FOR IMMEDIATE RELEASE
Monday, April 12, 2010
Contact: Dave Wellman, Director of Communications (304) 696-7153
Dr. Ron Walsworth of Harvard to deliver lecture at Marshall University
HUNTINGTON, W.Va. – Dr. Ron Walsworth, a senior lecturer with the Harvard-Smithsonian Center for Astrophysics and the Department of Physics of Harvard University, will present a free public lecture Thursday, April 15 in the Memorial Student Center, Room BE5 on Marshall University’s Huntington campus.
Walsworth’s lecture is made possible by a grant to Marshall University Professor Thomas Wilson of the MU Department of Physics from the American Physical Society Division of Laser Science “Distinguished Traveling Lecturer Program” and with support from the MU College of Science and Department of Physics.
The lecture, titled “The Search for Earth-like Planets Around Other Stars,” runs from 7 to 8 p.m. A reception will follow.
According to Walsworth, a historic event is expected to take place over the next several years – the discovery of a planet similar to the Earth that orbits another star. This discovery will open the door for exploration of habitable environments in the Universe, and could greatly advance our understanding of the origins of life both on Earth and elsewhere.
“To date, more than 400 planets have been discovered orbiting nearby stars,” Walsworth explains in his abstract for the lecture. “However, all these planets are large – somewhat like Jupiter, Saturn and Neptune in our solar system. The reason only large planets have been discovered is that telescopes have not been sensitive enough to detect small, Earth-like planets. Now, this is all about to change, due to two major technological advances – the launch of the Kepler space telescope and the development of a laser-based calibration tool known as the ‘astro-comb.’”
“Kepler was launched by NASA in March 2009 into an Earth-trailing orbit. Freed from the obscuring effects of Earth’s atmosphere, Kepler should identify a few dozen candidate “Sister Earths” over the next few years, by detecting small dips in the light from stars as orbiting planets pass in front. However, such detections by Kepler will only determine the diameter of these planets – not their mass. Knowing the planetary mass is essential to distinguish planets that largely consist of water and ice from true Sister Earths – rocky Earth-like planets that are thought to be optimal for life.
“The astro-comb uses very short (“femtosecond”) pulses of laser light, synchronized by an atomic clock, to provide a precise standard for telescopes that measure the wavelength of light coming from stars. The astro-comb corrects for inaccuracy and drift in the spectral sensitivity of such telescopes, thereby allowing detection of very small Doppler shifts induced in the spectrum of stars by the gravitational tug of orbiting Earth-like planets.”
Walsworth and his colleagues at Harvard, MIT and the Smithsonian Institution have led the development of astro-comb spectral calibrators, and will soon perform observations of promising planets located by Kepler, so that true Sister Earths can be identified. Over the next decade, new space-based telescopes – now in the planning stages – will probe the spectrum of reflected light from these Sister Earths to search for the chemical signatures of life and to acquire high-resolution images of these new worlds.