spaceSpace and Physics

It's A Really Good Time To Be A Planet-Hunter As Another New Mission Has Just Been Announced


Jonathan O'Callaghan

Senior Staff Writer

An artist's impression of the ARIEL mission. ESA/STFC RAL Space/UCL/Europlanet-Science Office

Good news, everyone. We’re going to get a new planet-hunting mission in 2028, adding to our ever-growing fleet of telescopes that are looking for worlds beyond our Solar System.

The European Space Agency (ESA) mission is called ARIEL, which stands for Atmospheric Remote?sensing Infrared Exoplanet Large?survey. The goals of the mission, costing about €450 million ($550 million), are to work out “the conditions for planet formation and the emergence of life,” according to ESA.


It’ll do this using a telescope that’s 1 meter (3.3 feet) wide, viewing planets in both visible and infrared. It’s going to be launch on an Ariane 6 rocket, and will be positioned 1.5 million kilometers (0.9 million miles) from Earth.

The idea is to use the telescope to see if certain stars play host to particular types of planet. It will look at the atmospheres of planets around other stars, to see if there is any sort of pattern to planet formation.

The mission will last four years, during which time it will observe 1,000 planets. It’s going to focus on warm and hot planets, like super-Earths and gas giants that are in tight orbits – known as hot Jupiters. And while it will look at some planets in habitable zones, it doesn’t look like it’ll be studying many Earth-like worlds.

“[ARIEL] will enable us to answer questions about how the chemistry of a planet links to the environment in which it forms, and how its birth and evolution are affected by its parent star,” Professor Giovanna Tinetti from University College London, the principal investigator on the mission, said in a statement.

Giant hot planets will be targeted by ARIEL. ESA/ATG medialab, CC BY-SA 3.0 IGO

It’ll be looking for things like water vapor, carbon dioxide, and methane on these worlds, as well as their metal content, to see how they compare to their host star. On some planets, ARIEL will also be used to look at cloud systems, and even see if there are seasonal or daily changes on the planet itself.

It will join a growing fleet of space telescopes that are being used to find exoplanets, itself a relatively new field of astronomy. NASA’s Kepler mission is perhaps the most famous, finding thousands of planets since it launched in 2009 – although the mission will come to an end in months.

Next month we’re expecting to see NASA’s newest planet-hunter launch, the Transiting Exoplanet Survey Satellite (TESS). ESA also has a couple of missions in the works, the CHaracterising ExOPlanet Satellite (CHEOPS), due to launch in late 2018, and the PLAnetary Transits and Oscillations of stars (PLATO), launching in 2026, which will be looking for planets like Earth.

Yep, that's a decent number of planet-hunting missions. Probably quite a good profession to be in right now. Just saying.


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