ALMA and San Pedro de Atacama

The astrowagon in the Atacama...

ALMA and San Pedro de Atacama!


As you know, we have left the VLT at Paranal ... and next on our itinerary are the Atacama Pathfinder Experiment Telescope (APEX) and the Atacama Large Millimeter/submillimeter Array (ALMA) near to the desert town of San Pedro de Atacama. So we set off once more in our astro-wagon for the foothills of the Andes...

ALMA finds early galaxies in the very young Universe!

So, to introduce these two incredible facilities... APEX operates only in the submillimeter range of the electromagnetic spectrum - the smaller wavelengths of light. It has a massive field of view, scanning the skies to find objects of interest in the Universe. One job of ALMA is to zoom in on objects found so that we can investigate them in more detail - it is the most ambitious and technologically advanced instrument on earth involving astronomical observations.

In case you're wondering what "millimeter/submillimeter range" means: it describes the size of the wavelengths of light. Using these instruments, we can see the cold matter in the Universe... the stuff which doesn't emit light and so it's not much of a stretch to say that APEX and ALMA help us to see things in our Universe which are invisible to the human eye! Boy was I going to remember this place…

The Observatory at the Tierra Atacama, our
heavenly basecamp for 6 nights at
San Pedro de Atacama!

Anyway a bit about San Pedro first: a bohemian town full of charm and backpackers! With muddy roads, dried under the hot desert sun and shops selling Alpaca jumpers and scarfs with a multitude of colours, tourists throng around planning desert adventures. As I arrive, it is dark and pouring with rain. I turn up one way dirt roads, get lost, am met by the local police who in no uncertain terms turn this gringo around… 2 hours later we find our hotel. After 7 days sharing a campervan with the film crew, I am about to have a bed to sleep in, a shower to wash in... could this be true?! We stay at the Tierra Atacama, a beautiful and eco-friendly hotel with a minimum-impact policy. Interested in our message of astronomy outreach and in our documentary, they offer us a deal which suits our charity budget, we can hardly believe it as we stroll through the gardens. We discover plants which they have grown in the deset soil... a small orchard, a vegetable garden and a medicinal herb garden as well as several fields of alfalfa and other crops. We swim in the infinity pool, gazing out at FIVE volcanoes. And I spot a little Observatory!

Next morning, we are well rested and off to ALMA however we were not expecting what happened next… the Atacama desert is the driest place on Earth and it very rarely rains: last time was 2 years ago, hmm and also the day I arrived! Not just the unlikely rain however - when we ascend to the summit 5,100m above sea level, we had a a blizzard, a total white out! I couldn't see a thing at all, there was a blanket of white, so we have a quick look around and see the 50 spectacular 12m diameter antennas and additional compact array of 7m and 12m diameter antennas. This is a little bit like seeing a 16km field of view into the Universe!

She said YES!!!

As the snow builds, we have to leave. But before we go, our executive producer Dr David Murphy chooses this spectacular and romantic location to propose to his girlfriend, and she says yes! We all celebrate before we head off... I was gasping for breath: at this altitude it is not easy to breathe and boy do you feel it. I especially at this stage am starting to feel quite low, exhausted from our filming schedule and the altitude. I have to admit I am even starting to crave coming home - so strange because I know this is the professional outreach project of a lifetime. I'm sure it's the altitude effects, but it's really hard...

Dr Andreas Lundgren

We hit base camp and meet some great scientists. I wake up enough to film interviews with some of them. Dr Andreas Lundgren is the Deputy Lead of the Programme Manager Group at ALMA and his PhD was in theoretical astrophysics. I feel slightly intimidated but Andreas was fantastic - approachable and fascinating. He tells me about the future of ALMA... the antennae will eventually spread out across the Chajnantor plateau, providing a large aperture instrument capable of seeing through the vast regions of cold dark gas: the gas which normally obscures visible light from objects like galaxies and star forming regions.

Base Camp at ALMA...with snow-topped
mountains in the background.

After a tour of the facility, we pause to get our breath back and some lunch we are met by Valerie who is a bubbly happy lady (a common theme happy people I mean…) who tells us that we are allowed to come back the following day to try again and visit the site, this time hopefully in better weather conditions!