Atacama Desert

The Atacama desert in northern Chile is known for the best stargazing in the world – and that’s why I HAD to come here. Ironically, I came during the two weeks of the year when it was cloudy and I didn’t get to do proper stargazing (other than a few minutes before the sunrise one morning.)

But, the sunsets!!! Even if I didn’t get to see the other suns of the universe, I got to see OUR sun in all its glory!

The dry desert air makes the incredible landscapes look exceptionally majestic and brilliant, and with a setting sun sending gold in all directions and casting deep blue shadows while tinting the clouds in pink, one will stop whatever she or he’s doing and run to catch the sunset every evening.

All the sunsets were awesome, but the most incredible was definitely in Laguna Tebinquinche*, where the sun set over the white, salt-covered lake and a rainbow emerged in the dark blue rainclouds opposite the sun.

Like many lakes here, the water appears to be covered in a layer of ice but is actually encrusted with a layer of white salt. The lakeshore is filled with “living rocks,” which are salty rocks made up of minerals and microorganisms that can survive some of the harshest environments on the planet. These microorganisms are some of the first living things that came into existence on Earth!

Contemplating the first life on earth, a flamingo flies across the sunset. And with friends made along the journey, we marvel at the beauty of life, the richness of the moment. We all just met each other, and yet we’re all family, born from Mother Earth, who is amazing us with her beauty.

But I digress. Being immersed in this vast desert, looking out across immense spaces and also out into the vast sky, makes one reflect on the grandness of the Earth, the universe, and the beauty of life.

While access to sensitive spots is limited to protect them, there was one salt lake that people can swim in. If you have never swam in a salt lake before, it’s definitely worth adding to the bucket list. Because salt water is more dense than fresh water, the saltier the water the more we float. I noticed the difference swimming in the Pacific Ocean in Lima, but it still didn’t compare to the unique sensation of floating in the salt lake in Atacama!

Look Ma! No hands!

When a large moist area of salty land has dried up, a salt flat (“salar”) is left behind. I saw many salt flats, with the the Salar de Atacama being the 3rd largest salt flat in the world (after those in Uyuni and Argentina). It is so large it can be seen from space.

I was lucky enough to see a few other marvels of the desert during my stay in Atacama, the most grandiose being the National Reserve of the Flamingos (Reserva Nacional de los Flamencos). At 4,200 meters (13,800 ft) above sea level, we saw two beautiful mountain lakes that used to be one great lake until seismic activity of the Nazca and South American tectonic plates created some hills that divided the lake in two.

Another breath-taking desert lake is the laguna aguas calientes. Here, the diversity of the landscapes was overwhelming. There were huge dune-like mountains of black lava rock, a lake of hot water fed by an aquifer that sits on top of a volcanic magma layer, and red hills rich in iron minerals. All accented by the pink flamingos looking for food in the lake below.

 

 

 

Finally, the bike ride through the Valle de la Luna was a challenging adventure through the desert heat, where we met friends along the way, saw incredible rock formations, and watched rain develop across the flat desert plains – the same rain that cooled us off a few hours later.

One final fun fact. The Atacama desert is located on the tropic of capricorn. I’m pretty sure I learned about the tropic of Capricorn at some point in my life, but I didn’t really remember what it was. The tropic lines are the points where the sun shines directly overhead, due to the tilt in the Earth. The regions of land between the two tropic lines are considered “tropical” areas since they receive the most direct sun, typically creating warmer year-round climates than the rest of the globe.

Our guide explains the tropic lines with a drawing in the desert sand. The sign marks where the tropic of capricorn passes, which also happens to be a part of the Inca Trail.

 

Famous Footnotes

Unless you rent (or have) a car to go see the sites (which would be a great way to explore Atacama), the way to see things is through the tours offered by the various tour companies in San Pedro de Atacama. The tours I took were:

-Tour 1: Laguna Cejar, Laguna Piedra (the salt lake where you can swim and float), Ojos del Salar, and Laguna Tebinquinche (the salt lake with the amazing sunset).*If you take the tour of Laguna Cejar in the afternoon, it usually ends at Laguna Tebinquinche so you can see the incredible sunset here.

-Tour 2: Reserva Nacional de los Flamencos (Laguna Miscanti and Laguna Miñiques), Laguna Talar, and Salar and Laguna Aguas Calientes with overlook to Piedras Rojas

-Observatory ALMA tour (free but you have to get to the meeting point early to get on the list, as I described in my blog post.)

-I rented a bike and rode through “Valle de la Luna” all day (about 6 hours), and another afternoon I rode through “Valle de Marte” and watched the sunset from an overlook point nearby.

**I didn’t get to do a stargazing tour because of weather, but would definitely recommend one!

**I didn’t get to do the geyser tour because rain had washed out the road, but would also recommend that!

 

ALMA – Not a Typical Telescope

The Atacama desert is the driest and highest in the world, and that’s one of the main reasons that we built “ALMA,”* the largest radio telescope in the world here! I say “we” because it was an international collaboration – an example of us humans working together to better understand the universe in which we live.

“The purpose of ALMA is to study star formation, molecular clouds and the early Universe, closing in on its main objective: discovering our cosmic origins.”

To most of us, a telescope is an apparatus of lenses pointed at the sky to see stars, (or far away visible light in the sky). But the ALMA telescope is not one, but 66 antenas pointed at the sky! Just like we have 2 eyes that give us a single image of the world, the telescope has 66 eyes to give us a single image – it’s like a mom that has eyes in the back of its head. Or like a fisheye camera.

The other unique thing about the ALMA telescope is that it isn’t viewing light in space like an optical telescope, it’s looking at the dark and cold part of space, capturing radio waves* emitted by stars and planets.

One of the antenas undergoing maintenance

That doesn’t mean that stars and planets are broadcasting songs. Radio waves are emitted by the cold and cool matter in the universe that doesn’t give off light and so can’t be seen with our eyes (or with optical telescopes). But the ALMA telescope can receive these signals and tell us about that matter out there in space.

For example, the ALMA telescope was able to detect sugar molecules around a young sun, indicating a good possibility for a life-supporting planet to develop in that solar system.**

In some cases, scientists can combine the information from an optical telescope and ALMA (and x-ray and infrared telescopes)* to give a fuller picture of a solar system or galaxy, and to “see” what’s happening in the dark spots of the sky.

Also, since it’s not optic, ALMA can point at the sun and study the sun’s atmosphere without burning.

For me, one of the most interesting abilities it has is to study the early universe – it has found evidence of the earliest known solar system – suns that formed just 250 million years after the Big Bang. (Sounds like a long time, but it’s only 2% of the universe’s current age, which is about 13.8 billion years.)

I know, this is a lot of high tech modern science stuff. But according to our guide, the basic principle behind the antena design is actually something that was used hundreds of years ago by the pre-Incan culture, the Tihuanacu.

Just outside of La Paz, you can visit an archeological site of the Tijuanacu. Then you can head a thousand miles south to the ALMA observatory in northern Chile to see the modern day use of this technology studying the origins of the universe!

While the tour to the observatory is free, it takes a bit of luck to get there. To be on the official list you have to reserve online, usually 6 months to a year in advance. If you don’t make the official list, you might be able to get on the online waitlist. But since the list fills up so far in advance, a lot of people on the list end up not making it on the dates they reserved. So you still have a chance to get on the “hope list” the day of the tour. The bus leaves at 9am, but people show up sometimes 2 hours early to wait in line to be on the “hope list”. If there are any empty spaces from people who didn’t show up from online reservations, next priority goes to the wait list and then to the hope list, in order of arrival. It makes it that much more exciting to get chosen from the hope list! It’s like winning the lottery!

Famous Footnotes

*The ALMA – Atacama Large Millimeter/submillimeter Array – captures electromagnetic radiation with wavelengths in the range of milimeter wavelenths in the electromagnetic spectrum.

(There are also other non optical telescopes that exist- infrared and X-ray telescopes that capture information from other non visible light parts of the electromagnetic spectrum.)

**https://www.almaobservatory.org/en/press-release/sweet-result-from-alma/