See Comet A3’s Rare ‘Anti-tail’ in Video From Space

I squinted at the western sky just after dark Monday night and barely caught sight of the misty-looking tail of Comet C/2023 A3 (Tsuchinshan–ATLAS). It makes me wish I was in a spacecraft with a can’t-miss view of our uncommon celestial visitor. 

The European Space Agency shared a video on Tuesday from its sun-watching SOHO spacecraft that shows Comet A3 looking like a glowing streak of light. You can even see an unusual “anti-tail” optical illusion.

The video covers the time period from Oct. 7 through Oct. 13 and shows the sun blocked out in the middle. Comet A3 — a cosmic snowball of dust, gases and ice — soars across the upper right of the frame. 

“The comet’s nucleus is clearly visible, surrounded by a dusty coma and trailing an impressively long tail,” ESA said. “SOHO sees the large dust tail edge-on, curving in on itself as it is pushed outward by solar wind.” The bright dot off to the left is the planet Mercury.

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Watch through to the end of the video and look for the thin bright line that reaches back to the sun. ESA says the “anti-tail” is a rare phenomenon. 

“This tail is an optical illusion coming from SOHO getting an edge-on view of the larger cometary dust particles that accumulate in the comet’s orbital plane,” the space agency said. It resembles a laser beam shooting through space.

The sun is incredibly active right now and is kicking out flares and solar material. Those outbursts are visible in the video. The sun’s peppy mood has been triggering impressive auroras on Earth. Stay up-to-date on all the celestial events for October.

Read more: See ‘Insane’ Aurora Views From Space Snapped by NASA Astronaut

SOHO stands for Solar & Heliospheric Observatory. The sun-studying spacecraft is a joint project from ESA and NASA. It launched in 1995. Comet A3 is the second brightest SOHO has ever witnessed. The top honor goes to Comet C/2006 P1 (McNaught) in 2007.   

Comet A3 will get progressively harder to spot from Earth, but Northern Hemisphere skywatchers can look to the west after sunset (try binoculars). Even if you miss it, you can still enjoy the views from the International Space Station and from the SOHO spacecraft. Comets are a rare treat, so be sure to say hello to A3 before it moves on.