Seth Shostak, Senior Astronomer at the SETI Institute, appeared on Tuesday night's show speaking about the possibilities for life in our galaxy, as well as closer to home in our solar system. "Everything in the universe is made up out of the same stuff," which could mean there are a lot of carbon-based life forms out there, he surmised.

Shostak explained that SETI doesn't target their radio telescope time on star systems such as Sirius or Zeta Reticuli because of stories or myths about aliens that hail from there. Rather, they use other criteria such as the age of a star system in making their selections. However, he pointed out that when the Allen Telescope Array comes online, these stars along with many, many others will be targeted.

That there could be a "Planet X" Earth-sized object way out on the edge of our solar system, Shostak acknowledged. There are many rocks out there in the Kuiper Belt, he said, and the recently demoted planet Pluto, which he called "an asteroid on steroids," could just be one of many of these objects. And yet, he believes it highly unlikely that any of these outer bodies would find their way into our inner solar system. The planet Mars, which is now the closest to Earth it's been in eons, requires patience to view through a small telescope Shostak said. It will appear as a small orange ball and the polar caps should be visible, he added.

The Antenna Orchard

One of the topics Seth Shostak, the Senior Astronomer addressed is the new Allen Telescope Array, now under construction. The facility at the Hat Creek Observatory on a remote patch of Northern California land, will be a veritable "antenna orchard," said Shostak, containing 350 small radio telescopes all working together to greatly expand SETI's "stellar reconnaissance."

Made possible through funding by former Microsoft technologists Paul Allen and Nathan Myhrvold, the Array will give SETI full time access for their missions, whereas previously they only got a meager number of weeks out of the year to use facilities like Arecibo. With this new form of radio astronomy, SETI's research could be taking a giant leap forward. SETI's current Project Phoenix currently tracks about a thousand stars. When the Allen Array goes online, they will have the ability to monitor transmissions from possibly 100,000 stars or more, because the Array can examine multiple stars simultaneously.