EXOPLANETS AND SEARCH FOR INTELLIGENT LIFE

 EXOPLANETS AND SEARCH FOR INTELLIGENT LIFE.

(sourece: News paper ‘Times of India’)

     Exoplanets are the planets outside our Solar system, rotating around other stars.

     The following statistics give the intensity of search for the exoplanets.

1.      3500-plus exoplanets were discovered since 1988 across 2600 planetary systems

2.      2000-plus planets are found by Kepler space telescope alone.

3.      TrES-4 is one of the largest exoplanets and it is 1.7 times the size of Jupiter.

4.      Of the 2600 planetary systems astronomers have details of around 20 of them.

     A few of those include

1.      TRAPPIST-1 PLANETARY SYSTEM.

     It is 40 light years away. (1 light year = 9 trillion km). Its seven planets are known by b, c, d, e, f, g, h. Trappist b, c and d are on the border of habitable zone and can have liquid water under certain conditions. Trappist e, f, g are in the habitable zone. They surround the star known as Trappist-1, which is 1/12^th the size of our Sun, and is located in the constellation Aquarius.

2.      KEPLER-11 SYSTEM.

     It is 2000 light years from the Earth. Planets orbiting Kepler-11, a yellow dwarf star are larger than Earth. They are Kepler 11c, Kepler 11d, Kepler 11e, Kepler 11f and Kepler 11g. They are all in constellation Cygnus.

3.      KEPLER-90 SYSTEM.

     It is about 2500 light years away from us. It has a planetary system of 8 planets which are the same in number as our solar system. Before its discovery the solar system was considered as having more number of planets than any other star systems. The planet Kepler- 90i is rocky and hot. It orbits its star about once in every 14 days. It is about 30% larger than Earth and about as hot as Mercury reaching about 800 degrees F(427 degrees C).