Our galaxy has billions of stars with just one or three planets orbiting them in their Habitable Zone. Researchers from Australia’s National University and Copenhagen’s Niels Bohr Institute believe that this means the Milky Way is likely to be alive with life. Also known as Circumstellar Habitable Zone or Habitable Zone (or just Habitable Zone), the Habitable Zone is the area around a star where planets may have enough atmospheric pressure, water, and temperatures to sustain life as it exists today. Because the conditions in this zone are “just right”, it is sometimes called the Goldilocks Zone. It could contain life, as we now know it. Image by Mark Garlick NASA. Scientists have discovered thousands upon thousands of exoplanets in the Milky Way. These are planets that exist outside of our solar system. The Kepler satellite indicates that a large number of these exoplanets orbit their star in the Habitable Zone. Researchers analyzed the planetary systems to determine the likelihood of their planets being orbited in the Habitable Zone. This latest research was published in the Monthly Notices of the Royal Astronomical Society. The researchers estimated that billions of stars in the Milky Way contain between one to three planets within the Goldilocks area. This means that our galaxy may have many billions of planets with potential life. Using NASA’s Kepler satellite, scientists have discovered approximately 1,000 planets orbiting stars in the Milky Way, plus another 3,000 potential planets. According to the Kepler satellite, these planet systems typically have between two and six stars. They could have many more. Our current technology is limited in its ability to detect larger planets that are closest to their star. It would not be possible to live on planets so close to their stars. Steffen K. Jacobsen, Charles H. Lineweaver, and Timothy Bovaird set out to find out how many of these planetary systems could also contain planets within the habitable zone. The Titius–Bode law, a version of an year-old technique was used to calculate their results. Calculating planet positions German astronomers Johann Daniel Titius (1729-1796), and Johann Elert Bode (1747-1826) developed what is now known as the Titius–Bode law. This hypothesis correctly predicted Ceres’ and Uranus’ orbits (before they were even discovered). The hypothesis states that there is an inverse relationship between the orbital periods for planets within a solar system. The orbital periods of the first and second planets are equal. Knowing how long each planet takes to orbit the star can help you calculate how many other planets will take. You can use the Titius–Bode law to determine if a particular planet is missing from the sequence. Dr. Jacobsen is a PhD student at the Niels Bohr Institute in Copenhagen’s research group Astrophysics and Planetary Science. He said that he used this method to determine the possible planetary positions within 151 systems where the Kepler satellite has found 3 to 6 planets. 124 of planetary system, the Titius Bode law fits with the positions of the planets.” We used T-B’s Titius Bode’s law to try and predict the locations of additional planets farther out in the solar systems. We only calculated for planets where you have a good chance of seeing them with the Kepler spacecraft.” It was obvious that the 27 planets observed in 151 did not conform to the T-B laws. The team then tried to position the planets in the right order. The planets they found missing were added to the list, along with one additional planet that was further from the star. They calculated that there were a total number of 228 worlds within the 151 solar systems. Jacobsen stated: “We made a priority listing with 77 satellites in 40 systems that we wanted to be able to see with Kepler. They have high chances of transiting, so they are easy to find with Kepler. These planets have been highlighted to other scientists. They are an indicator that our theory is valid.” The habitable zones of planets. This area isn’t fixed. It depends on the brightness and size of the star. The habitable zone will be further from the brightest star. The habitable zone in this illustration is the area that’s green. (Photo: Niels Bohr institute) Jacobsen and his colleagues calculated the number of planets within the habitable area based upon the additions to the 151 planet systems. Each planetary system contains 1 to 3 of the planets within its habitable zone. The 31 system was checked for any 151 planet systems that had found additional planets within the habitable zone. Jacobsen stated: “Our calculations revealed that in these 31 systems, an average of two of the 151 planetary systems were in the habitable zones. This would indicate that the Milky Way should contain billions of stars that have planets that are in this zone. Citation: Timothy Bovaird and Charles H. Lineweaver used the Kepler systems’ inclinations to prioritise new Titius Bode-based exoplanet forecasts. Monthly Notices of The Royal Astronomical Society. Published online for the first time March 2015. DOI: 10.1093/mnras/stv221. Video: Is life common on Earth? Uffe Grae Jorgensen is an astronomer with the Niels Bohr Institute. She explains how there are approximately 10 million stars in the Milky Way, and planets that look similar to Earth’s size and temperature.
The Milky Way is likely to be teeming in life, with billions upon billions of Planets in the Habitable Zone.
