Disappointment: Dwarf star's rocky planet lacks a detectable atmosphere

Tablizer writes: CNN: The hunt for planets that could harbor life may have just narrowed dramatically.

Scientists had long hoped and theorized that the most common type of star in our universe — called an M dwarf — could host nearby planets with atmospheres, potentially rich with carbon and perfect for the creation of life. But in a new study of a world orbiting an M dwarf 66 light-years from Earth, researchers found no indication such a planet could hold onto an atmosphere at all.

Without a carbon-rich atmosphere, it’s unlikely a planet would be hospitable to living things. Carbon molecules are, after all, considered the building blocks of life. And the findings don’t bode well for other types of planets orbiting M dwarfs, said study coauthor Michelle Hill, a planetary scientist and a doctoral candidate at the University of California, Riverside.

“The pressure from the star’s radiation is immense, enough to blow a planet’s atmosphere away,” Hill said in a post on the university’s website...

They pored over the data produced by Spitzer, searching for emission signatures, or signs that a gaseous bubble could encase the planet. The telescope captured the planet as it passed behind its home star, allowing researchers to “look at the starlight as it’s passing through the atmosphere of the planet,” giving a “spectral signature of the atmosphere” — or lack thereof, Hill said.

Hill added that she wasn’t shocked to find no signs of an atmosphere, but she was disappointed. She’s looking for moons and planets in “habitable zones,” and the results made looking at worlds circling the ubiquitous M dwarf stars slightly less interesting.