Megacomet 12 Times the Size of Mount Everest Is Hurtling Towards Earth

by Jennifer Shea

A megacomet that’s about 12 times the size of Mount Everest is whizzing toward Earth, and astronomers say it’s a window into the past.

Two astronomers at the University of Pennsylvania first discovered the Bernardinelli-Bernstein comet. And they’ve put out a paper summarizing what they know about the comet so far from sightings this summer, plus seven years of data collection.

Astronomers believe the comet can tell them a lot about our solar system. Its chemistry has basically remained unchanged since it formed.

“In essence, it’s a time machine,” University of Arizona comet expert Amy Mainzer told the Daily Beast.

Megacomet Is in ‘Pristine’ Condition

The megacomet comes to us from the space rock crashes that formed our planet and most of the rest of the solar system many years ago.

“The story told by the comet would tell us of what existed in the solar system billions of years ago. And we can use that to understand the things we see today elsewhere in the solar system,” comet co-discoverer Bernardinelli told the Daily Beast.

Most of the comets that scientists have studied before have transformed in some way. They’ve moved through the sun’s heat, which changed their chemistry. Or they’ve broken into smaller pieces. But the Bernardinelli-Bernstein comet is the same as ever.

“It’s pristine,” Bernardinelli told the Beast. “Not a lot has happened to this object since its formation in the early days of the solar system. And so we can think of it as a window into the past.”

The megacomet has spent most of its time in the frigid climes of the outer solar system. So it’s been frozen in time. And its whopping size has given it enough gravitational force to stay in one piece as it moves through space. So the comet likely mirrors the chemical state of the original nebula that formed our solar system.

Bernardinelli-Bernstein Will Pass by Earth in 2031

The megacomet will pass close by our planet in 2031. In the meantime, scientists will be frenetically studying its composition as its approach toward our sun finally changes its chemistry.

“One of the best things about this comet is that we’ve got a while until it makes its closest approach to the sun,” Mainzer said. “So we’ve got years to study how it brightens up as its surface gets exposed to the sun’s warmth.”

As it moves closer to the sun, the megacomet will give off dust particles. That will tell astronomers which chemicals are propelling it onward.

They’ll be looking for chemicals like Nitrogen, which is abundant on Pluto, the farthest planet or planetoid in our solar system. The abundance or scarcity of that chemical could tell them whether the comet was closer to the Sun (which would cause Nitrogen to evaporate) or Pluto in its early years.

As for the comet’s core, the composition of that could tell us about the cloud of gas and dust that birthed our solar system.

All told, the comet’s pass by Earth should provide scientists with a bonanza of information-gathering opportunities. And no, in case you were wondering, at this point, scientists aren’t worried it’s going to collide with Earth.