In the system of TRAPPIST-1 found two habitable planets
Two exoplanets system TRAPPIST-1 is likely to have water in liquid form, and therefore possible life. This is stated in the new study, researchers from the Planetological Institute of the USA.
However, experts believe the findings of Americans to premature, pointing out that these planets might not be necessary for life atmosphere. The arguments of the parties considered RT.
System TRAPPIST-1 © NASA/JPL-Caltech
«Relatives» Of The Earth
System TRAPPIST-1, perhaps the main space «newsmaker» since its opening in 2016. Ultracold dwarf located in the constellation of Aquarius at a distance of 39 light years from Earth. Size TRAPPIST-1 a little more than Jupiter, but is about 90 times heavier.
First around the star was discovered seven planets. Then it turned out that all of them earth-like.
An international group of scientists led by astronomers from the Planetological Institute of the USA suggested that the planet is made of ice, rocky material and iron, and with the help of computer modeling has determined their structure. In the end, the experts received a new, refined values of masses for each of the planets, and also assessed the amount of the contained water.
«Because star TRAPPIST-1 old and dull, on the surfaces of its planets relatively cool from 127 °C to -107 °C. the Planet is also very close to their star and make a full revolution around it in just a few days: from 1.5 to 12. As the orbits of planets slightly elliptical, not circular, revolving around a star they are then closer, then farther away.
Under the gravitational attraction of the star on the planets of change of the amplitude of the tides. This process is called tidal heating. All this contributes to the fact that in the subsoil generates heat, which maintains in the planets geological activity» — says one of the study’s authors, Amy Barr.
Planet system TRAPPIST-1 © NASA/JPL-Caltech
The report also elaborates on the processes of heat transfer in the mantle of each planet. The results showed that the second and third (if you count from the star) planets, probably partially molten mantle from the rocks.
Moreover, on one surface there are traces of siliceous magma that emerged, probably due to the eruptions caused by tidal heating. Such volcanic activity is characteristic of Jupiter’s satellite IO.
The planets in the system TRAPPIST-1 has another interesting feature: when they move directly towards the star, under the influence of its gravitational field deformed, becoming similar to the egg. When you delete a planet again become spherical.
«Quite reasonable» terms
Last year, scientists talked about the three planets of the system TRAPPIST-1, which are in the so-called habitable zone where it’s not too hot or too cold so that water could be in liquid state. And this, in turn, would create conditions for the emergence and development of life.
In the end, there were two of the most livable on the planet. They are called TRAPPIST-TRAPPIST 1d and-1e. At first, the average temperature is +15 °C. In the second cooler climate about the same as in Antarctica. But astrophysics is called «mild» conditions. Scientists believe that planet d may cover the whole ocean.
Jumping to conclusions
However, some scientists doubt that the Americans are sufficiently convincing and weighty scientific arguments for such conclusions.
«The study is purely theoretical. The authors did not mention the radiation levels on these planets is clearly greater than the earth performance. Star TRAPPIST-1 is very active. Still have a lot to learn before you declare the suitability of those planets for life — for example, to investigate in detail the composition and density of the atmosphere, to understand how it can protect exoplanets against emission of energy» — said in an interview with RT astronomer, academician, member of the Bureau of the division of physical Sciences of RAS Yuri Balega.
According to experts, in 2019, NASA will launch a new telescope, «James Webb», which will allow to learn more about this system, test it for the presence of water and potential habitability.
Space telescope named James Webb © NASA/Chris Gunn
Skeptics doubt that the planets of the system TRAPPIST — including those who have declared potentially suitable for life — there is a suitable atmosphere. Opponents of the «habitable» exoplanets say that radiation native stars often destroy the atmosphere of their satellites.
«Already opened more than 3,5 thousand exoplanets, and will open even more. Some of them already fall into the zone of habitability, there is liquid water, suitable temperature. We can say that the conditions for organic life are favorable. But many of these planets, including system TRAPPIST-1, revolve around red dwarfs — stars of low luminosity.
They are very chromosphere characterized by high activity, when there are very strong flares are many times stronger than in the Sun. Therefore, planets around red dwarfs may be a lot, but because of the activity of their stars they are certainly not suitable for life — at least as we know her on Earth,» explained RT, doctor of physico-mathematical Sciences, scientific Director of the Institute of astronomy, Boris Shustov.