Science Forums 2

[CraigD]

Originally Posted by Lord Hakk

Did we under estimate the age of our sun?

I doubt we’ve significantly misestimated the age of the sun or planets, because a pretty good sampling of similar stars (and less, but some data on their planets) appears to support our estimate of about 4,570,000,000 years. Most models have the planets reasonably good places for live by about 3,800,000,000 years ago. There’s pretty good evidence that some sort of live was present on earth almost as soon as this, and a lot of life by about 2,500,000,000 years ago. Despite evidence of some fairly awful catastrophes, since then, life seems firmly entrenched on Earth.

So, I don’t think it’s necessary for the solar system to be significantly older that current estimates to support a hypothesis of there having been life, and possibly still being life, on other planets

Maybe earth is the last planet to house life in the solarsystem.

Maybe. I think it’s premature to rule out the possibility of life on bodies of the solar system other than Earth, though evidence suggests that life on the other inner planets (Mercury through Mars) is anything from non-existent to paltry, compared to Earth.

Maybe those bumps on Venus are ruins of alien life.

I think this is unlikely, as we’ve only RADAR mapped a fraction of the surface of Venus at a resolution of about 1 km, a smaller fraction at a resolution of about 100 m, and imaged from landers a couple of tiny patches, at human eyesight-like resolution. With this resolution and coverage, even a fairly obvious large artifact, such as a road bed or a structure, could easily have been missed.

Although Earth seems clearly to be the “sweet spot” of the solar system for biological life, there’s much more unexplored than explored in the solar system in ways capable of detecting signs of past or present life. On the general principle learned from life on Earth that “where there’s usable energy, there’s life”, I harbor a strong suspicion that the atmospheres and moons of Jupiter and Saturn might also be “sweet spots.”

Whether and what sort of life we find in the solar system, the search will likely be exciting to participate in or follow!