The “super blood wolf moon” that lit up the night sky on Sunday marked the rare convergence of three lunar events: the January full moon, known as a “wolf moon,” appeared especially large because it was positioned unusually close to Earth, hence the “super," and a total lunar eclipse caused the celestial body to glow a deep crimson—or “blood” red, if you will. While this spectacular phenomena was ongoing, yet another special event occurred: a meteor collided with the moon and sparked a powerful flash that could be seen from Earth.
According to Scientific American’s Nadia Drake, this may mark the first time that a meteor strike has been observed during a total lunar eclipse. On the night of the super blood wolf moon, a Reddit user reported seeing the flash on multiple webcasts, and social media was soon filled with images and input from other people who said they caught the meteor collision. Eventually, Jose Maria Madiedo, an astronomer at Spain’s University of Huelva, confirmed on Twitter that the “impact flash has been recorded by telescopes operating in the framework of MIDAS Survey from Europe.
MIDAS, or the Moon Impacts Detection and Analysis System, has been monitoring lunar impact flashes since 1997. The moon is constantly being pelted by fast-moving celestial objects, typically fragments that have broken off from asteroids and comets. Space debris also hits the Earth, but it usually gets burned up in our planet’s atmosphere before it can hit the ground. The moon, by contrast, has only an “infinitesimal” atmosphere, so objects hurtling through space collide with it at high speed, causing brief but forceful flashes that can be spotted via telescope on Earth.
Madiedo tells Drake that the object that hit the super blood wolf moon may have weighed around 10 kilograms, and collided with the lunar surface at a speed of 61,000 kilometers per hour, creating a crater up to 10 meters in diameter.
“The most likely situation is that the impactor was a fragment of a comet,” he says. “The explosion would be equivalent to 0.5 tons of TNT.”
This is a relatively small collision, and not in itself unusual—debris of this size hits the moon frequently, around every two to three months, according to Madiedo. But MIDAS had never before captured a meteor strike during a lunar eclipse. In the days leading up to the super blood wolf moon, Madiedo worked day and night to get eight MIDAS telescopes fixed on the moon, hoping this would be the year he caught the coveted event.
“I had a very nice reward,” he tells National Geographic’s Maya Wei-Haas.
Scientists are keen to document lunar impacts because it can give them a better sense of collision frequencies here on Earth. The Earth and moon, which are on close proximity, experience similar rates of impacts, but craters don’t erode on the moon in the same way that they do on Earth. A recent study, in fact, used impact craters on the moon to determine that asteroid strikes on Earth have surged dramatically in the past 290 million years.
Knowing more about lunar impacts is also essential to future manned missions to the moon. “If you imagine this rock falling on your head, it’s not so pleasant,” Stephanie Werner, a professor at the University of Oslo’s department of geosciences, tells Drake. “There is definitely uncertainty in how well we understand the small projectile rate. The more information we can collect, the more exciting it is.”