In October 2017, scientists using the Pan-STARRS1 telescope on the island of Maui in Hawaii detected something no one had ever seen before.
They spotted an interstellar object in our solar system and named it 'Oumuamua (a Hawaiian term for "scout").
First, astronomers thought it was a comet, but no trace of comet-like activity was detected when it swung around the Sun at speeds of 196,000 miles per hour.
Then, astronomers thought it was an asteroid until further measurements detected something that didn't seem physically possible.
This object from another star system was accelerating, and natural rocks in space rarely speed up independently. The science community bubbled with excitement as theories mounted that this might not be a comet. Instead, it might be an alien artifact, like a probe or a derelict spaceship from another civilization.
Renowned Harvard Professor Avi Loeb of astrophysics lightly suggested in 2017 that 'Oumuamua might be refuse of alien technology. In a book he published in 2021, Extraterrestrial: The First Sign of Intelligent Life Beyond Earth, Loeb writes that "the excess push away from the sun — that was the thing that broke the camel's back" when it came to convincing him of the provenance of this space object.
Researchers in 2021 proposed another cause for what came to be known as 'Oumuamua's "rocket effect:" a form of ice called solid nitrogen — which is also on Pluto — could explain all of the observed on the interstellar interloper. And it was concluded that 'Oumuamua was probably a chunk of frozen nitrogen, knocked off of the surface of a planet, eventually evaporating into a flattened shape just like a bar of soap after heavy use.
The object is already leaving our solar system, but we might have another shot at examining something like it again, using the newly operational James Webb Space Telescope.
James Webb will give us an intimate encounter with the next 'Oumuamua
As of writing, we've only seen two interstellar objects pass through our solar system — 'Oumuamua in 2017 and Borisov in 2018 — but there are probably more on their way. When we find the next one, NASA's newest flagship telescope, the James Webb Space Telescope, will have the best view of the newest interstellar visitor.
With Webb now operating as the next generation of astronomy, the focus can easily fixate on the promise of potentially habitable worlds beyond our solar system. A fascination with aliens is understandable. After all, discovering a thriving (or not-so-thriving) alien civilization on a nearby exoplanet would fundamentally transform how we understand not only the universe but where the human race and Earth itself fit in an unthinkably vast and unconscionably complex cosmos.
The advanced tech on the Webb Telescope will enable astronomers to study where these objects come from, how they formed, and their composition faster, easier, and critically before they continue on their journey out of our solar system.
The Webb Telescope presents an "unprecedented opportunity"
When studying extrasolar objects from the Milky Way, scientists have had a limited suite of instruments to use. But with the James Webb Space Telescope, that's about to change forever.
"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 us in their home systems," explains Principal Investigator Martin Cordiner of Webb's Target of Opportunity program to analyze the makeup of interstellar interlopers.
"The ability to study one of these and find out its composition — to see material from around another planetary system close up — is truly an amazing thing," adds Cordiner, an astrophysicist of NASA's Goddard Space Flight Center in Greenbelt, Maryland, who's also with the Catholic University of America.
JWST could point the way to aliens
Scientists will use Webb's spectroscopic abilities to analyze both the mid-infrared and near-infrared bands to examine interstellar interlopers that visit our solar system. Its mirror segments "were coated with a thin layer of pure gold less than 100 atoms thick to best reflect infrared light," according to a NASA video on the flagship telescope's optical system.
Webb's infrared capabilities will be crucial in studying the next 'Oumuamua or Borisov making its way into our solar system and past our planet.
The near-infrared Spectrograph (NIRSpec) will help scientists investigate the chemical fingerprints of gases that cosmic objects release — this is a great method of studying them since any ice present on the bodies will be vaporized by the heat of the Sun.
With the mid-infrared instrument (MIRI), scientists will see dust coming off the object. These are tiny, microscopic particles, more visible grains, and even entire pebbles that could be pulled off of the surface of the object, floating along with it like a cluster of ping-pong balls.
Breadcrumbs to alien life — Studying interstellar objects like 'Oumuamua and Borisov, using the tools made available by the James Webb Space Telescope could connect eternal questions with long-sought answers. Among those are mysteries on how planets form from basic chemicals, whether the way it happens is universal, and whether our solar system is a notable exception of how planets generally form elsewhere. In turn, this could reveal how life comes to be in the universe — and possibly constitute a major hint about where and when we might find alien life in the galaxy. Webb will help us find out.