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“The achievements of Apollo were so bold and our subsequent efforts so timid that the energy of those years seems like a youthful dream.” -Buzz Aldrin
43 years ago today, humanity took our first steps on another world, venturing nearly 400,000 kilometers from home and walking on the surface of the Moon.
Image credit: NASA, Apollo 11, photo by Neil Armstrong.
Of course, what we found there was a world whose soil was very similar to our own, but devoid of any atmosphere, liquid, or signs of life, present or past. But out beyond the Moon, visible in the distance even when viewed from Earth, lies a world that’s excited our imaginations for generations.
Image credit: Gary Ayton, 2003, using a 10" Newtonian telescope.
Despite its tiny appearance, Mars is much larger than the Moon in terms of actual size. It only appears smaller because it’s up to 100 times farther away from us than the Moon is; if you were to put Mars and the Moon next to one another, the differences would leap right out at you.
Image credit: Paul Stansifer, 84user, NASA, Celestia, JPL/Caltech, under the Gnu Public License.
Unlike our dry, desolate, airless Moon, Mars has an atmosphere, polar icecaps, and plenty of hope that it once had a watery past. It made all the sense in the world, once we’d made it to the Moon, to set our sights on Mars.
While — as you well know — we’ve never sent a manned mission to Mars, it was exactly seven years later, on July 20th, 1976, that we landed our first spacecraft safely on the surface of Mars. Here’s the first (black-and-white) picture of the Viking 1 Lander on the surface of the Red Planet, photographing its own footprint.
Image credit: NASA, Mars Viking 1 Lander.
One of the most ambitious things the Viking landers were equipped to do was to look for signs of life. One of the experiments, in particular, was really interesting. What they did was they scooped up some martian soil and placed it in a chamber filled with a liquid, nutrient broth.
The hope was that, if there were any martian microbes in the soil, they’d react with the nutrient broth, giving off organic gases that Viking would be able to detect.
Image credit: Elaine R. Ingham (USDA).
Both Viking landers (1 and 2) performed this test twice: once with freshly-scooped-up soil, and once with soil that had been “sterilized” by heating it to high temperatures.
If there were microbes in the soil, you know what you’d expect to find: microbes reacting with the broth, giving off organic gases (carbon, nitrogen, and oxygen-rich gases) in the fresh soil, and none in the sterilized soil.
And — believe it or not — that’s exactly what both of them found.
Image credit: NASA / Jet Propulsion Laboratory, from Viking 2 on Mars.
So, does that mean there’s microbial life on Mars, just waiting for a drop of nutrient-filled Earth water to begin organic reactions? Or does that mean the original Viking spacecrafts were contaminated with Earth-based bacteria, and only after the sterilizing heat were we truly examining martian soil?
The other two tests that Viking did for life/organics came up negative, and so at this point, we have to say we can’t know for certain. But we’d love to find out, wouldn’t we? Well, since the successes of Viking 1 and 2, we’ve tried many times to land on Mars.
Image credit: NASA / JPL / color composites by Emily Lakdawalla.
Although there have been many failures, including Mars 6 and 7, Mars Polar Lander, the Beagle 2, and Fobos-Grunt (which sought to land on the Martian moon Phobos), there have also been four more successes: Mars Pathfinder, Spirit, Opportunity, and most recently, the Phoenix lander.
Image credit: NASA/JPL-Caltech/Cornell/Arizona State Univ., by Opportunity.
And while we’ve done some amazing science on the Martian surface with these four landers, we’ve not only been unable to successfully test for present or past life, we haven’t even sought to test for organics in the soil with the other landers.
But in just a couple of weeks, all of that is going to change, depending on how a very important seven minutes goes.
Image credit: NASA / JPL-Caltech / JPL's Mars Yard testing area.
Mars Curiosity, the giant rover depicted on the right, is (arguably) the most advanced robot ever built. An entire science laboratory is on board this rover, which dwarfs Opportunity (whose clone is on the left) in size, speed, and scientific power. Because, among other instruments, know what Curiosity has on board? From wikipedia:
Sample analysis at Mars (SAM): The SAM instrument suite will analyze organics and gases from both atmospheric and solid samples. It is being developed by the NASA Goddard Space Flight Center, the Laboratoire Inter-Universitaire des Systèmes Atmosphériques (LISA) of France’s CNRS and Honeybee Robotics, along with many additional external partners. The SAM suite consists of three instruments:
- The Quadrupole Mass Spectrometer (QMS) will detect gases sampled from the atmosphere or those released from solid samples by heating.
- The Gas Chromatograph (GC) will be used to separate out individual gases from a complex mixture into molecular components. The resulting gas flow will be analyzed in the mass spectrometer with a mass range of 2-535 Daltons.
- The Tunable Laser Spectrometer (TLS) will perform precision measurements of oxygen and carbon isotope ratios in carbon dioxide (CO2) and methane (CH4) in the atmosphere of Mars in order to distinguish between a geochemical and a biological origin.
The SAM also has three subsystems: the ‘Chemical separation and processing laboratory’, for enrichment and derivatization of the organic molecules of the sample; the sample manipulation system (SMS) for transporting powder delivered from the MSL drill to a SAM inlet and into one of 74 sample cups. The SMS then moves the sample to the SAM oven to release gases by heating to up to 1000 oC; and the pumps subsystem to purge the separators and analysers.
Image credit: NASA/JPL-Caltech.
The key, of course, is whether the first-of-its-kind landing, on a world many millions of miles away, will succeed or not. Well, you don’t have to wait much longer: on the night of Sunday, August 5th, Curiosity will enter the Martian atmosphere and descend, attempting to land safely and softly on the alien world below. Landings on Mars historically have about a 50% success rate, so everyone watching ought to have their hearts in their throats.
And what’s going to happen? You don’t have to rely on my explanation for it; NASA and JPL have put together a brilliant five minute video explaining exactly what this seven minutes of terror is all about!
My local planetarium will be broadcasting the landing live: will you be watching? In the meantime, for now, for the time leading up to August 5th, and for the days and weeks afterwards, I’ve built a spectacular trap on Mars for you, where all the news stories from around the world surrounding the red planet will be on display. (Got an iPad? I’ve got the brand-new #1 free news app for you to follow this story here!)
Image credit: The Mars trap via trapit, http://trap.it/.
It’s no secret how much I’ve loved the Opportunity rover, and we’ve got a chance with Curiosity to absolutely blow away everything we know about the surface of our rubicund neighbor. I’m hoping for a successful landing, and I can’t wait to see – literally – what Curiosity uncovers.
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