# What if an asteroid came very, very close to Earth? **URL:** \ **Category:** Factual Questions\ **Created:** [May 20, 2001, 12:18am UTC](https://boards.straightdope.com/t/what-if-an-asteroid-came-very-very-close-to-earth/65951 "2001-05-20T00:18:13Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![Road\_Rash](https://avatars.discourse-cdn.com/v4/letter/r/a8b319/32.png) [@Road\_Rash](https://boards.straightdope.com/u/Road_Rash)\ **Post date:** [May 20, 2001, 12:18am UTC](https://boards.straightdope.com/t/what-if-an-asteroid-came-very-very-close-to-earth/65951/1 "2001-05-20T00:18:13Z")
Possibly close enough to scrape the outer atmosphere, but not crashing to earth. I think there may be some interesting tidal activity, small rock sized debris making it to the ground, and an incredible light show. I have heard they fly by very close (like within 500,000 miles or so) more than we would like to think. Has there been recorded incidences of near misses happening? Of course, any incident more than 200 or so years ago would have been explained differently? In summary: What would happen? Has it Happened in recorded history? ---
**Author:** ![Qwertyasdfg](https://avatars.discourse-cdn.com/v4/letter/q/ecc23a/32.png) [@Qwertyasdfg](https://boards.straightdope.com/u/Qwertyasdfg)\ **Post date:** [May 20, 2001, 12:28am UTC](https://boards.straightdope.com/t/what-if-an-asteroid-came-very-very-close-to-earth/65951/2 "2001-05-20T00:28:04Z")
I don’t think it came quite that close, but I remember a science teacher telling me that a huge asteroid once came so close to Earth that if the Earth had been 3 hours behind in its revolutions around the sun, it would have hit. Meteors strike the Earth every day. Many burn up on entry, but a few make it. I have no idea what the difference is between meteors and asteroids, though. ---
**Author:** ![Cervaise](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cervaise/32/16693_2.png) [@Cervaise](https://boards.straightdope.com/u/Cervaise)\ **Post date:** [May 20, 2001, 12:49am UTC](https://boards.straightdope.com/t/what-if-an-asteroid-came-very-very-close-to-earth/65951/3 "2001-05-20T00:49:41Z")
[V] If a large body came grazing close to earth, its orbit would temporarily reverse, oceans would split down the middle, and food would fall from the sky. And yes, it has happened in recorded history. Read the Bible. [/V] 😃 ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [May 20, 2001, 2:39am UTC](https://boards.straightdope.com/t/what-if-an-asteroid-came-very-very-close-to-earth/65951/4 "2001-05-20T02:39:10Z")
[Here’s](http://www.airpower.maxwell.af.mil/airchronicles/apj/sum97/nici.html) one site about some near misses that were spotted, especially one that was recorded over Wyoming. ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [May 20, 2001, 5:08pm UTC](https://boards.straightdope.com/t/what-if-an-asteroid-came-very-very-close-to-earth/65951/5 "2001-05-20T17:08:45Z")
A meteor the size of the dinosaur killer might be the size of a mountain. There would be no gravitational effects felt on earth from something that small. The tides wouldn’t be effected, etc. Now, if you could find something the size of the moon and send it close enough to actually pass through the atmosphere, you might have some fun. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [May 20, 2001, 6:34pm UTC](https://boards.straightdope.com/t/what-if-an-asteroid-came-very-very-close-to-earth/65951/6 "2001-05-20T18:34:44Z")
It would scare the bejeezus out of a whole lot of people, and that’s about it. As to other near misses, what do you call “near”? I’ve seen hype over “near-misses” every couple of years or so, but in every case, the object’s closest approach has been several times the distance to the Moon. An object which grazed the atmosphere, but did not hit the surface, would be a very near miss indeed: If the Earth were scaled down to the size of a large apple, the atmosphere would be thinner than the apple’s skin. The surface would be a far easier target, and that’s only been hit by killer-sized bodies a handfull of times in the past few billion years. ---
**Author:** ![Road\_Rash](https://avatars.discourse-cdn.com/v4/letter/r/a8b319/32.png) [@Road\_Rash](https://boards.straightdope.com/u/Road_Rash)\ **Post date:** [May 21, 2001, 1:40am UTC](https://boards.straightdope.com/t/what-if-an-asteroid-came-very-very-close-to-earth/65951/7 "2001-05-21T01:40:59Z")
> [@](#): > > \*Originally posted by Lumpy \* > \*\*[Here’s](http://www.airpower.maxwell.af.mil/airchronicles/apj/sum97/nici.html) one site about some near misses that were spotted, especially one that was recorded over Wyoming. > \*\* Thanks a bunch! A very informative article. There was even a picture of a meteor scraping and skipping off the atmosphere. Although all that was noticeable was the people looking up in the sky. ---
**Author:** ![rowrrbazzle](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rowrrbazzle/32/414_2.png) [@rowrrbazzle](https://boards.straightdope.com/u/rowrrbazzle)\ **Post date:** [May 21, 2001, 6:28am UTC](https://boards.straightdope.com/t/what-if-an-asteroid-came-very-very-close-to-earth/65951/8 "2001-05-21T06:28:32Z")
I have seen a video of that Wyoming daylight meteor, but I couldn’t find it on the Web. One program that showed it was an episode of “Arthur C. Clarke’s Mysterious World” which was about UFOs. That link also says “From 1975 to 1992, nuclear detonation detecting satellites recorded 136 atmospheric blasts in the **megatons** -of-TNT range.” You’d think more people would notice those! But that’s probably wrong. The page at [http://www.tiac.net/users/lewkaren/meteorobs/msg03146.html](http://www.tiac.net/users/lewkaren/meteorobs/msg03146.html) quotes Los Alamos National Laboratory researcher Doug ReVelle: > [@](#): > > Each year, we see at least one object entering the atmosphere that’s about six meters in diameter…These make an infrasonic signal similar to what you’d see from a 15-kiloton explosion, an explosion of 15,000 tons of TNT, depending on the object’s velocity and density. And each year we see around 10 objects entering the atmosphere that are equivalent to a one- **kiloton** blast – or about two meters in diameter. ---
**Author:** ![Phobos](https://avatars.discourse-cdn.com/v4/letter/p/3d9bf3/32.png) [@Phobos](https://boards.straightdope.com/u/Phobos)\ **Post date:** [May 21, 2001, 12:51pm UTC](https://boards.straightdope.com/t/what-if-an-asteroid-came-very-very-close-to-earth/65951/9 "2001-05-21T12:51:20Z")
> [@](#): > > \*Originally posted by Qwertyasdfg \* > \*\*Meteors strike the Earth every day. Many burn up on entry, but a few make it. I have no idea what the difference is between meteors and asteroids, though. \*\* Meteors are generally specks of dust/sand-like particles (from comet tails etc.) that hit the atmosphere every day (a.k.a. shooting stars). Asteroids are big rocks (or rocks/ice or gravitationally-bound collections of gravel, etc.) that are left over from the formation of the solar system. These can range in size from 100s of meters to many, many kilometers in diameter. Not sure what you call the stuff in between. I suppose most of that stuff is not visible to our telescopes. But if it burns up in the atmosphere, it’s a meteor. ---
**Author:** ![Phobos](https://avatars.discourse-cdn.com/v4/letter/p/3d9bf3/32.png) [@Phobos](https://boards.straightdope.com/u/Phobos)\ **Post date:** [May 21, 2001, 12:53pm UTC](https://boards.straightdope.com/t/what-if-an-asteroid-came-very-very-close-to-earth/65951/10 "2001-05-21T12:53:20Z")
[JPL’s Close-Approach Tables](http://ssd.jpl.nasa.gov/ca_home.html) ---
**Author:** ![Spoke](https://avatars.discourse-cdn.com/v4/letter/s/a88e57/32.png) [@Spoke](https://boards.straightdope.com/u/Spoke)\ **Post date:** [May 21, 2001, 7:52pm UTC](https://boards.straightdope.com/t/what-if-an-asteroid-came-very-very-close-to-earth/65951/11 "2001-05-21T19:52:22Z")
Dunno about asteroids, but in 1910, the Earth is believed to have passed through the tail of halley’s Commet, to no ill effect. [More here.](http://school.discovery.com/homeworkhelp/worldbook/atozscience/h/243380.html) On the other hand,[according to Steven King](http://www.stephenkingnews.com/movies/maximumoverdrive.html) if we pass through a comet’s tail our lawnmowers are apt to come to life and try to kill us all. ---
**Author:** ![Spoke](https://avatars.discourse-cdn.com/v4/letter/s/a88e57/32.png) [@Spoke](https://boards.straightdope.com/u/Spoke)\ **Post date:** [May 21, 2001, 8:24pm UTC](https://boards.straightdope.com/t/what-if-an-asteroid-came-very-very-close-to-earth/65951/12 "2001-05-21T20:24:53Z")
**"halley’s Commet"??? Of course I meant Haileg’s comitt!** 😉 Let’s try that again: Dunno about asteroids, but in 1910, the Earth is believed to have passed through the tail of Halley’s Comet, to no ill effect. [More here.](http://school.discovery.com/homeworkhelp/worldbook/atozscience/h/243380.html) On the other hand, [according to Steven King](http://www.stephenkingnews.com/movies/maximumoverdrive.html) if we pass through a comet’s tail our lawnmowers are apt to come to life and try to kill us all. ---
**Author:** ![Olentzero](https://avatars.discourse-cdn.com/v4/letter/o/90ced4/32.png) [@Olentzero](https://boards.straightdope.com/u/Olentzero)\ **Post date:** [May 22, 2001, 3:55am UTC](https://boards.straightdope.com/t/what-if-an-asteroid-came-very-very-close-to-earth/65951/13 "2001-05-22T03:55:03Z")
> [@](#): > > \*Originally posted by cooldude \* > **Although all that was noticeable was the people looking up in the sky.** The meteor is in the upper right-hand corner of the frame. It is the left one of two roughly equally sized spots closest to the top of the frame. If you look very carefully you can see the meteor’s trail stretching out behind it almost all the way across the frame. A pretty unsettling picture, all in all, if you think about it. ---
**Author:** ![reprise](https://avatars.discourse-cdn.com/v4/letter/r/ea666f/32.png) [@reprise](https://boards.straightdope.com/u/reprise)\ **Post date:** [May 22, 2001, 4:06am UTC](https://boards.straightdope.com/t/what-if-an-asteroid-came-very-very-close-to-earth/65951/14 "2001-05-22T04:06:03Z")
We may all get to find out the answer. I recall reading recently that we are expecting one of these events in about 30-40 years time and scientists are looking for possible solutions. ---
**Author:** ![psiekier](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/psiekier/32/116_2.png) [@psiekier](https://boards.straightdope.com/u/psiekier)\ **Post date:** [May 22, 2001, 4:00pm UTC](https://boards.straightdope.com/t/what-if-an-asteroid-came-very-very-close-to-earth/65951/15 "2001-05-22T16:00:21Z")
> [@](#): > > \*Originally posted by cooldude \* > **What would happen?** Duh: > [@](#): > > **"The year is 1994. From out of space comes a runaway planet, hurtling between the Earth and the Moon, unleashing cosmic destruction. Man’s civilization is cast in ruin. Two thousand years later, Earth is reborn… A strange new world rises from the old: a world of savagery, super science, and sorcery. But one man bursts his bonds to fight for justice! With his companions Ookla the Mok and Princess Ariel, he pits his strength, his courage, and his fabulous Sunsword against the forces of evil. He is Thundarr, the Barbarian!"** Ah… the things we learn from Saturday morning cartoons… * * * Pete ake off every .sig for great justice!!