Second of 10 billion habitable planets discovered

Just spotted some news that the first rocky planet with a moderate temperature has been identified, and a very rough first estimate how many there are in our galaxy.

"That would mean perpetual daylight on one side of the planet and permanent shadow on the other. A first approximation suggests the temperature would be 71 °C on the day side and -34 °C on the night side, though winds could soften the differences by redistributing heat around the planet."

How do we define "habitable"?

If we lived in "the land of eternal sunrise", about how big would the start appear to be?  Would it be safe to look at?  How bad are the tides, and how did we get that image of the planet-sun system, if the only way to detect is is by detecting the star wobbling?

Maybe we could colonize it!  A little off topic, but around how fast do we need to go to cover 20 light-years in 20 years?  Normal car speed would take about forever, but light speed would get us there instantly (from our view), so what would make it 20 years from our perspective?

Well, that might sound uncomfortable for us, pawn_slayer666, but there are bacteria on Earth that live at over 100 degrees centigrade, and life may even have evolved at high temperature. If I recall correctly, the article also points out that this planet has temperatures in between these two  extremes, on the border between the hot side and the cold side (which is permanent if the rotation is synchronous).

pawn_slayer666's last question about how fast you need to go to travel 20 light years in 20 years perceived time is interesting, and an easy calculation.

If you go at a fraction f of the speed of light, distances will be contracted by the Lorentz factor: 1/sqrt(1-f^2)

So to go a light year in 1 year, you simply need 1/sqrt(1-f^2) = f, so that the contraction corrects perfectly for the amount you are slower compared to the speed of light.

This gives f = 1/sqrt(2), so the speed is about 0.707c

the numbers are starting to fall into place in Drake's Equation :-P

Well, rough estimates of the first factors are being supported.

There is vast uncertainty in some of the other factors for now  ...

Well well well... what have we here?  alien life?

http://www.foxnews.com/scitech/2010/10/11/scientist-claims-strange-signal-comes-alien-planet/ 

Nice one!

"It's life, Jim, but not as we know it..." 

Regarding Drake's equation, one of the most crucial parts of it is the development of complex life from single celled life. There's a new view that this can only have been achieved by the symbiosis that occurred when a single-celled organism engulfed the bacteria that have ended up as our mitochondria, something that always fascinates me.

"These obstacles were overcome when a cell engulfed some bacteria and started using them as power generators – the first mitochondria."

 Very interesting to me though i am still unclear about what the one time event is. Or was!

I think their idea is that the symbiosis with the precursors of mitochondria was essential before complex life arose. Such events are extremely unlikely, rare, and crucial. And this particular one probably occurred once after a couple of billion years of single celled life, without it happening.

I've always been fascinated by mitochondria. They are still fundamentally separate from everything else in an organism, because they pass their (rather different) DNA down through the maternal line, rather than having it incorporated into the DNA in the nucleus (although over time much of the mitochondrial DNA has been incorporated into nuclear DNA, and much of this DNA dropped from the mitochondrial DNA because the cell provides the mitochondrion with whatever proteins it made instead). What is left in the mitochondrion is utterly crucial, as it provides most of the energy all the cells need. As well as this, it is the most hazardous part of the cell, as the energetic reactions create most of the free radicals we are exposed to and, to compound the issues, the mitochondrial DNA is not as well protected from damage as nuclear DNA (probably because of its origin from an early primitive unicellular organism). On the plus side, mitochondrial DNA is circular, rather than having ends, so no telomeres are needed! But this is not enough to compensate for the other factors. Overall, this is why a lot of people believe in the mitochondrial theory of ageing, which says that it is the gradual degrading of our mitochondria (due mainly to damage from free radicals produced by them) which is the most important factor in ageing. A major issue is that as mitochondria degrade, they leak more free radicals and these damage the rest of the cell, including the nucleus (as well as further degrading themselves).

This is also why there was quite a lot of excitement about some research that showed that in mice, a combination of two key chemicals (acetyl L-carnitine and alpha lipoic acid) rejuvenated mitochondria, and made the mice behave as if they were younger . The combination appears to increase the efficiency of energy production from fats and reduce the amount of free radicals formed.

Thanks Elroch, it makes much more sense to me now!

"The University of California has patented the LA/ALC combo as a way to enhance metabolism and alleviate oxidative stress."

I could really use some of this stuff! ;-}