Questions tagged [asteroids]

Questions regarding relatively small rocky bodies in an orbit around the Sun.

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73
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2answers
13k views

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 ...
23
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1answer
3k views

What would an asteroid inside of Mercury's orbit be called?

The first Vatira asteroid has been discovered. This makes me wonder if there is already a name for the hypothetical class of asteroids that orbit entirely inside of Mercury's orbit. It wouldn't be the ...
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3answers
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Why did the distribution of asteroids discovered in 2010 have a radial modulation?

This answer links to one of Scott Manley's excellent asteroid videos Asteroid Discovery - 1970-2015 - 8K resolution. The animation highlights the positions of the meteors at the moment of their ...
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Whats the probability of a hazardous impact for human life on Mars?

Yesterday my sister and I have discussed the recent efforts of SpaceX to create a permanent colony on mars. When coming to the several dangers of creating a habitat on a different planet, we got ...
17
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2answers
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Why haven't Earth and Venus got any tiny moons? Or have they?

Why haven't some meteoroids gotten caught in Earth's or Venus' orbit? AFAIK most meteors are tiny fragments from comets. Shouldn't some comet tail sometime have passed Earth orbit at velocities ...
16
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1answer
409 views

Have we ever observed a body, such as a large asteroid, “hitting” the Sun?

Some other SE questions about launching ICBM's into the sun got me wondering whether we have ever observed an object on a path that intersected with the Sun? How close did it get?
16
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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?...
14
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1answer
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What are Trojan Asteroids and where are they located?

Asides from the main Asteroid Belt, there are Trojan Asteroids - what are these and where are they located?
14
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1answer
129 views

Why are asteroids with zero orbital inclination rare?

This is a plot of orbital inclination ($i_p$) vs. semi-major axis ($a_p$) of 96944 asteroids in the Main Belt, done by Piotr Deuar. Some structure can be seen in this diagram; clumps are asteroidal ...
13
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2answers
487 views

What is the difference between the Yarkovsky effect and YORP effect?

As far as I understand, both the Yarkovsky effect and the Yarkovsky–O'Keefe–Radzievskii–Paddack (YORP) effect exert forces upon bodies as a result of thermal photon radiation. How do both effects ...
12
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1answer
159 views

Is the Apophis asteroid a concern?

I was watching the TED lecture How to defend Earth from asteroids , and the speaker Phil Plait spoke of the possibility of this asteroid hitting Earth. Is this really a concern?
12
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781 views

How can astronomers determine the difference between “hydrostatic equilibrium” and “just happens to be spherical”?

This is relevant for the definition of a dwarf planet. I presume the answer will be, well, if we can tell the mass of the body and guess the material. I don't find this very satisfactory because (1)...
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1answer
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Could this estimate of the size and mass of the Chicxulub Impactor be accurate?

My understanding has always been that the Chicxulub Impactor was in all likelihood an asteroid with a diameter of about 8 - 12 km, but then, the other day, I came across this paper. In it, they say ...
11
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4answers
905 views

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 ...
11
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2answers
582 views

How was Earth's “quasi-satellite” 2016 HO3 “first spotted” and it's orbit determined?

Under a question I asked a few days ago Have there been any documented mini-moons since 2006 RH120? @Hobbes mentioned the recent news about 2016 HO3 - a near-Earth asteroid that stays near Earth ...
11
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1answer
601 views

What is the composition of an asteroid in percentages?

I am developing a RPG game (or so I like to tell myself) within outer space. Within the game, players would be able to mine small asteroids and collect resources, in order to make money. I'm having ...
11
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1answer
239 views

Why was this asteroid (4864 Nimoy) chosen to be named after Leonard Nimoy?

The asteroid 4864 Nimoy was recently named after Leonard Nimoy. It was discovered on September 2, 1988 so it went nearly 27 years without a name. Why was this asteroid chosen to be named after him? ...
10
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1answer
168 views

Why haven't more captured small moons been found?

Shouldn't captured moons have the same size distribution as asteroids? And asteroids are more common the smaller size they are. Moons are likely captured if they are in highly inclined orbits, and ...
9
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3answers
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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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2answers
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Gravitational Properties of Asteroids

How large would an asteroid have to be in order to hold a person so that the person could not escape?
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612 views

Why do planets tend to rotate in the same direction although they have formed from tumbling asteroids?

The axial tilts of asteroids seem to vary randomly (let me know if this premise is wrong), while the planets have a strong tendency to rotate in the same way. If planets were formed by colliding ...
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How well would the Moon protect the Earth from an Asteroid?

Would the Earth fare better if the Moon blocked the meteor, comet, rogue planet, or otherwise rather than a direct impact? At what point would the Moon's debris would be an extinction event? The ...
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3answers
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What is a dead comet?

How is a Dead Comet different from the normal comet? How are they formed? And why is the Halloween asteroid 2015 TB145 called a dead comet?.
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1answer
522 views

Asteroids between Mars and Jupiter

Is the cluster of asteroids between Mars and Jupiter two dimensional as seen in every model of solar system shown in books or television? Or is it three dimensional as i think it should be?
9
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1answer
483 views

How is the total mass of all the Solar System's small asteroids and meteoroids estimated?

This diagram from wikipedia (shown below) graphs asteroid Diameter against Number of asteroids, for the Solar System. (Graphic is courtesy of the Marco Colombo, DensityDesign Research Lab). ...
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2answers
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Why don't planets and asteroids have (cometary) tails?

Comets have tails. We all know that, and a lucky few have seen the better known. So why don't the planets (e.g. Earth, Mars) have tails? Why don't asteroids don't have tails?
9
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1answer
192 views

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 ...
8
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4answers
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Do asteroids have a gravitational field?

I know that asteroids are huge chunks of rock, orbiting a solar system. Do asteroids have a gravitational field and do they gravitationally attract each other to form planets?
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1answer
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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 ...
8
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2answers
477 views

Do NEA (Near Earth Asteroids) have minable water ice?

Water is very useful for rocket fuel and life support in space. But does water, in abundance and form which conceivably could be usefully mined this century, really exist in NEA's? Or do we have to go ...
8
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1answer
421 views

Could asteroid 'Oumuamua actually be round?

News articles have mentioned that the recently discovered asteroid 'Oumuamua is theorized to be greatly elongated based on observations of brightness variation. However, this hypothesis seems to be ...
8
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1answer
250 views

Detecting Deep Impact

There have been several accounts in media articles of asteroid near misses, many describe that the asteroid was not seen before the near miss. After reading the question and answer to How can we tell ...
8
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1answer
273 views

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 ...
7
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1answer
157 views

Are there any natural satellites in retrograde Sun orbit?

As I watch the video of the asteroids being discovered, all I see is prograde orbits. Their prevalence is fully understandable and justified, but the Sun gets interstellar visitors occasionally and I ...
7
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2answers
176 views

Can the Gaia telescope detect small temporarily captured asteroids near its Lagrange orbit?

The Gaia space telescope is in a Lissajous orbit around the Sun-Earth Lagrange point 2. The orbit period is about 180 days and the size of the orbit is 263,000 x 707,000 x 370,000 km. It has been ...
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1answer
2k views

If an Asteroid was to strike the Earth, would it affect the Earth's rotation?

If an Asteroid was to strike the Earth, would it affect noticeably the Earth's rotation, and if so, how large would this Asteroid have to be?
7
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1answer
214 views

Since when are we able to discover interstellar objects similar to 1I/ʻOumuamua?

Since when are our observation capabilities good enough to discover objects similar to the first discovered interstellar object 1I/ʻOumuamua (October 2017) with high probability? Could we make rough ...
6
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1answer
793 views

Can an asteroid have rings?

I know an asteroid can have moons, but how about rings? Does it also get affected by the Roche limit? The asteroid Florence has two moons.
6
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1answer
298 views

How can satellites be safe in the atmosphere when there are so many asteroids coming in?

How can artificial satellites be safe in the atmosphere when there are hundreds of tons of dust and asteroids coming into earth's atmosphere everyday? What is an orbit of an artificial satellite? At ...
6
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1answer
425 views

How can we tell if the asteroid 2013 TV135 will hit Earth in 2032?

Some astronomers in Ukraine have estimated that there is a small likelihood (1 in 63,000) that the asteroid 2013 TV135 will strike Earth in 2032. (source) Don Yeoman of NASA JPL says: with more ...
6
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2answers
338 views

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 ...
6
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1answer
63 views

Where can I find historic rates of meteor impact events?

I have a friend that watches a lot of TV news and they have the impression that impact events are becoming more common than in recent memory. Does the evidence support or refute this? Thinking it ...
6
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1answer
1k views

What would happen if asteroid 99942 Apophis collides with the earth?

In the news recently it's been said that in 2029 the asteroid called Apophis, aka 'The God of Chaos', will fly by very close to earth. To quote Geek.com In 2029, a massive asteroid called 99942 ...
6
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1answer
163 views

Would bagging an asteroid destroy valuable science about it?

NASA has a plan called "Asteroid Redirect Mission option A". It would robotically put an asteroid of a few meters diameter in a bag and push it into reach of astronauts for thorough examination. 44 ...
6
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1answer
179 views

How to estimate age of asteroid family Erigon

I have one problem: On picture below we can see Erigone family asteroids in plane semimajor axis - absolute magnitude. Based on V-type as a consequence of Yarkovsky effect, estimate age of this ...
6
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1answer
700 views

What are the most valuable meteorites and asteroids in terms of precious metals?

There were some suggestions that asteroids could one day be mined for precious metals. I have found an outdated study that says that some siderites contain as much as 0.001% of gold: http://pubs.usgs....
6
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1answer
167 views

What if there was an asteroid belt with the mass of a planet?

In the past, the asteroid belt was thought to be the remains of a shattered planet. Of course, that was all pseudoscience, the mass of the asteroid belt being 4% of the moon. I've been wondering, what ...
5
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2answers
255 views

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 ...
5
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1answer
593 views

How often do meteorites hit the Earth?

I heard of one that occurred in 2008 in the Nubian Desert in Sudan, how often does it happen? Is there a catalogue of all hits or are they very rare? Related link (This is what inspired my interest ...
5
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2answers
230 views

landing on a comet is more important than landing on an asteroid?

Philae landed on comet 67P this year. And it means a big breakthrough for the science and technology of human being. However Hayabusa mission of Japan not only landed on an asteroid but also returned ...

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