U.S. government confirms first interstellar, deep space object to hit Earth

Published 2022-04-14 18:33

Meteor too fast to have come from our solar system, say scientists


When we talk about space, we often talk about the things that are closest to us — the sun, the moon, the planets and the asteroid belt.

Or we talk about other solar systems: stars with planets that are impossibly far away, the closest of which would take tens of thousands of years to reach, even in our fastest spaceships.

But what about the darkness in between? What exists beyond our solar system?

Well, that’s called interstellar space, and some scientists are now saying that the first known object from that void came to our planet nearly a decade ago.

On April 6, the U.S. Space Command confirmed “with 99.999 per cent confidence” that a meteor that hit the Earth in 2014 is the first known interstellar object to enter our solar system, and the first ever known to hit Earth.

In that same memo, they note that a group of Harvard University astronomers originally made the claim in 2019, but that they are only now confirming those findings through their own analysis.

Interstellar objects like this meteor are significant because they could teach scientists a lot about planet formation in distant worlds.

Voyager 1, a probe sent out into space in 1977, is the first human-made object to leave our solar system. It reached interstellar space in 2012 after 35 years of flight. (Image credit: NASA)

The first known interstellar object

The interstellar object entered the Earth’s atmosphere on Jan. 8, 2014, over Papua New Guinea, a country north of Australia.

It was roughly the size of a couch and weighed as much as a moose, traveling 210,000 km/h.

Most of the object likely burned up upon entry and landed in the ocean.

In a memo posted to Twitter on April 6 titled “Confirmation of Interstellar Object,” the U.S. Space Command said “the velocity estimate reported to NASA is sufficiently accurate to indicate an interstellar trajectory.”

In other words, they claim it was moving too fast to have come from our solar system.

Why does the meteor’s speed suggest that it's interstellar?

To explain this question, it’s helpful to discuss ‘Oumuamua.

Until now, an object that briefly entered our solar system in 2017, dubbed ‘Oumuamua, was thought to be the first interstellar object known to enter the solar system.

Upon first spotting ‘Oumuamua, scientists wondered if the object was of alien origin because of its strange shape. Newer science suggests it is more likely to be a remnant from a distant, Pluto-like world. (Illustration by ​​William Hartmann and Michael Belton/The Associated Press)

The object was roughly the length of four school buses and was only visible as a pinpoint of light as it passed the sun at 315,000 km/h.

That’s fast enough to travel around the world in roughly eight minutes.

Objects in our solar system, in contrast, are gravitationally bound and orbit the sun.

They don’t usually reach these types of high speeds.

Due to ‘Oumuamua’s speed and unnatural flightpath, scientists determined the object to be of interstellar origins.

This is the same reason that the U.S. government is citing to explain why they think the 2014 meteor came from interstellar space.

There are only two other objects confirmed to have strayed from another star system into our own. The most recent is the comet 21/Borisov, discovered in 2019. (Image credit: NASA)

Why this matters

Our solar system is separated by vast oceans of space from other star systems, which we can look at through telescopes, but can’t yet visit.

To scientists, interstellar objects are like finding a message in a bottle that’s washed up to shore, and can teach us about worlds that, for now, are impossibly far to reach.

Comets from our own solar system, for example, are used to understand how planets are formed, and interstellar objects could help scientists do the same for distant planets.

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With files from Marcia Dunn/AP News and NASA

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