gowron007 wrote:I hope you got to the part in the video where you see the comet has 3 tails and the one pointing towards the sun can in no way be the end of the dust tail lagging behind and appearing in front of the comet from the viewers perspective simply because if it were so, the so called anti tail should have appeared to the right of the comet, not in front of it pointing directly to the sun.
We commonly see "tails" like that in SOHO videos, where the comets are very overexposed. Sometimes they are optical artifacts, sometimes they are short-lived jet structures. Sometimes they are true antitails.
There is no mystery at all to comet antitails. Indeed, one can apply known mathematical models which describe how different sized particles are ejected and respond to solar radiation pressure, and see exactly how the planar nature of the debris stream develops. It is that planar nature that is responsible for the illusion of the antitail.
BTW, the video seems focused on the position of the comet with respect to the Earth's orbital plane. That is irrelevant to the visibility of an antitail. The antitail becomes apparent when the
viewer is on the comet's orbital plane. We are seeing the antitail of C/2011 L4 right now because Earth is on the comet's orbital plane. The comet itself is very far off of Earth's orbital plane. If we see an antitail in a STEREO or SOHO image, it's because the instrument is on the comet's orbital plane (which doesn't mean the Earth is).
[quote="gowron007"]I hope you got to the part in the video where you see the comet has 3 tails and the one pointing towards the sun can in no way be the end of the dust tail lagging behind and appearing in front of the comet from the viewers perspective simply because if it were so, the so called anti tail should have appeared to the right of the comet, not in front of it pointing directly to the sun.[/quote]
We commonly see "tails" like that in SOHO videos, where the comets are very overexposed. Sometimes they are optical artifacts, sometimes they are short-lived jet structures. Sometimes they are true antitails.
There is no mystery at all to comet antitails. Indeed, one can apply known mathematical models which describe how different sized particles are ejected and respond to solar radiation pressure, and see exactly how the planar nature of the debris stream develops. It is that planar nature that is responsible for the illusion of the antitail.
BTW, the video seems focused on the position of the comet with respect to the Earth's orbital plane. That is irrelevant to the visibility of an antitail. The antitail becomes apparent when the [i]viewer is on the comet's orbital plane[/i]. We are seeing the antitail of C/2011 L4 right now because Earth is on the comet's orbital plane. The comet itself is very far off of Earth's orbital plane. If we see an antitail in a STEREO or SOHO image, it's because the instrument is on the comet's orbital plane (which doesn't mean the Earth is).