Where Grey Matter meets Dark Matter
Episode 8 - 25 March 2009
This week we talk to Marion Anderson from Monash University about the iMARS mission.
Despite the sickeningly transparent attempt to connect with the kids of today, iMARS is one of the coolest things happening in astronomy. Mars: far away, no oxygen, no food, no fuel. This all adds up to difficulty if we plan to send people there. So if we can't go to Mars, the next best thing is to bring Mars to us.
And that's what iMARS (the international Mars Architecture for the Return of Samples) is all about. They are a Working Group (read: 'committee', with associated cakes and biscuits at the meetings) formed to develop a mission that will land on Mars, collect dirt and bring it back to Earth. With a proposed launch before 2020, that doesn't leave much time for dilly-dallying.
Selection of the landing site is (duh) one of the key decisions that needs to be made; you want to land the thing near something interesting, but without it colliding with a giant boulder, falling down a crevasse or sliding down a dirt avalanche. The number of possible sites has been narrowed down, and no doubt the recent discovery and location of traces of methane will play a large part in the decision. [Since methane gas doesn't last very long in the atmosphere before being bombarded by cosmic rays, the traces must be constantly replenished. On earth, where you find methane, you almost always find life. There are some non-biological sources of methane (mostly volcanoes), but these are not known to occur on Mars. So even if it's not biological, we'll still find out some interesting stuff.]
But up to the point that the thing lands on Mars and collects samples, this is all old news. The difficult part is, to quote from the 2008 iMARS report, 'Returning the samples in a scientifically useful state'. This means that the brave little robot has to tightly pack away all its dirt, then take-off from the Martian surface, fly back to Earth, and somehow end up on the ground, in one piece, without sinking to the bottom of the ocean.
The precedent for this was set by Apollo, where they landed humans on the moon and then brought them back, in one piece and without sinking to the bottom of the ocean. However Mars is further away than the Moon (much further), it all has to be done robotically, and it has a lot more gravity than the Moon. But in other ways the situation is not all bad: the gravity is still a lot less than Earth's, so less energy is needed to take off from Mars than to get the thing off the Earth in the first place; also, there are no people on board meaning that the craft will be lighter and more expendable. The (dollar and ethical) cost of losing a multi-million dollar robotic probe is somewhat less than losing a multi-billion dollar spaceship populated by the first Martionauts.
And yet more problems: bringing all this Martian dirt (technically called regolith; soil and dirt imply some sort of organic material is present) back to Earth presents contamination hazards. First, if some earthly organic molecules find their way into the samples (either on the space probe, or in a lab after being brought back) we might mistakenly think that Martians knew the recipe for Coke, or the 11 secret herbs and spices. So to make the mission worthwhile in any sense, the samples have to be completely protected from all life on earth, which unfortunately has a track record of finding its way into almost any container.
Secondly, what if these space-boffins accidentally bring back virulent Martian plagues? That's just the sort of thing scientists would do - we should protest and burn effigies. The iMARS 2008 report makes a big deal about the public relations campaign required to prevent hysteria.
Of course, we already have a dozen or so chunks of Martian rock that fell to Earth as meteorites, presumably without causing worldwide biological catastrophe (although exogenesis of earth life is far from disproven, ie. we could have all come from Mars originally, and our treatment of this place has been something of a catastrophe). We should be more afraid of bird flu from China than microbes from Mars.In any case, rest assured, in the acronym list at the back of the 2008 report we see: 'BSL-4, Bio Safety Level 4, the highest level of containment'. Whew.
- The 2008 report that we referred to can be read by point-and-clicking at: http://esamultimedia.esa.int/docs/Aurora/iMARS_Report_July2008.pdf
- Here's an article that discusses what we can learn about the sample return mission from looking at Martian meteorites already on Earth: http://www.lpi.usra.edu/meetings/msr2008/pdf/4056.pdf
- A BBC report about the discovery and location of the Martian methane: http://news.bbc.co.uk/2/hi/science/nature/7829315.stm
- Here's the image Marion referred to of Phoenix landing, as seen by the Mars Reconnaissance Orbiter: http://www.nasa.gov/mission_pages/phoenix/images/press/9227-PHX_Lander.html
- And here's the 'Holy Cow!' image of the ice under the lander: http://www.nasa.gov/mission_pages/phoenix/images/press/20080531.html
BETA: "Wowsers! My limbs and organs have been replaced by complicated machinery, Penny. And yet I still can't tell the difference between an enemy agent and my dog."
The endearing buffoonery of Inspector Gadget had kids glued to the TV every day after school. And no doubt a lot of them dreamed of being enhanced in the same way. While a helicopter in Gadget's hat might well twist and pull his head off, the technology exists to manufacturer Gadget-esque monstrosities: flash memory drives in prosthetic fingers, legs that are designed to store and reuse the energy of running to achieve faster speeds, prehensile hands that can respond to nerve impulses in muscle, and matrix-like brain implants that can transfer commands directly to the machine (without the need for temperamental biological mechanisms). While Gadget's niece Penny didn't have any cybernetic modifications, she came equipped with a computer in the shape of a notebook. Sound familiar?
- The article from Wiredblog with the videos we were talking about is here: http://blog.wired.com/gadgets/2008/07/prosthetic-limb.html
- The numbers for the relative masses of helium and air were taken from: http://www.howstuffworks.com/helium.htm
- Here is an article about a USB finger: http://news.bbc.co.uk/2/hi/europe/7949018.stm
- The nanotube muscle article in Scientific American is here: http://www.sciam.com/article.cfm?id=cnt-artificial-muscle&sc=CAT_PHY_20090320
The info for the quiz this week was mostly taken from: Asimov, Isaac (ed.) (1993), The giant book of facts and trivia, Magpie Books, London.
Oops. Mistakes we shouldn't have made but did:
The writer who is usually credited with coining the list of the Seven Wonders is Philo of Byzantium - although he did not have the Lighthouse of Alexandria on his list, including instead the walls of Babylon. The Lighthouse was added later. See Romer, John & Romer, Elizabeth (1995), The seven wonders of the world: A history of the modern imagination, Henry Holt and Company, New York.