Can astronomers outsmart bus-sized asteroids in cosmic hide and seek?

Even small asteroids can cause tremendous damage while being barely detectable. But now, thanks to MIT astronomers’ technology, an asteroid as small as a bus can be detected in time.

The killer asteroid believed to have wiped out the dinosaurs had a diameter of ten kilometers. Such giant asteroids are unlikely to hit Earth any time soon – they’re predicted to meet our planet once every 100 million to 500 million years.

However, we aren’t entirely safe. Smaller asteroids, ranging in size from stadium-size to even as big as a bus, strike Earth every few years, impacting entire regions.

Small asteroids are more likely to escape the forces of gravity in the field of rubble between Mars and Jupiter where millions of asteroids orbit, called the main asteroid belt. These escaped asteroids become unwanted neighbors in our orbit, causing potential danger.

So far, the existing technology has only allowed scientists to detect asteroids sized around a kilometer in diameter. However, an international team led by physicists at MIT has found a way to spot the smallest asteroids within the main asteroid belt.

In the study, they identified 138 new space rocks ranging in size from a bus to several stadiums wide, which is record-breaking for asteroid detection.

“We have been able to detect near-Earth objects down to 10 meters in size when they are really close to Earth,” says the study’s lead author, Artem Burdanov.

“We now have a way of spotting these small asteroids when they are much farther away, so we can do more precise orbital tracking, which is key for planetary defense.”

Studying main-belt asteroids with a diameter of ten meters could offer insights into the origins of meteorites. Researchers believe this method could also be used to identify and monitor asteroids that are likely to approach Earth.

Out-of-the-box thinking helped

The researchers have been previously focused on studying exoplanets in search of habitable planets withinthe TRAPPIST-1 planetary system.

During the research, astronomers had to find a way to filter the “noise” in telescope images, such as any gas, dust, and planetary objects between Earth and the star, to more clearly decipher exoplanets. Often, the noise they discard includes passing asteroids.

The new method for asteroid discovery was found when researchers wondered whether the same data used to search for exoplanets could be recycled and mined for asteroids in our own solar system.

To look for even smaller asteroids, researchers employed data from the world’s most powerful observatory – NASA’s James Webb Space Telescope.

“This is a totally new, unexplored space we are entering, thanks to modern technologies,” Burdanov says.

“It’s a good example of what we can do as a field when we look at the data differently. Sometimes there’s a big payoff, and this is one of them.”