Another worlds

Over 200 planets have been discovered outside Solar System¹⁾: most of them are gas giants like Jupiter.

How many planets are inhabitated by intelligent beings?

One of them has following features:

• it rotates around a „recycled” star, i.e. a star of the second generation, created in a  gravity collapse of the remains of the previous star, which ended its life with an explosion
• the star is located at the outskirts of the galaxy, where  enough of heavy chemical elements is present, but where no strong gamma radiation sources exist and not too many black holes
• a satellite of a similar mass (1/6), travels around the planet  and stabilizes its orbit
• the atmosphere of the planet contains properly balanced amounts of the H2O and CO2, what causes a natural greenhouse effect (33K) and therefore water remains a liquid (not a gas or ice) – with an average temperature +15°C
• several global glaciations period happened in this planet’s history, what accelerated and differentiated the biological evolution

Do you know what that planet is?

If not, look out of the window!

Earth shape

Earth is not ideal ellipsoide. In real it is geoide with differences in height +/- 100m.

1) First of them was discovered by Alexander Wolszczan, see for example
Wolszczan A,   Confirmation of Earth-mass planets orbiting the millisecond pulsar PSR B1257+12 
Science 264 (5158): 538-542 APR 22 1994