Twinkle Satellite Sheds Light on the Evolution of Distant Exoplanet Atmospheres

Scientists may be getting a better glimpse at the atmospheres of exoplanets. A team of researchers and engineers have announced plans for a small satellite, named "Twinkle," that will give radical new insights into the chemistry, formation and evolution of planets orbiting stars.

"Twinkle is a very ambitious mission," said Giovanna Tinetti, the lead scientist of the new project, in a news release. "Nearly two thousand exoplanets-plants orbiting stars other than our sun-have been discovered to date, but we know very little about these alien worlds. We can measure their mass, density and distance from their star. From that, we can deduce that some are freezing cold, some are so hot that they have molten surfaces, some are vast balls of gas, like Jupiter, or small and rocky, like Earth. But beyond that, we just don't know."

Twinkle will actually be the first mission that's dedicated to analyzing exoplanet atmospheres. This, in turn, will tell researchers quite a bit about the exoplanets themselves. In fact, it could help scientists discover planets that are habitable and aid in the search of life on other planets.

So how will it examine these atmospheres? When an exoplanet passes in front of a star that it orbits, a tiny amount of starlight is filtered through the molecules and clouds in the planet's atmosphere. Twinkle will measure this light and pick out the characteristic spectral "fingerprints" that show if gases like water vapor or methane are present on the planet.

The current plan is for Twinkle to analyze at least 100 exoplanets in the Milky Way. Its infrared spectrograph will enable observations of a wide range of planet types including super-Earths, which are rocky planets that are one to 10 times the mass of Earth, and hot-Jupiters, which are gas giants orbiting close to their suns.

"The light filtered through the planet's atmosphere is only about one ten thousandth of the overall light from the star," said Tinetti. "That's a big challenge and one that requires a very stable platform outside the screening effects of Earth's atmosphere."

Twinkle will be launched into a polar low-Earth orbit and then will operate a minimum of three years. During this time, it will send back information to Earth and tell scientists quite a bit more about the exoplanets beyond our solar system.

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