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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I have a question about the wording in a paper about a planetary system and comets

I was reading a paper. This is the paper: https://arxiv.org/abs/2006.01711 (https://ui.adsabs.harvard.edu/abs/2020MNRAS.496.4979D/abstract In the method section in the second paragraph there is a bit ...
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Why would a planet form a cometlike tail under conditions of weaker rather than stronger solar wind?

This question is prompted by one posted on the worldbuilding stack exchange: https://worldbuilding.stackexchange.com/questions/189701/could-this-planets-tail-be-visible I understand that the ionized ...
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Does this galaxy resemble the Milky Way, and is it relatable as the “template” for the Milky Way?

Taking a look at this photo of comet 2I/Borisov and a background galaxy (2MASX J10500165-0152029): And compare it to this rendition of the Milky Way: The two galaxies slightly resemble each other. ...
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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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What calculations show that Comet Shoemaker-Levy 9 orbited Jupiter for several decades before its spectacular impact? (Chodas, Sekanina & Yeomans)

This answer to A moon in eccentric orbit dipping below Roche limit includes the following about Comet Shoemaker–Levy 9 Here is a nice figure of its last passes: I looked up "fragment A" in ...
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A comet orbits the Sun in the same plane as Earth's orbit

If the Earth around the Sun follows a practically circular orbit of radius equal to one astronomical unit, determine its orbital speed in astronomical units per year. If the Earth around the Sun ...
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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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Is there evidence for galactic “seasons”?

The Solar Year has huge effects on our climate, and the signs of passing seasons are physically evident on Earth. I recently learned about the Galactic Year. To my understanding, our sun orbits the ...
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Is it possible for a virus to come from a meteorite?

So I am not a true scientist and I was just wondering if an extraterrestrial rock from space can have some dangerous unidentified virus or bacteria that can be deadly and wipe out the Earth if it not ...
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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 ...
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How do comets' nuclei stick together?

Comets are commonly called icy dust balls or dirty snowballs and as such rather light: Known comets have been estimated to have an average density of $0.6 {\rm g}/{\rm cm}^3$. Because of their low ...
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Comet 289P/Blanpain sudden outburst?

So Sky Safari has shown that comet 289P/Blainpain has had a sudden increase in brightness, and is currently sitting at mag -1.4!!! Last week it was sitting at +15. It is due to reach Perihelion on ...
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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 ...
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Do some comets spin? If so, how fast?

The GIF below is copied from my question earlier What might a CN filter be in the context of comet watching? Is it showing dust, or gas, or something else? where I'd said: In this post on the website ...
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Why did the Comet Shoemaker-Levy-9 fragments cause such large explosions on Jupiter?

In July 1994, the comet Shoemaker-Levy 9 (D/1993 F2) tidally fragmented and these fragments collided into Jupiter, as per the image below. Image source The question is, what mechanisms resulted in ...
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Can a supernova or a close passing star create a transient sun gravity focus “habitable zone”?

This question was inspired by the previous question Would a black hole passing next to a star create a deadly focal point due to gravitational lensing?. I understand, as gravity also acts on light, ...
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The creation of comets

How are comet and meteors made, and what causes them to travel through space so fast? I have tried researching, but I decided this was the faster way.
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Why do we only have one major meteor shower from 3200 Phaethon?

When talking to my son about the Geminid meteor shower tonight, we read up on 3200 Phaethon, and were curious: why is there only one meteor shower from 3200 Phaethon, and not two? Given its orbit, ...
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Do astronomers generally agree that the distinction between comets and asteroids is not so clear?

edit: I just saw this tweet and find it incredibly relevant :) begin question: See this answer and then consider if there are known or likely solar system bodies that might be identified as both ...
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Earth Versus Catastrophic Meteor

How evasive is the Earth to Catastrophic Meteors? Google says the Earth is approximately 92.96 million miles from the Sun. It also says the suns radius is 432,474 miles. Therefore, it is 93,392,474 ...
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Are falling evaporating bodies (FEBs) and exocomets the same thing? How does one know they're falling and evaporating?

Looking for a (short) list of comets with heliocentric escape velocity I stumbled upon Wikipedia's exocoments which like exoplanets, are bound to other stars. I should have been looking for "...
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What comet's tail did Earth pass through before Halley's?

This answer to Any record of the Earth passing through the tail (not trail) of a comet? mentions Earth passed through the tail of Halley's Comet in 1910. It caused a bit of a panic due to claims that ...
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What were they expecting to see when Halley's comet appeared in 1910?

This answer to Any record of the Earth passing through the tail (not trail) of a comet? mentions Earth passed through the tail of Halley's Comet in 1910. It caused a bit of a panic due to claims that ...
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Any record of the Earth passing through the tail (not trail) of a comet?

Discussion below the Space SE question How hard is it to fly through the tail of a comet? Has it been done? has led me to ask if there is any record of the Earth passing through the tail of a comet. ...
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How do we know that comets definitely mase and not just fluoresce?

Wikipedia's Astrophysical_maser#; comets mentions some anecdotes of notable masers associated with comets, and Maser emissions from comets begins: The 18-cm lines of the OH radical are the only ...
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Long-periodic sungrazers

I'm searching for long- and non-periodic sungrazing comets, like the Kirch comet of 1680 and the (meanwhile destroyed) Comet ISON. If you know a(ny) long-/non-periodic sungrazing comet(s), let me know ...
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Is there any known asteroid or comet whose path goes through the Earth?

Is there any known celestial body of at least 500 ft (150 m) diameter whose Minimum Orbit Intersection Distance (MOID) is within the Earth, meaning it's sure that it can impact the Earth? I know Comet ...
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Luminosity of Neowise

So, I have been trying to figure out the bolometric luminosity of the comet C/2020 F3 (Neowise) on the 22nd of June, 2020. At that time, Neowise was $1.4$ AU away from Earth and had an apparent ...
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I witnessed a steady stream of falling stars slowly falling one after another this morning. What was it? [duplicate]

This morning at 6:18am I witnessed a steady stream of falling stars that lasted at least 90 seconds from the time I noticed it. I live on a farm east of Edmonton, Alberta, Canada and the stars were ...
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Does Halley's Comet travel past the outer bounds of the Oort Cloud?

We know Halley's Comet returns every 75-76 years. We can reasonably compute its elliptical orbit. We know that the Oort Cloud is a cloud of predominantly icy planetesimals proposed to surround the Sun ...
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What is the difference between asteroids, comets and meteors?

Some celestial objects seem to be referred to as asteroids, some as comets, and some as meteors or meteorites. What is the distinction between all of these different objects? Are any of them the same?...
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Fastest recorded apparent motion of a comet or asteroid seen from Earth (degrees/day)?

If I've done my maths correctly in this answer comet 2I/Borisov (C/2019 Q4) was seen to move about 0.2 degrees in 7 hours, which is almost 0.7 degrees per day. I'm assuming this is pretty rapid ...
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What is the difference between a depleted comet and an asteroid?

When a periodic comet flies by the Sun enough times, it can become depleted of its volatile elements. Once it is depleted, what distinguishes it from an asteroid, other than records of past sightings ...
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How can comets have tails if there's no air resistance in space?

I understand that solar radiation causes material to vaporize out of a comet into dust but why does the dust then trail behind the comet like a "tail"? Assuming gravity is the only applied force ...
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What meteor shower has the radiant that appears furthest west after sunset, and why?

When it finally gets answered, answers to How to calculate the position of a meteor shower's radiant point based on its associated comet's orbit? will help us understand why the radiant points ...
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How to calculate the position of a meteor shower's radiant point based on its associated comet's orbit?

Below this answer to Why are Delta Aquariids “for the southern hemisphere” while the Perseids are “for the north”? I wrote the comment: +1 To make this complete, ...
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What determines if a comet's debris will produce periodic meteor showers?

Background I was wondering if the debris from the comet NEOWISE that recently passed Earth would provide meteor showers in the future. I looked up that the Perseid meteor showers happen when the Earth ...
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Where is the Perseids meteor shower coming from?

Swift–Tuttle Comet has orbital period of 133.28 years. Yet, people say that debris and dust from this comet causes this meteor shower. This does not make any sense. Or do they want to say that from ...
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Has any of the orbiters or rover on Mars captured image of comet NEOWISE?

We are seeing stunning pictures of comet NEOWISE from earth (and ISS too), are there any pictures captured from Mars by an orbiter or rover, or any other spacecraft?
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Can a single impact event trigger a runaway greenhouse?

Somewhat related to this question: Is the Earth going to evolve towards Mars' fate or Venus' fate? Human civilization may be fragile, but life itself is extremely resilient, with extremophiles and ...
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How long can the comet C/2020 F3 (NEOWISE) will observed with the naked eye or small optics?

In the answer to the question Where should I be looking to see Neowise in southern Sweden? there is a picture with the comet positions till 30 July. In other sources I saw similar pictures also with ...
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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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Why are Delta Aquariids “for the southern hemisphere” while the Perseids are “for the north”?

In the video How to spot Comet NEOWISE, plus the largest 3D map of the Universe | Night Sky News July 20 after 05:28 Dr. Becky (Smethurst, Oxford astrophysicist) ...
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Seeing comet NEOWISE?

Today the NY Times published an article that explained how to see NEOWISE at night. The article explains it like this: To catch NEOWISE yourself, look up at the northwest skies about an hour and a ...
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Where should I be looking to see Neowise in southern Sweden?

I'm in the south of Sweden and just spent over an hour trying to find Neowise, but didn't see it. I live in a rural area, there are no lights nearby and there is a small hill with clear visibility ...
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Will NEOWISE be known as the Great Comet of 2020?

Many or all comets visible to the naked eye are referred to as Great Comets of their year(s). Might NEOWISE too be called like this? Why or why not? Is the IAU responsible for declaration of Great ...
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Comet Neowise c2020 f3 will return in ~6800 years, how can we be sure Earth will be in the right place to see it then?

I have read in several places that the orbital period of comet Neowise c2020 F3 is about 6800 years. In several popular media sources it is said that we will be able to see the same comet after ~6800 ...
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Why Comet C/2020 F3 Neowise returns even it's orbit is near- parabolic?

I have read in Wikipedia about Comet C/2020 F3 Neowise that it's orbit is near-parabolic. But in another section, it says that it is a non-periodic comet whlith orbital period ranging from 4500 years ...
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If Planet Nine is a primordial black hole could it explain 'Oumuamua and Borisov's orbits without them being interstellar?

There has been an increasing amount of interest in the possibility of primordial black holes and that Planet Nine may be one itself. Planet Nine is a potential explanation for the orbital ...
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Is Neowise viewable from my position?

I have had an impossible time trying to locate this comet. My lat/long is 38.3/-82.4. My elevation is 705ft. The application that I'm using shows me exactly where Neowise is supposed to be (North East,...