Earth's 2nd 'moon' has arrived: What you need to know
(KTLA) – A second moon has officially entered Earth's orbit — sort of.
Although it's being called a "mini-moon," the object is actually an asteroid named 2024 PT5. It has been temporarily captured by Earth's gravitational pull.
The tiny asteroid will remain in Earth's orbit from now until Nov. 25, when it will exit and continue its journey through the solar system.
“There’s no way for small telescopes to see this mini-moon. It’s far too small — about the size of a bus," Dr. David Reitzel, an astronomical lecturer at Griffith Observatory, told Nexstar's KTLA. "Only the world’s largest telescopes can detect it, or a very long exposure is required."
This type of event isn’t uncommon in the scientific community.
“We see something like this every few years. They stick around for a few weeks to months and then move on. There are typically two to three such occurrences per decade,” Reitzel said.
The last time Earth had a mini-moon was in 2022, when an asteroid known as NX1 entered Earth's orbit.
“Near-Earth objects that follow horseshoe paths and approach our planet at close range and low relative velocity may undergo mini moon events in which their geocentric energy becomes negative for hours, days or months — but without completing one revolution around earth while bound,” according to a study published in the journal Research Notes of the American Astronomical Society. “An example of an NEO experiencing such a temporarily captured flyby is 2022 NX1 which was a short-lived mini moon in 1981 and 2022.”
For anyone concerned about the asteroid, Reitzel offered some reassurance.
“This disrupts nothing at all. There’s no danger to anything in the solar system.”
The asteroid was discovered by a group of scientists at the Asteroid Terrestrial-impact Last Alert System (ATLAS) in August. They predict that the asteroid will return in 2055.
The International Astronomical Union's Minor Planet Center will track this mini-moon and other small objects entering our solar system.
“This is a fun and somewhat rare event that isn’t visible to the naked eye, but it’s exciting to think about and can inspire people to explore the universe,” Reitzel said.