49
votes
Accepted
Trying to identify something I saw in the sky
This is a rocket starting its engine.
More specifically, this was SpaceX Falcon 9 B1061.9 launching the Globalstar FM15 mission on June 19, 2022 at 4:27 UTC (0:27 EST). The specific event from this ...
- 660
45
votes
Does space dust fall on the roof of my house and if so can I detect it with a cheap home microscope?
Can you find (occasional) micrometeorites on the roof of your house? The Norwegian jazz musician Jon Larsen has more or less done exactly that, and even written books about it, including On the Trail ...
- 18k
40
votes
Does a meteor's direction change between country or latitude?
If you see the same meteor, it of course only has one path - even while the apparent movement differs for different observers. What you basically do in that case is triangulation - which you could use ...
- 20.4k
31
votes
Accepted
Where is the Perseids meteor shower coming from?
The comet sheds material each time it get close to the sun. The sun heats this dirty snow ball, the ice evaporates and tears dust and smaller rocks with it.
These dust particles then follow a similar ...
- 3,441
30
votes
Accepted
How long between the moment a meteor is first visible and the moment a meteorite hits the ground?
I'm a researcher at Curtin University working on the Desert Fireball Network. The DFN is the largest fireball observation network in the world, and our primary goal is to recover meteorites with ...
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27
votes
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How fast would a one mile asteroid have to go for it to match the impact that killed the dinosaurs?
This is a nice little Fermi problem, and can be answered if we don't take it too seriously. The Chicxulub impact was 20km/s and about 10 kilometers in diameter (with a density of about 3g/cm³). Mass ...
- 127k
21
votes
Accepted
Which kind of celestial body killed dinosaurs?
Definitions:
A meteoroid is a celestial object larger than an grain of dust and smaller than 1 meter in diameter.
An asteroid is a celestial object larger than 1 meter in diameter.
A meteor is a ...
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20
votes
Accepted
If two asteroids will collide, how can we call it?
They are both called asteroids.
There is neither logic, nor science, nor even a convention of calling either body a "meteor", since meteors are strictly atmospheric phenomena, that occur ...
- 127k
19
votes
Why did this meteor appear cyan?
The colour of a meteor depends mostly on its chemical composition emission spectrum. To simplify magnesium meteors are noted to have an emission spectrum which results in blue to green colour. ...
- 999
18
votes
Does a meteor's direction change between country or latitude?
Yes, but it depends on your reference system. If the meteor was moving East to West over England, it would appear to be going Left to Right from Norway, but Right to Left from Spain.
- 16.3k
17
votes
Does space dust fall on the roof of my house and if so can I detect it with a cheap home microscope?
If you live in a home with gutters and downspouts, you can easily attempt to collect micrometeorites. They aren't common, but with patience you should succeed sooner or later.
Select a piece of roof ...
- 301
15
votes
How complicated is the heating of meteors?
Your analysis is correct. Compression of the air is the cause of heating.
You call this "simple" but the compression depends on the ability of the air to flow around the meteoroid, and as the ...
- 127k
14
votes
How to tell if a meteor video or photograph is fake?
The linked image shows a de-orbiting space junk (as Darth Pseudonym notes it's likely the remains of a Soyuz rocket that was launched earlier that day). It's not "fake" per se, but it isn't ...
- 127k
13
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Does a meteor's direction change between country or latitude?
Yes, if the object is moving between the two of you then your reference systems are different. For example two people standing on opposite sides of a river. One sees it flowing from left to right, the ...
- 231
11
votes
Accepted
Did I see a mentionable event in Germany early morning on 6th of February 2019?
Fireballs are real but rare events. Meteors are formed when small rocks enter the atomsphere from space. Larger rocks or small asteroids will produce brighter meteors. The brightest meteors are called ...
- 127k
11
votes
Where is the Perseids meteor shower coming from?
The comet releases lots of dust particles. The sunlight pushes these particles into orbits not quite the same as the comet Some particles will be pushed into faster orbits, some will be pushed into ...
- 127k
10
votes
Accepted
If Earth had no atmosphere, how many people would be killed by meteors every year?
Three millions.
For this answer to be any fun, let's first assume that before removing the atmosphere, we have equipped all humans with oxygen supplies. In return, they are not allowed to go indoors ...
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10
votes
Accepted
Is it unlikely for a meteor to hit the day side of the earth?
Remember that the Earth, and the meteoroid, are both in orbit around the sun. As the meteoroid approaches Earth, it will also curve due to Earth's gravity. If you imagine the Earth to be stationary ...
- 127k
10
votes
Accepted
What factors influence the Widmanstätten pattern in iron meteorites?
It’s been a while since I studied this, and meteorites are very much not my field, so I’ll share my current understanding but would welcome corrections from those more informed :-)
These meteorites ...
- 288
10
votes
Which kind of celestial body killed dinosaurs?
Based on the Wikipedia article:
There is broad consensus that the Chicxulub impactor was an asteroid with a carbonaceous chondrite composition, rather than a comet.
And it cited a paper which ...
- 5,190
9
votes
Is a wavy path possible for a shooting star?
I saw a zig zag meteorite in Bukuru, Northern Nigeria, when I was about 13 in 1959. That started from small to increasing swings, then went out near the horizon. For many years I puzzled about this, ...
- 91
9
votes
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What percentage of a lunar meteor strike is blown back into space?
There are some invariances that actually lend themselves well to estimating an answer to this question. From the Deep Impact mission white paper:
A 1 mm projectile striking a target at 10 km/s will ...
- 16.3k
9
votes
How complicated is the heating of meteors?
Physically, the air in front of the meteor is experiencing adiabatic compression. The jump values of density and temperature before and after the adiabatic shock are given by the Rankine-Hugoniot ...
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9
votes
Accepted
What would happen if Venus was hit by a Chicxulub-like meteor?
Question: Would the dense atmosphere and high surface pressure and temperature lead to a different result compared to what happened here on Earth?
Short Answer: No. There will not be any significant ...
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9
votes
Which kind of celestial body killed dinosaurs?
Your question asks "Which kind of celestial body"
Meteorites and Meteors are not celestial bodies. Meteorites are not celestial, they are a type of stone that is sometimes found on Earth. ...
- 127k
8
votes
Are meteors visible on Mars?
First Shooting Star Seen from Mars
space.com 2005
The background image shows the meteor near the top-left and the horizon at the bottom. A red arrow shows the direction of travel. The inset ...
- 1,446
8
votes
How can I identify if my stone is meteorite?
Video evidence won't be conclusive. However the odds are stacked against you...
Meteorites are rare, far rarer than gold, even rarer than diamonds, (though unlike gold and diamonds they can be found ...
- 127k
8
votes
Accepted
Why is the Department of Defense so sure CNEOS 2014 is from outside the solar system?
Short answer
By tracing back from the known position and velocity of the object before it entered the Earth's atmosphere, the claim is that is was never in the vicinity of any major Solar System ...
- 158k
7
votes
Accepted
Any record of the Earth passing through the tail (not trail) of a comet?
Earth passed through the tail of Halley's Comet in 1910. It caused a bit of a panic due to claims that cyanogen detected in the tail would cause harm: https://en.wikipedia.org/wiki/Halley%27s_Comet#...
- 1,166
7
votes
how big would an asteroid have to be to leave a crater on Earth
Roughly 25 Meters
I don't know what you would consider a 'crater', because a pebble landing in mud will create a 'crater'. And very small particles can rain down as dust and make it all the way to the ...
- 1,171
Only top scored, non community-wiki answers of a minimum length are eligible