Is Anyone Out There?

The mission of SETI (Search for Extraterrestrial Intelligence) is to explore the universe for any signs of life similar to what we have on Earth and try to make contact if any is found. The organization may have gotten a big lead recently when NASA announced the discovery of an Earth-like planet, Kepler 452b.

Calling Kepler 452b Earth's "older cousin", SETI has ramped up the Allen Telescope Array to pick up any signals. Comprised of 42 large radio antennas at the Hat Creek Radio Observatory north of San Francisco, SETI uses the radio telescopes to scan the sky for signals from other planets.

NASA has said the newly discovered planet is the most similar to Earth ever found outside out own solar system. It orbits its own star, Kepler 452 and is smack in the middle of the "habitable" zone where it's neither too hot or too cold, allowing for intelligent life to exist. Often called the "Goldilocks" zone, planets found in areas like this are significant to NASA as well as SETI because they contain the most likely location for Earth-like life to be found.

SETI hasn't picked up any signals from the new planet but not for lack of trying. The telescopes in the array have monitored it on close to two billion frequency bands without hearing a thing. They aren't done however, there are more channels to check and the scopes could conceivably observe up to nine billion frequency bands total. SETI senior astronomer Seth Shostak is undeterred. In a webcast produced by the Slooh Community Observatory, he spoke about Earth's early days and said, "That's no reason to get discouraged. Bacteria, trilobites, dinosaurs-they were here but they weren't building radio transmitters." P

So what are the details on the new star in town? Well, Kepler 452 is the star, Kepler 452b is its orbiting planet, or exoplanet. They are about 1, 400 light years from Earth. The constellation Cygnus, where they were found, is an area researchers want to study closely, since it's likely more stars and exoplanets could be found there. According to NASA measurements, Kepler 452b has a radius a little over 1. 5 times bigger than Earth's. The actual mass and density of the planet is not known yet and without those measurements it will be difficult to know the exact composition of the planet.

The lead author of the NASA paper on Kepler 452b, Jon Jenkins from Ames Research Center said in a press release, "We would love to be able to do a direct mass measurement so we could measure density. That would be a big clue as to whether this is a rocky world or a water world or a gassy world."

Without that information the Kepler 452 team is crunching the numbers and looking to statistics from other data about the area to come up with educated estimates. Based on their calculations, they believe the planet is rocky. They also know that it takes 385 Earth days for it to orbit its star, Kepler 452, making a Kepler 452b year slightly longer than an Earth year.

Researchers from NASA and SETI believe the discovery of Kepler 452 and its baby, 452b, are just the beginning. It appears to have everything a planet would need to be considered habitable: location, a reasonable orbit and a size similar to Earth. Shostak summed it up by saying, "There could be tens of billions of such worlds in the galaxy." Check out the video below to learn more.