Spotting Meteorites: Unveiling the Mystery of Annual Showers

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In summary, the conversation discusses the mechanics of meteorite showers and the behavior of particles left behind by passing comets. The conversation touches on the predictability and annual occurrence of meteorite showers, which originate from the same part of the celestial sphere. It is mentioned that the dust from comets is constantly moving and does not remain frozen in the Solar System. The conversation also explores the difference between gas and particles in terms of their behavior in the solar wind. There is a discussion on the distribution of meteor showers along the orbital path of comets and the possibility of asteroid debris causing meteorite showers.
  • #1
sophiecentaur
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TL;DR Summary
We see meteor showers on a regular, annual basis. Can this be a stable situation?
I am planning to catch the Perseid Shower in the next few weeks and I've been thinking about the mechanics of meteorite showers.

So we see clusters of meteorites as we fly through the path of dust, left behind by passing comets. The showers seem to be predictable and some of them have been witnessed for many years on an annual basis, coming from the 'same part' of the celestial sphere (the radiant). I was thinking about what happens to this dust after the comet has left it behind. Why do they all turn up at the same time and in the same place, each year. I realize we are flying through a different part of the tail each year but . . .
Each grain will have an orbit around the Sun, that's determined by it orbital radius and its velocity and it won't be the same as Earth's orbit. Most particles won't have the same orbit period as Earth and they will be traveling (much?) slower than the parent comet but more or less in the same direction. The tail will not be 'frozen' in its position in the Solar System but it will carry on in the general direction of the Sun.
So how come we fly into remnants of any given comet at the same time every year and why does the radiant appear in the same place? Is the story we're told just too simple to be real?
 
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  • #2
Maybe the comet left a dust trail along it's entire orbital path. The particles move, but the path is constant. IDK, just a guess.
 
  • #3
Meteors, BTW. You look down for meteorites. Sorry, I know, it's annoyingly pedantic.
 
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  • #4
DaveE said:
Meteors, BTW. You look down for meteorites. Sorry, I know, it's annoyingly pedantic.
When I saw the title, I assumed he was looking in rockpiles or icefields...
 
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  • #5
I think you're conflating a couple of things, while missing the key elements.

1. While the remnants of Kuiper Belt objects certainly produce a large tail and coma when they near the sun, that is a temporary, ephemeral and spectacular phenomenon. The KBO has been around for eons, and will have distributed a halo of particles along its entire orbital path. It just happens to be too faint to see (and so we only them them when they intersect the Earth and burn up).

2. There is a difference between what gas does that comes off a Kuiper object and what particles do. Gas and molecules are easily pushed around by the solar wind. But the particles we see in showers are on the order of grains of sand and larger. These are pushed around a lot less by the solar wind, and thus keep to their orbit.

The takeaway here is that meteor showers are comprised of large particles that aren't shoved out of orbit easily, and are distributed along the orbital path, not just in the tail and not just when near the sun.

* see caveat in sig line
 
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  • #6
DaveE said:
Meteors, BTW. You look down for meteorites. Sorry, I know, it's annoyingly pedantic.
That was dumb of me, considering I just bought two!
DaveC426913 said:
shoved out of orbit easily, and are distributed along the orbital path, not just in the tail and not just when near the sun.

* see caveat in sig line
That’s what is always said but what orbit is an individual bit of dust in? They would be moving at speed and not sitting where they were left behind. A bit slower than the core perhaps so a trajectory closer to the sun?
Perhaps the explanation is that each year we run into a bunch that’s taken a year longer to get there but laying on the same path, more or less.
so there will be many comets that don’t have a trail that intersects our orbit so no meteors from them although we may see the comet.

The width of the path / orbit must depend on the range of velocities that matter is ejected from the comet.
Cheers: that picture makes sense to me.
 
  • #7
sophiecentaur said:
he width of the path / orbit must depend on the range of velocities that matter is ejected from the comet.
Cheers: that picture makes sense to me.
+1
 
  • #8
The trick would be to compare the magnitude of the orbital velocity at some given point to the magnitude of velocities at which particles are jettisoned from the primary body.

I suspect the former outstrips the latter by an order of magnitude or (possibly much) more. And that means - while particles may drift from the orbit somewhat - it won't be very much deviation on a scale that reaches from Pluto to the Sun.
 
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  • #9
 
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  • #10
DaveC426913 said:
And that means - while particles may drift from the orbit somewhat - it won't be very much deviation on a scale that reaches from Pluto to the Sun.
The same could apply to asteroids, only worse. If a rogue asteroid is merely broken up by Space Cowboys or others, the stuff will carry on in its original orbit plus-or-minus an shower us on some later pass. But the cross sectional area would be bigger and the scattergun effect could mean we get some of it but not all of it!

The statistics are not too scary though; we haven't been hit for a while but the orbit times for asteroids is in the order of only a few years so significant debris from a broken up asteroid could cross our path much more often than stuff from a comet. But the actual numbers would be very significant and the contents of an asteroid could perhaps (with a big enough nuke) spread out much more than the bits from a comet.
 
  • #11
sophiecentaur said:
The same could apply to asteroids, only worse. If a rogue asteroid is merely broken up by Space Cowboys or others, the stuff will carry on in its original orbit plus-or-minus an shower us on some later pass. But the cross sectional area would be bigger and the scattergun effect could mean we get some of it but not all of it!
Sure. Although:
- asteroids are less likely to have eccentric Earth-crossing orbits, and
- being rocky, rather than icy, asteroids don't tend to accumulate great trails of particles in their paths.
 
  • #12
DaveC426913 said:
Sure. Although:
- asteroids are less likely to have eccentric Earth-crossing orbits, and
- being rocky, rather than icy, asteroids don't tend to accumulate great trails of particles in their paths.
I was assuming it has been blasted into pieces by the Space Cowboy and the pieces spread over its otherwise unperturbed orbit. But isn’t the frequency of near misses of no negligible concern? (Compared with being whacked by comets.)
Good point of the difference in content and th
the trails are fairly harmless.
 
  • #13
sophiecentaur said:
I was assuming it has been blasted into pieces by the Space Cowboy and the pieces spread over its otherwise unperturbed orbit.
Yes, I bypassed that parameter of the scenario as I am not sure where you're going with it as it applies to the OP.
 
  • #14
DaveE said:
Meteors, BTW. You look down for meteorites
@davenn looks for them in his mailbox.
 
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  • #15
DaveC426913 said:
Yes, I bypassed that parameter of the scenario as I am not sure where you're going with it as it applies to the OP.
Having partly sorted out and found a mechanism for the apparently endless visits of Perseid etc., I fell to thinking about other random visitors to Earth's vicinity. That was how the segue arose.
 
  • #16
Vanadium 50 said:
@davenn looks for them in his mailbox.
And the result of their impact is on his Bank Balance!
 
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  • #17
DaveE said:
Meteors, BTW. You look down for meteorites. Sorry, I know, it's annoyingly pedantic.
Plus, why do we need two names anyway? We don't rename hail or rain drops when they hit the ground. Birds are still birds whether they are flying or not. I'm OK with asteroids vs. meteors, after all they are doing different things. But falling towards Earth and burning up in the atmosphere is a lot like falling towards Earth, burning in the atmosphere, and hitting the ground. It's not just pedantic, it's pointlessly pedantic.
 
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  • #18
Nobody mentioned explicity that the perturbations to the orbit of the comet detritus occurs very near the perihelion of a relatively eccentric orbit. This doubtless affects the paths of these particles at aphelion but when back near the sun not much will change except their arrival time. I hadn't thought this through previously... thanks to all.
DaveE said:
Birds are still birds whether they are flying or not.
We do usually call them dead birds...
 
  • #19
DaveE said:
We don't rename hail or rain drops when they hit the ground.
We call them a puddle when they have landed. And, anyway, you can't buy a meteor but you can buy a meteorite. There's a difference for you.
Many of these astronomical terms were introduced long before anyone actually knew what the things were but inappropriate names for things are still alive and well in the world of elementary particles. You could always demand an explanation for why Charm is Charm but I don't think you'd get very far with it.
 
  • #20
DaveE said:
Plus, why do we need two names anyway?
Because one is an astronomical object and one is a geological mineral - thus the obligatory suffix -ite.
 
  • #21
sophiecentaur said:
We call them a puddle when they have landed.
Like rocks and landslides, or cars and traffic, I guess.

sophiecentaur said:
Many of these astronomical terms were introduced long before anyone actually knew what the things were
And what an amazing coincidence that they choose to name one meteor and the other meteorite! Anyway, it's a losing position, I know. I'll just be happy that I don't hear meteoroid used too.
 
  • #22
DaveE said:
I'm OK with asteroids vs. meteors, after all they are doing different things. But falling towards Earth and burning up in the atmosphere is a lot like falling towards Earth, burning in the atmosphere, and hitting the ground. It's not just pedantic, it's pointlessly pedantic.
No it isn't pedantic ... it's two totally separate phenomena
and asteroids ARE meteors when blazing through the atmosphere
Asteroids vs meteoroids is the thing that you need to clarify.
1) Asteroid is any rock over 1 metre in diameter, meteoroid for anything smaller. When in space
2) Meteor describes the incandescent object in the atmosphere, bolide or fireball for larger
bursts of light
3) Meteorite describes any remaining rock/iron that makes it to the ground,
regardless of if it was a meteoroid or an asteroid
 
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  • #23
DaveE said:
I'll just be happy that I don't hear meteoroid used too.

It does get used, it has a very specific definition ... see my previous post
In the "space rocks" field of study (etc) meteoroid is used all the time
 
  • #24
sophiecentaur said:
Summary:: We see meteor showers on a regular, annual basis. Can this be a stable situation?

Most particles won't have the same orbit period as Earth
Of course not, many/most are on highly elliptical orbits through the solar system and around the sun.
There are probably none with the near circular orbit that the Earth or other planets have

sophiecentaur said:
Summary:: We see meteor showers on a regular, annual basis. Can this be a stable situation?

and they will be traveling (much?) slower than the parent comet but more or less in the same direction.

yes, they will follow the comets orbit around the sun

sophiecentaur said:
Summary:: We see meteor showers on a regular, annual basis. Can this be a stable situation?

The tail will not be 'frozen' in its position in the Solar System but it will carry on in the general direction of the Sun.

Not the tail but the trail (dunno if you typo'ed?) it position in the solar system relative to the sun and planets will remain relatively unchanged.

sophiecentaur said:
Summary:: We see meteor showers on a regular, annual basis. Can this be a stable situation?

So how come we fly into remnants of any given comet at the same time every year and why does the radiant appear in the same place?
because of my previous response, the Sun and all the planets, asteroids and every other thing in the solar system is moving through space collectively as a group
 
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  • #25
sophiecentaur said:
you can't buy a meteor
I'd be happy to sell you one. Delivery not included.
 
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  • #26
davenn said:
There are probably none with the near circular orbit that the Earth or other planets have
Wait. Earth - and the other planets - have their own co-orbiting objects, including - but not limited to -Trojans.
 
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  • #27
davenn said:
There are probably none with the near circular orbit that the Earth or other planets have
It turns out there is...drum roll please...one. 2010 TK7.

Period: 365.10 days
Semimajor axis: 0.99972 AU
Aphelion: 1.2 AU
Perihelion: 0.8 AU
Eccentricity: 0.19 (less than Mercury)
 
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  • #28
Vanadium 50 said:
It turns out there is...drum roll please...one. 2010 TK7.
It's not the only one, there is another trojan (2020 XL5 - significantly more eccentric though) discovered recent and if you go to the JPL Small-Body Database Search Engine you can find (say searching for NEOs AND a = [ 0.98, : 1.02 ] (au) AND e < 0.2 ) a bunch of (non-trojan) asteroids in similar orbits to Earth like 469219 Kamo'oalewa.
 
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  • #29
I don't know which requirement of mine 469219 Kamo'oalewa failed. 2020 XL5 was not included because a) it's eccentricity, and b) the observation arc is only 6 weeks.
 
  • #30
The co-orbital asteroids are also good candidates, very low eccentricity in some of them like 2002 AA29 and 2003 YN107.
 
  • #31
davenn said:
There are probably none with the near circular orbit that the Earth or other planets have
This may be true (or nearly true) but there are a lot of objects with orbits that intersect Earth's orbit +/- little enough to worry us sometimes. (I'm still trying to tie in the trail of a comet with what happens to the resulting bits from a blown-up asteroid) The products of an exploded asteroid will have a range of orbits spread around the CM of the original asteroid. At some point in the future (next or tenth time round - depending) when the orbits of those bits of rock again rendezvous with the Earth, there is a greater chance of a collision with one of them, So they need to be broken up into relatively harmless sized bits, with a consequently greater chance of actually hitting us.
The alternative of guiding an asteroid out of harm's way is more attractive - but only if the rocket power exists. From what I understand of orbital mechanics, shifting an object into a significantly different orbit would involve more than just one impulse. So the rocket would need to sit on the asteroid and give it another nudge at a suitable time.
 
  • #32
sophiecentaur said:
From what I understand of orbital mechanics, shifting an object into a significantly different orbit would involve more than just one impulse.
Not necessarily. A single impulse would change the eccentricity of its orbit, though one of its *apses (either apsis or periapsis) will remain the same.

This surely reduces the overall collision risk by many orders of magnitude - which is probably sufficient.

Consider also that it may be effective to simply change the inclination of a menacing asteroid's orbit. Little energy required for maximum reduction in collision risk.
 
  • #33
DaveC426913 said:
Wait. Earth - and the other planets - have their own co-orbiting objects, including - but not limited to -Trojans.
Those are NOT comet trails which is what is being spoken of ... ... dust trails left my comets and the resulting meteor showers

:wink: :smile:
 
  • #34
sophiecentaur said:
This may be true (or nearly true) but there are a lot of objects with orbits that intersect Earth's orbit +/- little enough to worry us sometimes.

Yes, there's lots of meteoroids and asteroids with orbits that cross Earths orbit, but as I just replied to DaveC ... you are asking about comet dust trails :smile: and their paths are all highly elliptical
 
  • #35
glappkaeft said:
The co-orbital asteroids are also good candidates, very low eccentricity in some of them like 2002 AA29 and 2003 YN107.
Again ... those are asteroids you speak of, not cometary dust trails that the thread is about :smile:
 
<h2>1. What are meteor showers and when do they occur?</h2><p>Meteor showers are celestial events that occur when Earth passes through the debris left behind by a comet or asteroid. They happen at specific times of the year when Earth's orbit intersects with the orbit of the comet or asteroid. Some of the most well-known meteor showers include the Perseids in August and the Geminids in December.</p><h2>2. How can I spot a meteorite during a meteor shower?</h2><p>The best way to spot a meteorite during a meteor shower is to find a dark, open area away from city lights. Lie down on a blanket or lawn chair and look up at the night sky. Be patient and allow your eyes to adjust to the darkness. You may see bright streaks of light as the meteorites enter Earth's atmosphere and burn up.</p><h2>3. Are all meteorites visible during meteor showers?</h2><p>No, not all meteorites are visible during meteor showers. Some meteorites may be too small to produce a visible streak of light, while others may enter the atmosphere at an angle that makes them less visible. Additionally, the brightness of the moon and light pollution can also affect visibility.</p><h2>4. How can I tell if I've found a meteorite?</h2><p>If you think you've found a meteorite, the best way to confirm is by having it examined by a professional. Look for a dark, smooth exterior with small pits or depressions. Meteorites are also usually magnetic and may have a fusion crust, which is a thin layer of melted rock on the surface. However, there are many earth rocks that can look similar to meteorites, so it's important to have it verified by an expert.</p><h2>5. Why is it important to study meteorites?</h2><p>Meteorites provide valuable information about the formation and evolution of our solar system. They can also give us insight into the composition of other planets and moons. Additionally, studying meteorites can help us understand the potential hazards of near-Earth objects and how to better protect our planet from potential impacts.</p>

1. What are meteor showers and when do they occur?

Meteor showers are celestial events that occur when Earth passes through the debris left behind by a comet or asteroid. They happen at specific times of the year when Earth's orbit intersects with the orbit of the comet or asteroid. Some of the most well-known meteor showers include the Perseids in August and the Geminids in December.

2. How can I spot a meteorite during a meteor shower?

The best way to spot a meteorite during a meteor shower is to find a dark, open area away from city lights. Lie down on a blanket or lawn chair and look up at the night sky. Be patient and allow your eyes to adjust to the darkness. You may see bright streaks of light as the meteorites enter Earth's atmosphere and burn up.

3. Are all meteorites visible during meteor showers?

No, not all meteorites are visible during meteor showers. Some meteorites may be too small to produce a visible streak of light, while others may enter the atmosphere at an angle that makes them less visible. Additionally, the brightness of the moon and light pollution can also affect visibility.

4. How can I tell if I've found a meteorite?

If you think you've found a meteorite, the best way to confirm is by having it examined by a professional. Look for a dark, smooth exterior with small pits or depressions. Meteorites are also usually magnetic and may have a fusion crust, which is a thin layer of melted rock on the surface. However, there are many earth rocks that can look similar to meteorites, so it's important to have it verified by an expert.

5. Why is it important to study meteorites?

Meteorites provide valuable information about the formation and evolution of our solar system. They can also give us insight into the composition of other planets and moons. Additionally, studying meteorites can help us understand the potential hazards of near-Earth objects and how to better protect our planet from potential impacts.

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