Nearest Solar Systems

Alpha Centauri System

• Alpha Centauri, our nearest solar system, is only visible in the southern sky, which makes it impossible to view from locations farther north than Florida. One of the key differences between Alpha Centauri and our own solar system is that the Alpha Centauri system comprises three stars. Its first star, Alpha Centauri A, is similar to our own star Sol, while Alpha Centauri B burns with a more orange hue than our sun. The third star in the system is a small red dwarf called Alpha Centauri C. Scientists from the European Space Agency theorize that earth-like planets may orbit Alpha Centauri A, though the theory lacks hard evidence as of 2010. The Alpha Centauri system is the most likely destination for humanity's first interstellar voyage. However, spaceflight technology does not yet allow humans to undertake this 4.37-light-year journey in a single lifetime.

Barnard's Star

• The second-closest solar system to earth is Barnard's Star, discovered by Edward Emerson Barnard in 1916. NASA has identified this system, which is 6 light years away, as a primary target for its space interferometry mission, which will gather data on earth-sized orbital bodies around the star. Some of these bodies exist in the habitable zone for earth-like planetary environments, making them an interesting subject for further investigation. Only 17 percent the size of Sol, Barnard's Star is a red dwarf star, and produces significantly lower amounts of energy than our sun. Barnard's Star also comprises a far greater percentage of heavy elements than Sol, due to its later stage in the stellar life cycle.

Wolf 359

• At a distance of approximately 7.8 light years, Wolf 359 is the third-closest solar system to Earth. The star takes its name from astronomer Maximilian Franz Joseph Cornelius Wolf, who was a pioneer in the field of astrophotography. The faint star is not visible to the naked eye, which is why it remained unknown until Wolf's discovery. Wolf 359 is a faintly burning red dwarf, the dimmest within a 10-light-year radius of our own sun. Daytime for an earth-like planet orbiting Wolf 359 would be roughly ten times brighter than full moonlight on earth. Wolf 359 is a flare star, meaning that it displays periods of increased brightness at seemingly random intervals. Attempts by the Hubble Space Telescope to locate orbiting bodies around Wolf 359 have failed to show any planet-like objects. Furthermore, researchers believe that life is unlikely to develop in the region, due to the fact that Wolf 359's light is too far in the red spectrum to sustain photosynthesis.