Life -Sustaining Planets

Abiogenesis is the natural process of life arising from non-living matter, such as simple organic compounds. The prevailing scientific hypothesis is that the transition from non-living to living entities was not a single event, but a gradual process of increasing complexity. Life on Earth first appeared as early as 4. 28 billion years ago, soon after ocean formation 4. 41 billion years ago, and not long after the formation of the Earth 4. 54 billion years ago. The earliest known life forms are microfossils of bacteria. Researchers generally think that current life on Earth descends from an RNA world, although RNA-based life may not have been the first life to have existed. The classic 1952 Miller–Urey experiment and similar research demonstrated that most amino acids, the chemical constituents of the proteins used in all living organisms, can be synthesized from inorganic compounds under conditions intended to replicate those of the early Earth. Complex organic molecules occur in the Solar System and in interstellar space, and these molecules may have provided starting material for the development of life on Earth.

"Cassini's seven-plus years... have shown us how beautifully dynamic and unexpected the Saturn system is," commented project scientist Dr. Linda Spilker of NASA's JPL to Time Magazine's online edition on March 23, 2012. Therefore, the results of the new study support the idea that primitive life could potentially have evolved on Ganymede. This is because places where water and rock interact are important for the development of life. For example, some theories suggest that life arose on our planet within hot, bubbling seafloor vents. Before the new study, Ganymede's rocky seafloor was believed to be coated with ice--not liquid. This would have presented a problem for the evolution of living tidbits. The "Dagwood sandwich" findings, however, indicate something else entirely--the first layer on top of Ganymede's rocky core might be made up of precious, life-sustaining salty water. This gigantic "King of Planets" is considered by some astronomers to be a "failed star". It is about as large as a gas giant planet can be, and still be a planet. It is composed of approximately 90% hydrogen and 10% helium, with small amounts of water, methane, ammonia, and rocky grains mixed into the brew. If any more material were added on to this immense planet, gravity would hug it tightly--while its entire radius would barely increase. A baby star can grow to be much larger than Jupiter. However, a true star harbors its own sparkling internal source of heat--and Jupiter would have to grow at least 80 times more massive for its furnace to catch fire.