Discovery of Earth-like Planets Outside the Solar System

NASA announced the discovery of other Earth-like planets outside the solar system. The existence of Earth-like planets has intensified the temptation to discover life in other parts of space. According to the Associated Press, NASA astronomers announced on Tuesday, January 6, that they have discovered three or four planets nearly the size of Earth. These planets are located in regions of space where the temperature is neither too hot nor too cold, scientifically referred to as the 'Goldilocks Zone,' which has suitable conditions for the formation of liquid water. These planets are not made of massive gas or ice and are likely rocky like Earth. Based on the latest research conducted by NASA's Kepler space telescope, these planets receive heat from their star that is almost similar to the heat received by Earth from the Sun. However, astronomers remind us that while these planets may be similar to Earth in size and temperature compared to the vastness of the universe, these similarities do not mean they are habitable. Guillermo Torres, the senior astronomer responsible for this research at the Harvard-Smithsonian Center for Astrophysics, says that two of the newly discovered planets can be considered the most similar to Earth. He added that if their atmospheres are similar to Earth's, which seems unlikely, one of them would have a temperature of 140 degrees Celsius, while the other would be around zero degrees. Guillermo Torres states that life could emerge and adapt in such temperature conditions. The Associated Press further notes that these two planets are not located close enough to Earth to be suitable for human travel, with distances ranging from 500 to 1100 light-years away. One light-year is equal to 9.5 trillion kilometers. Douglas Caldwell, an astronomer at the SETI Institute and a collaborator on this research, said during the presentation of these findings at the American Astronomical Society meeting in Seattle that the important point is that astronomers are getting closer to finding Earth twin planets and answering the eternal question, 'Are we alone?' Guillermo Torres said in a phone interview from Cambridge, Massachusetts, 'These planets really exist, and we didn't know this before. We are eagerly searching for signs of life. We have not reached that yet, and it may take many years. But this is the first step.' Guillermo Torres's research group confirmed previous and new findings, bringing the number of known planets that are not more than twice the size of Earth and have habitable temperatures to eight or nine. However, this result comes from short-term research in a small part of the galaxy. Therefore, Guillermo Torres believes that while proving this point is still not possible, Earth-like planets exist throughout space. Guillermo Torres and Douglas Caldwell focused on two planets that are most similar in size to Earth. Guillermo Torres says the closest planet, named Kepler-438b, is only 12% larger than Earth and receives 40% more energy than Earth does from the Sun, which means it should be warmer than Earth. According to these astronomers, the Sun of this planet appears red in its sky, unlike our Sun, which appears yellow. This planet orbits a smaller and cooler star than the Sun, and its year is equivalent to 35 Earth days. Guillermo Torres added, 'It may be warmer, but there are bacteria on Earth that easily live at such temperatures.' The other planet, Kepler-442b, is about 34% larger than Earth and, like Earth, receives only two-thirds of its energy from its star. NASA also announced that the Kepler space telescope has successfully discovered its thousandth planet outside the solar system, which is very similar to Earth but not habitable. Including previous findings, astronomers have discovered 1,800 planets outside the solar system so far.