4 ms·
> The Rubin observations also show hints of a dusty tail, but oddly this elongation points directly toward the Sun. Typically, the push of the Sun’s radiation m
by drewg123 1y ago
> The Rubin observations also show hints of a dusty tail, but oddly this elongation points directly toward the Sun. Typically, the push of the Sun’s radiation moves dust in comet’s tails so that it points away from the Sun.
Deceleration burn?
- bee_rider 1y agoI guess at some point we should expect dust to launch toward the Sun as that side gets heated more, right? But I have no idea when that is supposed to happen…
- jandrewrogers 1y agoWhile uncommon, some ordinary comets also have an "anti-tail" that points toward the sun. As a recent famous example, the very bright comet in October 2024 [0] had a prominent anti-tail. The main photo on the wikipedia page shows it clearly. [0] https://en.wikipedia.org/wiki/C/2023_A3_(Tsuchinshan–ATLAS) https://en.wikipedia.org/wiki/C/2023_A3_(Tsuchinshan–ATLAS)
- ge96 1y agoWe might be the blue people
- mkw5053 1y agoGas released from fresh ice on the illuminated hemisphere can push millimeter-scale grains out at a few m/s, and since these particles weigh thousands of times more than typical cometary dust, solar radiation pressure at 3 au is too weak to bend their trajectories, letting them overtake the nucleus and form a sunward anti-tail. Finson–Probstein dust dynamics predicts this plume should flip to the normal anti-solar direction or fade once 3I/ATLAS moves inside 1 au later this year. Watch the position angle around September to see the theory tested.
- ordu 1y agoPity it travels too fast to decelerate enough to be captured by the Sun.