A huge space rock is barreling its way toward Earth, threatening to wipe out all life on the planet – well, not really, but it will certainly provide a fascinating scientific opportunity for astronomers, and it shows that NASA’s early warning system is working as it is supposed to.

NASA is using a tool called Scout at the Jet Propulsion Laboratory in California to act as an “intruder alert” of sorts, scanning data from telescopes around the globe to see if “Near Earth Objects” are in the vicinity and headed toward our planet. It then makes a calculation of whether it could strike Earth, and then informs other telescopes to watch it closely.

So far, NASA is finding about five asteroids per night, according to an NPR report. The tricky part is figuring out which ones are most dangerous to Earth.

Scientists spotted the rock in question Oct. 25-26 using the NASA-funded Panoramic Survey Telescope & Rapid Response System (Pan-STARRS) in Hawaii.

“A near-Earth asteroid is defined as one whose orbit periodically brings it within approximately 1.3 times Earth’s average distance to the sun — that is within 121 million miles (195 million kilometers) — of the sun (Earth’s average distance to the sun is about 93 million miles, or 150 million kilometers),” NASA states on its website. “This distance also then brings the asteroid within roughly 30 million miles (50 million kilometers) of Earth’s orbit. Observers have already discovered more than 90 percent of the estimated population of the large NEOs — those larger than 0.6 miles (one kilometer).”

“The rising rate of discovery is due to dedicated NEO surveys and upgraded telescopes coming online in recent years,” said NASA’s NEO Observations Program Manager Kelly Fast. “But while we’re making great progress, we still have a long way to go.”