VSSEC Educator Danielle Shean Returns from Spaceward Bound Mojave
From March 28th to April 2nd, Danielle Shean was invited to participate in the NASA Spaceward Bound program. She spent four days at the Zzyzx Desert Research Institute in the Mojave Desert, California, learning about the new techniques and ideas NASA and Desert Research Institute scientists have regarding the search for life on other planets and moons, including Mars, Europa, Titan and Enceladus.
In those four days Danielle learnt about thermography and the search for caves on Mars, both as places where life might develop and where astronauts could potentially be stationed to protect them from Mars’ heavy radiation bombardment. She learnt about biological sampling techniques in dry cave environments and also wet environments. Danielle also had a chance to participate in some field work carried out by one of the students doing research with NASA AMES and to play with the Sensetta Rovers currently being researched by under- and post-graduates from Carnegie-Melon.
Day 1: Caving in the Cima lava tube and thermography.
We went to the Cima lava tube; this is an extinct tunnel that was made by flowing lava which eventually stopped flowing and the last bits drained out. What was left behind was this awesome cave. Over time, parts of the cave roof had collapsed creating skylights.
The main reason we were looking at lava tubes is because they are really interesting to NASA scientists because this could be where life hangs out, or where we station astronauts to protect them from the Sun’s radiation while they stay on Mars. But how can we find these lava tubes quickly and easily? That where infra-red photography, or thermography comes in.
|To see the infra-red spectrum you need an infra-red camera, the one we had on the trip was called a FLIR (Forward Look infra-red), and this allowed us to see the differences between the hot rocks at the surface and the cold rocks within the cave. Pretty cool huh?|
Day 2: Caving in the Upper and Lower Glove lava tubes and looking for life.
|So day two was also spent in a cave. These caves were a little different from the Cima lava tube, as they are much deeper and much better developed. Plus they host heaps of different micro-organisms. The quarry where the caves are located was a pretty weird place. Everywhere you looked were man-made dunes of black sand (the bi-product of basalt quarrying) and very little vegetation. In fact, we could very well have been standing on the surface of Mars. |
To find organisms in a cave was not the simple business I thought it would be. I have to admit, I thought it would be pretty straight forward to identify life in a cave – wouldn’t it be the slimy stuff on the wall, or the orange fuzzy patch of lichen by the cave entrance? It turns out, it’s much harder to find life and it requires a lot of guesswork.
Unfortunately it seems that life doesn’t carry with it neon signs and pointers. It could be just another white patch on the cave wall, alongside the seeping salts and mineral deposits. Sometimes we can’t even sure what it ate! There are heaps of different types of organisms – the ones who like to hang around caves can be either autotrophs (life that creates its own food from inorganic substances like light, or the common metals found in basalt (magnesium, manganese and iron); or heterotrophs (life that needs organic substances such as carbohydrates to survive).
The only way you can tell is to take a scraping of what you think might be an organism and put it in a whole lot of different growth mediums and hope that one might be the little bug’s liking. We had eight different growing mediums designed to appeal to both heterotrophic and autotrophic organisms. Once the samples are taken, the organisms are incubated for a couple of days and then we see if anything grows in the media. Watch this space – if we found anything good in our field trip I’ll post it to let you know.
Day 3: Stromatolites and the ‘death from outer space’.
|Sounds cool don’t it? Unfortunately as much as Dr McKay might wish it, I don’t think it was ‘death from outer space’ that killed the stromatolites. |
Day three tooks us out to the border of the Death Valley National Park, and to visit a rather beautiful collection of ancient stromatolites. Stromatolites for those who don’t know are algae some of which are still alive today and are probably the MOST successful organisms to ever inhabit the planet.
What makes this particular collection of stromatlites interesting is that there are periods of time where a layer of goo (read ‘death from outer space’) has travelled in and buried the stromatolites, effectively killing them off. Then after that there is a period where the stromatolites strike back and recolonise. Unfortunately then we have the return of the goo and the death of these brave stromatolites. Why are they doing that? And most importantly what is killing the stromatolites?
I have no idea, but one of the NASA team, student Meredith Perry, is studying just these things. So, you’ll just have to stay tuned and see what she discovers as she continues her research.
Day 4: Geology field trip and playing with the Sensetta Rovers
|In the morning we did a field trip to have a look at some really big, ancient lake beds.You know that Mojave is a desert. What you probably don’t know is that it is literally covered in plants. Doesn’t make sense does it? Well, the reason that Mojave is classified as a desert is not because it has sand dunes, camels or oasis (I did see sand dunes and an oasis, but I didn’t see any camels). It is because of the annual amount of water that Mojave receives every year (only about 10 cm) of rain. |
Thousands of years ago that wasn’t the case. It was really hard to look around this incredibly flat, dry looking land and image enormous lakes and river systems all the way through. But during the Late Pleistocene (approx. 20,000 years ago) that is just what Mojave looked like. All the sand flats and what they call playas are in fact the preserved fossils of ancient lakes.
|So what happened to change Mojave from a wet, lake environment, to a desert? Mountains. During the Pleistocene there were mountain building events which pushed up a range of mountains through much of Nevada and California. The mountains changed the weather patterns. So, the lakes dried up and most of the animals living in this area either migrated or died out. The change in climate meant that the rains needed to recharge the lakes and the groundwater were heavily restricted and only small quantities of water could fall at a time. Pretty sad huh?|
|The afternoon was spent with the Sensetta Rovers. These little guys are awesome! The gents at Carnegie-Melon University have been playing around with these Rovers, testing their ability to navigate terrain, how far they can travel by remote and how the Rovers behave with different equipment attached to them. |
Because of their small size, the large size of their wheels and their excellent weight distribution, scientists have even been taking these little guys out onto crust surfaces to do photography. The Rovers can travel over the crust without damaging it. Which is very handy because we want to preserve as much of this stuff as we can. Some scientists even believe that desert crust is responsible for keeping the topsoil in place in these desert environments.