Europa Clipper and Juice make simultaneous UV light observatoins of interstellar comet 3I/Atlas
Overview of November 2025 observations.
Click for original image.
By viewing interstellar comet 3I/Atlas when it was between the Jupiter probes Europa Clipper and Juice (on their way to Jupiter) in November 2025, the science teams for both were able to get a 360 degree view of the comet in ultraviolet wavelengths.
“As the comet passed between Juice and Europa Clipper, we were able to informally coordinate observations between the two spacecraft,” said Dr. Kurt Retherford, the principal investigator of Juice-UVS and Europa-UVS. “Crucially, we observed hydrogen, oxygen and carbon emissions. These elements are produced when gases escaping the comet’s nucleus break apart into atoms when exposed to sunlight.”
…“Observing the interstellar comet was some exciting bonus science. The resulting rare and unique dataset includes gas emissions and scattered dust,” said SwRI’s Dr. Philippa Molyneux, co-deputy principal investigator for the Juice-UVS instrument. “This was the first time we’ve had simultaneous direct views of a comet’s coma of escaping gas from two directions. Europa Clipper showed us the night side of the comet, with a great deal of scattered dust, while Juice imaged mostly glowing gas on the day side.”
…The researchers found higher levels of carbon emissions from 3I/ATLAS than expected early on, especially in comparison to typical comets from our solar system, corroborating similar findings through other observations about the interstellar comet’s origin and composition. Observing the trends of emissions over several days revealed how the ratios of these molecules changed and how the comet evolved during its journey through our solar system.
These results confirm once again that while Comet 3I/Atlas is from outside our solar system and has some unique features, it is still remarkably similar to ordinary comets found within our solar system.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Overview of November 2025 observations.
Click for original image.
By viewing interstellar comet 3I/Atlas when it was between the Jupiter probes Europa Clipper and Juice (on their way to Jupiter) in November 2025, the science teams for both were able to get a 360 degree view of the comet in ultraviolet wavelengths.
“As the comet passed between Juice and Europa Clipper, we were able to informally coordinate observations between the two spacecraft,” said Dr. Kurt Retherford, the principal investigator of Juice-UVS and Europa-UVS. “Crucially, we observed hydrogen, oxygen and carbon emissions. These elements are produced when gases escaping the comet’s nucleus break apart into atoms when exposed to sunlight.”
…“Observing the interstellar comet was some exciting bonus science. The resulting rare and unique dataset includes gas emissions and scattered dust,” said SwRI’s Dr. Philippa Molyneux, co-deputy principal investigator for the Juice-UVS instrument. “This was the first time we’ve had simultaneous direct views of a comet’s coma of escaping gas from two directions. Europa Clipper showed us the night side of the comet, with a great deal of scattered dust, while Juice imaged mostly glowing gas on the day side.”
…The researchers found higher levels of carbon emissions from 3I/ATLAS than expected early on, especially in comparison to typical comets from our solar system, corroborating similar findings through other observations about the interstellar comet’s origin and composition. Observing the trends of emissions over several days revealed how the ratios of these molecules changed and how the comet evolved during its journey through our solar system.
These results confirm once again that while Comet 3I/Atlas is from outside our solar system and has some unique features, it is still remarkably similar to ordinary comets found within our solar system.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News