Discovery of a Star with Seven Earth-like Planets Orbiting It

Astronomers have discovered a star for the first time that has seven Earth-like planets orbiting it. They are searching for signs of life on these planets. According to the Associated Press, a group of NASA scientists announced the discovery of these Earth-like planets on Wednesday, February 23. These seven planets are located 39 light-years away from Earth in the constellation Aquarius in the Milky Way galaxy. The seven Earth-like planets orbit the dwarf star TRAPPIST-1, which is approximately the size of Jupiter. NASA scientists say they need to analyze the atmospheres of these planets to determine if they are suitable for life. Last spring, the University of Liège in Belgium reported the discovery of three Earth-like planets orbiting the dwarf star TRAPPIST-1. Now, the number of these Earth-like planets has increased to seven. All of these planets are roughly the size of Earth and are likely composed of rock and stone. Amory Triaud, one of the scientists in this research group, says that a "significant step has now been taken to find life there." The TRAPPIST-1 system currently holds the record for the most Earth-like planets discovered to date. These seven planets are in the most suitable "temperature range" compared to other Earth-like planets; in other words, they are neither too cold nor too hot, with temperatures necessary for life to emerge. The dwarf star TRAPPIST-1 has less than 10% of the mass of the Sun. These seven planets are much closer to their star than our Earth is to the Sun, but because the dwarf star TRAPPIST-1 has a much lower temperature and its radioactive emissions are weaker, the surface temperatures of these planets fluctuate between 0 to 100 degrees Celsius. These scientists will determine whether life exists there by examining the chemical compositions of these planets. For example, the presence of a combination of methane, oxygen or ozone, and carbon dioxide is nearly certain to indicate some form of life.