The Sound of Science - 'Interstellar Objects'

Oct 4, 2019

Jeremy: I’m Jeremy Benson with Sam Watt from NIU STEM Outreach, and it’s time for another episode of the Sound of Science on WNIJ.

Sam: Today’s question comes from Pablo, and it’s not just out of this world - it’s interstellar. Pablo asks, “How do scientists know if an object came from outside our solar system?”

Jeremy: That’s a really good question, Pablo. Especially since scientists are now studying the second interstellar object that we’ve detected.

NIU STEM Outreach

Sam: The easiest way to tell where these objects came from is to look at where they’re going. By analyzing the speed and direction of a moving object, it’s not hard for scientists to calculate where that object must have come from.

Jeremy: What really interests scientists, though, is what we can learn about places outside our solar system by studying these celestial visitors.

Sam: The first interstellar object was spotted in late October of 2017.  Oumuamua, as it was called, sparked a flurry of excitement and speculation about what it could be and where it may have come from. But Oumuamua was already heading out of our solar system when it was discovered, and so scientists only had a couple months to study it before it faded from view.

Jeremy: But astronomers have recently spotted another interstellar object, and this one is expected to be visible until October of 2020. That means we’ll have over a year to study it.

Sam: Scientists think that Oumuamua was mostly made of rock and minerals because they didn’t observe any sort of tail behind it.  The new object has been named Borisov, and we know it to be a comet because it has a hazy cloud surrounding it, and is leaving a long tail of dust and gas behind it.

Jeremy: This is very exciting because comets are created from the icy leftovers of newly formed star systems.  By analyzing the composition of that hazy cloud and tail we can determine the chemical makeup of the comet and the system it formed in.

Sam: This will allow scientists to see if other star systems have the same chemical makeup as our own, or if our system’s composition is unique. Thanks for the great question Pablo. We’d love to answer your questions on-air too. If you have a burning science question for us, send it STEMoutreach@niu.edu.

Jeremy: This has been the Sound of Science on WNIJ.

Sam: Where you learn something new every day.