Astronomy Stack Exchange
Astronomy Stack Exchange

Questions tagged [comets]

Icy bodies that usually consist of methane, water, and other materials that originate from beyond the jovian planets, and occasionally fall into the inner solar system giving off a massive tail as material is boiled off.

Icy bodies that usually consist of methane, water, and other materials that originate from beyond the jovian planets, and occasionally fall into the inner solar system giving off a massive tail as material is boiled off.

References

218 questions
21
votes
2 answers

How do we know that a comet passed by earth 50,000 years ago?

This article (https://gothamist.com/news/a-green-comet-is-sailing-over-new-york-and-earth-for-the-first-time-in-50000-years) claims that a comet will pass by earth soon for the first time in 50,000 years. How do we know that this exact comet passed…
coco
  • 313
  • 2
  • 5
12
votes
1 answer

Long term development of Comets

When an exocomet passes by our Sun in a trajectory that leads it to establish a Solar Orbit what eventually happens to it? In addition to its original inertia and vector being altered what are the longer term affects that occur?
chaonomy
  • 1,129
  • 8
  • 16
11
votes
2 answers

Why all the photos from 67p are black and white?

I was wondering why every picture we saw on internet about Rosetta's landing on 67p just black and white ? Is there something i should know ?
John DOE
  • 231
  • 1
  • 3
  • 7
10
votes
2 answers

Can two comets travel together as one?

If two comets come together in space, will they bounce apart, merge into a single body, or could they travel together through space, either touching or orbiting a shared center of gravity?
James Jenkins
  • 787
  • 5
  • 17
10
votes
1 answer

How frequently does a comet drastically change its orbit in the Solar System (like 67P did in 1959)?

Comet 67P/Churyumov–Gerasimenko flew by Jupiter at only 0.05 AU distance in 1959. This encounter lowered its perihelion from 2.7 to 1.3 AU (almost becoming an Earth crossing comet). Since it happens to be the target of the Rosetta mission (and was…
LocalFluff
  • 11,383
  • 4
  • 31
  • 73
8
votes
1 answer

What is the direction of a comet's dust tail before and after perihelion?

I recently created a visualisation of comet ISON's orbit. However, I received a critique that the dust tail of the comet should be pointing away from the Sun after perihelion. As far as I know, the ion tail of the comet definitely points away from…
HRJ
  • 211
  • 2
  • 5
8
votes
2 answers

What ever happened to the "Small Comet Theory" of water influx on present-day Earth?

This comment (below the question Is there any new water formed on, or brought to, Earth?) links to the 2002 Article in the New Scientist Was all the Earth’s water brought here by comets? which states: Evidence that there is a constant rain of small…
uhoh
  • 31,151
  • 9
  • 89
  • 293
8
votes
2 answers

How big do comets get?

If my understanding is correct, Chury, the best explored comet so far is rather on the smallish side as comets go. Most comets observable with naked eye were so because they flew close to Earth, not because they were so big. I wonder, though, how…
SF.
  • 6,259
  • 2
  • 26
  • 53
7
votes
2 answers

What's the estimated remaining life of Halley's Comet?

I know that Halley's comet is seen from Earth every 76 years or so since a couple centuries. As it travels, and particularly when it comes near the sun, it loses some of its material (ice). Someday, all of this material will be exhausted and the…
MaxiWheat
  • 439
  • 1
  • 4
  • 12
5
votes
2 answers

What known comets are binary?

Many asteroids are today known to be binary, to have "moons". But what comets are known to be binary? Or what fraction of them are theoretically thought to be binary? And if possible, then separate Oort cloud comets from comets with more local…
LocalFluff
  • 11,383
  • 4
  • 31
  • 73
5
votes
1 answer

Was comet ISON in a Kepler orbit prior to disintegrating?

Was comet ISON in a Kepler orbit prior to disintegrating? If so, it is possible over time that Kepler orbits can be altered by increases or decreases in the mass of of celestial bodies? For instance if ISON was in a Kepler orbit and it lost mass did…
chaonomy
  • 1,129
  • 8
  • 16
4
votes
0 answers

How commonly observed is H2 forming in H2O ice, among comets?

How common is H2 forming under a shell of normal ice, among comets? The context is the Oumuamua discussion, and its latest tentative solution. "Acceleration of 1I/‘Oumuamua from radiolytically produced H2 in H2O ice"…
Mark Besser
  • 633
  • 5
  • 9
4
votes
1 answer

Mass loss rate in a typical visible-from-Earth comet

What is the typical range of a comet's mass loss per second to its dust and gas tails, while it is naked-eye visible from Earth? I'm aware this is going to be a very broad range and expect it to cover multiple orders of magnitude, so any specific…
BenRW
  • 153
  • 5
4
votes
1 answer

Halley's Comet current location in sky and visibility?

I am an amateur in astronomy, but recently I wonder if it is possible to see (in a photo, maybe, if not in a telescope) Halley's Comet when its not close to earth. If there is such photo, how I can find it. Thanks in advance.
Ale
  • 143
  • 5
4
votes
2 answers

Is a comet necessarily confined to the solar system?

I had the following question: A comet enters the solar system. Assume that it is influenced only by the Sun, not by any of the planets. Which statement about its orbit is correct? And I chose as correct statement: Its orbit might be an ellipse,…
K Split X
  • 1,069
  • 2
  • 11
  • 14
1
2