# 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:** 2
**Author:** ![ParallelLines](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/parallellines/32/3575_2.png) [@ParallelLines](https://boards.straightdope.com/u/ParallelLines)\ **Post date:** [January 27, 2024, 7:56pm 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/996737/21 "2024-01-27T19:56:27Z")
May I pause the (wonderful) conversation to ask who put the Bessie in the (LONG) duration survival space suit? I suspect taking into account space for the supplies and energy for thermoregulation, that the Cow is certainly spherical after dressing, if not before. Although I suspect “spacesuit” would more accurately be considered a small scale form-fitting spacecraft than a suit. And, if I may submit an additional question, because we all want to know, how much damage was done to the immediate vicinity in the initial jump? I mean ye average American cow of common breeds runs around 650 kg, plus, let’s say, another 350 kg in suit and supplies (just to make nice round numbers). We’re going to have to assume a launch area that is incredibly rigid as the points of contact from the hooves are pretty small, and the acceleration period is unspeakably brief! Oh, and let’s ping our friends in the [Kerbal Space Program thread](https://boards.straightdope.com/t/kerbal-space-program-2/838913) to see if they can do the rocket science version of this experiment! Paging @Dr.Strangelove! ---
**Author:** ![markn\_1](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@markn\_1](https://boards.straightdope.com/u/markn_1)\ **Post date:** [January 27, 2024, 8:14pm 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/996737/22 "2024-01-27T20:14:50Z")
Maybe she got a running start. That would reduce the force on the ground at the point of liftoff. When we’re finished with this discussion, I hope we will also consider the question of how fast flatware can run. ---
**Author:** ![AHunter3](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ahunter3/32/368_2.png) [@AHunter3](https://boards.straightdope.com/u/AHunter3)\ **Post date:** [January 27, 2024, 8:27pm 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/996737/23 "2024-01-27T20:27:08Z")
I think maybe when you start off by positing a cow that can jump at escape velocity and hold her breath and maintain body warmth long enough to orbit the moon and return, you should not assume she’s going to be in serious trouble from reentry or the impact of sticking the landing. Just sayin’. ---
**Author:** ![Bear\_Nenno](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bear_nenno/32/3358_2.png) [@Bear\_Nenno](https://boards.straightdope.com/u/Bear_Nenno)\ **Post date:** [January 27, 2024, 8:28pm 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/996737/24 "2024-01-27T20:28:20Z")
> [@Stranger\_On\_A\_Train](#): > > If the characteristic energy C3 of the cow is negative, 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, and a trajectory returning from beyond the Moon can’t be much less I had thought that there would be a larger difference depending on how far from perigee the cow was when it actually entered the atmosphere. So like, if perigee is theoretically on the other side of Earth, but the orbit now intersects the Earth, so the cow hits head-on so to speak versus whether the cow only touches the atmosphere right at its perigee and only then experiences air braking. Or if perigee is well past the Earth, and the cow misses the atmosphere on the way to perigee, reaches perigee and beyond, then then hits the atmosphere on its way back. Obviously didn’t do any math. Or couldn’t she be slowed down a decent amount if she was in front of the moon on the encounter vs behind? Not enough to matter? ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [January 27, 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/996737/25 "2024-01-27T20:33:26Z")
> [@AHunter3](#): > > I think maybe when you start off by positing a cow that can jump at escape velocity and hold her breath and maintain body warmth long enough to orbit the moon and return, you should not assume she’s going to be in serious trouble from reentry or the impact of sticking the landing. Just sayin’. Possibly not, but it’s pretty much certain that the cow will be so traumatized by the experience that any milk she produces thereafter will forever be pre-curdled. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [January 27, 2024, 8:37pm 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/996737/26 "2024-01-27T20:37:32Z")
> [@Pardel-Lux](#): > > As a matter of fact she misses the Earth anyway, because during the cow’s coasting in space the Earth has moved along its orbit. Is this really a factor? The cow and the moon were already moving along the same orbital path as the Earth, around the sun - the jump takes place relative to the earth-moon system, doesn’t it? ---
**Author:** ![Dallas\_Jones](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dallas_jones/32/3277_2.png) [@Dallas\_Jones](https://boards.straightdope.com/u/Dallas_Jones)\ **Post date:** [January 27, 2024, 8:52pm 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/996737/27 "2024-01-27T20:52:55Z")
Cows don’t jump. Show me a cow jumping. A cat can’t play they fiddle either, but with enough training they could play the violin, but everyone knows cats are not easily trainable. And don’t get me started about the relationships between a dish and a spoon. Were they dirty dishes? ---
**Author:** ![RickJay](https://avatars.discourse-cdn.com/v4/letter/r/bb73d2/32.png) [@RickJay](https://boards.straightdope.com/u/RickJay)\ **Post date:** [January 27, 2024, 8:56pm 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/996737/28 "2024-01-27T20:56:35Z")
> [@Stranger\_On\_A\_Train](#): > > If the characteristic energy C3 of the cow is negative, 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, This is 40,320 km/h. That is a very fast cow. ---
**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 27, 2024, 9:03pm 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/996737/29 "2024-01-27T21:03:46Z")
> [@ParallelLines](#): > > Paging @Dr.Strangelove! The guidance system on this cow isn’t working so well! [![](https://img.youtube.com/vi/DiJoS9Fdat4/maxresdefault.jpg "Cowbal Space Program") ](https://www.youtube.com/watch?v=DiJoS9Fdat4) ---
**Author:** ![markn\_1](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@markn\_1](https://boards.straightdope.com/u/markn_1)\ **Post date:** [January 27, 2024, 9:21pm 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/996737/30 "2024-01-27T21:21:08Z")
> [@Dallas\_Jones](#): > > Cows don’t jump. Show me a cow jumping. [![](https://img.youtube.com/vi/ElM7N6a8qO8/maxresdefault.jpg "Calves frolicking on the first day out of the barn") ](https://www.youtube.com/watch?v=ElM7N6a8qO8) ---
**Author:** ![ParallelLines](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/parallellines/32/3575_2.png) [@ParallelLines](https://boards.straightdope.com/u/ParallelLines)\ **Post date:** [January 27, 2024, 9:23pm 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/996737/31 "2024-01-27T21:23:17Z")
Thanks for that! I see why the Cowbal/bell space program shifted to jumping, rather than rocket propelled cows. ---
**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 27, 2024, 9:38pm 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/996737/32 "2024-01-27T21:38:08Z")
> [@AHunter3](#): > > I think maybe when you start off by positing a cow that can jump at escape velocity and hold her breath and maintain body warmth long enough to orbit the moon and return… The problem is more likely staying cool, as the cow will mostly be in direct sunlight and will only be able to lose heat via radiation on the shadowed side. > [@Bear\_Nenno](#): > > Or couldn’t she be slowed down a decent amount if she was in front of the moon on the encounter vs behind? Not enough to matter? The delta velocity for escape speed from the Earth’s sphere of influence (SOI) at Lunar orbit is only about 1 km/s more than the orbital speed of the Moon. There are a wide array of different trajectories that might pass around the Moon but a pretty narrow range of specific orbital energies and a corresponding small range of return speeds. > [@Dallas\_Jones](#): > > Cows don’t jump. Show me a cow jumping. > **[https://i.redd.it/hi8p3takavm21.jpg](https://i.redd.it/hi8p3takavm21.jpg)** Stranger ---
**Author:** ![Dallas\_Jones](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dallas_jones/32/3277_2.png) [@Dallas\_Jones](https://boards.straightdope.com/u/Dallas_Jones)\ **Post date:** [January 27, 2024, 9:53pm 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/996737/33 "2024-01-27T21:53:38Z")
A calf frolicing is not a cow jumping. ---
**Author:** ![Dallas\_Jones](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dallas_jones/32/3277_2.png) [@Dallas\_Jones](https://boards.straightdope.com/u/Dallas_Jones)\ **Post date:** [January 27, 2024, 9:54pm 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/996737/34 "2024-01-27T21:54:43Z")
Again, a bull is not a cow. ---
**Author:** ![Marvin\_the\_Martian](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/marvin_the_martian/32/2898_2.png) [@Marvin\_the\_Martian](https://boards.straightdope.com/u/Marvin_the_Martian)\ **Post date:** [January 27, 2024, 10:08pm 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/996737/35 "2024-01-27T22:08:50Z")
This thread was already udderly ridiculous, now there is a lot of bull being tossed about. How fast would our cow need to jump so that she had the necessary velocity once she exited the atmosphere? There has to be a lot of velocity lost from a ballistic launch due to air resistance. Heating from which, as I think was mentioned at least once up thread, would result in a large hunk of well-done steak well before the cow reaches space. ---
**Author:** ![TroutMan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/troutman/32/6721_2.png) [@TroutMan](https://boards.straightdope.com/u/TroutMan)\ **Post date:** [January 27, 2024, 10:28pm 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/996737/36 "2024-01-27T22:28:01Z")
Assuming the OP is ok with a loose definition of jumping, I propose a long parabolic ramp so the cow can build up enough speed running and launch itself off the end. That seems easier than a traditional jump for a cow. ---
**Author:** ![Dallas\_Jones](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dallas_jones/32/3277_2.png) [@Dallas\_Jones](https://boards.straightdope.com/u/Dallas_Jones)\ **Post date:** [January 27, 2024, 10:33pm 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/996737/37 "2024-01-27T22:33:27Z")
Only cattle who are female and have been pregnant are called cows. A bull is an uncastrated male cattle usually used for breeding. A male that has been castrated is a steer. A calf is a newborn of either sex. A dogie is motherless or abandoned young calf. A heifer is a young female that has not yet had a calf. A young male is called a bullocks. It gets more complicated from there. ---
**Author:** ![ParallelLines](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/parallellines/32/3575_2.png) [@ParallelLines](https://boards.straightdope.com/u/ParallelLines)\ **Post date:** [January 27, 2024, 10:34pm 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/996737/38 "2024-01-27T22:34:14Z")
In terms of cow based propulsion, and in the truest sense of the SDMB, I cite Cecil: > **[How much flatulence would it take to become airborne?](https://www.straightdope.com/21344031/how-much-flatulence-would-it-take-to-become-airborne)** > I’ll spare you the details — [you probably remember the basics from college anyway](https://www.straightdope.com/columns/columns/read/68/what-exactly-is-a-fart). Una ran various scenarios. At one point we had the internal pressure up to 250 atmospheres, the combustion temperature at 3,600 degrees Kelvin, and exhaust gas exit velocity at 12,000 feet per second. It wasn’t pretty, K. It also didn’t work, unless we were willing to accept catastrophic failure of the containment vessel — I’m sure you’ve heard the expression “flaming asshole”? It’s fine giving your all for science, but you want to leave ’em something for the wake. Granted, scaled to a human, but we could attempt to apply it to a cow, but we’d be past the “jump” stage and well onto the internal biological rocket stage. ---
**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 27, 2024, 10:42pm 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/996737/39 "2024-01-27T22:42:12Z")
> [@Dallas\_Jones](#): > > Again, a bull is not a cow. Steer are at least colloquially referred to as “cows”, and I have personally witnessed both male and female cattle jumping fences. No, a cow (of either sex) cannot literally “jump over the moon”, nor would it survive being fired into space; the o.p. is just asking a purely hypothetical question about an absurdist nursery rhyme. Are we done with this hijack? Stramger ---
**Author:** ![Dr\_Paprika](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr_paprika/32/3042_2.png) [@Dr\_Paprika](https://boards.straightdope.com/u/Dr_Paprika)\ **Post date:** [January 27, 2024, 11:12pm 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/996737/40 "2024-01-27T23:12:19Z")
> [@RickJay](#): > > This is 40,320 km/h. That is a very fast cow. Perhaps it is a Harrierford? [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=1) [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=3)