A secret society of inventors has been hiding for years. Finally, they have designed their Mars base in the year 2019! Unfortunately, they "borrowed" most of their supplies. If they were to build a glass survival dome say, 200 meters in length, would NASA or any of the other space agencies be able to find it in the next few years?

Assuming that no Martian rovers or anything come across the dome, would satellites or telescopes notice the domes, and how long until they do?

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    $\begingroup$ How do they get to Mars unnoticed? $\endgroup$ – Keith Morrison Oct 31 '18 at 3:43
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    $\begingroup$ Many proposed Martian colonies are at least partially underground, to protect them from radiation. Making them harder to spot by satellite would be a side benefit. $\endgroup$ – Cadence Oct 31 '18 at 4:05
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    $\begingroup$ @RedwolfPrograms I know this isn't related to the question, but how would you be able to hide something from NASA, let alone the additional supplies and equipment you would need. It costs like $20,000 to send a kilo payload and the location and weight distribution is going to have a huge impact on the flight plan. $\endgroup$ – Shadowzee Oct 31 '18 at 4:07
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    $\begingroup$ @Shadowzee: To extend your comment, a 200m glass dome is well beyond anything we can currently ship while publically known, let alone hiding it on a ship with a tightly controlled weight/volumne budget. $\endgroup$ – Flater Oct 31 '18 at 12:19
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    $\begingroup$ @RedwolfPrograms, it kind of is relevant to the question. If they can get to Mars unnoticed, they evidently have tech such that creating a base with a highly visible dome isn't necessary. $\endgroup$ – Keith Morrison Oct 31 '18 at 14:49

A good answer by L.Dutch regarding sensor resolution, but remember that people knew where to look for the rover.

There are good chances that pictures would be taken and fed to an automated analysis system, which would not be programmed to spot domes. Scientists might not look at the data as it comes in, until some grad student tries to analyse weathering patterns or whatever years later.

Perhaps the data would be fed into a public database. Some random guy running a flight simulator on Mars might spot it.

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    $\begingroup$ Excellent point and it's definitely worth mentioning. Conceivably some pulsar in our own galaxy is sending a weak but readable signal to earth demonstrating that there is intelligent life but is otherwise uninteresting, and we'd never know because we've never bothered listening to it before. It would likely eventually get discovered, but it isn't like NASA is constantly scanning the surface of mars for domes on a regular basis. $\endgroup$ – Neil Oct 31 '18 at 9:11
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    $\begingroup$ While detecting a dome (especially if camouflaged) may be difficult, automated systems which detect changes on the surface would be rather trivial. Perhaps an orbiting satellite is mapping out the surface and making measurements of topographical changes for climate pattern analysis. It has a massive "what is this" moment when it scans the dome. Or, more likely, it alerts during the construction of the dome, and a set of human eyes easily guesses what is going on. $\endgroup$ – ColonelPanic Oct 31 '18 at 13:01
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    $\begingroup$ We might not accidentally see it, but would we accidentally hear it? If so much as one teeny-tiny wave got picked up by a satellite or antenna coming from Mars, I bet we'd start to take a pretty close look at where it came from. $\endgroup$ – Lord Farquaad Oct 31 '18 at 20:33
  • $\begingroup$ @ColonelPanic, that would work if the software was already in place, or run retroactively on old data, instead of being run only on new data as it comes in. $\endgroup$ – o.m. Nov 1 '18 at 5:29
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    $\begingroup$ What about the thermal differences? Wouldn't a sudden spike in temperature be recognised and immediately flagged as interesting? $\endgroup$ – Jack Aidley Nov 1 '18 at 15:08

The rover Curiosity, way smaller than 200 m, can be seen from Martian orbit:

Curiosity seen from martian orbit

So, for a martian satellite in polar orbit it would be just a matter of days before capturing visual proof of the presence of "something" that big on the surface. If instead its orbit wasn't polar, and the dome was built in a suitable location, it could go unnoticed.

For Earth based telescopes the task is harder, and they cannot spot anything of that size.

So, maybe an "incident" can take care of the martian satellites before the building work starts...

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    $\begingroup$ That's really awesome, considering that the rover is basically car sized. Why can't we see similar sized objects from Earth satellites? $\endgroup$ – Adrian Zhang Oct 31 '18 at 4:16
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    $\begingroup$ @AdrianZhang Military spy satellites circling Earth can resolve objects down to one foot -- about 30 cm -- in size (at least). Are you asking why Earth-based satellites cannot discern car-sized objects on Mars? Note that the terrestial atmosphere is much denser than the Martian one, and that there are clouds. $\endgroup$ – njuffa Oct 31 '18 at 6:06
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    $\begingroup$ No, I was asking why we can't see things of that resolution on Earth. Evidently, I was wrong haha $\endgroup$ – Adrian Zhang Oct 31 '18 at 6:08
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    $\begingroup$ @AdrianZhang: BBC, in 2014: "The latest US spy satellites, in comparison, are reported to be able to pick out objects less than 10cm (4 inches) across." $\endgroup$ – njuffa Oct 31 '18 at 6:10
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    $\begingroup$ @AdrianZhang, we can see them just fine. Pulling up my handy satellite-imagery viewer, the the resolution limit seems to be around 10cm for high-contrast objects (eg. road markings), and about 1 meter for objects in general (a car is between 2 and 3 pixels across). Note that this is commercially-available imagery, not military imagery. $\endgroup$ – Mark Oct 31 '18 at 23:25

No need to look for the base

It's not really possible to sneak anything to Mars in the first place. Any rocket launched on the secret will be tracked by thousands of telescopes, missile defense radars, satellites, and other sensors, and from there it will be tracked no matter where it goes. The mystery and the uncommon nature of such a large rocket heading to Mars would make it the most observed object in the Solar System.


If you somehow get over that hurdle, your secret society can simply dig underground. This is a pragmatic option as well, since it provides shielding from radiation and insulation from temperature extremes, and allows constructing a living space with far less materials than would be needed otherwise. And once satellites inevitably take pictures of the spot and someone at NASA notices, they'll simply see a disturbance where the entrance is, rather than a greatly obvious man-made structure. With a bit of clever concealment, the entrance could even be made to blend in with the environment from above and make discovery through satellite photos alone nearly impossible.

  • $\begingroup$ As for hiding it in the natural terrain, the door could just be carved into the side of a cliff or overhang; then, nothing can see it. $\endgroup$ – Redwolf Programs Jun 2 at 15:18

Security through Obscurity

Mars is a big place. If nobody is looking, it's unlikely anyone will find it.

The reality is that the surface of mars has largely been mapped topologically, so nobody is likely to run a radar scan to map it again any time soon, and even if they did, nobody is going to go over every mile of it looking for unusually regular shapes like domes.

It's very possible the dome would be faithfully reproduced in imagery and radar mapping by a satellite passing overhead and nobody will notice.

If they did tell a computer to scan through the data looking for hallmarks of artificial structures, it's likely they'd get a lot of false-positives too, there are a lot of big rocks, hills and in some places dunes.

The fact is that if NASA realises there's definitely a base and has any idea what to look for, they'll find it in a few days if they've previously gathered the data, or a few weeks if they haven't.

But in the normal course of things, unless you've been foolish enough to put the dome near any sort of obvious landmark or in the middle of one of the big-name valleys then it's highly unlikely to be found.

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    $\begingroup$ "nobody is going to go over every mile of it looking for unusually regular shapes like domes." - Unrelated to the problem. Computer software is really good and really fast at detecting both changes and unusually regular objects / patterns, and id usually employed when studying topological changes. Thus, if someone will make a scan again, he won't need to manually go thorough data. He'll just get a list of changes, probably with base on top. $\endgroup$ – Mołot Oct 31 '18 at 12:41
  • $\begingroup$ The assumption here is that anyone is looking for topological changes on the geologically rather stable Mars :P More likely nobody is going to be updating that data until better equipment is sent, and even then. we have no reason to be looking for artificial structures. Why include anything to flag them up? All we could reasonably expect is a hell of a lot of false-positives. Secret bases on Mars? That's crazy conspiracy stuff and We at NASA will have no truck with that! $\endgroup$ – Ruadhan Oct 31 '18 at 14:07
  • $\begingroup$ I never disputed lack of reasons to scan terrain again. I only disagree with manually going thorough that data if this scan happens. $\endgroup$ – Mołot Oct 31 '18 at 14:13
  • $\begingroup$ I was mostly discounting the manual approach as a prelude to mentioning the computerised approach and saying why that wouldn't necessarily be a factor. $\endgroup$ – Ruadhan Oct 31 '18 at 14:16
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    $\begingroup$ The surface of Mars, or at least large parts of it, is getting re-scanned on a regular basis to find things like recent meteor impacts. $\endgroup$ – Mark Oct 31 '18 at 23:27

They find them all the time.


An alien dome and a pyramid on Mars or just rocks? Nasa satellite spots two mystery objects on the red planet sending conspiracy theorists into a frenzy.


In the description for the video, ArtAlienTV wrote: 'We have a clear 50 foot dome or sphere in a Mars Crater with large pipes coming out of it on the left.

'Also, a triangular pyramid shaped structure about 500 feet away from it that is 120 ft wide.'

He added: 'These features look artificial in nature and are clearly visible on Google Mars with no enhancements.

'The structures are between the Mawrth Vallis region and Oyama Crater in an area that was short listed for a Mars Rover to explore for possible signs of life before Gale Crater was eventually chosen.

'It is not hard to find.'

Spotting a dome - sure. Recognizing it as an artificial construct - maybe not.

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    $\begingroup$ A friend was very into his aliens and conspiracy theories. One evening at a party he turned up with printouts of alleged structures on the Moon which looked too regular to be natural. Me and a friend (whose day job happened to be cartography) had to gently break it to him that he'd discovered JPEG artifacts. $\endgroup$ – Graham Oct 31 '18 at 19:21

it would be easier to provide radiation-shielding. thermal insulation if the enclosure were built sub-surface. also easier to camouflage the installation. best of all to make an excavation large enough to facilitate sub-surface mining, especially for water-drilling.

some facility would have to be devised to excavate & distribute any mineral debris in a non-detectable way. but that would be the case wherever the enclosure is located.

there is going to be a need for access to sub-surface water in any case.


Why does the base have to be visible from above? They could simply use a cave in a mountain (and get radiation shielding) or at the side of a cliff/canyon or build their base inside a large natural cavity under the dry ice (solid carbon dioxide) of the polar cap like Zygote in Red Mars.


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