Feb 16

STScI: Studying the Next Interstellar Interloper with Webb

his artist's illustration shows the wayward interstellar visitor 'Oumuamua (pronounced oh-MOO-ah-MOO-ah) racing toward the outskirts  of our solar system.
This artist’s illustration shows the wayward interstellar visitor ‘Oumuamua (pronounced oh-MOO-ah-MOO-ah) racing toward the outskirts of our solar system. Credits: ARTWORK: NASA, ESA, Joseph Olmsted (STScI), Frank Summers (STScI) 

One of the most exciting findings in planetary science in recent years is the discovery of interstellar objects passing through our solar system. So far, astronomers have confirmed only two of these interlopers from other star systems — 1I/’Oumuamua in 2017 and 2I/Borisov in 2018 — but many, many more are thought to exist. Scientists have had only limited ability to study these objects once discovered, but all of that is about to change with NASA’s James Webb Space Telescope.

“The supreme sensitivity and power of Webb now present us with an unprecedented opportunity to investigate the chemical composition of these interstellar objects and find out so much more about their nature: where they come from, how they were made, and what they can tell us about the conditions present in their home systems,” explained Martin Cordiner, principal investigator of a Webb Target of Opportunity program to study the composition of an interstellar object. 

“The ability to study one of these and find out its composition — to really see material from around another planetary system close up — is truly an amazing thing,” said Cordiner, an astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland and The Catholic University of America. The first two interstellar objects detected were very different: One was very comet-like, and one was not. Cordiner and his team hope to find out how unique those objects were and whether they’re representative of the broader population of interstellar objects.

Triggering Process

Astronomers are constantly monitoring various sources of information, ranging from amateur observers to professional observatories, in the hopes of finding the next interstellar interloper. When the next such object is first detected, scientists won’t immediately be certain if it’s an interstellar object. They’ll need additional observations over a period of days, weeks, or even months to confirm it — depending on its brightness.  

Once they have confirmation that the object came from outside the solar system based on its “hyperbolic” orbit, and they are certain the object didn’t come from the outer reaches of our own solar system or the Oort cloud, they can calculate the trajectory of the object across the sky. If that trajectory intersects with Webb’s viewing field, Cordiner and his team will make the observations.

Read more on the Webb Telescope site.