CLOSE
Hagai Perets
Hagai Perets

Astronomers: Multiple Cosmic Collisions May Have Created Our Moon

Hagai Perets
Hagai Perets

It looks so tranquil up there. So still. But we know space is neither tranquil nor still. Our own Moon is no exception. New research suggests the Moon was the product of some very, very violent moshing: Around 4.5 billion years ago, a rowdy gang of stellar objects smashed into our young planet, creating the debris that would one day become the Moon. The astronomers published their report in the journal Nature Geoscience.

We’ve known for a while now that the Moon is made at least partially out of pieces from a banged-up Earth. But we’re still trying to sort out the details of the collision itself. At first, scientists thought Earth had been hit by one big object, like another planet. Then they thought there must have been a bunch of objects all striking around the same time. As we learned more, the single-impactor theory returned to prominence and stayed there for decades.

One 2016 study named the object—the planet Theia—and even the angle of impact. The researchers theorized that the extremely similar molecular makeup of Earth and the Moon could only have resulted from a head-on collision.

Other astronomers disagree. The authors of the new paper ran hundreds of simulations, and they argue it’s far more likely that Earth was walloped by a score of different objects called planetesimals. Each of the repeated impacts smashed up a huge amount of the young planet’s matter. That debris then drifted into orbit around Earth, where it settled into disks, which then resolved into little (gargantuan) chunks called moonlets. Over time, the baby moonlets merged into one single, spinning rock.

“Our model suggests that the ancient Earth once hosted a series of moons, each one formed from a different collision with the proto-Earth,” co-author Hagai Perets said in a statement. “It’s likely that such moonlets were later ejected, or collided with the Earth or with each other to form bigger moons.”

Perets says the moonlets could easily have crossed orbits with one another, smashed together, and been rolled up into larger bodies. “A long series of such moon-moon collisions could gradually build-up a bigger moon—the Moon we see today.”

nextArticle.image_alt|e
iStock
arrow
Space
Don’t Miss Next Week’s Incredibly Rare 'Super Blue Blood Moon Eclipse'
iStock
iStock

A blue moon—the second full moon to occur in one calendar month—isn’t as rare as the common saying suggests. But on January 31, skygazers will be in for a much rarer lunar event: For the first time in 35 years, a blue moon coincides with a total lunar eclipse, and as a bonus, the moon will seem bigger than usual, TIME reports.

The "super blue blood moon," as it’s been dubbed, is the result of a perfect storm of celestial conditions. First, it’s the second full moon this month following the first on January 1. Second, the full moon will rise at the part of its monthly orbit that dips closest to Earth, a point called perigee. This causes the moon to appear larger and brighter in the night sky. And finally, all of this is occurring during a total lunar eclipse, which happens when the Earth’s shadow fully blankets the moon.

Because a blue moon really isn’t blue at all, the moon on January 31 will display the same reddish (or bloody) tint that typically comes with a lunar eclipse. To catch it, you’ll have to rise early: Totality begins around 7:51 a.m. on the East Coast of the U.S. and at 4:51 a.m. for the Pacific side. The moon will fall totally within the Earth’s shadow for approximately one hour and 16 minutes after that. Because they'll see it occurring farther from sunrise, spectators in the western half of the country will have the better view.

The super blue blood moon is the second lunar event with an epic name to take place this month. The night of January 1 saw a wolf moon, the name given to the first full moon of the new year.

nextArticle.image_alt|e
Mike Hewitt, Getty Images
arrow
Space
The Fastest Way to Sync the Biggest Space Events of 2018 to Your Calendar
Mike Hewitt, Getty Images
Mike Hewitt, Getty Images

If you missed last year's meteor showers, supermoon, or total solar eclipse, don't dismay: There are plenty of spectacular celestial events to catch in 2018. Start with our January skywatching guide. This year, your resolution to watch as many of them as possible is more doable than ever. Along with a list of the year's biggest space events, The New York Times released a tool that allows you sync them all to your digital calendar in seconds.

Whether you use Google calendars or iOS calendars on your mobile device, the feature makes uploading the dates and descriptions of the year's most significant days for stargazers easy. Just follow the links provided to automatically input them into your account. This way, you won't forget to look up at the year's most dramatic cosmic displays no matter how hectic life gets.

With your calendar updated, now you can start planning for events like the total lunar eclipse of a super blue moon (January 31), the vernal equinox (March 20), and a partial solar eclipse (August 11). In addition to natural phenomena, The New York Times also includes events in space exploration. On May 5, for example, NASA could launch the Mars InSight spacecraft which will monitor the seismic activity of the red planet deep beneath its surface. That comes about a month after the March 31 deadline for the Google Lunar X Prize, the date by which participating companies must land a spacecraft on the Moon to win a cash prize.

While some of these events can be predicted down to the hour, others, like rocket launches, are subject to last-minute schedule changes. The New York Times plans to track the year's biggest dates in space as they develop and update their calendar accordingly.

[h/t The New York Times]

SECTIONS

arrow
LIVE SMARTER
More from mental floss studios