Is presence in Goldilocks belt enough for having life on a planet? No, besides distance from the sun, if the atmospheric condition of the planet is accurate to form and sustain water to its surface, can only have the possibility of life. For instance, like Earth and Mars, Venus too considered in the habitable zone of the sun, but life chosen the earth only. Why? NASA's Mars rover mission evidences the ancient bacterial life on mars . Later, due to the thin atmospheric layer it was not able to sustain water to its surface. On the other hand, Venus is too hot to origin the life. Its atmosphere consist a very thick layer of carbon dioxide. It absorbs sun energy and restricts revert it back, thus create a non habitable furnace. Bottlenecks for origin of life in the Goldilocks zoned planets: Billions planets in such zones in the universe orbit around different stars. For instance, NASA claims its recently discovered TRAPPIST-1 planetary system have ...
Subsequent evolution The planets were originally thought to have formed in or near their current orbits. From that, a minimum mass of the nebula i.e. the protoplanetary disc was derived that was necessary to form the planets – the minimum mass solar nebula. It was derived that the nebula mass must have exceeded 3585 times that of the Earth. However, this has been questioned during the last 20 years. Currently, many planetary scientists think that the Solar System might have looked very different after its initial formation: several objects at least as massive as Mercury were present in the inner Solar System, the outer Solar System was much more compact than it is now, and the Kuiper belt was much closer to the Sun. Terrestrial planets At the end of the planetary formation epoch, the inner Solar System was populated by 50–100 Moon- to Mars-sized planetary embryos . Further growth was possible only because these bodies collided and merged, which took les...
Before observations of dark energy, cosmologists considered two scenarios for the future of the universe. If the mass density of the universe were greater than the critical density , then the universe would reach a maximum size and then begin to collapse. It would become denser and hotter again, ending with a state similar to that in which it started—a Big Crunch. Alternatively, if the density in the universe were equal to or below the critical density, the expansion would slow down but never stop. Star formation would cease with the consumption of interstellar gas in each galaxy; stars would burn out, leaving white dwarfs , neutron stars , and black holes . Very gradually, collisions between these would result in mass accumulating into larger and larger black holes. The average temperature of the universe would asymptotically approach absolute zero —a Big Freeze .Moreover, if the proton were unstable , then baryonic mat...
Comments
Post a Comment