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In Andy Weir's "The Martian" NASA are able to track Mark Watney's activities using the satellite images.

I'm curious if the imaging equipment the Mars satellites have is powerful enough to deliver that level of detail?

For example they were able to see the rovers, popup tents, rover tracks, even Mark Watney himself.

Is it real or is a just about the only tech inaccuracy Andy Weir allowed in his work?

  • I couldn't find a picture to back this up, but current orbiters can barely make out rover tracks, that's with image enhancement. Rovers are the size of minivans. A person is unlikely. – user16696 Jan 9 '15 at 15:02
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Since the book refers to "12 satellites in orbit around Mars" (which we don't currently have), and they use the satellites to image each and every landing site to ensure the automated systems are going well before the astronauts land, I would suggest that the imaging technology isn't based on what is currently orbiting Mars but rather an extrapolation of what could be used in the future.

Putting an imaging satellite of such capability in orbit around Mars would be no more difficult than any other satellite around Mars - the imaging tech isn't particularly onerous, as Mars has a less dense atmosphere than Earth it wouldn't have the same requirements as imaging the same resolution would here, as well as the orbits being lower due to the size difference between Mars and Earth.

Edit: I'm in the middle of rereading the book at the moment anyway, and have come across a few additional bits of information and a discrepancy as well.

The additional information is that at least one of the satellites used is called "SuperSurveyor7", a satellite we currently do not have, which indicates that the satellites in place are not of current technology.

The discrepancy is that early on in the book the fact that they could fairly easily identify various things at the Ares 3 landing sight from satellite photos, including the fact that the MDV had been dismantled, the emergency pop tents had been erected and lined up, the solar panels were clean and there was no body on show.

However, later on in the book, they struggle to get anything more than a blurry shot even after the NSA has enhanced the image.

Now that could indicate that not all satellites are equal, but the batch of shots is part of 17 taken during a 10 minute period, which indicates more than one satellite involved. This is the only time they seem to have issue with satellite imagery.

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    I may be wrong about this, but I believe that satellite orbits around Mars would have to be higher, not lower, than around Earth. Mars has a much thinner atmosphere than the Earth does at ground level, but because of the lower gravity it thins out much more slowly with height. – Mike Scott Jan 9 '15 at 19:34
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    You're about right. The scale height of the Mars atmosphere is greater, 11 km vs. 6 km. This is countered though by the fact that the Mars atmosphere is very thin at the bottom, starting effectively four scale heights higher than Earth. In the end it doesn't matter, since spy satellites are Earth have perigees around 300 km, and the Mars Reconnaissance Orbiter is at 300 km. – Mark Adler Jan 10 '15 at 1:39
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    The discrepancy listed here is probably explained by two different satellites taking the different pictures. The high res picture would have been taken by a high quality (i.e. newer) satellite: they weren't in a hurry and they specifically wanted to pick out fine details. After they discover Wattney, they started using every satellite they had, including old ones that only got low quality images, even with enhancement. – Retsam Jun 25 '15 at 1:48
  • NSA? or NASA :) – Ash Sep 29 '15 at 15:22
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    @GeekDunkman in relation to the image enhancement? Its the NSA who step forward for that one in the book. – Moo Sep 29 '15 at 15:33
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Take a look here: http://www.nasa.gov/jpl/mro/curiosity-tracks-20140109/. These are tracks made by the Curiosity rover (and Curiosity itself) photographed by the Mars Reconnaissance Orbiter which is currently orbiting Mars.

Given that "the Martian" takes place at some realistic point in the future (say the 2030's/2040's), it is absolutely realistic to expect the satellites in that era to be able to image a person.

And even Opportunity, which is a lot smaller, has been photographed by the same camera: enter image description here

Also, check out this image to get a sense of the scale of the different rovers:

enter image description here

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    Ha! That second pictures proves conclusively that we never landed on Mars and it's all a soundstage! :-P – FuzzyBoots Jan 12 '15 at 11:57
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From HiRISE at Univ. of Arizona:

We previously released an image near the Ares 3 landing site from “The Martian” by Andy Weir. Andy then sent us the exact coordinates, which we targeted, and this is it.

The closeup shows some wind-blown deposits inside eroded craters. We can’t see the Ares 3 habitat because it arrives sometime in the future, so this is the “before” image. The dark areas appear bluish in HiRISE color but would appear grey to humans on the surface, or maybe a bit reddish when the air is dusty. Ares 3’s 6-meter-diameter habitat would be just 20 pixels across at this scale, about 1/10th the diameter of the largest crater in the central cluster. If protagonist Mark Watney were laying flat on the surface, he would be 6 pixels tall.

Written by: Alfred McEwen and Andy Weir (16 April 2015)

HiRISE picture at Ares 3 site

Image: NASA/JPL/University of Arizona

So, to answer your question: Yes, currently active satellites around Mars are able to give some detail near the level of the book (tents, rovers, Mark himself). This can be improved an order of magnitude if existing state-of-the-art technology is used, but to see something on the scale of AREC and signal boulders doesn't need more than two-threefold improvement.


A further note on terrain: Alfred McEwen was quick to notice that Weir was mistaken in passability of Acidalia Planitia and Arabia Terra. Acidalia has many boulder fields (described as flat in the book) while Arabia is much more passable than described in the book if viewed from orbit (one has to get there to be really sure).

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There are three major inaccuracies that I've noticed with the book:

  1. 175km/h wind is not that strong at all, due to atmospheric pressure on Mars being only 0.6% of Earth's (near vacuum). This gives an apparent wind resistance similar to a 1km/h wind on Earth, which isn't even enough to be felt, much less knock over anything. (note that suspended dust particles would make this feel a bit more than 1km/h but not that much more)

  2. When he does his 'dirt doublings'. Martain regolith is FAR too salty and high in peroxides for this to work without at least first washing the soil thoroughly to remove salts and peroxides. I'm afraid that using Martian 'soil' in the way he did in the book would have killed all the microbes instantly and potatoes would never have grown in it.

  3. He mentions the solar panel efficiency approaches 10%, where in actuality current space grade solar panels already approach 40% efficiency. efficiency is a measure of energy received to wattage produced, so it doesn't matter that the panels are on Mars rather than Earth.

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    What does this have to do with the quality of NASA's satellite imaging equipment? – Jason Baker Apr 9 '15 at 23:51
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    @JasonBaker - This answer seems to be addressing the final part of cppalex's question; "Is it real or is a just about the only tech inaccuracy Andy Weir allowed in his work?". Don't forget that partial answers need love too... – Valorum Apr 10 '15 at 0:08
  • iflscience.com/space/… – Ash Sep 29 '15 at 15:24
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You can see satellite images in Google Maps after switching to Satellite View. You can easily see homes, cars and people in satellite view. So, it's not surprising if Mars satellites could capture such details.

The Martian took place in near future. So, the technology should be slightly better, too.

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    Some of the photos shown by the "satellite view" are aerial photos taken from airplanes, and those are the ones that usually cover more densely populated areas. You can make out cars from the satellite images, but not humans usually. – b_jonas Jul 24 '15 at 12:21
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I think its clear that new Sats in orbit would certainly have that capability - given our current spy Sats can read a plates on a car from space.

The biggest scientific bugaboo (i.e. not washing the soil, Weir in next edition can add one sentence saying "after washing the soil to remove..." and take care of it) is the wind that causes the whole problem in the first place. I imagine there are plenty of other ways to die on Mars - heck, an airlock explosion/failure similar to what happened later in the book, would have done it as well.

  • Weir can't just say "after washing the soil to remove...", because he then has to explain why Watney has access to the large amount of water than would be required. – Mike Scott Feb 21 '17 at 10:16

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