Fact Checking “The Martian”

So I’m clearly late to the bandwagon, but I just watched The Martian this weekend (maybe it’s not so bad timing since The Martian just won a Golden Globe last night). Loved the movie which is essentially Interstellar meets Apollo 13 meets Castaway, but as with all sci fi flicks, I was constantly trying to figure out how realistic the movie was. Thankfully, I’m not the only one. According to Space.com, The Martian might be the most scientifically realistic movie ever! There are obviously technical mistakes (this is Hollywood afterall), but the Guardian has a nice list discussing how accurate (or not) the film is (CAUTION, SPOILERS):

'You're not on Mars to study your fecal waste'  … The Martian.

Overall it’s a very good movie, and while there are mistakes in it, it is the first genuine Mars movie. It is the first movie that attempts to be realistic and that is actually about human beings grappling with the problems of exploring Mars, as opposed to various movies set on Mars that are essentially either shoot ’em ups or horror films. It does not engage in fantasy: no monsters, no magic, no Nazis. However, there are a number of technical mistakes.

The storm

This is the only thing I noticed that was completely impossible, as opposed to improbable or sub-optimal. The Martian atmosphere is only 1% as thick as Earth’s, so a Mars wind of 100mph, which is possible although quite rare on the surface, would only have the same dynamic force as a 10mph wind on Earth. You could fly a kite in it, but it wouldn’t knock you down.

The spacecraft

The diameter of the torus and the rate of rotation on the Mars Orbiter spacecraft looked about right to create an artificial gravity level somewhere between Mars and Earth, so that was OK. It’s just that the ship was so big and elaborate and expensive-looking. Going to Mars is not about realising the vision of a giant science-fiction spaceship, it is about sending a payload from Earth to Mars that is capable of supporting a small group of people, and then sending that or a comparable payload back. There’ll be ships like that some day, just like there were ocean liners a few hundred years after Columbus made his voyage. But if Columbus had waited for ocean liners, or even clipper ships, he never would have gone anywhere.


Mars has about one third the gravity of Earth, which is an asset to explorers because you’re wearing a heavy space suit, but it doesn’t feel that heavy. If you’ve got a 150lb person with a 150lb suit, that’s going to feel like 100lb on Mars– lighter than the person alone on Earth. As far as I can see they didn’t bother with that in the movie. Even climbing the ladders in the initial scenes, they seem to be exerting themselves.

Making water

Matt Damon’s character took hydrazine from the rocket fuel and dissociated it into nitrogen and hydrogen, which you can do, and he burned the hydrogen with oxygen to make water. That’ll certainly work, but if I was stranded on Mars I would just make water out of the soil. Water is available in its natural state on Mars as ice, permafrost, or soaked into the soil. Martian soil is about 5% water by weight at low latitude, and up to 60% water near the poles. Martians are not going to get their water by importing hydrazine from Earth and burning it with precious cabin oxygen, they are going to bake it out of the soil.

The toilets

This was a little odd. The easiest way to deal with waste is to bag it, seal the bags in something and then burn them once a day. We do something like that with Arctic exploration. But it’s more productive to recycle the waste, using greenhouse systems or physical chemical processes, and turn it into fuel, water and oxygen. Would they really seal them individually and label them with the astronauts’ names for later scientific study? I can’t imagine anyone wanting to bring that stuff back to Earth, or study it on Mars. You’re not on Mars to study your fecal waste, you’re there to study Mars.

The nerd-genius solution

The Martian.

One thing in the movie that is possible, and perhaps the producers knew the story, is the character of the nerd (played by Donald Glover) who comes up with the gravity-assist trajectory that rescues the mission. It may appear to be a Hollywood device, but in fact there is a basis in history for such a person. His name is Michael Minovitch. He was a trajectory analyst at Nasa’s Jet Propulsion Laboratory in the 1960s and he came up with the idea of the gravity assist that became the basis of the Voyager programme to go to Jupiter, Saturn, Uranus and Neptune. Initially no one believed him. He was a very junior person, somewhat analogous to the character in the movie. The managers making the decisions are typically people who were once engineers but haven’t done it in a while and perhaps are not so good at maths any more. So Minovitch had to get out the chalk and walk them through it and convince them that it would actually work.

Removing the windows from a rocket

Would you need windows in a rocket to survive a launch from Mars? It’s an interesting question. The atmosphere is very thin, so can you get high enough that the atmosphere becomes irrelevant before you’re going fast enough that the atmosphere is a threat? It depends on the thrust profile. The question is, at what altitude do they reach 1km per second? Let’s figure it out: OK, so 1,000 metres per second squared, divided by … [Zubrin mutters some equations to himself] … you want to go slow in this case, so let’s say 1G. Let’s try [more muttering] … 50 kilometres. So, with a slow acceleration of 1G taking off from Mars you’d get to 50 kilometres before you’re travelling at 1km per second. So I’d lean towards yes, it’s possible.

Nasa communications

Would Nasa not tell the other astronauts that Watney [the Matt Damon character] was still alive? Well let me put it this way: they didn’t tell the Columbia astronauts everything [the space shuttle Columbia disintegrated on re-entry in 2003, killing all seven crew members]. And it was unfortunate, because they didn’t give those astronauts their best shot at potentially solving the problem they had. I don’t know if those astronauts could have saved themselves if they had all the info, but they should have had all the info. What was unrealistic to me was that you had the whole Earth knowing that Watney was alive, but the crew on the interplanetary spaceship did not. That’s impossible right now. The crew on the International Space Station can email you. Not all of their communications go through mission control, so they can be in touch with their loved ones at home. It’s tremendously useful to have the crew be able to directly access people on Earth. If they’re exploring Mars and they come across a very odd-looking mineral, say. To be able to access a professor at some university somewhere and say is this a fossil? A mineral? What do you think? Or, how do I reboot my computer, it’s locked up? If you have all this going through one person at mission control, it isolates the crew much more than is necessary.


The US space programme today is frozen in its tracks. Nasa talks about sending humans to Mars in 2043, but that’s just postponing it for another generation. We’re much closer today to being able to send people to Mars than we were to sending people to the Moon in 1961. If Barack Obama’s successor were to commit the nation, in the spring of 2017, with the same kind of courage and determination that JFK did in 1961, we could be on Mars before the end of his or her second term. It’s a question of political will to me. That’s the real positive message of The Martian. It’s saying, “we can do it. If we use our minds, we can take on all these challenges”.

Dr Robert Zubrin is an aerospace and astronautics engineer and an advocate for manned exploration to Mars. He is founder and president of the Mars Society and co-author of Mars Direct, a strategy for manned expeditions to Mars that has been broadly adopted by Nasa (and replicated in The Martian).

Dr Robert Zubrin was speaking to Steve Rose


NASA looking for Astronauts – for future missions geared toward traveling to Mars! #OutofthisWorld

For the first time since the end of the space shuttle program in 2011, NASA is accepting applications for astronauts to start a new series of missions aimed at further space exploration with the goal of traveling to Mars.  Applications will be accepted from December 2015-February 2016, and successful candidates will be announced mid-2017.  From NASA:

In anticipation of returning human spaceflight launches to American soil, and in preparation for the agency’s journey to Mars, NASA announced it will soon begin accepting applications for the next class of astronaut candidates. With more human spacecraft in development in the United States today than at any other time in history, future astronauts will launch once again from the Space Coast of Florida on American-made commercial spacecraft, and carry out deep-space exploration missions that will advance a future human mission to Mars.

The agency will accept applications from Dec. 14 through mid-February and expects to announce candidates selected in mid-2017. Applications for consideration as a NASA Astronaut will be accepted at:


The next class of astronauts may fly on any of four different U.S. vessels during their careers: the International Space Station, two commercial crew spacecraft currently in development by U.S. companies, and NASA’s Orion deep-space exploration vehicle.

From pilots and engineers, to scientists and medical doctors, NASA selects qualified astronaut candidates from a diverse pool of U.S. citizens with a wide variety of backgrounds. 

“This next group of American space explorers will inspire the Mars generation to reach for new heights, and help us realize the goal of putting boot prints on the Red Planet,” said NASA Administrator Charles Bolden. “Those selected for this service will fly on U.S. made spacecraft from American soil, advance critical science and research aboard the International Space Station, and help push the boundaries of technology in the proving ground of deep space.”

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Liquid Water confirmed on Mars!! #NASA

From NASA today:

New findings from NASA’s Mars Reconnaissance Orbiter (MRO) provide the strongest evidence yet that liquid water flows intermittently on present-day Mars.

Using an imaging spectrometer on MRO, researchers detected signatures of hydrated minerals on slopes where mysterious streaks are seen on the Red Planet. These darkish streaks appear to ebb and flow over time. They darken and appear to flow down steep slopes during warm seasons, and then fade in cooler seasons. They appear in several locations on Mars when temperatures are above minus 10 degrees Fahrenheit (minus 23 Celsius), and disappear at colder times.

“Our quest on Mars has been to ‘follow the water,’ in our search for life in the universe, and now we have convincing science that validates what we’ve long suspected,” said John Grunsfeld, astronaut and associate administrator of NASA’s Science Mission Directorate in Washington. “This is a significant development, as it appears to confirm that water — albeit briny — is flowing today on the surface of Mars.”

These downhill flows, known as recurring slope lineae (RSL), often have been described as possibly related to liquid water. The new findings of hydrated salts on the slopes point to what that relationship may be to these dark features. The hydrated salts would lower the freezing point of a liquid brine, just as salt on roads here on Earth causes ice and snow to melt more rapidly. Scientists say it’s likely a shallow subsurface flow, with enough water wicking to the surface to explain the darkening.

Garni crater on Mars

Dark narrow streaks called recurring slope lineae emanating out of the walls of Garni crater on Mars. The dark streaks here are up to few hundred meters in length. They are hypothesized to be formed by flow of briny liquid water on Mars. The image is produced by draping an orthorectified (RED) image (ESP_031059_1685) on a Digital Terrain Model (DTM) of the same site produced by High Resolution Imaging Science Experiment (University of Arizona). Vertical exaggeration is 1.5. Credits: NASA/JPL/University of Arizona

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Two worlds, one sun #AstroPicoftheDay #WereAllInThisTogether

Loving this Astro Pic of the Day brought to you by NASA:

How different does sunset appear from Mars than from Earth? For comparison, two images of our common star were taken at sunset, one from Earth and one from Mars. These images were scaled to have same angular width and featured here side-by-side. A quick inspection will reveal that the Sun appears slightly smaller from Mars than from Earth. This makes sense since Mars is 50% further from the Sun than Earth. More striking, perhaps, is that the Martian sunset is noticeably bluer near the Sun than the typically orange colors near the setting Sun from Earth. The reason for the blue hues from Mars is not fully understood, but thought to be related to forward scattering properties of Martian dust. The terrestrial sunset was taken in 2012 March from Marseille, France, while the Martian sunset was captured last month by NASA‘s robotic Curiosity rover from Gale crater on Mars.

Left Image Credit & Copyright: Damia Bouic;  Right Image Credit: NASA, JPL-Caltech, MSSS; Digital processing: Damia Bouic

Left Image Credit & Copyright: Damia Bouic;
Right Image Credit: NASA, JPL-Caltech, MSSS; Digital processing: Damia Bouic

Organics on Mars!! A clue to finding life? #AGU14

A new update from the Mars Curiosity rover reveals that methane has been detected on Mars… which could be a clue suggesting there was or is life on mars!

The new information was revealed at the AGU meeting yesterday:

NASA’s Mars Curiosity rover has measured a tenfold spike in methane, an organic chemical, in the atmosphere around it and detected other organic molecules in a rock-powder sample collected by the robotic laboratory’s drill.

“This temporary increase in methane — sharply up and then back down — tells us there must be some relatively localized source,” said Sushil Atreya of the University of Michigan, Ann Arbor, a member of the Curiosity rover science team. “There are many possible sources, biological or non-biological, such as interaction of water and rock.”

Researchers used Curiosity’s onboard Sample Analysis at Mars (SAM) laboratory a dozen times in a 20-month period to sniff methane in the atmosphere. During two of those months, in late 2013 and early 2014, four measurements averaged seven parts per billion. Before and after that, readings averaged only one-tenth that level.

Curiosity also detected different Martian organic chemicals in powder drilled from a rock dubbed Cumberland, the first definitive detection of organics in surface materials of Mars. These Martian organics could either have formed on Mars or been delivered to Mars by meteorites.

This illustration portrays possible ways that methane might be added to Mars' atmosphere (sources) and removed from the atmosphere (sinks). NASA's Curiosity Mars rover has detected fluctuations in methane concentration in the atmosphere, implying both types of activity occur in the modern environment of Mars.

This illustration portrays possible ways that methane might be added to Mars’ atmosphere (sources) and removed from the atmosphere (sinks). NASA’s Curiosity Mars rover has detected fluctuations in methane concentration in the atmosphere, implying both types of activity occur in the modern environment of Mars.

Organic molecules, which contain carbon and usually hydrogen, are chemical building blocks of life, although they can exist without the presence of life. Curiosity’s findings from analyzing samples of atmosphere and rock powder do not reveal whether Mars has ever harbored living microbes, but the findings do shed light on a chemically active modern Mars and on favorable conditions for life on ancient Mars.


NASA MAVEN spacecraft prepping for Mars orbit insertion on Sunday #science #phrasing

On Sunday March 21st NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft will enter into orbit around Mars Or as NASA puts it, ‘NASA Mars Spacecraft Ready for Sept. 21 Orbit Insertion’ … phrasing (see below)?? Regardless, MAVEN has traveled 442 million miles over 10 months to reach Mars and begin its mission, which will help pave the way for a human journey to Mars.

Following orbit insertion, MAVEN will begin a six-week commissioning phase that includes maneuvering the spacecraft into its final orbit and testing its instruments and science-mapping commands. Thereafter, MAVEN will begin its one-Earth-year primary mission to take measurements of the composition, structure and escape of gases in Mars’ upper atmosphere and its interaction with the sun and solar wind.

To learn more about the MAVEN mission, visit: http://www.nasa.gov/maven