NASA’s Europa Clipper spacecraft has captured essential new information on the interstellar comet 3I/ATLAS utilizing its Southwest Analysis Institute-led Ultraviolet Spectrograph (UVS). In July, 3I/ATLAS turned the third formally confirmed interstellar object identified to enter our photo voltaic system. The UVS instrument was in a position to observe the comet throughout a window when viewing from Mars and Earth was troublesome or not attainable.
“We’re excited that this chance to view one other goal on the way in which to Jupiter was fully sudden,” stated SwRI’s Dr. Kurt Retherford, the principal investigator for Europa-UVS. “Our observations have allowed for a singular and nuanced view of the comet.”
Europa Clipper launched in 2024 and is predicted to succeed in the Jovian system in 2030. As soon as there, it is going to orbit Jupiter and perform 49 shut flybys of the moon Europa. UVS collects ultraviolet mild to check the make-up of Europa’s atmospheric gases and supplies on its icy floor.
Timing issues when telescopes can’t see
Lower than per week after the comet was found, analysts at NASA’s Jet Propulsion Laboratory (JPL) mapped its path by means of the photo voltaic system. The Europa Clipper workforce quickly acknowledged that the spacecraft may watch 3I/ATLAS in November, a interval when the comet’s place close to the Solar would block a lot of the view from Earth and when Mars-based observing circumstances have been now not at their finest.
That timing let Europa Clipper fill a essential hole, connecting Mars-based observations from late September with later viewing alternatives from Earth. As a result of the comet’s trajectory positioned it between Europa Clipper and the Solar, the spacecraft had an uncommon vantage level. This issues as a result of comets sometimes present two principal tails, a mud tail that trails behind and a plasma tail that factors away from the Solar.
A behind-the-tails view and a second spacecraft perspective
From its sunward location, Europa-UVS captured a downstream view of each tails, wanting largely from “behind” the tails again towards the comet’s nucleus and coma (cloud of fuel surrounding it). On the similar time, observations from the SwRI-led UVS instrument aboard ESA’s Jupiter Icy Moons Explorer (JUICE) will add an anti-sunward view, giving scientists a extra typical angle throughout the very same interval.
“We’re hopeful that this new view, together with observations from Earth-based belongings and different spacecraft, will assist us to piece collectively a extra full understanding of the tails’ geometries,” stated SwRI’s Dr. Thomas Greathouse, co-deputy principal investigator of Europa-UVS.
Europa-UVS recognized oxygen, hydrogen, and dust-related signatures. These findings help the broader set of observations indicating that 3I/ATLAS went by means of a stretch of excessive outgassing exercise shortly after its closest method to the Solar.
“Europa-UVS is especially adept at measuring elementary transitions from atoms and molecules,” Retherford stated. “We will see gases come off the comet, and water molecules break aside into hydrogen and oxygen atoms.”
These measurements permit Europa Clipper to carefully examine these atomic species, providing a extra detailed take a look at what is going on within the comet and what it’s fabricated from.
Clues to the comet’s origin past our photo voltaic system
“Understanding the composition of the comet and the way readily these gases are emitted can provide us a clearer view of the comet’s origin and the way it could have advanced throughout transit from elsewhere within the galaxy to our photo voltaic system,” SwRI’s Dr. Tracy Becker, co-deputy principal investigator of Europa-UVS stated. “What are the chemical processes at play, and the way can we unravel the comet’s origin in its personal star system? Have been these processes just like how we imagine our photo voltaic system shaped? These are large questions.”
JPL manages the Europa Clipper mission for NASA’s Science Mission Directorate in Washington, D.C. The mission was developed in partnership with the Johns Hopkins College Utilized Physics Laboratory (APL), in Laurel, Maryland.

