NPR’s Ari Shapiro talks with astronomer David Jewitt about what we will study from the third interstellar object to have entered our photo voltaic system, a comet-like object referred to as 3I/ATLAS.
ARI SHAPIRO, HOST:
A exceptional object is rocketing via our photo voltaic system. It is a comet referred to as 3I/ATLAS. NASA caught a pointy picture of it, which is placing as a result of astronomer David Jewitt says that is like glimpsing a rifle bullet for a thousandth of a second. Jewitt is lead creator of a forthcoming paper concerning the object within the Astrophysical Journal Letters, and he is right here to share his group’s discovering with us. Welcome.
DAVID JEWITT: Hi there.
SHAPIRO: That is solely the third interstellar object noticed getting into our photo voltaic system. However we do not know the place within the universe it got here from. How have you learnt for positive that it got here from outdoors the photo voltaic system?
JEWITT: The important thing signature is that it is touring actually, actually quick relative to the solar. So it is going so quick that the gravity of the solar can’t maintain onto it. It got here in at about 40 miles per second, and that is simply approach too quick for the solar’s gravity to have the ability to maintain it again.
SHAPIRO: And that type of factors to the problem of capturing it. How extraordinary is it to really have a picture of one thing going at that pace?
JEWITT: Nicely, we thought objects like this is perhaps on the market, for many years, possibly centuries. However we did not see something like that till the primary one – the well-known one – ʻOumuamua in 2017. It was very thrilling as a result of it is actually the tip of the iceberg. So that is the beginning of the examine of a very new inhabitants of our bodies that we will take a look at with our telescope. So it’s totally thrilling for that purpose.
SHAPIRO: Yeah. It is type of wonderful that astronomers have all the time believed this stuff are on the market, but it surely’s solely within the final decade that pictures of them have been caught – three of them. So how does this develop the potential for scientific discovery?
JEWITT: Nicely, it simply reveals the inhabitants for the primary time. So we will start to attempt to measure them and attempt to perceive them. And we’ve all these questions that we might wish to reply about them – not simply the place are they from, however what number of of them are there? We predict there’s most likely an enormous variety of them. How massive are they? And, you realize, the primary two look utterly totally different from one another. So the primary one – ʻOumuamua – seemed like mainly a rock, an asteroid with no signal of any materials popping out of it. Second one – Borisov – seemed similar to an everyday comet within the photo voltaic system. So I feel many individuals, together with me, have been questioning, nicely, what is the third one going to be like? And are they…
SHAPIRO: And what’s it like? What’s this third one like?
JEWITT: It is really far more like the second than the primary one. So it has ice within the nucleus, and the ice will get warmed by the solar, and it turns right into a gasoline. The gasoline streams away from the nucleus, and it blows out bits of mud, after which the bits of mud replicate daylight and we see it as type of a cloud or a coma surrounding the thing. So it is an ice-containing physique. It appears to be like like a comet, so we expect it’s a comet. However it’s a comet that does not come from our photo voltaic system. It comes from any individual else’s planetary system some other place within the Milky Method, some most likely very very long time in the past.
SHAPIRO: You’re in your 60s. You have been at this for some time. What’s it wish to lastly have this new space of analysis simply speak in confidence to you for the primary time?
JEWITT: Yeah. It’s extremely good, after all. It is occurred earlier than, proper? So we discovered the Kuiper belt additionally in my lifetime. So it offers you this recognition that photo voltaic system is, although you suppose we all know the whole lot about it – oh, we have despatched a spacecraft right here and a spacecraft there – offers you this recognition that truly we do not know a lot concerning the photo voltaic system. So these objects, although they don’t seem to be from the photo voltaic system, they’re within the photo voltaic system. We now have a whole lot of them, and we’re going to have the ability to examine them – work out what number of there actually are and possibly work out the place they got here from.
SHAPIRO: Nicely, if we assume that many extra of those objects will quickly be detected and studied and documented, is that this one – 3I/ATLAS – going to imply something particular to you, or will it simply be one in a protracted lineage?
JEWITT: It’ll fade away, you realize (laughter)? So now we’ve three. When we’ve 300, for me, the sector will likely be boring – proper? – by that point.
SHAPIRO: (Laughter).
JEWITT: After which I will not work on it anymore. Different individuals can have it so far as I am involved.
SHAPIRO: David Jewitt leads evaluation of pictures captured by the Hubble Area Telescope, and he is a professor of astronomy at UCLA. Thanks a lot for speaking with us.
JEWITT: OK. You are welcome.
(SOUNDBITE OF HANS ZIMMER’S “CORNFIELD CHASE”)
Copyright © 2025 NPR. All rights reserved. Go to our web site phrases of use and permissions pages at www.npr.org for additional info.
Accuracy and availability of NPR transcripts could fluctuate. Transcript textual content could also be revised to right errors or match updates to audio. Audio on npr.org could also be edited after its authentic broadcast or publication. The authoritative file of NPR’s programming is the audio file.
