Near-Earth Objects

In movies, asteroid threats usually come with dramatic music and last-minute heroics as a single rock hurtles towards Earth. But how do real-life scientists find smaller, harder-to-spot space rocks that could someday become a problem? In the real world, identifying asteroids that could threaten Earth is less about one looming object and more about watching lots of small ones over time.

Near-Earth objects (NEOs) are small Solar System bodies, mostly asteroids with some comets mixed in, whose orbits bring them close to Earth. Knowing where they are and where they’re headed is important, and many of them are challenging to spot because they’re small, faint, and on the move.

While scientists have already identified most of the really large NEOs (over a kilometer wide), only about a third of the mid-range ones (larger than 140 meters) have been discovered. Objects that size are still big enough to cause serious damage if they end up on a collision course with Earth — an unlikely event but not impossible, which is why scientists pay close attention to these objects long before they pose any real risk.

Rubin’s powerful telescope and its ability to scan the entire visible sky every few nights will enable us to fill in the blanks in our NEO inventory. Using Rubin data, scientists expect to discover millions of previously unseen asteroids throughout our Solar System. Of these, about 90,000 will be brand new NEOs — more than double the number currently known.

In addition to spotting new NEOs in the first place, Rubin’s frequent imaging — and the alerts Rubin sends out for moving objects it detects — will ensure that scientists can keep close tabs on interesting or concerning asteroids.

Rubin Observatory will help transform asteroid detection from science fiction into everyday science — a steady, systematic effort to find, track, and understand near-Earth objects long before they might pose a threat.

Further exploration:

• Explore NEOs and other Rubin Solar System discoveries in the Orbitviewer app

• Watch A Swarm of New Asteroids, a video featuring Rubin’s first asteroid discoveries

• Check out the record-breaking fast-spinning asteroid discovered with Rubin data

• Contribute to Rubin science with the Comet Catchers project on Zooniverse

• Educators, engage your students in a Hazardous Asteroids investigation