Four “potentially hazardous” asteroids zoomed past Earth this week — three of which were discovered mere hours before they made their pass.
They narrowly missed us this time around, but NASA scientists say they could pose a threat in the future as they cycle back through Earth’s orbit.
On Oct. 1, asteroid 2019 SM8 was spotted by astronomers at Mount Lemmon Observatory near Tucson, Arizona, and made its way past Earth, according to NASA. They estimated a size of approximately 16 feet (4.8 meters) wide — about the length of an SUV.
At one point it came as close as 99,000 miles away. For perspective, our moon is about 238,900 miles away. The other three asteroids whizzed by outside the moon.
Asteroid 2019 SE8, also discovered at Mount Lemmon on Oct. 1, came as close as 674,000 miles away, which is about 27 times the circumference of Earth.
While it wasn’t nearly close enough to cause alarm, the asteroid — estimated at 47 feet across — is about the size of a semi truck. Still not an Earth-shattering size. For example, the asteroid that wiped-out the dinosaurs was between 7 and 8 miles wide. Scientists estimate that an asteroid would have to be about 60 miles wide to decimate all life on Earth.
On Oct. 2, asteroid 2019 SD8 passed at about 331,000 miles away. Researchers at the Catalina Sky Survey near Tucson, Arizona, found the 38-foot-wide rock, about the size of a city bus. And, finally, the 24-foot-wide 2018 FK5, which scientists have been tracking since it was discovered at Mount Lemmon last year, was the furthest away at more than 3 million miles.
Scientists around the world have been studying various ways that we might prevent an asteroid collision with Earth, including sending a nuclear warhead to blow it up, and devising emergency response plans should any cosmic boulders start a course toward our planet.