Something exciting is happening in Northern Chile. The most precise spectrograph ever built is about to start a very big project: searching the universe for planets that may contain signs of life. This spectrograph, called “Espresso” is 10 times stronger than its most powerful predecessor. It will be installed in the Atacama desert, in northern Chile, where it will be connected to four super large telescopes simply called ‘Very Large Telescopes” or VLT’s. Together they will scour the skies for exoplanets - are planets outside our own solar system. Their mission: to find planets similar to Earth.
Deserts cloudless skies calling
To complete such a mission you need very clear weather conditions that the Atacama Desert can provide. It has clear skies almost all year round. The VLTs will be joined by an increasing amount of space observation groups. By 2020 the cloudless desert will be home to approximately 70% of the world’s astronomy infrastructure. The Espresso machine, which stands for ‘Echelle Spectrograph for Rocky Exoplanet and Stable Spectroscopic Observations’ will measure the light coming in from stars observed by the VLTs and use this information to look for evidence that there are planets orbiting them. Not only can this powerful machine look for planets it’s able to sift through a lot of information about them to determine what their atmosphere is like. By processing the light data Espresso is able to determine whether these planets have oxygen, nitrogen, and carbon dioxide present and even more importantly whether there is water. The right combinations of these gases are the building blocks for supporting life. "Espresso will be available on all four telescopes at once, which is something that had never been done before. That means the likelihood of finding planets similar to Earth in mass and size, or the conditions for life, are greater," said Italian astronomer Gaspare Lo Curto.
Ten years in the dark
Espresso’s predecessor is also located in the Atacama but the instrument, dubbed HARPS HARPS (High Accuracy Radial Velocity Planet Searcher), could only measure planets that are larger than Earth. Scientists believe a planet smaller than Earth will more likely be a host to life. HARP was also receiving data from a much less powerful telescope than the VLTs. "Espresso will be 10 times more precise than the most precise instrument in the world, HARPS, and will also have the flexibility of serving each of the telescopes at the Paranal observatory," where the VLT program is housed, said Lo Curto. The telescopes and Espresso are run by the European Southern Observatory (ESO). Espresso is located inside a giant metal cylinder, which is chilled to an average temperature of -150 C (-238 F). The cold temperatures are required for the precise instrument to be able to work consistently for long periods of time. Espresso is currently in testing phase and will begin its mission in approximately 10 months time. Once up and operating the machine is expected to be locked in its climate-controlled room without disturbance for at least a decade.