The number of potentially habitable planets is greater than previously thought, according to a new analysis by a Penn State researcher, and some of those planets are likely lurking around nearby stars.

"We now estimate that if we were to look at 10 of the nearest small stars we would find about four potentially habitable planets, give or take," said Ravi Kopparapu, a post-doctoral researcher in geosciences. "That is a conservative estimate," he added. "There could be more."

Rock in an Icelandic hot spring near Reykjavik with sulfur and Galdieria sulphuraria. Credit: Christine Oesterhelt

In the movie Alien, the title character is an extraterrestrial creature that can survive brutal heat and resist the effects of toxins. In real life, organisms with similar traits exist, such as the "extremophile" red alga Galdieria sulphuraria. In hot springs in Yellowstone National Park, Galdieria uses energy from the sun to produce sugars through photosynthesis.

Using new technology at the telescope and in laboratories, researchers have discovered an important pair of prebiotic molecules in interstellar space. The discoveries indicate that some basic chemicals that are key steps on the way to life may have formed on dusty ice grains floating between the stars.

Even dying stars could host planets with life -- and if such life exists, we might be able to detect it within the next decade. This encouraging result comes from a new theoretical study of Earth-like planets orbiting white dwarf stars. Researchers found that we could detect oxygen in the atmosphere of a white dwarf's planet much more easily than for an Earth-like planet orbiting a Sun-like star.

Antarctica's Don Juan Pond might be the unlikeliest body of water on Earth. Situated in the frigid McMurdo Dry Valleys, only the pond's high salt content -- by far the highest of any body of water on the planet -- keeps it from freezing into oblivion.

Now a research team led by Brown University geologists has discovered how Don Juan Pond gets the salty water it needs to exist.