The Martian: Getting Home Is Just Half The Problem

"The Martian" movie is coming soon! Starring Matt Damon and based on the bestselling novel by Andy Weir, "The Martian" has a lot of Sci-Fi fans very excited.

"The Martian" is about an astronaut stranded on Mars who is trying to devise a clever way to get back home. But today, we humans here on Earth still have to think of clever ways to survive a trip to the red planet in the first place.

NASA, the ESA, and many other space programs are taking aim at Mars. We have sent probes, rovers, and satellites; now it’s time for humans to make the trip. But this brings big problems along with the big promise. Space is full of cosmic rays, high-energy electrons, high-speed protons and even heavier atoms. They can all kill you over time or fry your equipment.

Radiation in space will make you sick at the least, and don’t underestimate the problem of being sick in space – think about vomiting in a space suit. But it can also damage DNA and most certainly lead to infertility, given enough time and exposure.

All this damage could occur inside the space ship on a long journey to Mars or beyond, not just on space walks. Most high-energy radiation will pass through the hull of a spacecraft and do damage to the occupants. We need protective shields to keep out the bad particles and waves.

Six months on ISS doesn’t give an astronaut anywhere near the 
radiation exposure that six months on Mars, or going to and from 

Mars, would. The reason is that the ISS is still within the Earth’s 
magnetosphere, so it’s protected from most of the dangerous 

radiation. To go to Mars, we’ll have to take 

our own shield along.

Star Trek: Insurrection showed us an example of using a force field to protect the crew. When Picard and mates were observing Ba’ku from a cloaked duckblind, they used a “chromodynamic shield” to deflect or block the metaphasic radiation that inundated the planet. A force field protected the crew, although it was protecting them from rays that would stop their aging and did in fact restore Geordi’s eyesight for a while.

We don’t have a chromodynamic shield, so we've been looking to more conventional mechanisms of shielding. We could always make the walls of a long distance spacecraft thicker. Concrete would work pretty well, if it was dense and about 2 ft thick. A foot or so of aluminum might do just as well. But these are very heavy. Heavy things don’t make for good space gear.

Interestingly, water is a great absorber of radiation. We could put it between the walls of a spacecraft and it could do a pretty good job of protecting the crew and the electronics.  Hydrogen gas might work as well; notice how water is just hydrogen and oxygen. The sleeping quarters on the ISS are lined with impregnated polyethylene as an additional radiation shield. 

But what might work best? – human waste. A privately funded mission to Mars led by Dennis Tito plans to use the astronaut's own excrement as a radiation shield by packing it between the walls of the spacecraft. Organic molecules and water block radiation very nicely, and they’ll be producing more shielding every day. It’s a strange thought that a Mars mission might be jeopardized by constipation.

Dennis Tito is a billionaire investment manager, but first he 

was an engineer. He was the first person to purchase a ride 

into space (Russian rocket) and now he wants to fly 

people around Mars – not to Mars - just a flyby in 2018 

or so. The planets will be aligned to give a 501 day round 

trip then. He wants to use their waste as radiation shielding.

Thank goodness science has kept looking for radiation shields. It's quite the boon that we have natural examples to learn from. The ionosphere of Earth is a great deflector. It’s the reason short wave radio operators can send weak signals very, very far. They bounce off the bottom layers of the ionosphere and back down to Earth, called skywave or skipping. The lower the angle on the way up, the far they will be over the horizon when they bounce back down. 

The ionsophere (80-1000 km altitude) is part of the atmosphere of Earth that protects us from cosmic radiation. It consists of ionized air molecules; the ionization comes from the Sun’s energy. What's an ionized gas called?  – plasma.

So we have a plasma shield around Earth – remember this as it will come up again. The magnetosphere (a 40,000 nanoTesla field goes out hundreds of thousands of km) is produced by the spinning of the Earth’s metallic outer core. It participates in the protection because the ions of plasma in the ionsophere are charged, and electrical charges in a magnetic field produce an electric field.

The magnetosphere, in coordination with the 

plasmasphere, shunts most of the electrons of 

the solar wind and the high energy protons 

around the Earth. Where the magnetic lines 

come out of the Earth at the poles, you have the 

polar cusps. Some radiation can get in there – 

we see them as the auroras.

A new study shows that the plasma interacts with the magnetic field and it becomes more important when there are solar storms that greatly increase the energy of the radiation coming at earth. The plasmasphere, a portion outside the ionosphere, reacts to greater energies coming from the Sun and will plume out to be more protective.  

All this protection comes from the fact that ions in plasma are charged, and the magnetic field is charged – and like charges repel. So the high speed electrons of the solar wind and the protons and heavy ions of cosmic radiation that come close to Earth are repelled by the magnetosphere, the plasma sphere, and most importantly by the electric field produced by the interaction between the plasma and the magnetic field. The vast majority of charged particles and waves are swept around Earth and merge again safely behind us. Now that’s a force field.

Several research groups have begun to think about how this could be mimicked on a small scale to protect astronauts in space. A 2005 project from NASA contemplated using vectran balloons covered in gold that could be charged to positive or negative values. Placed above a moon base and electrified, the balloons might create a magnetic bubble that would shunt radiation away and produce a protected cavity underneath.

No one has thought more about producing a plasma shield than Dr. Ruth Bamford of the Rutherford Appleton Laboratory in England. Since 2008 she has been working on producing mini-magnetospheres that would buffer the small amount of plasma in space; using a magnetic field to hold it in place and build up its density. Together, they would produce an electric field just like the Earth does, and this would shunt radiation and particles away from the protected object.

On the left is the Reiner Gamma lunar swirl. On the right is the 

Reiner crater – no, not for Carl Reiner. We used to think 

the swirls (three on the moon) were dead areas, no magnetic 

field, no water, no nothing. Now we see they are the protected 

areas and are the most interesting places on the Moon.

NASA has also thought about this, using a plasma cloud (probably made from hydrogen gas) on the Sun side of a spacecraft, held in place by a superconducting wire mesh. Unfortunately, superconductors only work to produce a magnetic or electric field if below their transition temperature. And even for the best of materials (YBCO and BSCCO) this is somewhere in the range of -265˚F. If the mesh was exposed to the Sun in space, it would be several hundred degrees at least. Better keep thinking.

A discovery in 2013-2014 brought the thinkers back to Dr. Bamford's mini-magnetospheres. It was discovered that small parts of the moon’s surface are protected from radiation. It turns out that these areas produce weak magnetic fields (few hundred nanaoTesla), and those fields are holding the thin plasma of space in place above them. The field concentrates the plasma, and together they produce a protective electric field to deflect particles and keep the surface of the moon at those spots from being irradiated. Irradiation turns the surface dark, while these “lunar swirls” remain light colored.

This is not a cartoon. The pinkish gas is plasma 

and on top of the middle cylinder is a magnet. The 

magnetic field deflects the plasma and some builds 

up in density on the leading edge. This leading edge 

and the magnetic field form an electric field that 

would shunt more particles. The dark area around 

the magnet is a protected cavity, no cosmic radiation 

gets to that point. It’s a real-life deflector shield.

Bamford’s discovery of the mechanisms behind the swirls made her idea of a mini-magnetosphere plasma shield more attractive, since the protective magnetic forces on the moon are much weaker than previously estimates had thought necessary. Therefore, a smaller (lighter, less energy consuming) superconducting coil could be used to create a magnetic field and hold a thin layer of plasma in a bubble around a spacecraft. Bamford’s group has built such a force field in their lab and predicts that a 1.5 ton apparatus could do the job in space! 

But wait, there’s more. A plasma shield could also protect a ship from high energy weapons. Plasma has the capability to absorb photons of energy like from lasers or phasers!!! And since plasma has to be at a very high temperature to keep the electrons from re-associating with the nuclei, being in space would help since there would be no air to carry the heat away from the plasma. It would stay hot and maintain itself. In fact, incoming weapons fire would reinforce the plasma state by adding energy. 

Contributed by Mark E. Lasbury, MS, MSEd, PhD

As Many Exceptions As Rules

Bamford, R., Kellett, B., Bradford, J., Todd, T., Benton, M., Stafford-Allen, R., Alves, E., Silva, L., Collingwood, C., Crawford, I., & Bingham, R. (2014). An exploration of the effectiveness of artificial mini-magnetospheres as a potential solar storm shelter for long term human space missions Acta Astronautica, 105 (2), 385-394 DOI: 10.1016/j.actaastro.2014.10.012

Bamford, R., Gibson, K., Thornton, A., Bradford, J., Bingham, R., Gargate, L., Silva, L., Fonseca, R., Hapgood, M., Norberg, C., Todd, T., & Stamper, R. (2008). The interaction of a flowing plasma with a dipole magnetic field: measurements and modelling of a diamagnetic cavity relevant to spacecraft protection Plasma Physics and Controlled Fusion, 50 (12) DOI: 10.1088/0741-3335/50/12/124025

Walsh, B., Foster, J., Erickson, P., & Sibeck, D. (2014). Simultaneous Ground- and Space-Based Observations of the Plasmaspheric Plume and Reconnection Science, 343 (6175), 1122-1125 DOI: 10.1126/science.1247212

The Friday Five

Highlighting some of the coolest science news we’ve seen lately.

1. Paleo, Atkins, raw, juice...diets, diets, diets! Sort the fact from the fiction with this excellent article, “10 Fad Diets, Debunked”, by Esther Inglis-Arkell.

2. The new film odyssey, Interstellar, blasted into theatres recently. Director Christopher Nolan went to great lengths to try and get the science right in the movie, which included consultation with theoretical physicist Kip Thorne. The video below details how they worked together to imagine a real black hole.

Unfortunately, not all of the science in the movie is accurate. 

3. In this week's episode of “The Big Question”, Craig Benzine explains why your voice gets higher when you inhale helium. Interestingly, it is not the pitch that changes…

4. Here, kitty kitty…what’s the difference between a wildcat and a domesticated one? Nothing – they both hate you. Jokes aside, scientists have recently performed a genetic comparison between the two and found a number of genes that were enriched due to domestication. These genes may explain why your housecat is less shy, tamer, and more responsive to a reward. Interpreted another way, they also explain why we can't really stroll through the woods with tigers.

5. Our ongoing coverage of new species named after celebrities converged with another subject that constantly fascinates us: Ozzy Osbourne. A new species of frog was recently found in Brazil and named Dendropsophus ozzyi. The males have a bat-like mating call, which reminded the researchers of the infamous concert when Ozzy bit the head off a bat during the show.

Scientists named this new species of frog after Ozzy because it makes a bat-like noise, which reminded them of Ozzy's strange stage diet in the 1980s.

Science quote of the week:

"Science fiction has become science fact today - Hollywood is good, but Rosetta is better" –Dr. David Parker, in reference to the first time humans have landed a probe on a comet.

Contributed by:  Bill Sullivan

Follow Bill on Twitter: @wjsullivan

ORRICO, V., PELOSO, P., STURARO, M., SILVA-FILHO, H., NECKEL-OLIVEIRA, S., GORDO, M., FAIVOVICH, J., & HADDAD, C. (2014). A new “Bat-Voiced” species of Dendropsophus Fitzinger, 1843 (Anura, Hylidae) from the Amazon Basin, Brazil Zootaxa, 3881 (4) DOI: 10.11646/zootaxa.3881.4.3

  Montague, M., Li, G., Gandolfi, B., Khan, R., Aken, B., Searle, S., Minx, P., Hillier, L., Koboldt, D., Davis, B., Driscoll, C., Barr, C., Blackistone, K., Quilez, J., Lorente-Galdos, B., Marques-Bonet, T., Alkan, C., Thomas, G., Hahn, M., Menotti-Raymond, M., O'Brien, S., Wilson, R., Lyons, L., Murphy, W., & Warren, W. (2014). Comparative analysis of the domestic cat genome reveals genetic signatures underlying feline biology and domestication Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.1410083111

A Four Billion Mile Road Trip to Grandma’s

A comet is a celestial body that is trapped in orbit

around something large. When close to the sun they

have tails. The tail is material from the frozen comet

that is released from the comet when the sun’s energy

heats it. But the tail doesn’t follow the comet. It

always points away from the sun – blown by the solar

wind. Comet 67P/C-G’s tail will be 100,000 miles long

when it is closest to the Sun next year.

On November 12, 2014, man will perhaps accomplish something unprecedented. That is, with a ton of good planning and more than a little luck. The landing craft, Philae, will set down on a comet. I hope you realize how amazing that is.

The comet, named 67P/Churyumov–Gerasimenko, or 67P/C-G for short, has a period of 6.6 years. Every 2/3 of a decade or so, it travels in from deep space to make a trip around the sun. For this particular trip, there was a probe waiting on it, the Rosetta orbiter. After going into orbit around 67P/C-G, Rosetta is now set to release Philae to drop down and land on the comet's surface.

But how did Rosetta meet the comet? It took a lot of doing. Comet 67P/C-G is traveling at a steady rate of 24,600 mph (39,589 kph). That means it travels from NYC to Boston in 30 seconds. Let’s see the planned NYC-Boston maglev train match that!

When we send rockets into space to meet the International space station, they only have to travel 17,000 mph (27,358 kph). The ability to reach this higher speed, just to get into the orbit of the comet could be achieved two ways.

One - you could put all the fuel on board the orbiter and thrust yourself to the proper speed. But that would require a space ship the size of a football field. You just can’t get all that fuel into space for a price anyone could pay. So that’s out.

Second - you could use the power of gravity. By launching Rosetta out into space and then having it swoop by a planet, it can use the gravity of the planet to pull it to a higher speed and then curve around the planet and get shot out the other side. Every time you do this, you gain some speed.

Rosetta achieved its amazing pace by three separate Earth gravity assists and one Mars gravity assist. It has traveled over 3.8 billion miles just to gain enough speed so it can sneak up behind the comet. And how long did this take? Rosetta/Philae were launched in 2004! And my kids have a hard time planning for a paper due in two weeks.

You can see the gravity assists that Rosetta used to catch

up with 67P. Also notice that Rosetta went into

hibernation for three years. It’s instruments run on solar

power, but it was 500 million miles from the sun. Out

there you only get about 4% of the sunlight we get here on Earth.

They’ve come a long way at ESA (European Space Agency) and NASA, the two agencies running the mission. Compare Rosetta’s progress to that of Voyager 1. True, Voyager has traveled farther (4.4 billion miles, 7.1 billion km), but it was launched in 1976!

After all this chasing, now Philae is ready to separate from Rosetta and land on 67P/C-G. This is where the luck comes in. Once Philae leaves Rosetta, there is no controlling it’s path. The plan, based on thousands of photographs taken of 67P/C-G’s surface by Rosetta while in orbit, is to land on Philae somewhere flat and sunny.

Flat is obvious, the comet’s surface is mostly irregular, with huge boulders and deep crevices; finding a good parking spot on 67P is harder than the week before Christmas at the mall. Flat is also important so Philae can get a good grip. Gravity is so low on 67P that there is a fear that Philae will just bounce off the surface, even though it will be moving at a pace similar to a slow walk.

The ESA had a naming contest for the landing spot for

Philae, shown above. The winner – Aglilkia. Suggested by

150 people, Agilkia is an island in the Nile River where

several temples were moved when the Nile Valley was

flooded by the Aswan dams. The Island they were moved

from – Philae. The numbers show the diameters of the

boulders to give it some scale.

To help with this, Philae has several hooks it will deploy to stab into the surface of the comet – hopefully. We don’t know how hard the surface is, or if the lander will come down in a place where there isn’t a rock in the way. See what I mean by luck?

As far as sunny is concerned, the sun is needed to charge the instruments on Philae. If they land in the shade, she’s only going to be functional for about 60 hours. With a good sunny spot, she might work for up to 6 months.

The question you’re now asking is, “Work to do what?” Why spend all this money and time to land on a comet? In response, I ask if you care where your parents came from, or their parents. Go back far enough and you have to wonder where life on Earth came from. Did life start here on its own or was it brought here?

Philae may help answer these questions. Comets are rock, ice, and who knows what else. Water is needed for all life that we know about, so did comets bring water to Earth? Is there something alive in the ice, or are the building blocks for life present on that comet? Philae has nine instruments to help answer these questions.

If Philae finds organic molecules, then we better start preparing a list of questions for our neighbors, because that finding will almost assure us that they’re out there. And it may mean more -chirality in organic molecules is important here on Earth.

Amino acids in Earth based life are all left-handed (called

L). Their mirror image is the D-amino acid, but they don’t

work the same way in proteins. D- amino acids would

make a protein fold differently, and the way a protein

folds determines its function. If there are amino acids of

67P/C-G, will they be L- or D-?

Many organic molecules have a handedness in how they are constructed. Our amino acids are all left-handed (see this post), while our sugars are right-handed (see this post). If the organic compounds on 67P/C-G are the same, then life elsewhere is going to look a lot like we do.

If they are opposite handed, then Star Trek got it wrong with all those humanoid aliens, and we may be for some real surprises in the future.

A 2012 paper explains how one of the instruments on Philae is designed just for chirality question. It will determine the handedness of any organic molecules found on 67P/C-G. After all, it is important to find Grandma, and 67P/C-G might be her house, or at least her hulking old sedan with the 35 gallon gas tank and steering wheel as big as a hubcap.

Comets are remnants from when the solar system was young; they are where we were, and we need to know them in order to get a better idea of where we should be going. I personally am very excited to find out if we are alone in the universe – that would be so sad. Isn't that important enough for a 3.8 billion mile road trip?

Contributed by Mark E. Lasbury, MS, MSEd, PhD

As Many Exceptions As Rules

Evans, A., Meinert, C., Giri, C., Goesmann, F., & Meierhenrich, U. (2012). Chirality, photochemistry and the detection of amino acids in interstellar ice analogues and comets Chemical Society Reviews, 41 (16) DOI: 10.1039/c2cs35051c