The Grand Hall of the Main Building was filled with the chatter of over 500 college and high school students, faculty and staff on Thursday, March 12, 2009, all of whom were gathered for the 14th annual Kaczmarczik Lecture. Dr. Geoffrey W. Marcy, professor of astronomy at the University of California, Berkeley, was the featured guest, and his presentation focused on the search for other "Earths" and intelligent life.
Before Marcy began, Dr. Mark Greenberg, the Dean of the Pennoni Honors College, honored Alyssa Wilson for being named the 2009 Gates Cambridge Scholar, commending her on her hard work and studies.
Dean of the College of Arts and Sciences, Dr. Donna Murasko, then spoke about the Kaczmarczik Lecture, asking for a moment of silence for Dr. Kaczmarczik, who passed away January 20th, and for whom the lecture series is named. Murasko said the lecture's purpose was to "excite and stimulate you to learn more," and Kaczmarczik himself always succeeded at inspiring not just his students, but Murasko herself.
Murasko then introduced Dr. Michael Vogeley, physics professor, who then introduced Marcy.
Marcy's search for other "Earths" – planets that are like Earth and could possibly sustain life – is really a quest to find other intelligent life in the universe.
"Will life spring up in other hospitable planets?" Marcy asked.
There has been no evidence of life on Mars, Jupiter or Saturn, so scientists have expanded their search past our universe and into the Milky Way Galaxy for other planets that could possibly sustain life by watching the wobble of a star. Marcy explained that planets can pull a star by their gravitational shift – as Earth and other planets pull the sun – which scientists can detect by using the Doppler Effect. Scientists collect starlight using the Keck Telescope in Hawaii to collect data in 24 megapixel pictures, which they then examine down to one-thousandth of a pixel to compare the Doppler shifts.
Scientists then compare the Doppler shifts of the data and can infer many things from this data by using Fourier analysis – a complicated type of math – on graphs of power versus orbital period. Scientists have used Fourier analysis to determine the number of planets that orbit a star, the mass of these planets, their orbital period, and their distance from the star. By analyzing these graphics, which Marcy presented, it was obvious by giant spikes in the data how many planets were present around a star.
By using Fourier analysis over and over again, scientists found that Star 55 Cancri in the Cancer galaxy has five planets, and found each planet's orbital period. However, there is a large gap between the fourth and fifth star.
"What's in it?" Marcy asked. It was clear Marcy's thirst for knowledge was only heightened by this mystery.
Marcy presented other stars that had planets in their solar systems, like HR8799, a star with three planets. In fact, scientists have found 27 stars that have multi-planet systems like ours, but haven't yet found another Earth-like planet.
However, Marcy is optimistic about finding an Earth-like planet. He estimates that 15 percent of stars have planets around them, and there are some 200 billion stars, which would mean that approximately 30 billion planetary systems exist. Even from a very pessimistic viewpoint, Marcy said, if only one percent of those 30 billion planetary systems had Earth-like planets, that would still leave 300 million planets; surely one of them must contain life.
Many conditions must be met for a planet to be considered "Earth-like," however. Most planets are ten or 100 times the size of the Earth's mass, which makes them too large to sustain life. The planet also must be lukewarm, because life depends on H20 in liquid form, so the planet cannot be too far from or too close to its sun, otherwise its climate would be too cold or hot.
But Marcy insists that forms of life – even single-celled life – can be found in the most inhospitable of places. For example, Yellowstone National Park has lakes that are freezing, hot, highly acidic, and yet algae still grows. From this example, he concludes that life can be found in many places and has a recipe for microbial life which includes: a planetary system, organic molecules, water, and energy.
"Single-cell life must be out there," Marcy said.
But just because single-cell life may exist does not mean that intelligent life does, Marcy said. Despite the lack of proof, Marcy is convinced that there must be a plethora of intelligent, more advanced civilizations. No evidence of any such civilization exists – even the moon, which still holds the footsteps of those who have walked on its surface, is untouched by other life.
"It's a little surprising that a galaxy teeming with planets shows no signs of other intellectual life at all," Marcy said.
He does admit, though, that he could be wrong. Perhaps the Earth is a special case –only .03 percent of the Earth's mass is water, which formed from asteroids and comets hitting the Earth; any less water, and the Earth would be a desert; any more, and it would be a water world.
Also, Marcy asked, does evolution favor intelligence? The dinosaurs were around for 200 million years and did not evolve; even animals on Earth and insects don't appear to be evolving. This could possibly mean that intelligence is not strongly favored. Perhaps humanity is merely a quirk, Marcy posited.
Lastly, another civilization would need a lifetime of at least five million years for our civilization to overlap with theirs. It is possible that intelligent life once flourished, but did not last long enough for us to discover them – or that we will not last long enough for another civilization to discover us.
New technologies in this field include the Keplar telescope, which was launched on the original date of the Kaczmarczik Lecture, March 6, and which Marcy attended. He showed the audience footage he had taken of the launch on his cell phone. The Keplar telescope can detect the dimness of stars and makes it easier to search for rocky, Earth-like planets. There are also Doppler observations, which measure density and can distinguish between rocky and gas-like planets.
Marcy mentioned that scientists are also trying to pick up radio and TV signals and communications from elsewhere in the galaxy, but so far haven't found anything. However, if a planet were all water, it would be impossible for these electronics to exist, and therefore there would be no signals.
Despite all this searching that has yet to find intelligent life – or even single-celled life – Marcy predicts scientists will be able to detect an Earth-like planet in two to three years. Primitive life, he said, would be common, although technological life would be rare. However, he remains hopeful and optimistic.
Marcy finished his presentation to resounding applause, and then answered questions from audience members.
