In October 2017 Katherine Joy and Romain Tartese from the DEES Isotope Group joined a joint French-Chilean led expedition to the Atacama desert in Chile to search and recover meteorites that will be used for scientific analysis. You can read on our past blog of the significance of why we search for meteorites in the Atacama desert. We have just come back from another fieldtrip to the same regions of the Atacama, where group PhD student Javeria Villalobos-Orchard (you can read more about her research here) joined the team.
2019 Fieldwork: The expedition was organised by Jerome Gattacceca from CEREGE and Matthieu Gounelle from the Natural History Museum in Paris, and field party members came from a range of universities and institutions across France, Germany, Belgium and the US. This year, 13 of us spent 9 days in the field and collectively recovered over 700 meteorite stones! These ranged in size from a cm or so, up to a monster ~20 cm diameter stone, and a collection of tens of stones from the same meteorite scattered over a ten metre radius that that we nicknamed the pinata meteorite. Several of the recovered stones are likely paired with each other, representing different fragments of the same parent meteorite that exploded and scattered debris across a strewn field. Several others have more diverse origins representing different meteor entry events. Some may be related to those samples we helped collect in 2017 and on other meteorite recovery trips, and some might be completely unique. The recovered meteorites will now undergo formal classification and be made available for research to test all these different possible origins.
Fieldwork life: The lifestyle of a desert meteorite search team is a lot of fun – we live in the desert, staying in tents, and cooking big one pot meals over an open fire all together. The food is delicious, especially considering we have no mod cons. Every few days we visited a nearby coastal town to take on supplies and have a shower to clean the every present desert dust out of hair (this is a very welcome break after the extreme dryness). The desert itself is an achingly beautiful place to work and live with spectacular Mars-like vistas and rare desert animals (lizards, fox) and birds (vultures). The night’s sky is clear, this year affording us good views of the southern-skies with the Moon, Venus, Jupiter and Saturn shining brightly.
VLT Telescope visit: One of the many highlights of our trip is that we were given a guided tour of the European Southern Observatory’s Very Large Telescope at Paranal. The telescope is located high up in the Atacama to make the most of the mostly exceptionally clean and clear skies (limited cloud cover, limited light pollution from towns).
The Paranal site is made up of a service area to maintain parts of the the telescopes, a scientists living area (which notably featured in a Bond film!), and the telescope sites and control centre. The main site is on top of a flattered hill – an incredible engineering effort to build – and houses four 8.2 m optical telescopes and four smaller 1.8 m auxiliary telescopes. Each telescope has its own set of experiments, designed by consortia in different countries, and tailored to address a range of science questions. The telescopes can work in combination with each other as an array (known as interferometric setup), or work independently to undertake astronomical observations of remote galaxies, effects of black holes, star-forming regions, exoplanets orbiting around other suns, and even the distant planets in our own Solar System. One of the large 8.2 m telescopes has a state-of-the-art optics system, called adaptive optics, to automatically adjust for effects caused by the atmosphere. Scientists can request observing time through a competitive review process, and either visit the site themselves, or are sent their data by a local team of telescope astronomers.
Our tour included visiting the facility to help recoat the telescope mirrors – amazingly they are removed every few years (and driven a few km down a road…) to be cleaned and recoated with a very very thin reflective aluminium coating. We also went inside one of the telescopes whilst it was being setup for the evening’s observing – seeing the tests of its tilting and rotating mechanism. The tour of the command center gave an insight to the amazing amount of work undertaken to operate and coordinate the science planning for every night of observations.
From the main telescope site, we could see the 40 odd kms over to the location that will house an even bigger telescope – the Extremely Large Telescope, planned to be operational within about 5/6 years time. The already flattened site will be similar in size to Paranal, but will house one enormous 40 m telescope. Scientists will travel to work there each day from the current Paranal site, which will be expanded to accommodate the extra workers.
Many thanks to the local staff who helped organise and deliver the tour – it was a huge privilege to visit to see this incredible international collaborative science centre.
Some relevant research papers about meteorites in Chile:
- Gattacceca et al. “The densest meteorite collection area in hot deserts: The San Juan meteorite field (Atacama Desert, Chile)”
- Muñoz et al “The Atacama Desert: A preferential arid region for the recovery of meteorites—Find location features and strewnfield distribution patterns“
- Hutzler et al. “Description of a very dense meteorite collection area in western Atacama: Insight into the long-term composition of the meteorite flux to Earth”
- Drouard et al. ” The meteorite flux of the past 2 m.y. recorded in the Atacama Desert”
Want to know more about searching for meteorites? You can follow the UK Antarctic meteorite hunting team at https://ukantarcticmeteorites.com/blog/. You can also follow the current US ANSMET eam blog via the ANSMET website at http://caslabs.case.edu/ansmet/