# 'Space ball' falls out of the sky in Namibia - what are these things? **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [December 22, 2011, 10:58pm UTC](https://boards.straightdope.com/t/space-ball-falls-out-of-the-sky-in-namibia-what-are-these-things/607128 "2011-12-22T22:58:33Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Cunctator](https://avatars.discourse-cdn.com/v4/letter/c/43a26b/32.png) [@Cunctator](https://boards.straightdope.com/u/Cunctator)\ **Post date:** [December 22, 2011, 10:58pm UTC](https://boards.straightdope.com/t/space-ball-falls-out-of-the-sky-in-namibia-what-are-these-things/607128/1 "2011-12-22T22:58:33Z")
[Link to story](http://www.smh.com.au/technology/sci-tech/space-ball-drops-on-namibia-20111223-1p7nk.html) This one is a metallic ball, about 35cm in diameter. I love the phrasing that the metal of which it’s composed is an alloy “know to man”. So what are these things? Aeroplane parts? ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [December 22, 2011, 11:17pm UTC](https://boards.straightdope.com/t/space-ball-falls-out-of-the-sky-in-namibia-what-are-these-things/607128/2 "2011-12-22T23:17:00Z")
All I see is a metal ball with weld joints. Made by humans, obviously. How do we know it was really dropped from the sky? :dubious: How do we know there were explosions? :dubious: How do we know there’s a hole in the ground? :dubious: (If there was a hole in the ground, where is the photo?) ---
**Author:** ![Askance](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/askance/32/8281_2.png) [@Askance](https://boards.straightdope.com/u/Askance)\ **Post date:** [December 22, 2011, 11:19pm UTC](https://boards.straightdope.com/t/space-ball-falls-out-of-the-sky-in-namibia-what-are-these-things/607128/3 "2011-12-22T23:19:56Z")
This may call for speculation and so end up in IMHO, but I’ll start here to try for some factual content first. For background read this [‘Space Ball’ drops on Namibia](http://www.smh.com.au/technology/sci-tech/space-ball-drops-on-namibia-20111223-1p7nk.html): I thought originally there must be some random dude in Namibia who’d built a home-made cannon or catapult, but then we read that the balls are 35cm across and weigh 6kg, so probably bigger than someone like that would probably need, and also > [@](#): > > Several such balls have dropped in southern Africa, Australia and Latin America in the past 20 years, authorities found in an internet search. But my internet searches only found the above story. Judging from that photo they’re fairly rough’n’ready. And what the purpose of those protrusions to each side is I’m not sure. ---
**Author:** ![Ogre](https://avatars.discourse-cdn.com/v4/letter/o/ecb155/32.png) [@Ogre](https://boards.straightdope.com/u/Ogre)\ **Post date:** [December 22, 2011, 11:22pm UTC](https://boards.straightdope.com/t/space-ball-falls-out-of-the-sky-in-namibia-what-are-these-things/607128/4 "2011-12-22T23:22:06Z")
That photo is strange. Assuming it’s supposed to be an actual photo of the object, it does not look, judging from the background grass, twigs, and sand, that it could _possibly_ be of an object 3 and a half feet across (1.1 meters). The scale just looks all wrong to me. That photo appears to be of a much smaller object, but maybe that’s just me. ---
**Author:** ![Chipacabra](https://avatars.discourse-cdn.com/v4/letter/c/e19b73/32.png) [@Chipacabra](https://boards.straightdope.com/u/Chipacabra)\ **Post date:** [December 22, 2011, 11:25pm UTC](https://boards.straightdope.com/t/space-ball-falls-out-of-the-sky-in-namibia-what-are-these-things/607128/5 "2011-12-22T23:25:14Z")
> [@Ogre](#): > > That photo is strange. Assuming it’s supposed to be an actual photo of the object, it does not look, judging from the background grass, twigs, and sand, that it could _possibly_ be of an object 3 and a half feet across (1.1 meters). The scale just looks all wrong to me. That photo appears to be of a much smaller object, but maybe that’s just me. 1.1 meters is the circumference. The diameter is 35cm. ---
**Author:** ![Ogre](https://avatars.discourse-cdn.com/v4/letter/o/ecb155/32.png) [@Ogre](https://boards.straightdope.com/u/Ogre)\ **Post date:** [December 22, 2011, 11:27pm UTC](https://boards.straightdope.com/t/space-ball-falls-out-of-the-sky-in-namibia-what-are-these-things/607128/6 "2011-12-22T23:27:01Z")
> [@Chipacabra](#): > > 1.1 meters is the circumference. The diameter is 35cm. Oh goddamn it. Sorry. :smack: ---
**Author:** ![Mr.Accident](https://avatars.discourse-cdn.com/v4/letter/m/f05b48/32.png) [@Mr.Accident](https://boards.straightdope.com/u/Mr.Accident)\ **Post date:** [December 22, 2011, 11:28pm UTC](https://boards.straightdope.com/t/space-ball-falls-out-of-the-sky-in-namibia-what-are-these-things/607128/7 "2011-12-22T23:28:51Z")
Obviously they’re test projectiles from the Martians. Now that they know they can hit Earth, the real bombs will soon be on their way. I tried to warn Nasa about leaving our trash there, but noooo, they wouldn’t listen. Now we’re all doomed. ---
**Author:** ![Oakminster](https://avatars.discourse-cdn.com/v4/letter/o/77aa72/32.png) [@Oakminster](https://boards.straightdope.com/u/Oakminster)\ **Post date:** [December 22, 2011, 11:35pm UTC](https://boards.straightdope.com/t/space-ball-falls-out-of-the-sky-in-namibia-what-are-these-things/607128/8 "2011-12-22T23:35:43Z")
Hmmm…in units I’m more familiar with, this thing would be 13.8 inches across, and weigh about 13.2 pounds. Hollow. Metal alloy. About the size of a basketball, but much heavier I guess. Would probably float…I have seen similar spheres placed on guy wires holding up large radio/cell towers, maybe something like that? No idea why it would be falling “from space” though… ---
**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:** [December 23, 2011, 12:07am UTC](https://boards.straightdope.com/t/space-ball-falls-out-of-the-sky-in-namibia-what-are-these-things/607128/9 "2011-12-23T00:07:42Z")
It would appear to be a small spherical pressure tank on launch vehicle upper stages, probably used for pressurizing liquid stage ignition systems or attitude/reaction control systems, or as an in-line accumulator on a liquid propellant feed system. Because the tank is spherical, it will tend to survive intact more frequently than other pieces. This is because they lack sharp edges or center of pressure offset from the center of mass, so they both act like blunt bodies, creating a sheathing layer that insulates against ram pressure heating, and tend to spin in flight further distributing incident heat flux. Pressure tanks are also inherently pretty strong and so tend to survive buffeting and impact. As for why they land more frequently in Africa, South America, and Australia, space launch vehicles are flown on trajectories that avoid re-entry ground tracks for expended stages pass over highly populated areas. It is virtually impossible, however, to have a trajectory that doesn’t pass over some land mass, so trajectories are selected that pass over mostly sparsely populated areas, hence why these appear frequently in land masses in the Southern Hemisphere rather than in North America or Europe. Hazards analyses are preformed to assure that the risk to populated areas is under an accepted threshold (usually \<10[sup]-4[/sup] chance of fatality) but it is impossible to build an expendable rocket launch system that is both robust enough to survive on the way up and will fragment into small enough or controlled enough pieces not to pose any threat on the ground. Stranger ---
**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:** [December 23, 2011, 12:17am UTC](https://boards.straightdope.com/t/space-ball-falls-out-of-the-sky-in-namibia-what-are-these-things/607128/10 "2011-12-23T00:17:11Z")
[POST=14594903]Duplicate thread[/POST] in **General Questions**. Stranger ---
**Author:** ![Askance](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/askance/32/8281_2.png) [@Askance](https://boards.straightdope.com/u/Askance)\ **Post date:** [December 23, 2011, 12:31am UTC](https://boards.straightdope.com/t/space-ball-falls-out-of-the-sky-in-namibia-what-are-these-things/607128/11 "2011-12-23T00:31:58Z")
So there would have to be some inlet and outlet, which you’d think they might have mentioned … maybe that’s what the bulges on the side are? Oh, and any ideas on who’s vehicles these are from? I’d assume given the timespan they must be from Russia or the US. ---
**Author:** ![mcgato](https://avatars.discourse-cdn.com/v4/letter/m/ac8455/32.png) [@mcgato](https://boards.straightdope.com/u/mcgato)\ **Post date:** [December 23, 2011, 12:48am UTC](https://boards.straightdope.com/t/space-ball-falls-out-of-the-sky-in-namibia-what-are-these-things/607128/12 "2011-12-23T00:48:53Z")
When I saw “strange things falling out of the sky in Namibia,” I figured that it must have been a [Coke bottle.](http://www.imdb.com/title/tt0080801/) ---
**Author:** ![davidm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidm/32/225_2.png) [@davidm](https://boards.straightdope.com/u/davidm)\ **Post date:** [December 23, 2011, 1:12am UTC](https://boards.straightdope.com/t/space-ball-falls-out-of-the-sky-in-namibia-what-are-these-things/607128/13 "2011-12-23T01:12:45Z")
There’s a very weird turn of phrase in that article: > [@](#): > > It was made of a “metal alloy known to man” and weighed six kilograms, said Ludik. Why would you say it like that? Is it a misprint? Was he claiming that it was an alloy _un_known to man? Maybe he was trying to be funny? ---
**Author:** ![twickster](https://avatars.discourse-cdn.com/v4/letter/t/ec9cab/32.png) [@twickster](https://boards.straightdope.com/u/twickster)\ **Post date:** [December 23, 2011, 1:23am UTC](https://boards.straightdope.com/t/space-ball-falls-out-of-the-sky-in-namibia-what-are-these-things/607128/14 "2011-12-23T01:23:59Z")
Merged in duplicate thread from MPSIMS. The GQ mods may wish to move the whole shebang back to MPSIMS. ---
**Author:** ![Askance](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/askance/32/8281_2.png) [@Askance](https://boards.straightdope.com/u/Askance)\ **Post date:** [December 23, 2011, 2:06am UTC](https://boards.straightdope.com/t/space-ball-falls-out-of-the-sky-in-namibia-what-are-these-things/607128/15 "2011-12-23T02:06:36Z")
> [@davidm](#): > > There’s a very weird turn of phrase in that article: > > > [@](#): > > > > It was made of a “metal alloy known to man” and weighed six kilograms, said Ludik. > > Why would you say it like that? Is it a misprint? Was he claiming that it was an alloy _un_known to man? > > Maybe he was trying to be funny? No doubt he’s thinking of the invariable claim from UFO nuts that whatever they’ve just found couldn’t be of human origin as it’s made from some material “unknown to science” :rolleyes: ---
**Author:** ![Gary\_Robson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gary_robson/32/3448_2.png) [@Gary\_Robson](https://boards.straightdope.com/u/Gary_Robson)\ **Post date:** [December 23, 2011, 3:03am UTC](https://boards.straightdope.com/t/space-ball-falls-out-of-the-sky-in-namibia-what-are-these-things/607128/16 "2011-12-23T03:03:20Z")
> [@twickster](#): > > Merged in duplicate thread from MPSIMS. The GQ mods may wish to move the whole shebang back to MPSIMS. Yeppers! It’s all yours, m’dear. ---
**Author:** ![Leaffan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leaffan/32/299_2.png) [@Leaffan](https://boards.straightdope.com/u/Leaffan)\ **Post date:** [December 23, 2011, 3:16am UTC](https://boards.straightdope.com/t/space-ball-falls-out-of-the-sky-in-namibia-what-are-these-things/607128/17 "2011-12-23T03:16:28Z")
Google hydrazine tanks. ETA: Specifically images thereof. ---
**Author:** ![wedgehed](https://avatars.discourse-cdn.com/v4/letter/w/8edcca/32.png) [@wedgehed](https://boards.straightdope.com/u/wedgehed)\ **Post date:** [December 23, 2011, 4:31am UTC](https://boards.straightdope.com/t/space-ball-falls-out-of-the-sky-in-namibia-what-are-these-things/607128/18 "2011-12-23T04:31:40Z")
[What are they?](http://news.yahoo.com/space-ball-drops-namibia-133326985.html) ---
**Author:** ![Idle\_Thoughts](https://avatars.discourse-cdn.com/v4/letter/i/838e76/32.png) [@Idle\_Thoughts](https://boards.straightdope.com/u/Idle_Thoughts)\ **Post date:** [December 23, 2011, 4:43am UTC](https://boards.straightdope.com/t/space-ball-falls-out-of-the-sky-in-namibia-what-are-these-things/607128/19 "2011-12-23T04:43:18Z")
Merging another topic. ---
**Author:** ![cochrane](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cochrane/32/10441_2.png) [@cochrane](https://boards.straightdope.com/u/cochrane)\ **Post date:** [December 23, 2011, 5:41am UTC](https://boards.straightdope.com/t/space-ball-falls-out-of-the-sky-in-namibia-what-are-these-things/607128/20 "2011-12-23T05:41:04Z")
Spaceballs? [Oh, shit. There goes the planet!](http://www.youtube.com/watch?v=IS4aXCqzKgc&feature=youtube_gdata_player) [Next page](https://boards.straightdope.com/t/space-ball-falls-out-of-the-sky-in-namibia-what-are-these-things/607128.md?page=2)