The Most Powerful Alien-Hunting Telescope on Earth Is Now Operational
Chile's Very Large Telescope, or VLT, added the ESPRESSO instrument last December, and it achieved first light.
The VLT's combination of four individual 8.2-meter telescopes, each with a mirror quadruple the size of an average human, was an impressive enough feature despite not reaching full capacity. The addition of ESPRESSO, a spectrograph that uses radial velocity and transit detection to find the invisible signatures of exoplanets, was more impressive still.
Now, the European Southern Observatory's VLT has finally used the combined light of each telescope for the first time. This means that the VLT is now the largest optical telescope in existence, with regard to the vast areas of space it covers. And with the ESPRESSO, it will reach the full potential in reading the universe for signs of life.
Though space for this calibration of all four telescopes was built into the underground mountaintop structure of Northern Chile's Cerro Paranal from the start, the combination of all light from all four telescopes, or "incoherent focus", was not part of ESPRESSO's initiation due to the complexity of the process.
"Stars and their exoplanets are bound together by gravity: an exoplanet orbits its distant parent star just as the planets of the Solar System orbit the Sun," explains the ESO about how ESPRESSO works. "But a planet in orbit around a star exerts its own gentle gravitational pull so that the center of gravity of the entire system (the barycentre) is a little away from the center of the star and the star itself orbits about this point. This regular movement of the star along our line of sight creates a tiny shift in the spectrum of the star, through the Doppler effect. This minute effect can be detected by very sensitive instruments and is the evidence for the presence of a planet that can then be further studied. This tug of war between stars and their exoplanets can be seen (or rather, measured) by ESPRESSO."
Now quadruple that.
Suffice to say, a newfound vastness of area from which to collect data also opens up boundless possibilities in ESPRESSO's search for alien life, gazing up at the dry, clear skies of the Atamaca desert.
We've already uncovered to many potential new worlds, from the thousands of exoplanets that were discovered earlier this year using gravitational microlensing to the discovery of a whole system of Earth-like, habitable planets called Trappist-1.
The ESPRESSO spectrograph now operating at full capacity also means we'll be able to find many more such systems with similar biosignatures and atmospheric conditions to the Trappist-1 exoplanet suggesting that they have a capacity to sustain alien life. Hence, were closer than ever to solving the question as to whether or not we are alone in our universe.