3I/ATLAS caught by JUICE & Europa Clipper
Last year, interstellar comet 3I/ATLAS blasted its way into the record books with its high-speed passage through the inner solar system. Due to a lot of bad luck with planetary alignments, the Earth was on the wrong side of the Sun to see the comet make its closest approach to the Sun. What we missed, however, our spacecraft got to see. Missions at Mars as well as the JUICE and Europa Clipper missions all turned their cameras at this icy invader.
JUICE and Europa Clipper are both on their way to the Jupiter system, but they are taking different routes. JUICE launched in 2023 and will arrive in 2031 after doing a series of flybys of Earth and Venus. Europa Clipper launched in 2024 and will reach Jupiter in 2030. Quite by accident, these two missions were lined up on the same side of the Sun and positioned on either side of 3I/ATLAS’s orbit, allowing them to image both sides of the comet. They weren’t close enough to see anything in detail. What they could do was measure the comet’s composition in detail.
As explained by Kurt Retherford (SWRI), the principal investigator of the Ultraviolet Spectrographs on both missions, “As the comet passed between Juice and Europa Clipper, we were able to informally coordinate observations between the two spacecraft. 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.”
Europa Clipper, which is further out in the solar system, saw the night side of the comet, where scattered dust was visible. JUICE imaged glowing gas on the daytime side of the comet. This was the first time we’ve been able to see the day and night time sides of a comet at the same time.
Currently, 3I/ATLAS is out beyond the planet Jupiter as it heads back out of our Solar System. According to The SkyLive, it’s around 21st magnitude, making it too faint for all but the largest many meter telescopes.
Last year, interstellar comet 3I/ATLAS blasted its way into the record books with its high-speed passage through the inner solar system. Due to a lot of bad luck with planetary alignments, the Earth was on the wrong side of the Sun to see the comet make its closest approach to the Sun. What we missed, however, our spacecraft got to see. Missions at Mars as well as the JUICE and Europa Clipper missions all turned their cameras at this icy invader.
JUICE and Europa Clipper are both on their way to the Jupiter system, but they are taking different routes. JUICE launched in 2023 and will arrive in 2031 after doing a series of flybys of Earth and Venus. Europa Clipper launched in 2024 and will reach Jupiter in 2030. Quite by accident, these two missions were lined up on the same side of the Sun and positioned on either side of 3I/ATLAS’s orbit, allowing them to image both sides of the comet. They weren’t close enough to see anything in detail. What they could do was measure the comet’s composition in detail.
As explained by Kurt Retherford (SWRI), the principal investigator of the Ultraviolet Spectrographs on both missions, “As the comet passed between Juice and Europa Clipper, we were able to informally coordinate observations between the two spacecraft. 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.”
Europa Clipper, which is further out in the solar system, saw the night side of the comet, where scattered dust was visible. JUICE imaged glowing gas on the daytime side of the comet. This was the first time we’ve been able to see the day and night time sides of a comet at the same time.
Currently, 3I/ATLAS is out beyond the planet Jupiter as it heads back out of our Solar System. According to The SkyLive, it’s around 21st magnitude, making it too faint for all but the largest many meter telescopes.
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