Science & Astronomy

New French Telescope Trio Will Scan the Sky for Earth-Like Planets

The ExTrA telescopes at ESO's La Silla Observatory in Chile will be used to locate and analyze Earth-size planets orbiting nearby red dwarf stars. ExTrA's new design allows for greater sensitivity compared to previous searches. In this nighttime image, the ExTrA three domes are seen under a beautiful sky featuring the constellation Orion (the Hunter) and the Pleiades star cluster. Original Image
Credit: Petr Horálek/ESO
There's a new exoplanet-hunter in town.

Three new telescopes at the La Silla Observatory in northern Chile successfully peered into the night sky for the first time, providing scientists with a new tool to search for light signals from distant worlds.

The French-led ExTrA (Exoplanets in Transits and their Atmospheres) project will help scientists look for moments when the light coming off small "red dwarf" stars is subtly dimmed due to planets passing in front of them (as seen from Earth), according to a statement from the European Southern Observatory (ESO), which manages the La Silla Observatory. [The European Southern Observatory's Greatest Observatories]

The ExTrA telescopes at ESO's La Silla Observatory in Chile will be used to locate and analyze Earth-size planets orbiting nearby red dwarf stars. ExTrA's new design allows for greater sensitivity compared to previous searches. In this nighttime image, the ExTrA three domes are seen under a beautiful sky featuring the constellation Orion (the Hunter) and the Pleiades star cluster. Original Image
Credit: Petr Horálek/ESO

The three 0.6-meter (1.97 feet) ExTrA telescopes can observe changes in a star's brightness in many different wavelengths of light, in order to catch the dimming of the star that might be caused by a planet passing in front of the star. This approach is slightly different than existing transit methods and differential photometry techniques, and by taking observations in different colors, the ground-based telescopes can correct for variations caused by Earth's atmosphere.

In short, these telescopes are aiming for a level of precision that will allow scientists to see Earth-size planets, which are often difficult to spot because of their relatively small size compared to their parent stars, according to the statement. And that's important, because the leaders of the ExTrA project don't want to just find exoplanets; they want to learn about exoplanet atmospheres with the telescopes, too.

The ExTrA telescopes are seen at ESO’s La Silla Observatory in Chile. Original Image
Credit: ESO/Emmanuela Rimbaud

"With the next generation of telescopes, such as ESO's Extremely Large Telescope, we may be able to study the atmospheres of exoplanets found by ExTrA to try to assess the viability of these worlds to support life as we know it," the project's lead researcher, Xavier Bonfil, said in the ESO statement. He is based at the University of Grenoble in France, and the telescopes will be operated remotely from there.

One of the three ExTrA telescopes at ESO's La Silla Observatory in Chile. This view shows the telescope in its dome. Original Image
Credit: Petr Horálek/ESO

Red-dwarf stars are ideal candidates for study, according to the ESO statement, because they are "expected to host many Earth-size planets," according to the statement. One example is the sun's closest neighbor, Proxima Centauri, an M dwarf that has been found to have an orbiting Earth-size world.

Follow Doris Elin Salazar on Twitter @salazar_elin. Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com.

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Author Bio


Doris Elin Salazar, Space.com Contributor

Doris Elin Salazar joined Space.com as an intern in the summer of 2017. She received a B.A. in Sociology and Communications at Fordham University in New York City. Her work was previously published in collaboration with London Mining Network. Her passion for geology and the cosmos started when she helped her sister build a model solar system in a Bronx library. Doris also likes learning new ways to prepare the basil sitting on her windowsill. Follow her on twitter at @salazar_elin.