香蕉视频

Spanning two days, the Annual Trottier Public Science Symposium 鈥淎re We Alone?鈥� took the audience to the moon, Mars, and beyond. Focusing on the origin of life in our solar system, the series explored the where and how of alien life.

Monday
Monday鈥檚 first speaker, Planetary Society President Jim Bell, discussed the journeys of Spirit, Opportunity, and Curiosity鈥攖hree Mars rovers鈥攁s they furthered the search for microbial life in our solar system. Following him was Jill Tarter, director of the Search for Extra-Terrestrial Intelligence (SETI) Institute, explaining the possibility of sentient life and our current methods of finding it.

Bell started by presenting the idea that if we can prove that life evolved on another planet, then we know that it is not a cosmic coincidence鈥攁ll of the universe should be full of life. Mars, due to the presence of water on its surface, is a prime target for this. Rovers have been sent to ancient lakes and bodies of water in order to study potential traces of life. By observing soil and air samples, or by taking photographs of the Martian surface to investigate the different layers of rock, scientists can extrapolate the conditions and determine how habitable they may be.

One of the major goals for NASA鈥檚 next mission is to set up a sample-return capsule, which could be brought back to Earth and analyzed.

Tarter pointed to the hundreds of thousands of confirmed extrasolar planets that have been discovered within a 鈥榟abitable zone鈥欌�攔egions with sufficient atmospheric pressure to support liquid water鈥攁s necessary to study. She believes that there are more habitable planets than we are testing for because our definition of what makes planets livable is too narrow.

The goal of Tarter鈥檚 and SETI鈥檚 efforts is to detect a signal from an alien species, in order to answer two major questions: How close are other intelligent civilizations, and how far away are we?

Tuesday
Professor Sarah Seger began Tuesday鈥檚 talks by addressing some common questions about the search for another Earth. Called the 鈥業ndiana Jones of astronomy,鈥� Seger researches the edges of exoplanets鈥攑lanets that do not orbit Earth鈥檚 sun鈥� and their identification.

To set the stage for her talk, Seger gave the audience a glimpse of the vastness of the universe and the diversity of star systems. However, the detection of exoplanets is only the first step in the search for life. After astronomers find a planet, they still need to determine whether it contains any signs of biological activity.

So far, the search has produced an impressive list of exoplanets, but no sign of extraterrestrials. Even if scientists do find life markers, interstellar distances mean that a trip to visit any celestial neighbours would take millennia.

So why bother? Why search for something so far away when humans won鈥檛 be able to visit it for thousands of years?

The answer, according to Seger, is because one day, humans will make the trip.

鈥淭he desire to explore is so huge, so amazing, that one of our legacies of finding exoplanets is the thought that hundreds, thousands of years from now, people going on this trip [to other star systems] will look back at all of us here and they鈥檒l say, 鈥榃ow, those were the first people who went out and tried to find those other worlds,鈥欌�� she said.

Skeptic Joe Nickell shifted the audience鈥檚 focus away from the stars and back to Earth. As the world鈥檚 only full-time, professional paranormal investigator, Nickell touches upon tales of Earth鈥檚 more mythological inhabitants. The two mythologies represent different aspects of humanity鈥檚 relationship with the planet.

鈥淏igfoot is the symbol for [the world鈥檚] endangered species,鈥� he said.

As Nickell put it, humanity鈥檚 fascination with the infamous Sasquatch reflects the curiosity about our own origins in the natural world.

鈥淲e鈥檙e looking away from this planet,鈥� Nickell said. 鈥淲e鈥檙e looking to the moon, the stars, and so forth, and we鈥檙e imagining that there may be life out there.鈥�

The speakers鈥� descriptions of the search for life beyond Earth revealed more about humans than about aliens. Even if life is not universal, the desire to find it is.

听

Read More:听