Astronomers: two planets system TRAPPIST-1 suitable for life
Last year, NASA astronomers have discovered a planetary system with seven Earth-like planets. Dubbed TRAPPIST-1 system not only has the largest number of Earth-like worlds, accessing the same system, but also contains the largest number of planets that are in the so-called "habitable zone" stars - the region where it is not too hot or cold, and on the surface planets can be water, as well as the necessary conditions for the existence of life.
After a study of three potentially habitable planets TRAPPIST-1 system, scientists have found new evidence to suggest that at least two of them can actually support life. About his work, scientists have shared in the journal Astronomy & Astrophysics.
For the research team of astronomers led by planetary geophysicist Amy Barr US Planetologicheskogo first institution to create a mathematical model of the seven planets TRAPPIST-1, as well as geology. Using these models, the researchers found that six of these worlds may have water on its surface or in the liquid or solid state, and one planet at all can be home to a global ocean.
The next step consisted of scientists to determine the surface temperature of each of the planets. Worlds TRAPPIST-1 system have very unusual, ovate orbits, forcing them a little stretch, then slightly compressed, thereby creating a heat their surface, as well as the internal structure. This phenomenon is called tidal heating and makes the temperature rise on the outer planet, but also contributes to the launch of various chemical processes and the movement of the mantle layer, which creates favorable conditions for life, as is the case on Earth.
"This is one of the major discoveries. Planets are also on eccentric orbits egg-shaped, so every time when the planet passes a star, it stretches and shrinks, "Barr said in an interview with Guardian.
The scientists determined that the planet b, c, d and e are experiencing tidal heating. Researchers believe that the planet b, and c are experiencing tidal heat, and the planet c, probably almost no water, and is mainly composed of iron and stones. However, the planet d and e are exposed to tidal heating is much smaller than the others, and they may be the most livable.
Barr told the newspaper Guardian, that planet d and e, which are "in this type of region", are "very reasonable surface temperature." Astronomers believe that the average temperature on the surface of the planet d may be about 15 degrees Celsius, or perhaps slightly warmer than the melting point of ice. Planet e, according to Barr, in turn, somewhat cooler, and its surface temperature can be similar to the average value characteristic earth arctic regions.
At the moment, mathematical modeling is the most effective method for studying the possible features of the planets TRAPPIST-1 system, but it leaves some important gaps in our knowledge, such a model can not answer the question of whether the any of the planet's atmosphere.
Fortunately, there are several development projects that will observe and explore distant worlds with an even greater level of detail. One such project is unfinished James Webb Space Telescope (JWST). It is expected to launch by astronomers from around the world and is scheduled for early 2019. One of its key objectives of the study will be just exoplanets, including TRAPPIST-1 system. In addition to the JWST, are expected to be discovered in the near future and several new ground-based observatories. They, too, will make a significant contribution to the study of exoplanets. For example, the Giant Magellan Telescope and the European Extremely Large Telescope should start in 2025 and 2021, respectively, and will be able to tell you more about the potential habitability of planets described today.
exoplanet research is still at an early stage. The first evidence of the existence of exoplanets by scientists only happened in 1992. Since then, astronomers have confirmed the existence of the planets among 3726 2792 systems, only 20 of which are considered by scientists potentially habitable. With the development of technology and the creation of new tools to search for other worlds, we can learn much more about what surrounds us in this universe.