Hey, down in front!
NASA has announced the accidental discovery of what it's calling an "extremely small" asteroid by the James Webb Space Telescope — though in space, size is relative.
In an update, NASA noted that while the asteroid imaged by the JWST is "roughly the size of Rome’s Colosseum — between 300 to 650 feet (100 to 200 meters) in length," they still describe the "interloper" as diminutive.
Indeed, one of the most well-known objects in the asteroid belt region located between Mars and Jupiter, the dwarf planet Ceres, was known as an asteroid until 2008 and has a radius of just under 300 miles.
By comparison, this new asteroid is described as being about less than one kilometer in length. While it's certainly not the smallest known asteroid — that distinction goes to 2015 TC25, a teeny tiny asteroid that's only six feet in diameter — this new guy is still a baby by Asteroid Belt standards, and is per NASA the smallest ever detected in the main belt.
This little guy's accidental discovery within the main asteroid belt occurred "completely unexpectedly" during the calibration of the Mid-Infrared Instrument (MIRI), which according to the agency houses "both a camera and a spectrograph that sees light in the mid-infrared region of the electromagnetic spectrum" invisible to the naked human eye.
What's more, the calibration actually "failed" in the eyes of Webb scientists for jargony technical reasons, but nevertheless led to observations that were recently published in the Astronomy and Astrophysics journal.
As the statement notes, it appears that this asteroid is "likely the smallest observed to date" by the Webb telescope, which in itself is pretty cool.
"Our results show that even ‘failed’ Webb observations can be scientifically useful, if you have the right mindset and a little bit of luck," Thomas Müller, an astronomer at the Max Planck Institute for Extraterrestrial Physics in Germany that works on Webb, said in the NASA statement. "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."
This accidental discovery is yet another reminder of how high-powered the Webb telescope really is — and how even when it's off its A-game, it's still spitting out fascinating data.
More on Webb: NASA Adjusting James Webb Orbit to Get Damaged by Asteroids Less