘failed’ Webb observations can be scientifically useful, if you have the right mindset and a little bit of luck,” said Thomas Müller, an astronomer at the Max Planck Institute for Extraterrestrial Physics in Germany. “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.”

James Webb gets excellent images of distant objects like the “Pillars of Creation.” It can also find early galaxies, observe new stars’ formation, and find exoplanets. However, it isn’t designed to find asteroids, making this relatively small object a lucky find.

Scientists are still waiting on confirmation of the newly discovered asteroid. Small ones are harder to find and observe due to their size. However, scientists expect that many observations using the James Webb Space Telescope along the solar system’s plane will include a few previously unknown asteroids and make it easy to find and study asteroids that are less than one kilometer long. So researchers are unlikely to be upset about the occasional photobomb – naturally, as long as it’s not an artificial satellite that messes up readings.

Preliminary results on the new technique for calculating the radiometric size, distance, and orbit constraints of asteroids have already been published in Astronomy and Astrophysics.