File:Webb Detects Extremely Small Main Belt Asteroid (52672254127).jpg

While combing through test data from Webb’s mid-infrared instrument (MIRI), scientists made a surprise discovery. Though the test observed a different object, Webb serendipitously captured an asteroid just 300-650 feet (100-200 meters) in length! Located in the main asteroid belt (which lies between Mars and Jupiter), it is likely the smallest object observed to date by Webb.

If this asteroid is confirmed as a new discovery, it’ll have important implications for our understanding of the formation and evolution of the solar system. Small asteroids in the main asteroid belt have been studied in less detail than their larger counterparts because they are harder to observe that far away. Future dedicated Webb observations will allow astronomers to study main belt asteroids smaller than 0.6 mi (1 km) in size, providing the necessary data to refine our models of the solar system's formation.

According to astronomer Thomas Müller, we can thank Webb’s incredible sensitivity for allowing us to see this tiny object at a distance of more than 60 million miles (100 million kilometers). What’s more, this surprise probably won’t be the last. The science team’s work suggests that when Webb’s MIRI instrument is used to observe the plane of the solar system, we can often expect a few asteroids. There will be even more “photobombers,” more objects to detect.

Read more: www.nasa.gov/feature/goddard/2023/webb-detects-extremely-...