Do aliens exist? When it comes to answering the question of whether or not there is other life in the universe, astronomers are on their way. The first step is to find other planets that are similar to Earth in terms of size, composition and distance from a star. Dr. Sarah Ballard, a NASA Carl Sagan fellow from the University of Washington, spoke about this in her Nov. 13 lecture, “Directions to the nearest alien Earth-like planet.”
“When looking deeper into it, our solar system is surprisingly unusual and not like others, based on the latest research,” said Ballard.
For one, the sun is small compared to other solar systems of the same size. Looking at how the planets are positioned around the sun gives astronomers an idea on what kind of solar systems to look at when finding planets that can potentially have life.
“Our research made leaps and bounds with the launch of the Kepler space telescope in March of 2009,” said Ballard. Before the launch, there were only a few discovered planets outside of the solar system. The Kepler space telescope now has pictures of around 150,000 stars, each with their own set of planets.
Kepler was able to detect a number of planets the size of earth. To astronomers’ surprise, the number of Earth-like planets was more frequent in small stars. The problem is that there is very little chance for life to have formed on these planets.
Of course, merely being the same size as Earth is not enough for a planet to sustain life. Planets must also be roughly the same distance from their star as the earth is from the sun, so they don’t get sucked in by the star’s gravitational pull. They also have to have the same spin synchronization as the Earth and the sun.
Planets that orbit around small stars may have these things, but they still tend to have lower temperatures, due to the lower brightness of the stars. This makes it difficult for them to support life.
Another necessity for supporting life is the atmosphere.
“Right now, Kepler cannot detect the atmosphere of a particular planet,” said Ballard. She said that the James Webb Space Telescope, the successor to the famous Hubble Space Telescope, which is set to be launched in October 2018, should be able to detect atmospheric content.