Caroline, Friday, November 10th, 2006
For the next few weeks Gretchen and I will be working on other projects until the Nullabor meteorites arrive here at the Museum. We are expecting them before the end of the year, so will begin classifying them in 2007.
Gretchen, Wednesday, November 8th, 2006
Caroline and I had our day at Buckingham Palace last Tuesday, sharing a stand with our colleagues Liz and Frances, who were talking about volcanoes, and Sally from Learning who was there to do some practical demonstrations.
As expected the security at the Palace was very tight. Most of the equipment and samples had already been shipped to the Palace, but all of our boxes with samples and equipment had to be x-rayed on the way in.
We took lots of meteorites with us, as well as volcanic rocks that the visitors could handle and some of our special samples including two Martian meteorites.
In addition to our rock samples, we also brought a largish cut-away model of a stratovolocano, which Liz and Frances used to explain where their mantle xenolith samples were coming from in the earth.
We also had microscopes which people could use to examine a thin section of rock, 3-D glasses to look at an image of crater made by a tiny meteorite (called a micrometeorite) in one of the Hubble Space Telescope Solar Cell panels while it was in orbit around the earth, and of course there was the chance to hold some meteorites.
We also took part in a mini-Nature Live on how we hunt for meteorites.
Sally was a big hit with the crowds. She was using custard powder to demonstrate how the rock that lies between the crust and mantle of the earth behaves!
There were lots of VIPs, including the Duke of Gloucester and Duke of Kent, and the evening included a reception with the Queen and the Duke of Edinburgh, amongst a variety of scientific VIPs (including Stephen Hawking).
We had a great time, and leant a lot, as I hope, did the visitors!
Gretchen, Friday, October 20th, 2006
Each time we find a fresh meteorite, we record its position in latitude and longitude using a Global Positioning System (GPS). The biggest meteorite we’ve found is about the size of a small apple and the smallest about the size of the tip of my thumb.
We then make a preliminary guess about what kind of meteorite each one might be.
There are three main types of meteorite: Stony, Iron, and Stony-Iron. All the ones we’ve found have fallen into the Stony category. We can tell this by their weight - slightly heavier than an Earth rock of the same size - and also because theyâ€™re not very magnetic, unlike the many meteorites which contain some metal and so have some magnetism.
We’ve found two different kinds of Stony meteorite in our search. The first type, ordinary Chondrites, are quite common and come from asteroids that have been only slightly heated, and not melted.
The other type, which we found at Camel Donga, are called Eucrites (a type of Achondrite). These come from an asteroid that had melted and differentiated - like the Earth - into a core, mantle and crust. These Eucrites are thought to come from the crust of a specific asteroid - 4 Vesta. This type of meteorite is much more unusual, so we were happy to be able to find several pieces of this one.
There have also been some meteorites about which we’re not quite sure, so we’re going to have to wait until we get them in the lab to determine what kind they are.
After our preliminary assessment, we’ll put the meteorite into a bag, label the bag with a field number, the date it was found and the area.
We’ll take the meteorites to the Western Australia Museum, where Alex will give them numbers, then cut off a portion of each meteorite to send to the Natural History Museum where Caroline and I will classify them when we get back.
Caroline, Thursday, October 19th, 2006
We were up bright and early today at our usual getting-up time of about 5.15am. After we had breakfast and got the camp ready we left for more filming and meteorite hunting around Camel Donga.
All of the meteorites here are related to each other and came from the same parent meteoroid, which broke up as it came through the atmosphere to form a shower of stones. These stones are scattered along a line about 7km long, which is known as a ’strewnfield’.
We started our usual searching method, where we go in a line spread over approximately 50m and walk along together, searching the ground in front of us and between us.
We were feeling confident and very soon after starting we found some lovely tektites. After about half an hour the BBC turned up to do more filming with Phil. I stopped to have some water and glanced down and I couldnâ€™t believe it, I was standing just next to small piece of Camel Donga, the first one we found that day! Even with the breaks for filming we managed to find eight pieces of Camel Donga and quite a few tektites so we were really pleased.
Gretchen, Tuesday, October 17th, 2006
Setting up camp in the Nullarbor desert is a whole new experience. We sleep in â€˜swagsâ€™ - single person tents which come with a three-inch thick mattress, so even sleeping on the ground is comfortable. Putting the swag on a camp bed is a whole new level of luxury! The swags also close up completely to prevent bugs from coming in to say hello.
Phil generally digs a fire pit while Caroline, Martin and I gather wood from the local trees (although Nullarbor technically means ‘no trees’, there are still a few hearty ones around that we can tap for fires). These are dead trees and they come apart easily by hand.
To make dinner we use an iron ‘plate’, half of which is a solid piece of metal and the other half of which is a grill. Frying is done on the solid side, while the grill side is used for boiling water and cooking in pots.
The BBC filmed us setting up, and also had Iain help us for the documentary. The picture shows the finished product with our swags unrolled.
We tend to get to bed around 8pm, in part because we’ve worked a hard days work, but partly because we also get up with the sun, which rises around 5am. Itâ€™s fantastic to see the stars in the southern hemisphere. We’ve now seen the Milky Way, as well as the small and large Magellanic clouds, which are not visible from the northern hemisphere. We’ve also seen Mercury and Jupiter.
Caroline, Sunday, October 15th, 2006
We left Forrest and set off with the BBC team to a place called Camel Donga, our next meteorite collecting location. Camel Donga’s only a couple of hundred kilometres from Forrest, but it took us a while because the BBC were doing quite a bit of filming along the way. It was VERY hot, over 40Â°C, with strong, hot and dry winds coming from the north.
The BBC took lots of footage of us driving the 4-wheel drives, as well as filming us actually hunting for meteorites. Camel Donga is a great place to look for meteorites. In the mid-1980s there was a large fall of eucrite meteorites here - about 25 kg have been found so far. These are called Camel Donga meteorites after the place where they fell. Iain Stewart, the BBC presenter, actually found a meteorite while we were filming! They can be quite hard to spot, even when youâ€™ve been looking for a while and have got used to the terrain.
We were all very tired by the end of the day, and tried to get as much sleep as possible although it was difficult as it was still very warm.
Caroline, Friday, October 13th, 2006
We’ve been travelling quite a bit through the desert. The roads aren’t that bad (relatively speaking)! There are patches where we can get up to 30mph, but most of the time it’s quite rocky and we try to keep it under 20mph. We’ve seen a whole variety of wildlife, including camels and dingos.
There are also lots of kangaroos, but it’s difficult to get a reasonable picture because they always start to run away any time they see the cars within a couple of miles of them! They are weird and interesting to watch as they jump along. Theyâ€™re very speedy, but it does look like a tiring way to get about.
We’ve now arrived at Forrest, where we’re meeting up with some BBC people who are filming a documentary. Forrest is an amazing place, with an airstrip and six bungalows where people can stay. Darryl and Lynn, who run the place, also provide meals and sundries. Forrest even has postal services â€“ a rare find in the middle of a desert.
Tonight we’ll sleep in real beds and we’ve all had a shower - just the most amazing thing after you’ve not had one for a few days. Tomorrow we head out again, with the BBC people who’ll be filming along the way.
Gretchen, Wednesday, October 11th, 2006
Heading into the Nullabor from Kalgoorlie, we ran out of paved road within about a half hour, but the road had a pretty good surface and surprisingly we could move at a pretty fast clip - until we popped a tyre.
No one other than Phil had experienced this while driving. When the tyre popped there was a slight pull, followed by a noise that sounded exactly like a 747 landing. We stopped and saw the very flat tyre. The hardest part was getting the spare off the roof, and the sandy ground didnâ€™t help. But in a bit we were on our way again â€“ until a tyre popped on the other car. In all it took about six hours to get to our first stop.
The next day, we headed off to camp further into the desert to begin our meteorite hunt, checking one of the cameras in the Desert Fireball Network on the way. The hardest thing when looking for meteorites is to get your eye acclimatised to the local rock types, so you can spot the meteorites â€“ rocks that donâ€™t fit in with the local rocks.
Caroline was the first to find a meteorite, within about 30m of the camp. We walked about another 2km before turning around, but didnâ€™t find any more meteorites, only kektites (pieces of glass from impactors that hit the Earth and launch molten earth rock into space, where it canâ€™t escape gravity and falls back down). We did find lots of â€˜meteowrongsâ€™ though, meaning we are recognising things that look a bit out of place but are the local rock!
The following morning was spent searching for meteorites systematically in a line. We went out about 1.5km before turning around and heading back to the cars. The whole thing took over two hours because we have to walk fairly slowly, but we did find several meteorites. Then, in the afternoon, we found more by going out in pairs and searching in a much more random pattern.
That night we had a fabulous dinner to celebrate Martinâ€™s birthday. The fridges weâ€™ve brought give us some opportunity to have fresh fruit and vegetables, and we had roast lamb, potatoes and onions. Delicious! The wind was blowing a gale and the clouds were gathering, which made eating the dinner interesting - we had five minutes to eat it while it was hot!
Caroline, Tuesday, October 3rd, 2006
Yesterday was a national holiday to celebrate the Queen’s birthday, so Kalgoorlie was very quiet. We went to the DIY warehouse to buy more equipment for when weâ€™re in the desert. We need a huge amount of jerry cans â€“ not just for petrol and diesel but for water, because we have to bring enough to cover all we need for drinking and cooking.
Today started very early, with all four of us catching up on email and other work-related items back in the real world.
We then went and picked up our second car. This one’s a ‘ute’ â€“ a 4WD that has an open bed in the back for carrying our massive supply of the jerry cans.
The town was much busier today and we could begin to understand that this really is one of the major towns in Western Australia. We went shopping for food for our trip, and then spent a lot of time organising and packing everything. We even had to pack all of our vegetables individually in newspaper to help to stop them bruising and going rotten.
We’ll be starting off early tomorrow for our five hour trip to Kanandah, our first location out in the Nullarbor!
Caroline, Friday, September 29th, 2006
This dramatic image was taken by one of the cameras in the Desert Fireball Network that we’ll be visiting in the Nullabar. The white streak across the bottom of the picture is a meteorite fireball, shooting across the sky in the middle of an electrical storm. Less than ten of the 32,000 or so known meteorites have their falls recorded by camera or video.
As well as looking for meteorites, one of our most important tasks will be to check that the cameras are working correctly, and fix any problems that we find.