What is the theory behind how life became extinct on other planets in our solar system?

[fuadalami]

So yesterday my buddies and I were watching a Neil deGrasse Tyson video and he was talking about space and how we've seen traces of life on other planets. As he talked about the planets he kept on referencing some sort of changing factor that tweaked the system which caused like to disappear from there. Thinking to myself what could be that factor? I concluded that over time as the sun continues to shrink, the exterior planets begin receiving smaller amounts of heat, eventually not enough to sustain life on the planet. Then planet by plant slowly we arrived at earth and our next planet to live on is not Mars but Venus. Are their any studies that say anything like that or can you guys point out any flaws in my thoughts?

[pzkpfw]

Organic molecules have been detected "out there", but that doesn't mean "life".

 

No direct evidence of life has yet been found off Earth (apart from on craft we've sent up ourselves).

[Robittybob1]

So yesterday my buddies and I were watching a Neil deGrasse Tyson video and he was talking about space and how we've seen traces of life on other planets. As he talked about the planets he kept on referencing some sort of changing factor that tweaked the system which caused like to disappear from there. Thinking to myself what could be that factor? I concluded that over time as the sun continues to shrink, the exterior planets begin receiving smaller amounts of heat, eventually not enough to sustain life on the planet. Then planet by plant slowly we arrived at earth and our next planet to live on is not Mars but Venus. Are their any studies that say anything like that or can you guys point out any flaws in my thoughts?

The Sun is actually getting more intense. Eventually the Sun will expand rather than shrink.

[StringJunky]

The Sun is actually getting more intense. Eventually the Sun will expand rather than shrink.

Yeah,Earth will get boiled dry eventually, apparently. as the Sun transforms to a giant red.

[Phi for All]

Then planet by plant slowly we arrived at earth and our next planet to live on is not Mars but Venus.

 

In about a billion years, our sun is going to start burning more of the helium it's been converting from hydrogen, and the Earth will get about 10% more sunlight. This will basically turn us into another Venus, and our oceans will evaporate into space. Eventually, when the sun goes red giant in a few more billion years, the sun's corona will be out past Mars, so the inner planets will be gone.

 

We need to find another star, but we'll be using this one for quite a while. We probably don't need to worry about the sun as much as keeping our own ecosystem viable until we figure out how to remain off planet.