Yahoo News – It’s one of the most profound questions of all time: Are we alone in the universe?
There are some scientists who think we probably aren’t.
Of course, we haven’t yet discovered any life beyond Earth, but many scientists take the possibility very seriously and are actively looking for it.
This is often a tricky subject for scientists to discuss — remember the “alien megastructure” incident? — because when some people hear the word “alien,” it often conjures up images from science fiction like Independence Day or Contact or conspiracy theories about Area 51 and UFOs.
But there’s compelling scientific evidence and simple statistics that support the idea that some form of alien life exists. For one, there are billions of other planets in our galaxy and billions of other galaxies in the universe. Surely one of those has life on it — right?
1. Jason Wright
“The primary argument is that life exists here, and has existed here for billions of years,” Wright said in an email. “That is, life on Earth presumably arose via natural processes, those natural processes are universal and the requirements for life (rocky planets, water, carbon, etc.) appear to be widespread in the galaxy.”
“Since it happened here on Earth relatively quickly after the Earth formed and cooled, it must be possible for it to happen elsewhere. Even if the probability of it happening is very low, there are billions of planets in our galaxy alone that should have conditions similar to early Earth, so it stands to reason that some fraction of them also have life.”
2. Debra Fischer
Fischer, a professor of astronomy at Yale University, said that on a chemical level, the same thing that happened on Earth should happen elsewhere.
“We are beginning to understand that the earliest life on Earth was a natural consequence — not a freak accident — of early, pre-biotic chemistry,” Fischer said in an email to Mic.
“If it is true that life is a common outcome of chemistry, then it is a good bet that this process is happening on other worlds.”
“This understanding has emerged from research in biochemistry (for example, by Gerald Joyce at the Scripps Institute), showing that RNA will undergo a process of natural selection and adaptation to the environment much like Darwinian evolution,” she said.
“If it is true that life is a common outcome of chemistry, then it is a good bet that this process is happening on other worlds. Now, it’s our job to find supporting evidence by searching for biosignatures in the atmospheres of other planets!”
3. Seth Shostak
The Search for Extraterrestrial Intelligence Institute’s Shostak thinks that based on the sheer number of planets in the universe, finding alien life is only a matter of time.
Yahoo News - Kelly Dickerson