First aired on Quirks & Quarks (02/26/11)
Fifteen years ago, if you were a young astronomer seeking a field to specialize in, deciding to look for planets in other solar systems would have been a risky but promising choice. Though a new field at the time, it had the potential to be the next big thing.
Fast-forward to today, and that potential has been realized. Thanks to new technology and innovative methods, more than 1,000 planets outside our solar system have been identified. And ground-based telescopes, along with NASA's Kepler satellite, add several hundred new sightings each year.
Dr. Ray Jayawardhana has been at the forefront of this field. A few years ago, he was part of the team that made the first direct observation of an extra-solar planet. His new book, Strange New Worlds: The Search for Alien Planets and Life Beyond our Solar System, takes the reader inside the search for alien planets -- from its storied past and exciting present to its future goal of finding Earth-like planets, and even life, elsewhere in the galaxy.
According to Dr. Jayawardhana, one of the greatest surprises of the search for extra-solar planets has not only been how many there might be, but how different they are.
"Of course, as human beings, we're very interested and focused on finding an Earth twin," Dr. Jayawardhana told Quirks & Quarks host Bob McDonald in a recent interview. "But I really think the big story of the last 15 years has really been the incredible diversity of worlds that have emerged [...] The fact that nature produces planets in such prolific numbers and in such prolific systems is quite shocking in many ways."
It has also changed ideas of how solar systems came to be in the first place. The emerging picture points toward a more dynamic, if not chaotic, origin, Dr. Jaywardhana says. The planets within them move around and even interact with each other.
With potentially thousands of extra-solar planets out there, one can't help but wonder about the possibility for life as well. If Dr. Jayawardhana is correct in predicting the discovery of Earth-like planets around sun-like stars in orbits similar to ours, attention will turn to the detection of biosignatures like oxygen, water and methane -- substances that indicate the possibility, but not the necessarily the existence, of life. And, as Dr. Jayawardhana points out, the mere existence of life is very different from an established civilization. Still, these are exciting times.
"We really are living through the unfolding of a revolution," he said. "We have an incredible amount of evidence that planetary systems are common. Now we're very close to finding the answer to 'are there other planets like ours?' And then the next big question of are we alone or not is almost within reach."
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