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Date: April 14, 2006
Author: Pamela Emery

PLANETS OUTSIDE OUR SOLAR SYSTEM?

Imagine zipping out into space and exploring planets other than Earth. If this were possible, we could answer some age-old questions about space.

On Tuesday, the public is invited to meet San Francisco State University research astronomer Chris McCarthy at Explorit Science Centers' Cutting Edge of Science Lecture. Attendees will hear McCarthy's review of what scientists have learned in the past decade about the first planets discovered outside our solar system. The free talk begins at 7:30 p.m. at the Davis Branch Library, 315 E. 14th Street.

It was only ten years ago that the first planets outside of our solar system were discovered. Today over 170 such planets are known, with 162 of them less than about 500 light years from Earth. That is relatively close to Earth. These discoveries have revealed an amazing diversity of planetary systems, none, though like ours. Learn about what the next decade of discovery should look like as predicted by McCarthy, one of the area's leaders in planet discovery.

McCarthy said this age-old question remains unsolved: "Is our life-bearing planet simply a lucky happenstance or is it instead one world among many which are home to other living beings?"

By using very large telescopes, precise spectrometers, and the Doppler method this question may eventually answered. Special telescopes such as the Rocky Planet Finding Telescope being built at the Lick Observatory near San Jose are dedicated to finding planets.

Of the recent discoveries is the planetary system around Rho Cancri a star in the constellation Cancer, the Crab. There are four planets revolving around the star. It took 14 years of constant observation of this star to discover the fourth planet, which has an orbit almost as long as Jupiter's. This star also has a planet that orbits every 14 days. The diversity of planet orbit and size is quite fascinating.

The most recent planetary discovery was made just last summer. "What is exciting about this planet is that is passes in front of its host star creating a little eclipse," said McCarthy. The eclipse has allowed scientist to learn a lot about the composition of this planet. It has a dense center and an atmosphere. Scientists hope to determine if is contains elements like potassium, lithium and sodium.

McCarthy's talk is part of the Cutting Edge of Science Lecture Series offered by Explorit Science Center. It is sponsored by Novozymes and is hosted by the Davis Branch Library.

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Explorit Science Center is at 3141 Fifth St. in East Davis. The current exhibition "What an Animal! Fins and Feathers and Other Creature Features" runs through June 11. Public hours are Saturday and Sunday from 11 a.m. to 4:30 p.m. and Tuesday through Friday from 2 to 4:30 p.m. For more information, visit www.explorit.org or call Explorit at (530) 756-0191.