SCOTT DETROW, HOST:
Time now for an interstellar flyby. Let's meet a very old comet, 3I/ATLAS.
DARRYL SELIGMAN: 3I/ATLAS is probably somewhere between 3 billion to 11 billion years old. So it's presumably been traveling around the galaxy for billions of years, potentially before even the solar system formed.
JUANA SUMMERS, HOST:
That's Darryl Seligman. He's a professor at Michigan State University in the physics and astronomy department.
SELIGMAN: Unlike all of the planets in the solar system that orbit around the sun and keep going around and round and always come back, this thing is coming through but is also on its way out. So it's leaving, and it's never going to come back.
DETROW: This is not the first object to buzz by from outer, outer space.
SUMMERS: The name 3I/ATLAS is a direct reference to the fact that it's the third interstellar object we've observed. And it was the ATLAS consortium of telescopes - A-T-L-A-S - that discovered this celestial body.
SELIGMAN: It stands for Asteroid Terrestrial-impact Last Alert System. So it is an all-sky survey. So it looks at the entire sky basically every night with a network of telescopes, some in Hawaii, some in Chile, some in South Africa. And they are scanning the whole sky for anything that moves at all.
DETROW: As the 3I/ATLAS cuts across our planetary system, the comet is making its way close to our sun, which is great news for scientists because it offers a peak opportunity, known as the perihelion, for astronomical research.
SELIGMAN: So the perihelion of any celestial object is, as it moves throughout its orbit, that point in time and also the point in its orbit when it is closest to the sun. So that is also, for a comet, when it is at its warmest because the closer you are to the sun, the more sunlight you get. That's when you get the most holistic view of the kind of pristine nucleus and its composition.
DETROW: Seligman says that as it heads towards the sun, scientists will have the opportunity to get a clear image of the rare space object and not just using tools here on Earth.
SELIGMAN: NASA and other space agencies have assets all over the solar system. And ATLAS does get close to Mars around now. So ATLAS is currently close to Mars. We have plenty of cameras and space missions around and on Mars. So those assets are all obtaining data on 3I/ATLAS as we speak.
DETROW: Now, important to say, scientists say that 3I/ATLAS is not a threat to Earth. The closest it will come is more than 150 million miles away.
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