Planet expert talks search for another Earth
Published: Tuesday, October 25, 2011
Updated: Tuesday, October 25, 2011 05:10
Increased capabilities are drawing scientists closer and closer in the search for habitable planets, according to Professor Greg Laughlin.
Laughlin, chair of astronomy at the University of California Santa Cruz, delivered a lecture titled "The Search for Another Earth" Wednesday night in Clayton Hall.
Throughout his speech, Laughlin focused on the process of discovering Earth-like planets. He emphasized that advancements in technology have made that search much easier. He said NASA's Kepler Satellite Mission, which searches for habitable planets, is monitoring 150,000 stars and 90 to 95 percent are predicted to have planets orbiting them.
"Results from Kepler have reinforced idea that planets are extremely common around nearby stars and that our own solar system is just one of a huge variety of architectures that are out there," Laughlin said.
Laughlin utilized a picture of Jupiter to show the rapid advancements solar technology has made. The picture showed Jupiter half-illuminated by the sun, an impossible shot from Earth, where Jupiter is always observed fully lit. The picture was taken in space at Jupiter's orbit.
"The very fact that this is a photograph [that] exists is a testament to what we can do," Laughlin said.
Laughlin also used Venus as an example of researchers' increased capabilities.
Astronomers expected to find a "steamy, jungle-like world" underneath the planet's cloud cover, leaving hope that Venus might be habitable, he said.
"It seemed like there might be a real target right next door," Laughlin said.
Technology progressed, and astronomers measured that Venus' surface was hot enough to melt lead. Laughlin said scientists are now focused on stars outside of our solar system in the search for habitable planets.
Recently, a planet formally called HD 85512 b was discovered 36 light-years away from Earth in the constellation Vela, which astronomers have called the best known chance to host life. In the W. M. Keck Observatory in Hawaii, astronomers utilize a Doplar velocity method to detect planets like HD 85512 b, the same method police use to gauge speed. Laughlin said scientists can now measure a star's speed to within one meter per second. Changes in speed can indicate that a planet is orbiting the observed star.
Laughlin pointed to a particular star, 61 Virginis, and said it was the most sun-like star within Earth's stellar neighborhood. Planets with masses 23, 18 and five times larger than Earth's orbit 61 Virginis.
This solar system's alignment, with larger planets closer together, is more common than Earth's solar system's formation of smaller planets with greater distances between them. He also said Earth's orbit is much more circular than many orbits of known planets outside of the solar system, which are closer to oval-shaped.
Their eccentric orbital patterns cause them to move more rapidly when they are closest to their star and very slowly when further from the star, thus affecting the planets' weather and decreasing the chance of habitability.
"So the seasons of a planet that has an eccentric orbit are going to be very extreme and very bizarre," Laughlin said.
He also stressed that knowing how stars are created can help predict how planets come to orbit them. Laughlin said the way dust accumulates under a bed into "dust bunnies," and eventually grows larger and attracts each other is similar to the way stars pull gas from the disk of gas that surrounds them after birth.
Tony Goldston, coordinator of the university's intramural sports program, has held an interest in astronomy since college and attended Wednesday's lecture.
"I definitely believe that there is life out there," Goldston said. "I don't think it will be exactly like us and I don't think anyone around now will be hanging out having coffee with E.T. anytime."
Senior Josh Martin, a mechanical engineering major, said he enjoyed the lecture and thought it helped provide perspective.
"It was inspiring. It's always good to be reminded just how small we are and how little we know," Martin said.