# If a cow jumped over the moon, how fast would it be going when it got back and hit earth's atmosphere? **URL:** \ **Category:** Factual Questions\ **Created:** [January 27, 2024, 4:27pm UTC](https://boards.straightdope.com/t/if-a-cow-jumped-over-the-moon-how-fast-would-it-be-going-when-it-got-back-and-hit-earths-atmosphere/996737 "2024-01-27T16:27:55Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![Pardel-Lux](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pardel-lux/32/20182_2.png) [@Pardel-Lux](https://boards.straightdope.com/u/Pardel-Lux)\ **Post date:** [January 27, 2024, 11:25pm UTC](https://boards.straightdope.com/t/if-a-cow-jumped-over-the-moon-how-fast-would-it-be-going-when-it-got-back-and-hit-earths-atmosphere/996737/41 "2024-01-27T23:25:26Z")
> [@Dallas\_Jones](#): > > Show me a cow jumping. Your whish is my [command](https://www.youtube.com/watch?v=aKeNTj5cKM4). ---
**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:** [January 28, 2024, 1:19am UTC](https://boards.straightdope.com/t/if-a-cow-jumped-over-the-moon-how-fast-would-it-be-going-when-it-got-back-and-hit-earths-atmosphere/996737/42 "2024-01-28T01:19:04Z")
From the perspective of the Apollo astronauts, every cow on Earth was jumping over the Moon. ---
**Author:** ![don\_t\_ask](https://avatars.discourse-cdn.com/v4/letter/d/e68b1a/32.png) [@don\_t\_ask](https://boards.straightdope.com/u/don_t_ask)\ **Post date:** [January 28, 2024, 2:13am UTC](https://boards.straightdope.com/t/if-a-cow-jumped-over-the-moon-how-fast-would-it-be-going-when-it-got-back-and-hit-earths-atmosphere/996737/43 "2024-01-28T02:13:33Z")
> [@RickJay](#): > > Is anyone here smart enough to come up with a rough estimate of how fast Bessie will be going before becoming beef jerky in the upper atmosphere? Would the cow become beef jerky if it was a dairy cow? ---
**Author:** ![Q.Q.Switcheroo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/q.q.switcheroo/32/5713_2.png) [@Q.Q.Switcheroo](https://boards.straightdope.com/u/Q.Q.Switcheroo)\ **Post date:** [January 28, 2024, 2:50am UTC](https://boards.straightdope.com/t/if-a-cow-jumped-over-the-moon-how-fast-would-it-be-going-when-it-got-back-and-hit-earths-atmosphere/996737/44 "2024-01-28T02:50:04Z")
> [@Dallas\_Jones](#): > > And don’t get me started about the relationships between a dish and a spoon. I heard they raised their children as forks. ---
**Author:** ![scudsucker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/scudsucker/32/14101_2.png) [@scudsucker](https://boards.straightdope.com/u/scudsucker)\ **Post date:** [January 28, 2024, 1:40pm UTC](https://boards.straightdope.com/t/if-a-cow-jumped-over-the-moon-how-fast-would-it-be-going-when-it-got-back-and-hit-earths-atmosphere/996737/45 "2024-01-28T13:40:23Z")
> [@Dallas\_Jones](#): > > Cows don’t jump. Show me a cow jumping This is not true. In rural areas in Zimbabwe, where I grew up, it was not exactly common, but often noticeable for a cow or bull to have a “Y” shape log tied around its neck in order to retard its ability to jump over the typical 4 foot wire farm fences. And, closer, probably, to Dallas, have you never seen a rodeo cowboy riding a steer? (An aside. Elands, which are considerably bigger than cattle, can easily clear a 10 foot fence. I mean, sure they are built for speed, but they are very similar herd animals that have just never been domesticated. [Wikipedia](https://en.m.wikipedia.org/wiki/Common_eland#:~:text=Elands%20are%20capable%20of%20jumping,live%20up%20to%2025%20years.) suggests that can do 8 feet from a standing start.) ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [January 28, 2024, 2:24pm UTC](https://boards.straightdope.com/t/if-a-cow-jumped-over-the-moon-how-fast-would-it-be-going-when-it-got-back-and-hit-earths-atmosphere/996737/46 "2024-01-28T14:24:02Z")
> [@SuntanLotion](#): > > Cow would need an engine to send her anywhere. Cows are certainly capable of jet propulsion. This was the original ending for Sandra Bullock in _Gravity_ until someone thought of using a fire extinguisher instead. ---
**Author:** ![Bosda\_Di\_Chi\_of\_Tricor](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bosda_di_chi_of_tricor/32/16845_2.png) [@Bosda\_Di\_Chi\_of\_Tricor](https://boards.straightdope.com/u/Bosda_Di_Chi_of_Tricor)\ **Post date:** [January 28, 2024, 2:27pm UTC](https://boards.straightdope.com/t/if-a-cow-jumped-over-the-moon-how-fast-would-it-be-going-when-it-got-back-and-hit-earths-atmosphere/996737/47 "2024-01-28T14:27:18Z")
{ahem} SDMB Orbital Goat Cannon. ---
**Author:** ![Really\_Not\_All\_That\_Bright](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@Really\_Not\_All\_That\_Bright](https://boards.straightdope.com/u/Really_Not_All_That_Bright)\ **Post date:** [January 28, 2024, 2:50pm UTC](https://boards.straightdope.com/t/if-a-cow-jumped-over-the-moon-how-fast-would-it-be-going-when-it-got-back-and-hit-earths-atmosphere/996737/48 "2024-01-28T14:50:47Z")
I am so sorry for wondering if the SDMB was losing its way. ---
**Author:** ![mbh](https://avatars.discourse-cdn.com/v4/letter/m/a6a055/32.png) [@mbh](https://boards.straightdope.com/u/mbh)\ **Post date:** [January 28, 2024, 2:54pm UTC](https://boards.straightdope.com/t/if-a-cow-jumped-over-the-moon-how-fast-would-it-be-going-when-it-got-back-and-hit-earths-atmosphere/996737/49 "2024-01-28T14:54:30Z")
> [@Bosda\_Di\_Chi\_of\_Tricor](#): > > SDMB Orbital Goat Cannon. I presume you are referring to this thread? > [@Do they make PVC big enough to launch a goat out of?](https://boards.straightdope.com/t/do-they-make-pvc-big-enough-to-launch-a-goat-out-of/35720): > > Also, would PVC be the right material to make a goat cannon? Can structural soundness of the barrel be counted upon while properly launching the cloven ones? What would be the best propellant? Black powder, butane, gasoline, semtex? Would you use newspaper for batting? Would the goat remain integrated without trussing it or using duct tape or something? Also, what’s the terminal velocity of an object with similar mass, surface area and shape of a goat? How high would the goat have to go to reach… ---
**Author:** ![Bosda\_Di\_Chi\_of\_Tricor](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bosda_di_chi_of_tricor/32/16845_2.png) [@Bosda\_Di\_Chi\_of\_Tricor](https://boards.straightdope.com/u/Bosda_Di_Chi_of_Tricor)\ **Post date:** [January 28, 2024, 6:29pm UTC](https://boards.straightdope.com/t/if-a-cow-jumped-over-the-moon-how-fast-would-it-be-going-when-it-got-back-and-hit-earths-atmosphere/996737/50 "2024-01-28T18:29:14Z")
Yes. 🐄 🌛 🐐 ---
**Author:** ![Isilder](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@Isilder](https://boards.straightdope.com/u/Isilder)\ **Post date:** [January 29, 2024, 4:34am UTC](https://boards.straightdope.com/t/if-a-cow-jumped-over-the-moon-how-fast-would-it-be-going-when-it-got-back-and-hit-earths-atmosphere/996737/51 "2024-01-29T04:34:15Z")
> [@Stranger\_On\_A\_Train](#): > > i.e. the cow is not on an Earth escape trajectory, the return speed of the cow can’t be more than 11.2 km/s, But the moons gravity can increase its speed and aim it back toward earth. Perhaps better to consider the cow jumped over the moon, the cow wouldn’t want to go close to the moon, or else careful trajectory adjustment would be required… . We don’t know how many times the cow jumped to above moon altitude but missed the moon before the successful moon jump. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [January 29, 2024, 5:52am UTC](https://boards.straightdope.com/t/if-a-cow-jumped-over-the-moon-how-fast-would-it-be-going-when-it-got-back-and-hit-earths-atmosphere/996737/52 "2024-01-29T05:52:57Z")
> [@Isilder](#): > > But the moons gravity can increase its speed and aim it back toward earth. No. Any energy and radial velocity relative to Earth gained by approaching the Moon will be lost when receding from it. A spacecraft might pick up a slight increase in energy and tangental velocity on s trajectory coming from behind the Moon, but because the Moon is only orbiting at 1.022 km/sec and has an escape speed at the surface of 1.4 km/sec, the amount of momentum transfer isn’t going to be much. The cow is ultimately limited to 11.2 km/sec at Earth reentry or else will be on an escape trajectory from the Earth system. Stranger ---
**Author:** ![EdwardFound](https://avatars.discourse-cdn.com/v4/letter/e/4af34b/32.png) [@EdwardFound](https://boards.straightdope.com/u/EdwardFound)\ **Post date:** [January 29, 2024, 7:34pm UTC](https://boards.straightdope.com/t/if-a-cow-jumped-over-the-moon-how-fast-would-it-be-going-when-it-got-back-and-hit-earths-atmosphere/996737/53 "2024-01-29T19:34:42Z")
If the cow would burn up on re-entry, wouldn’t it also burn up on launch? ---
**Author:** ![Prof.Pepperwinkle](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/prof.pepperwinkle/32/13627_2.png) [@Prof.Pepperwinkle](https://boards.straightdope.com/u/Prof.Pepperwinkle)\ **Post date:** [January 29, 2024, 7:52pm UTC](https://boards.straightdope.com/t/if-a-cow-jumped-over-the-moon-how-fast-would-it-be-going-when-it-got-back-and-hit-earths-atmosphere/996737/54 "2024-01-29T19:52:48Z")
It seems to me a matter of synecdoche: using a part of something as a reference for the whole. In this case, the “moon” is a reference to an outhouse (with the moon carved into the door), which makes the whole unbelievable fiasco only slightly less lunicrous (er, ludicrous). ---
**Author:** ![Jasmine](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jasmine/32/2964_2.png) [@Jasmine](https://boards.straightdope.com/u/Jasmine)\ **Post date:** [January 29, 2024, 7:55pm UTC](https://boards.straightdope.com/t/if-a-cow-jumped-over-the-moon-how-fast-would-it-be-going-when-it-got-back-and-hit-earths-atmosphere/996737/55 "2024-01-29T19:55:46Z")
She would burn up upon reentry. ---
**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:** [January 29, 2024, 8:33pm UTC](https://boards.straightdope.com/t/if-a-cow-jumped-over-the-moon-how-fast-would-it-be-going-when-it-got-back-and-hit-earths-atmosphere/996737/56 "2024-01-29T20:33:23Z")
No, because launches take much more time to get up to speed than atmospheric re-entry takes to scrub it. That’s why launched rockets don’t have red hot glowing noses heading into space. But I suspect a cow would have a hell of a time with the G forces. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [January 29, 2024, 8:45pm UTC](https://boards.straightdope.com/t/if-a-cow-jumped-over-the-moon-how-fast-would-it-be-going-when-it-got-back-and-hit-earths-atmosphere/996737/57 "2024-01-29T20:45:57Z")
> [@Sam\_Stone](#): > > That’s why launched rockets don’t have red hot glowing noses heading into space. Well, [some do](https://en.wikipedia.org/wiki/Sprint_(missile)): > Sprint accelerated at 100 [_g_](https://en.wikipedia.org/wiki/G-force), reaching a speed of Mach 10 (12,300 km/h; 7,610 mph) in 5 seconds. Such a high velocity at relatively low altitudes created skin temperatures up to 6,200 °F (3,427 °C), requiring an ablative shield to dissipate the heat.[[2]](https://en.wikipedia.org/wiki/Sprint_(missile)#cite_note-Sprint-2)[[3]](https://en.wikipedia.org/wiki/Sprint_(missile)#cite_note-Parsch-3) The high temperature caused a [plasma](https://en.wikipedia.org/wiki/Plasma_(physics)) to form around the missile, requiring extremely powerful radio signals to reach it for guidance. The missile glowed bright white as it flew. Ok, _technically_ it wasn’t going to space… ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [January 30, 2024, 12:03am UTC](https://boards.straightdope.com/t/if-a-cow-jumped-over-the-moon-how-fast-would-it-be-going-when-it-got-back-and-hit-earths-atmosphere/996737/58 "2024-01-30T00:03:22Z")
> [@EdwardFound](#): > > If the cow would burn up on re-entry, wouldn’t it also burn up on launch? By the time a rocket gets moving fast on ascent it is already above the bulk of the atmosphere; in fact, rockets first fly upward and then perform a ‘gravity turn’ to get oriented to apply impulse to increase tangential velocity, albeit not to reduce heating (although that can occur, especially in depressed trajectories or with hypersonic space planes) but to reduce aerodynamic loads and aeroacoustic vibration environments. Space capsules and meteors are moving at orbital or higher speeds and have to lose all of that kinetic energy, which they do by compressing the air in front of them which produces a superheated ‘sheath’ of plasma that emits intense thermal radiation. It is actually this heating due to “ram pressure”, and not ‘skin friction’ that causes vehicles to experience such intense heat upon reentry. Of course, a cow that is launched with a single impulse from the surface with no ascent propulsion will have to already have all of the impulse and kinetic energy to loop around the Moon plus enough to overcome atmospheric drag, so yes, the hypothetical leaping cow would actually heat up very quickly during ascent and will promptly explode in a flash of flaming carbon, nitrogen, calcium, phosphorous, other trace elements, and superheated steam. Stranger ---
**Author:** ![Kent\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kent_clark/32/105_2.png) [@Kent\_Clark](https://boards.straightdope.com/u/Kent_Clark)\ **Post date:** [January 30, 2024, 1:35am UTC](https://boards.straightdope.com/t/if-a-cow-jumped-over-the-moon-how-fast-would-it-be-going-when-it-got-back-and-hit-earths-atmosphere/996737/59 "2024-01-30T01:35:54Z")
> [@Jasmine](#): > > She would burn up upon reentry. The cow was prepared with a heat shield. ---
**Author:** ![abcdefghij](https://avatars.discourse-cdn.com/v4/letter/a/43a26b/32.png) [@abcdefghij](https://boards.straightdope.com/u/abcdefghij)\ **Post date:** [January 30, 2024, 1:58am UTC](https://boards.straightdope.com/t/if-a-cow-jumped-over-the-moon-how-fast-would-it-be-going-when-it-got-back-and-hit-earths-atmosphere/996737/60 "2024-01-30T01:58:04Z")
Was there any telemetry on Mrs. O’Leary’s cow before she impacted Chicago? [Previous page](https://boards.straightdope.com/t/if-a-cow-jumped-over-the-moon-how-fast-would-it-be-going-when-it-got-back-and-hit-earths-atmosphere/996737.md?page=2) [Next page](https://boards.straightdope.com/t/if-a-cow-jumped-over-the-moon-how-fast-would-it-be-going-when-it-got-back-and-hit-earths-atmosphere/996737.md?page=4)