Because discovering alien worlds has become a somewhat easier task, analyzing every detail researchers find is, oddly enough, a waste of time for all the tools and computers.
Until now, scientists have found 4,104 confirmed exoplanets, but for every one of them, there is a huge amount of maybe-planets in the data, along with signals that might come from stars expelling energy, or duos of stars and many other things.
No More Uniqueness
Researchers don’t have the resources to assay every potential planet’s circumstances anymore.
“It’s gotten to the point that we have so many to choose from now — there are so many exciting candidates coming in that we actually don’t have to look at every single one and confirm every single one,” Jessie Christiansen, an astronomer at Caltech and NASA’s Exoplanet Science Institute, explained. “You really have to prioritize; you have to look at this list of planets that are coming out and say, ‘OK, which one do we really think we’re going to learn the most about?”
The process of accurately confirming an exoplanet is arduous, as it requires experts to identify the size and the mass of the cosmic object in order to exclude other events posing as a planet. This data uses instruments that are currently highly requested by scientists to study a multitude of phenomena. Then, the confirmation process can take a lot of time. More so in intricate situations, which could extend to years of time, according to Christiansen.
There are two different methods to discover exoplanets. One way focuses on individual planets in order to observe as much as possible, for instance, if it is rocky or gaseous, or if it has an atmosphere and what that looks like, as well as how it may have ended up the way it is. However, this information can only be confirmed about planets that rotate around particularly bright stars.
The second method looks at the variety of planets from all over the Universe as a population.
More Data From New Satellites
According to Christiansen, “the Kepler mission was interested in statistics,” Christiansen said. “The point was to get thousands of planets to put in our buckets and say, ‘OK, this one is the most common, this one is the next most common and that kind of thing.”
This is exactly what the Kepler Space Telescope managed to do between 2009 and 2018 while engaged in its two separate missions, known as Kepler and K2. The instrument discovered more than 2,500 confirmed exoplanets; therefore, individual assays of the planets became not so unique anymore.
“If it’s the 80th hot Jupiter that’s been found, and we don’t have any reason to believe it’s going to be different from the 79 that came before it,” she said, “are we really going to scrutinize it in the same way that we scrutinized the first 79?”
This way, while the Kepler findings piled up, scientists came with a new method of analyzing potential planets, known as validation. With more easily obtained information, experts run a statistical model calculating the probability of non-planet reasons for the data they have gotten. If the result is below a certain level, it is sufficient evidence for astronomers aiming to observe populations of exoplanets.
In April last year, NASA launched its new planet hunter, the Transiting Exoplanet Survey Satellite (TESS). Astronomers hope that the new tool will confirm approximately 16,000 planets captured in its data. However, that requires hunting in close vicinity of 100,000 to 300,000 potential planets and analyzing each of them.
NASA‘s upcoming exoplanet hunter, the Wide Field Infrared Survey Telescope (WFIRST), may enable researchers to find 100,000 confirmed exoplanets, which means even more hundreds of thousands of potential objects to assay.