Giordano Bruno, a sixteenth-century philosopher, was one of the first to postulate an infinite and homogeneous universe where multiple suns and earths existed. For his beliefs, which ran contrary to church doctrine, Bruno was burned at the stake, but his words survived to inspire scientific investigation centuries later.
Last Friday’s Expanding Canada’s Frontiers symposium, hosted by the Astronomy and Space Exploration Society, shows we have come a long way since the era scientists like Bruno were executed for their beliefs.
U of T professor Ray Jayawardhana and Dr. Max Bernstein of NASA both spoke at the event, discussing findings about the diversity of planets and the prospect of finding life beyond earth.
A renowned astronomer and an internationally known science nonfiction writer, Jayawardhana received the 2003 Science Writing Award for popular science writing by a scientist. His primary research area is the formation and early evolution of stars, brown dwarfs, and planets, and he called the diversity of planets a mystery yet to be solved. He spent most of his time talking about planets orbiting stars other than our sun.
Existing far beyond our solar system, planets called exoplanets (short for extra-solar planets) were first reliably observed in the 1990s. Every year since 2002, more than 20 exoplanets have been discovered. Recently, scientists hit a 200 exoplanet milestone.
Jayawardhana spoke enthusiastically about the history and diversity of exoplanets and their similarity to the planets of our solar system. A large number of exoplanets have orbits around their star similar to Earth’s around the sun, but some earthlike exoplanets have orbits that take them around their star in as little as three days or as long as five years.
The discovery of exoplanets raises the question of whether some of them might support extraterrestrial life. Some astrobiologists believe large, Jupiter-sized planets that take longer to orbit their star may act as comet “barriers,” shielding from harm the Earth-sized, life-bearing planets closer to the star.
Bernstein, A researcher at NASA Ames Research Center and the recipient of the Zeldovich Medal for his contributions to space science, encouraged the audience to learn more about the stuff life is made of. On earth, life is based on DNA and RNA, but Bernstein challenged his audience to think about the possibility of alternative ingredients for life.
“[We] cannot count on Martian DNA to be like ours,” he said.
As well as focusing on the combination of genetic molecules that might give rise to E.T.-like aliens, Bernstein also advocated trying to conceive of alternate possibilities for forms of life out there.
Staying open to new possibilities is a hopeful beginning for the exploration of life on other planets. One thing is for certain-the ideas Bruno was burned at the stake for were nowhere near as paradigm-shifting as the facts that scientists have observed with their own eyes today.
With information from The Astrophysical Journal
