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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.

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What's going on in this photo of Halley's comet's tail?

When researching for this answer I was looking at Space.com's 2011 article Photos of Halley's Comet Through History I saw the image below, and read the caption. Halley's Comet in 1910 ...
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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 ...
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How uniformly is cometary debris distributed along the entire orbit of the comet?

Meteor showers occur when Earth passes through debris shed by a comet (if I get that right). Does this mean that the entire orbit of the comet is strewn with debris? I suppose that the debris follows ...
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How to see Comet 46P/Wirtanen?

I've got a Celestron Astromaster 114 telescope. I live in Los Angeles and would like to get a look at 46P/Wirtanen. Can anyone tell me when this comet is going to brightest and how best to locate it ...
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very bright object (visible even after sun risen)

Brevard Co. FL. At first I thought it was a comet it appeared to have a tail. Starts out low in the east and gains elevation as the sun rises. As the sun is just above the horizon it is still visible ...
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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 ...
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What cosmic disaster is most likely to happen? [closed]

Of all the different ways that the Earth can be destroyed what ways is the most likely that could happen?
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Will comet 21P that just passed Earth on Sept 10 produce Draconid storm on Oct 9?

Comet 21P/Giaccobini-Zinner just made its closest pass to Earth and also made its Solar perihelion on the same day (Sept 10) which is roughly one month ahead of the annual Draconids meteor shower (Oct ...
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Water Content of Space Bodies

In general, are carbonaceous chondrites (CC) or comets more water rich? I know that evidence has suggested that both CC and comets are partly composed of water, but which body is generally more water ...
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Why would the Perseids meteor rate fall off after maximum faster than the increase before maximum?

Writing about the 2018 occurrence of the annual Perseids meteor shower, the EarthSky.org Astronomy Essentials article Start watching for Perseids now says: People tend to focus on the peak mornings ...
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How bright is Comet PANSTARRS C/2017 S3 now?

The LiveScience article Incredible Hulk? Nah, This Glowing, Green Light in the Night Sky Is a Comet published just hours ago discusses Comet PANSTARRS C/2017 S3 and mentions: bright bursts ...
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Would the dynamic pressure of the Sun’s solar wind be strong enough to trap plasma ions within an open container?

If you were to place a long cylinder, open at one end and closed at the other end, and position this cylinder so that the open end is facing the Sun, and then you were to inject plasma ions, such as ...
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Do the cometary gas ions which make up the plasma tail of a comet reach the velocity of the Sun's solar wind?

Do the cometary gas ions which make up the plasma tail of a comet reach the velocity of the Sun's solar wind?
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New NEOs are found daily. Is there any evidence gravity is pulling them to a centralised location?

With all of the new NEOs (near-earth objects) are they being pulled in or are they interacting with each other?
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How significant are the recent results that Scholz’s Star has perturbed several observed hyperbolic objects?

The Gizmodo article A Visiting Star Jostled Our Solar System 70,000 Years Ago refers to the the three year old ApJ. paper The Closest Known Flyby of a Star to the Solar System (also ArXiv) which ...
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Could the dinosaurs have seen the asteroid that killed them?

Wikipedia says the Chicxulub impactor is thought to have been a 10-15 km diameter object. Would it have been visible to a (human*) naked eye before impact? And if so, would it have appeared like a ...
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when are you able to see Halley's comet, and for how long?

I've been hearing about Halley's comet for a while now, and I'm just curious as to when and where to see it, and for how long. :)
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How often do comet occultations of stars happen?

By travelling to specific places, astronomers can see three thousand star comet transition events every year at m15 for the major (50km+) comets and asteroids averaging about 20 seconds, perhaps that'...
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Can we measure comets in a similar way to exoplanets?

A 2km comet at 40AU's can dim a sun sized star at 100 light years by 3%, and a 10km comet can cause an eclipse (is that right?) So would 2,3,10 km objects be easy to measure via star dimming if we had ...
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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: ...
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How do comets and other solar system bodies gain energy to exit the solar system?

I recently learnt that some comets like C/1980 E1 (Bowell) interacted with objects like gas giants in the solar system and gained enough energy to exit the solar system. But from Physics, I know that ...
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Do comets have a limited number of orbits? [closed]

Do comets have a limited number of orbits?
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What documented comet has/had the highest specific orbital energy?

After reading this answer I wondered if there have been document comets with orbits on non-return, hyperbolic trajectories as they approached the Sun. This means that they would not be ...
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Would a direct hit by a small comet be catastrophic?

Would a direct hit by a short-period comet with a 3 mile diameter nucleus cause enough damage on Earth to threaten or destroy human life and the ability to produce crops?
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What would people on Earth see during a close comet pass?

What would people, standing on Earth, see, hear and smell, if a short period comet, with a two mile diameter nucleus, came by at 100,000 miles above us?
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Would a comet break up during a close pass of the Earth

Would a short-period comet, with a 2-mile nucleus, be able to come within 200,000 miles of Earth without breaking up?
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Is it true that Jupiter protects Earth? [duplicate]

I am curious to know whether Jupiter is a reason that we have life on earth as it protects earth from comets, without Jupiter – comets would be more likely to hit us?
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Pluto is fuzed to all the asteroids, comets, other minor planets, etc. Would it be big enough to hold an atmosphere without forming a tail? [closed]

Pluto is fuzed to all the asteroids, comets, other minor planets, etc. Would it be big enough to hold an atmosphere without forming a tail? All minor planets, asteroids, comets, etc that aren't ...
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A question about calculating the radius of a comet

A Comet is orbiting around the sun with period of $T= 5.5$ years. The comet has radius $R$. After 5.5 years (A period) we understand that its radius has decreased about $20cm$. How can we calculate ...
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How large are the effects of nongravitational forces on comet Halley?

The effects of outgassing on comet orbits can be noticeable. Yeomans, in Cometary orbit determination and nongravitational forces, 2004, wrote: As the astrometric datasets improve and lengthen and ...
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Do comets contain any significant amounts of iridium?

I have Googled "iridium content of comets" and can't find anything that suggests comets contain iridium in any detectable quantities. Yet, whenever I read an article about the Chicxulub impactor, the ...
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Why are these objects moving at Vastly Different Speeds along the same orbit?

UPDATE: The on-line simulation seems to be working beautifully now! I'd recommend anyone to go back and take another look to enjoy both the mathematical beauty of orbital mechanics, and the aesthetics ...
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Observing Comet 45P - reliable sources of position data

Yesterday night I have tried find comet 45P, that should be still easily visible with my equipment at hand, however I was unable to find it. I used data provided by this website. Today I've checked ...
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Average effect of a planet on a comet

I'm considering a problem involving star S, planet A, and a comet B. The orbits of the planet and comet are eccentric, with eccentricities $e_A$ and $e_B$. I'm trying to calculate the average change ...
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Is there an alternative (potentially easier to understand) Euler diagram of the new solar system body classification?

note: This question is asking for a representation of the astronomical classification scheme now used for solar system bodies as established (presumably) by the Working Group for Planetary System ...
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Do astronomers generally agree that the distinction between comets and astroids is not so clear?

edit: I just saw this tweet and find it incredibly relevant :) begin question: First see this answer and then consider if there are known, or likely to be identified cases of solar system bodies that ...
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extrasolar comets - basic question

How can an extrasolar comet be detected - this is based on an article regarding the influence on a extra solar gas giant on these comets causing changes in their orbit and leading to them being ...
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Why the comets can cross the orbits of planets?

Why are comets able to cross planetary orbits without colliding with the planets - Why is the comets' orbits elliptical, intersecting all the other planets' orbit. Why don't they get attracted by the ...
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How does this comet have alcohol in it?

Recently I read about comet C/2014 Q2 (Lovejoy).The thing got me amazed was that scientists found it was dumping ethyl alcohol all along its way, at a rate of around 300-500 bottles per second. So I ...
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Is this object an asteroid or comet, and how can it produce so many tails?

The NASA Hubble Space Telescope Science Release HEIC 1320 - When is a Comet not a Comet? - Hubble astronomers observe bizarre six-tailed asteroid is self-explanatory, but it doesn't explain what ...
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Period coincidence of Planet Nine with furthest Kuiper belt objects

A lead scientist of the Planet Nine theory said that "The period with which it goes around the sun is a rational multiple of the periods of all the furthest Kuiper Belt objects" To what degree of ...
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Are exo-meteoroids possible?

Is it possible that meteoroids, comets, asteroids or other small bodies from around a nearby star (such as Alpha Centauri) could get into the solar system? How low is that possibility? Edit: ...
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Which measurements have shown that 2014 MU69 is red? (New Horizons' next target)

The recent NASA feature article New Horizons: Possible Clouds on Pluto, Next Target is Reddish MU69 is actually the smallest KBO to have its color measured – and scientists have used that data to ...
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Why does Kepler's “Big Picture” of comet 67P look so strange? And what is the significance?

The observation of comet 67P by the Kepler space telescope has been reported in various science news outlets recently. For example, the image below appeared in the recent NASA news article NASA's ...
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How long does a comet “live”?

When a comet loses all his volatile material after many orbits around the Sun, it becomes a "dead" comet (like an asteroid, a centaur or whatever), see for example 2015 TB145. Is there any way to ...
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Does the loss of mass create an observable change in a comet's orbit?

Comets lose their mass through water evaporation due to close encounter with sun, so my question is does the loss of mass create an observable change in a comet's orbit? What kind of change that may ...
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Does Jupiter help to protect the Earth against comets/asteroids impacts?

Does Jupiter help to protect the Earth against comets or asteroids impacts? Some astronomers believe that one reason Earth is habitable is that the gravity of Jupiter does help protect us from some ...
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Do comet orbits lie in the same plane as the other planets?

Two typical comets that I know are Donati's and Halley's. So comets also have orbits, but are their orbits on the same plane (such as the ecliptic) as the other planets?
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safeguards against comets?

I read one of the related questions here, but what i'm curious to know is how do we deflect imminent collision courses of comets, if we detect them at a later stage? I read somewhere else that there ...
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What (actually) is Jupiter doing to this year's Perseids meteor shower?

After reading the Astronomy Magazine article Perseid meteor shower set for its best show in nearly 20 years and NASA's Look Up! Perseid Meteor Shower Peaks Aug. 11-12, I understand that Jupiter's ...