A meteor hit the moon during the lunar eclipse. Here's what we know.
On Sunday, January 20, viewers across the Western Hemisphere were treated to the rusty hues of the decade's last “blood moon” eclipse. But as people across the planet watched the moon glow crimson, some lucky observers caught an unexpected delight: the flash of a space rock striking the lunar orb.
“It's a rare alignment of infrequent events,” says Justin Cowart, a Ph.D. candidate at Stony Brook University in New York. “A [meteoroid] about this size hits the moon about once a week or so,” he says. But if this event is confirmed, it may be the first time such an impact has been recorded during a lunar eclipse.
An eagle-eyed viewer on Reddit spotted the potential impact during the eclipse and reached out to the r/space community to see if others could weigh in. The news spread quickly on social media, as people from across the path of totality posted their images and video of this tiny flicker of light.
Many scientists initially approached the claims with appropriate skepticism. After spotting the buzz on Twitter, “I was wondering if it was maybe a local effect, or maybe something with the camera,” says planetary scientist Sara Mazrouei of the University of Toronto.
Flashes of light from an impact are faint and short lived, making them easy to confuse with an errant pixel. But image after image showed the same thing: At 4:41 UT, when totality was just beginning, a tiny speck of light glinted south of the crater Byrgius, a nearly 55-mile-wide pockmark in the western part of the moon.
“They all seem to see the same bright pixel,” Mazrouei says. This confluence points strongly toward the flash of light actually being an impact.
“This is something that people all around the world didn't know that they were going to sign up for” says Noah Petro, a research scientist at NASA's Goddard Space Flight Center.
Try, try again
Backyard astronomers and starstruck citizen scientists weren't the only ones watching. Jose Maria Madiedo, an astrophysicist at the University of Huelva in Spain, is co-director of the Moon Impacts Detection and Analysis System, MIDAS for short. He had been working overtime to get eight of the project's telescopes trained on the moon during the eclipse to watch for just such an event.
The MIDAS team usually scours the moon in search of faint flashes, the telltale signs of an impact, to learn about the array of space rocks that bombard our lunar companion. But most of these events are too dim to spot when the moon is full. The team does the bulk of their observing in the five days before and after a new moon. An eclipse, however, dulls the full moon's usually vibrant glow, providing one more rare opportunity to spot the tiny flashes of light.
So far, they hadn't successfully spotted an impact during an eclipse, but Madiedo didn't lose hope: “Something inside of me told me that this time would be the time.” And sure enough, his efforts paid off.
“I had a very nice reward,” he says.