# How to prove Mars landing

I was watching the movie The Martian and I realised afterwards that thanks to its really great CGI, some people think it is based on real story and there are even some who think it was made on Mars.

While both is false, it opens another question: How to prove you actually landed on Mars?

Setup:

The year is 2025. After your least favorite candidate for POTUS of 2016 had their 2 terms, a cool guy is elected president in 2024. One of his promises is get us to the Mars. For reals.

Thing is, that 2024's blockbuster movie was completely generated by computers. And about 80% of viewers could not tell that the actors are made up. Even though the movie did cost awful lot of money, it opens lot of conspiracy theories.

You are NASA director. The rocket to Mars is fully tested. Astronauts ready. Probability of mission to Mars success: Over 97 percent.

Even though you communicated all the preparation steps openly to the public, everything is communicated through electronical media. Photoshop version released in 2023 is really easy to use and average home computer can make really great CGI.

How to convince the people that you are actually going to get there physically and walk on Mars by 2026?

• How did we prove the Lunar landing? – Frostfyre Oct 14 '15 at 19:55
• I find these huge conspiracy theories to be mostly impossible. As soon as more than one person knows it's a conspiracy, the easier it is to leak; with the number of people who have to be involved in the making of the film, this would get out that it was fake. If it doesn't, then I'm convinced it was real. – Mikey Oct 14 '15 at 19:57
• Possible duplicate of Cheapest way to fake the Mars landing – o.m. Oct 15 '15 at 5:55
• @o.m. Why would this be a duplicate? The questions are diametrically opposed. That one asks how to fake it and this one asks how to prove it wasn't faked. – Frostfyre Oct 15 '15 at 12:57
• some people think it is based on real story really? – njzk2 Dec 1 '15 at 21:31

Leave a large reflector on Mars. We left a specialized retro-reflector on the Moon. It's a special mirror the reflects light back along the path it came. With a strong sensor and laser you can bounce light off of it and measure it. Ahead of time you do it to prove there is no reflector later you do it again to prove there is. So anyone could test and verify its presence, if they had a very strong laser and receiver, because Mars is farther than the Moon.

• What keeps them from having a rover leave a reflector? Or is it something a human has to do (just curious)? – Mikey Oct 15 '15 at 6:11
• Good comment. You wouldn't need a rover. Just a dumb Mars-shot that manages to dump a reflector, in one piece, facing up, on the Martian surface. It's a fairly tough item. – nigel222 Oct 15 '15 at 12:02
• A radio transmitter on Mars would be far easier to detect than a reflector. But the real problem is, how to prove that there are people on Mars? Not how to prove that there is human-manufactured equipment on Mars. – nigel222 Oct 15 '15 at 13:01
• Leaving a reflector on the Moon is relatively easy; the landscape of the Moon doesn't change much. Mars has recurring sand storms, which are likely to cover a reflector left unattended with dust for any significant amount of time. This could be both an advantage and a disadvantage! – a CVn Sep 21 '16 at 15:06

Participatory Public

The public can (and likely would) be watching the astronauts a lot. Allow them from time-to-time in a true lottery system to ask the astronauts to do some fun things, like a backflip or to throw a rock or whatever in Mars' light gravity. You can use CGI, etc. to fake lighter gravity, but you can't do it on the spot. The studio would have as low as 8 minutes (4min each way) of "lag time" only to make the astronaut do something in half-gravity.

Return Samples - Lots of Them

Obviously, we can find Earth-based Martian rocks that have entered our atmosphere as meteors. A large volume of return samples can only be collected by people (rovers are delicate things, and would require a lot of energy for just a small sample).

The samples can include regolith, small rocks, etc. that would not have naturally made it through Earth's atmosphere.

Have independent scientists of different backgrounds around the world verify the authenticity of these.

• It wouldn't be "on the spot", but close enough; there'd be a two-way delay of between 4 and 24 minutes depending on the planets' respective positions around the Sun. Definitely not enough time for a graphics house to produce a full shot... Or, in 2024, would computer power be good enough to crunch that much data that quickly, that graphics indistinguishable from recorded reality were possible with the average WiiStation360? – KeithS Oct 14 '15 at 20:36
• currently, we have basic CGI that can track, interpret and display artificial components in sports games (lines on fields, object trails, etc.). Live video alterations go back to events like the Beijing Olympics in 2008... live video to the public should not be trusted for "verification" purposes – Jim Oct 15 '15 at 1:27
• @KeithS that is exactly what I said in the first paragraph; I only meant that the quickest return time would be 8 minutes (closest Mars is to Earth). It would take a studio eight minutes to simulate a running jump off a low hill or to toss a prop that follows precise martian gravity for its mass. – Mikey Oct 15 '15 at 6:13
• With respect to returning samples, there's a small but extreme bio-hazard. If there is independently evolved life extant on Mars and we infect Earth with it, there is some small possibility of Martian microbes destroying all life on Earth. So if such a crazy thing were done (and it didn't kill us all) many would argue that this proved that "they" knew it was harmless because the rocks didn't come from Mars at all. – nigel222 Oct 15 '15 at 12:36
• I suspect that if the entire computer resources of (say) the NSA were focussed on the problem, one could simulate images of a Mars mission indistinguishable from images transmitted from Mars even today. Don't forget they'd have years to build the studio, write the programs, etc. Personally I wouldn't believe that such a project could be kept secret, but far too many people would. – nigel222 Oct 15 '15 at 12:40

1) make something visible from Earth with a telescope on Mars. A big, round object, kilometers across - it could be just a large white sheet of paper. The windstorms will eventually cover it, but until that happens, any person can just take a telescope and verify you've been to mars himself. According to this post, you would need a 22800 m object, so it's visible as well as the moon with a telescope magnifying 60x:

2) (in case #1 doesn't work) show and explain the technology you have and use(d). Why to fake a mission when it's anyway so much easier to do then a CGI, when you have the techno?

• A structure that can be resolved by telescopes accessible by amateurs has to be quite large! As in really large. Think the "canals"/canyons. It's also hard to prove it was done by a real human and not an autonomous rover - same restrictions as with the retroreflector apply. – Ghanima Sep 21 '16 at 9:22