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Although the Sun is a star, it differs from most of the other stars in the galaxy in two key respects. First, it supports the only known civilization in the universe: us. And second, it’s bigger and brighter than most other stars — only a few percent of stars have about the same color, temperature, and luminosity as the Sun. But based on our example, Sun-like stars may be the best places to find planets that host intelligent life.
Two such stars orbit each other in Cygnus, the swan, which looks like a giant cross. This double star, 16 Cygni, is just 70 light-years away — quite close as stars go — but it’s just barely visible to the unaided eye. One of the stars even has a planet, although it’s much larger than Earth.
Kepler Space Telescope measured each star’s brightness every minute for two and a half years. It detected small oscillations similar to those in the Sun. These oscillations change as stars age, so the observations reveal 16 Cygni’s age: seven billion years — about half-again the age of the Sun.
At that age, if either star has an Earth-like planet, there’s probably been enough to time for it to develop advanced life.
No one has ever detected radio signals from any residents of 16 Cygni, though, so its planets may have no life at all. Or perhaps, given how old the star is, life there may be so advanced that it regards us Earthlings as primitive — and not worth talking to.
More about the search for other civilizations tomorrow.
Script by Ken Croswell