On a trick-or-treat scale for potentially hazardous
objects, newly discovered asteroid 2022 RM4 is a treat. The sneaky cosmic rock is relatively large and will come in for a safe but close flyby of Earth on Nov. 1, just missing Halloween by a hair.
The Pan-Starrs observatory in Hawaii first spotted 2022 RM4 in September and the International Astronomical Union's Minor Planet Center issued a formal announcement of the asteroid on Sept. 15. Researchers are still dialing in the details of the asteroid, but it could be up to 2,430 feet (740 meters) in diameter. You can mentally stack the Eiffel Tower on top of itself to get a general idea of that size.
Astronomers find new asteroids all the time, but the size and closeness of 2022 RM 4 make it notable. It's set to come within 1.4 million miles (2.3 million kilometers) of our planet. That's roughly six times the distance of the moon from Earth.
Amateur astronomer Tony Dunn shared a look at the asteroid's orbit earlier this month. Dunn emphasized the asteroid poses no danger to Earth, but that it's expected to be bright enough for some backyard telescope users to spot it. "This is very close for an asteroid this size," he tweeted.
The NASA JPL Center for Near Earth Object Studies curates a list of close approaches. It shows 2022 RM4 as having a rarity of "2." Rarity is a "a measure of how infrequent the Earth close approach is for asteroids of the same size and larger." The "2" designation means asteroids like this only come along roughly once a year.
While 2022 RM4 is big and cosmically close, it doesn't pose a danger to us. I've spotted a few headlines that make it sound like the space rock is a harbinger of doom, but don't worry. Here's how to assess asteroid risks for yourself.
Scientists around the world have been working on improving our ability to spot potentially hazardous asteroids and track their future paths. NASA's DART mission demonstrates one possible way we might defend our planet against a truly dangerous asteroid: by smacking it onto a safer course.
For now, you can just relax and enjoy the telescope view of 2022 RM4, which is merely a cosmic tourist passing by Earth and continuing on its merry way.