Hacker News new | past | comments | ask | show | jobs | submit login

Yes, relatively speaking.

First likely hit I found:

"Meteors enter the atmosphere at speeds ranging from 11 km/sec...to 72 km/sec ... The wide range in meteoroid speeds is caused partly by the fact that the Earth itself is traveling at about 30 km/sec (67,000 mph) as it revolves around the sun. On the evening side, or trailing edge of the Earth, meteoroids must catch up to the earth’s atmosphere to cause a meteor, and tend to be slow. On the morning side, or leading edge of the earth, meteoroids can collide head-on with the atmosphere and tend to be fast."

https://www.amsmeteors.org/meteor-showers/meteor-faq/




The "relatively slow" 11 km/sec is still 39.600 km/h, or around Mach 30 (although that depends on air density and temperature), so still pretty fast I would say...


There's no authoritatively correct reference for what "slow" or "fast" should mean in extraterrestrial contexts, however, I think it makes sense to look at it like this:

Suppose you were watching a (CGI) movie or a video of a meteor hitting Earth, with the whole globe on screen.

The diameter of the Earth is almost 13,000 km. So a meteor(oid) going even 70 km/s is going to take 3 minutes to hit from one diameter away.

It should look like it's barely moving on a planetary scale.


The scale of things in astronomy is humbling to say the least. "Close" can be 1 light-year away... That's 9.4607e+12 km. "Slow" is Mach 30. We're nothing at that scale.


I wonder, if a meteor was moving very slowly (relatively) and basically just gently falling to earth, if we'd notice.


Yes. They are the largest source of extraterrestrial mass. https://www.sciencealert.com/5-200-tons-of-micrometeorites-a...


And one has been caught on film (we think) https://www.universetoday.com/110963/norwegian-skydiver-almo....

There’s also a nice coffee table book about them:

https://www.amazon.com/Search-Stardust-Micrometeorites-Terre...


> one has been caught on film

apparently it was just a rock[0]

[0]https://www.universetoday.com/111076/follow-up-on-skydiving-...


Damn nearly getting cut in half by a meteor while skydiving!


"Ann Elizabeth Fowler Hodges...was an American woman known for being the first documented individual not only to be struck by a meteorite, but also to live through the encounter."

https://en.wikipedia.org/wiki/Ann_Elizabeth_Fowler_Hodges


Neat! I hadn’t thought that through, but it makes sense.


So this can't be a meteor then. That's not 11 km/s unless the video has been drastically slowed down.


I just read a page on meteors that said they tend to blow up starting around 300,000 to 200,000 feet or so.

If I make a wild-ass guess that the fireball was visible over a trajectory of about 100,000 feet, that's about 30 km.

At 11 km/s, then, it should appear for around 3 seconds.

I rewatched the video, which is 5 seconds in all, and it looks to me like the light is pretty close to three seconds long.

Aside from that, sure, it could've been slowed down, and could be at an angle, so it may all be a coincidence.


I'm sure you've seen a plane traveling 400 mph but seemingly hovering in one spot in the sky. It's just not moving perpendicular to your vision.


Not sure what you're getting at but 400 mph is 0.178816 km/s. Off by two orders of magnitude from 11 km/s.

I am sure everyone has seen a shooting star. Planes don't move like shooting starts or whatever is in this vide.

I think it's safe to conclude that this is not a plane nor a meteor.


Here's another factor: When something is far away from you, it appears to travel slower. For example, the sun is ~150M kilometers away. As the earth rotates through a day, from our perspective it travels ~942M kilometers, meaning it appears to be traveling at 40 million kph through the sky. However, it's just sitting there in one spot.




Consider applying for YC's W25 batch! Applications are open till Nov 12.

Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact

Search: