Kepler: Don't Count Your Exoplanets Before They Hatch

Allison Loudermilk

Keep your fingers crossed for Kepler tonight. Here techs check out Kepler inside the Hazardous Processing Facility at Astrotech in Titusville, Fla. (Photo courtesy NASA/Tim Jacobs)

As the countdown to the Kepler launch tonight nears its final hours, it's hard not to let your mind run wild with what the planet-seeking satellite will find. But don't. Kepler is just one, albeit awesome, step in a multiphase, multigenerational journey to discover if Earth is the only spot in the universe capable of supporting, well, life like us. It may well be. Giant Jupiter-type balls full of braggadaccio and gas are more commonly sighted than Earth-like planets with delicate constitutions.

What's more, Kepler won't directly observe any exoplanets. Rather, it will be taking its planet-hunting cues by noting the dimming of stars. If a star looks dimmer to Kepler, that may be a sign that a planet is orbiting the star since someone or something passing in front of a light source can temporarily decrease the light emanating from it. This technique of detecting planets is called the "transit method." NASA compares it to watching a flea creep across a car headlight at night.

Like a cosmic stalker, Kepler will fixate on the same 100,000 or so stars, ensuring that it's not just observing a fluke occurrence. And Kepler's "eyesight" is fantastic. NASA reports that the satellite's telescope is so powerful that from its perch in space it can "detect one person in a small town turning off a porch light at night."

But I'm still worried that the launch won't go off without a hitch. Although Kepler isn't piggybacking on the same sort of rocket used by the recent ill-fated Orbiting Carbon Observatory, you never know. That kind of pressure makes me glad that I'm just an editor, not a rocket scientist.

Read more about the search for exoplanets and extraterrestrial life at HowStuffWorks.com: How Planet Hunting Works How SETI Works How Rocket Engines Work How Satellites Work