What we are up to in Antarctica…

Katie Joy | 30 Nov 2019

If you have been following the blog for a while then hopefully you will have seen the growth of our Lost Meteorites of Antarctica project from its infancy through to having a team of four people deployed to search for meteorites in Antarctica. If you are new to the blog (welcome!) you can read down the a couple of posts ago to see Geoff’s overview of the season’s plans and how we got here for some background…

The Lost Meteorites project team 2019-2020 season: from left Katie, Romain, Geoff and Wouter rubbing the Magellen’s foot in Punta Areas for good fortune in fair weather!

The Lost Meteorites of Antarctica project is an interdisciplinary science investigation bringing together mathematicians, electronic engineers, cold weather specialist engineers and meteoriticists (scientists who study meteorite samples), working with a large team of amazing people at the British Antarctic Survey to help support us and deploy us out to our field site. You can find out more about the team here. Currently four of us (Geoff, Katie, Wouter and Romain) are based at Rothera Research Station, the British Antarctic Survey’s largest crewed station in Antarctica getting prepared to get out to our field site (more about life on the station in the next couple of posts).

You can find out more about the science of what we are up to by heading over to the Science tab and about the science of meteorites here (what do we hope to find from all the rocks we collect?). Having already recovered tens of meteorites (we estimate 36 at this stage*) from the surface of the ice last field season, the challenge is on to collect more this time around as well as trying to locate iron-rich meteorites that are buried within the ice.

Location of Rothera Research Station in relation to the South American peninsula and Punta Areas in Chile; our departure city.

Thanks to those at Rothera who are taking good care of us — from the chefs who are cooking plentiful amazing meals, to our field guides Taff and Rob who have been helping get our kit together and train us for what to expect, the doctors training us in field medical techniques, the field and science operation leads Al and Maz who are working hard to put together the logistics to get us out to the field and are drawing on the skills of weather observation and forecast teams to help understand when the weather is a go for launch…

We likely have about another week or so here on station to get our metal detection system checked out and to finish off our training before we transfer out to the field (although as always, with Antarctica field campaigns, anything is controlled by the weather, so we will wait and see what happens…).

** more on what we found last season later on… Our team back in the UK are working hard to prepare and classify the samples as the team down here are working on finding them more rocks to play with!

Visiting new field sites and a new skidoo

Katie Joy | 08 Jan 2019

We have been a week in the field now, with a few search days under our belts and three meteorites in the bag. It has been pretty warm here — in the last couple of days in the sun the air is between 0 and 5°C — really balmy with very little wind. There has been a mix of clear sunny skies and some high cloud as a system hangs around the area. When it clouds over here we lose contrast on the snow and ice surface and it becomes difficult to navigate between icefields. When it was cloudy yesterday we did a bit of a foot searching along the edge of our local icefield to see if we could spot any meteorites. We donned our boot chains to stop us from slipping around on the ice surface, when the sun shines there is a layer of water that starts to form on the surface making it very slippy. However, the recent snowfall from last week (or perhaps earlier in the season) has lightly covered up the surface in this particular spot, making it very challenging to spot much exposed surface blue ice and meteorites.

Taking in the field site [Credit: K H Joy]

We ventured further afield on Sunday, driving up to a large well-exposed (no snow cover) ice area close to a small nunatak (exposed mountain top) where we discovered our first meteorite samples of the season. Whoop whoop! When the sun shines and there is no wind and there are meteorites it is a pretty great day and it feels good to demonstrate that we are visiting meteorite stranding zones.

Meteorite and skidoo [Credit: K H Joy]

Alas later that afternoon we also had some skidoo issues, and despite some great remote trouble-shooting from the Halley and Rothera mechanical teams, and some in-field mech action from Julie, we needed a replacement, which arrived today. Thanks to all for the amazing response and helping get a new one out to us so quickly, and for Mark and Robbie for flying in the new ride and taking out the injured ‘doo’ (and for bringing in some fresh food!). Goodbye unlucky number 13, and hello number 11 — may you drive well for the rest of the field season. We plan to get back to work tomorrow and drive out to a new icefield — fingers crossed for some more meteorite discoveries and hopefully there won’t be much surface snow where we plan to visit.

It is amazing to live (albeit for a short time) in such a remote place — when there is no wind and you are lying in the tent at night it is so quiet and warm in the sleeping bag it is pretty hard to imagine that we are in the middle of Antarctica really (apart from being able to see your breathe as the tent cools down). We are eating well — are working our way through different types of rehydrated food options (sweet and sour chicken last night) and are trying to keep up with some of the comforts of home through improvised barista coffee making (it doesn’t work that well to be honest!), chocolate bars, and evening games.

Coffee making attempt [Credit: K H Joy]

PS Thanks Barbara for the Christmas present which was delivered to Julie in field today.
PPS Thanks Jess for the Rothera news in your letter 🙂

What do we want to do with the meteorites we find?

Katie Joy | 04 Jan 2019

Whilst we sit and wait for the weather to improve in the field it gives a good opportunity for a sciencey blog post about the meteorite science side of the project. If you take a look over at the main ‘Science’ tab and follow the links to the ‘Meteorite Science’ tab it should give you some background information about why meteorites are scientifically important.

As an overview — meteorites provide us with direct samples of other rocky Solar System bodies, and, therefore, we can use them as probes to answer lots of different questions about how our Solar System formed and changed with time. The type of question we ask depends on the type of meteorite that we are studying and the lab equipment that we can use. Hopefully, any samples we find will be worked on by lots of different scientists in the meteorite community who are specialists in their particular meteorite group or laboratory method. Some questions we can ask of meteorite samples include:

What types of stars existed in the local area before our Sun formed?

Tiny (micron-sized) mineral grains trapped within very primitive dusty meteorites provide hints to what was happening prior to the Sun forming. These presolar grains — often made of minerals like diamond and silicon carbide — are chemically distinct from any of the material we have found within our own Solar System. These chemical (isotopic) anomalies can be related to how these grains formed in other stars, before they were included in the starting materials of our own Solar System.

How old is the Solar System?

We can date the earliest minerals that formed in our Solar System using a range of mass spectrometry isotopic techniques. This technology means that we have a very good precision on the timing of the oldest solid materials to form around our Sun. These grains — called calcium aluminium inclusions — are found in carbonaceous chondrite meteorites and have ages of 4567 million years old (4.56 billion years). This is the reference point we have for understanding the timing of other major events that occurred like the formation of the planets and the Earth itself.

What types of planetary bodies existed early on in the Solar System at the time the planets were forming?

Meteorites provide us with an insight to the diversity, size and number of the earliest formed planetesimals (small planetary bodies) that would have grown through run away collisions to form larger bodies. Recent estimates suggest that the 60,000 or so meteorites we have in the collection originate from only ~110 parent bodies (mostly asteroid-like), when you relate different groups together. We know that some of these parent bodies represent the very earliest assemblages of dust that first formed around the Sun (take a look at the Osiris-Rex space mission and Hayabusa-2 mission that are currently en route to these types of asteroids ready to collect material to return to the Earth, others have come from bodies that must have been larger and were heated from the inside out by radioactive decay-driven heating. Some meteorites are completely unique examples of potentially quite large parent bodies that must have been >200 km in size and melted completely to differentiate into an iron-rich core, a silicate mantle and a silicate crust. These bodies may have remained intact to still exist as large bodies in the asteroid belt (we think that a group of meteorites likely originated from a very large asteroid called Vesta), others were smashed apart leaving smaller asteroids formed of just a part of an original larger one (the NASA Pschye mission hopes to visit an asteroid we think is made of iron-metal, like the iron meteorites we have in the sample collection, formed from a core of an early planetessimal body). Every meteorite we find has the potential to come from a previously recognised rocky planetary body, giving us the motivation to keep on collecting and studying the populations of bodies that exist in the asteroid belt and those bodies that have broken apart early in the Solar System’s history.

How did the Earth get its volatiles including water?

One of the big questions we have is how did the Earth form, what were its starting materials, and why is it similar and different to the other large rocky Solar System bodies (Mercury, Venus, the Moon and Mars). Meteorites help to chemically constrain the starting materials for the Earth, although we have no perfect chemical match to known meteorite groups — there is similarity to some of the enstatite chondrites, but we also need contributions of other starting chondritic groups as well. We also know that different asteroid groups likely later delivered some of the Earth’s highly siderophile element chemical component and also likely some of its volatiles (water and other elements) to help form our planet’s atmosphere and hydrosphere. We can compare and contrast the chemical makeup of the different meteorite groups to understand how much of Earth’s chemical budget is original, and how much has been added early in its history.

What is the geological history of the Moon?

We have about 300 stones of lunar meteorites that originated from the Moon. We know they are from the Moon as they are chemically similar to the samples that were collected by the Apollo missions. Each one potentially provides us with a new region of the Moon to study and has allowed us to identify new types of rock samples, and help test our ideas of how the Moon has geologically evolved through time. We have some meteorites that were formed very early on in the Moon’s history, others than were made in impact cratering events and some that were formed in volcanic eruptions.

What is the geological history of Mars?

To date we have not yet collected any Mars rocks by sending a spacecraft there and returning it to Earth (there are sample return missions planned for about 10-15 years’ time). Therefore, martian meteorites are our most direct way to investigate Mars’s past. We know that this group of samples come from Mars as the gas trapped within them matches that measured by orbiting satellites and the Mars Curiosity Rover. Most of the martian meteorites we have were formed in volcanic eruptions that occurred on Mars’s surface about 600 million years ago, and we have some older intrusive magmatic examples as well. One special meteorite — nicknamed Black Beauty — found in Northwest Africa, gives us insights to Mars’s volcanic and impact evolution over a very long period of time from before 4 billion years ago to as recently as 1.1 billion years ago.

In addition to these planetary science questions – meteorites in Antarctica can also provide an indication of the history of the ice flows they are sitting in, and give a constraint on the age of the ice itself. This allows us to potentially use meteorites as probes of very recent terrestrial cryosphere processes, allowing us to understand the history of Antarctic glaciers and ice flow movement.

Avoiding the Italian Job

Geoff Evatt | 19 Dec 2018

At the end of the Italian Job, the looted gold is left at the rear of a coach that dangles dangerously over a precipice; tangentially close, yet also so far away: “Hang on boys, I’ve got an idea….”. Well, I too have had an idea. Chainsaws. OK, so that might not have helped Michael Caine in his predicament, but hopefully it’ll help us should we locate any englacial meteorites.

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Essential course material: chainsaw, underlying theory, vape… [Credit: G W Evatt]

To be ready for sawing out some meteorites in a year’s time, I will give it a practise this coming January down at the BAS base, Sky-Blu. (the chainsaw bar length is 40 cm, the meteorites could be 50 cm deep: hmmm). And before I can even practise in the field, I was sent on a chainsaw course on an industrial estate in Chesterfield. Yes, it was a long long way from Antarctica, but it was freezing and the corrugated iron all around had a certain monotonous colouring, so maybe that will all come in useful. More importantly, I learned a lot about fixing basic chainsaw issues, how to sharpen chains, and how to cut logs the correct way (I’ve done a reasonable amount of chainsawing at home, but now I know sooo much more). The course instructor, James, also gave good suggestions as to how to cut ice and deal with the cold. In short, I feel much more prepared and confident about using the saw down there.

2018-12-04_10-32-06 chainsaw training GWE small
Tools of the trade. [Credit: G W Evatt]

And what if it’s a total failure (as in does not let me extract lumps of ice)? Well, I’ve also sent down a farm-shop of ironmongery, saws and ice drills. Between these, I hope that we will find an efficient method that allows us to extract any iron meteorites we detect. After all I want be prepared and confident, and we don’t wan’t to face any Italian Job conundrums….

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Practising for Antarctica [Credit: G W Evatt]

PS For those of you really into their chainsaws, I’ll be using battery powered DeWalt one. Whilst it cut the Chesterfield logs very effectively, it may be a totally different matter in the cold, in which case I’ll have to opt to using a petrol one instead next season.