[Flipside]

http://story.news.yahoo.com/news?tmpl=story&u=/afp/20040825/sc_afp/space_astronomy_planets

Not much to go on yet, but interesting nonetheless

[aldo_14]

'super earth'

Neat.

[Rictor]

Proably just my general ignorance, but I though that there was millions if not billions of planets discoevered outside our solar system. But I guess I was wrong, in which case this is a very exciting find indeed.

And only 50 light-years away. Why, we're practically neighbors

[TopAce]

Interesting ...

[Styxx]

Originally posted by Rictor
Proably just my general ignorance, but I though that there was millions if not billions of planets discoevered outside our solar system. But I guess I was wrong, in which case this is a very exciting find indeed.

And only 50 light-years away. Why, we're practically neighbors

Not really. Planets in other solar systems are really hard to see, that's why up to now mostly gas supergiants had been positively identified...

[Ford Prefect]

It's 14 times the mass of Earth? That's a big motha f*ckin' rock, motha f*cka!

[karajorma]

Originally posted by Rictor
Proably just my general ignorance, but I though that there was millions if not billions of planets discoevered outside our solar system. But I guess I was wrong, in which case this is a very exciting find indeed.

And only 50 light-years away. Why, we're practically neighbors

The theory is that there are millions of planets out there but until now we've only found a small number of them. They've found lots of Jovian and super-jovian planets cause until now that was pretty much all we could find. This on the other hand is a rocky planet with an atmosphere. What's more if the atmophere contains significant quantities of oxygen it's almost certain that there is life on the planet.

From the original story However, there is the tantalising question as to whether it lies within the "Goldilocks Zone" -- a distance from its star that is not too hot, not too cold, just right.

I guess by this they mean the zone which Europa, the biggest chance for life in the solar system apart from Earth is OUTSIDE of?

I wish astrobiologists would stop talking about habitable zones. The science moved on about 20 years ago.

[phreak]

the planet's orbital period is 9.5 days.  I don't think thats very good for water

[Vaelinx]

Originally posted by karajorma

I guess by this they mean the zone which Europa, the biggest chance for life in the solar system apart from Earth is OUTSIDE of?

I wish astrobiologists would stop talking about habitable zones. The science moved on about 20 years ago.

Not necessarily.  The "goldilock's zone" that they speak of isn't necessarily a set band around the primary star.  Europa is close to Jupiter, and would have NO chance for life if it were not close to Jupiter.  Jupiter was almost a star is the cosmic sense, as it's mass is only two-three orders of magnitude off.  Jupiter emits certain forms of radiation, primarily infra-red, nearly as much as a star.  So what you have with Jupiter, and any other similar gas giant of its mass/composition, is a mini-system of sorts.  Europa is lucky in that it may be in an acceptable zone to sustain certain forms of life.  It's surface may be frozen, but not all the way down...  :devil:

[Gloriano]

Somewhere there is life in this Galaxy.. maybe in that planet that would be kinda cool




Vaelinx  

[karajorma]

Originally posted by Vaelinx
Not necessarily.  The "goldilock's zone" that they speak of isn't necessarily a set band around the primary star.

That's exactly what they say it is in the article. Hence my condemnation of it.

Originally posted by Vaelinx
Europa is close to Jupiter, and would have NO chance for life if it were not close to Jupiter.  Jupiter was almost a star is the cosmic sense, as it's mass is only two-three orders of magnitude off.  Jupiter emits certain forms of radiation, primarily infra-red, nearly as much as a star.  So what you have with Jupiter, and any other similar gas giant of its mass/composition, is a mini-system of sorts.  Europa is lucky in that it may be in an acceptable zone to sustain certain forms of life.  It's surface may be frozen, but not all the way down...  :devil:

I know full well why Europa is a good candidate. In fact it's the squeezing of the planet by Jupiter's gravitational field not it's radiation output that makes it viable. I know full well about the oceans below Europa and the fact that it may have black smokers similar to Earth. That doesn't change my viewpoint one bit.

The whole concept of habitable zones is bollocks. 20 years ago black smokers were considered uninhabitable. Any part of a system with conditions similar to a black smoker would be considered impossible for life but now we know that not only are they good conditions for life but that on top of that life on Earth may have started in one.

The simple fact is that liquid water isn't a requirement for life. There are other ways to get the complexity required. Water is however a very good solvent and as such life becomes more likely when it is present.  Scientists get hung up on looking for planets exactly like Earth. In fact there are probably scientists ruling out this newly discovered planet because the gravity on the planet would be too high. Like that makes a difference to the formation of amino acids or whatever chemicals life on this planet could have chosen to use.

Life may be able to evolve in other conditions other than the ones we have here on Earth. Just because life did evolve here doesn't mean that this is the only possibility.

Anyway Vaelinx.  Enjoy your stay

[jdjtcagle]

We are Carbon based life, and there are a whole LOT of other elements

[StratComm]

Originally posted by PhReAk
the planet's orbital period is 9.5 days.  I don't think thats very good for water

I noticed that too.  The star may be a brown dwarf though, which would mean much smaller solar radiation output and therefore a habitable zone that extends very close to the star.  And that concept is far from obsolete as some have indicated; life needs a sustainable energy source to survive, while not one so intense that it destroys anything less dense than solid rock.  Mercury, for example, is not a candidate for life in any form, because our sun has not only fried the surface by its proximity but quite possibly cooked much of the surface rock away over the past 5 billion years.  The outer planets and moons don't recieve enough solar radiation to sustain life, and none are large enough to still have active geothermal activity either.  Europa, on the other hand, is a bit of an exception; the amount of solar radiation it recieves is less than the commonly assumed requirements for life, but it is protected to a large degree by Jupiter's gravity well that serves to sweep the inner solar system of smaller debris that will have serious disruptions on life (it has also likely helped Earth avoid a constant bombardment of asteroids as well) and it does recieve some boons from Jupiter's radiation output and magnetic field as well.

EDIT:  In other words, habitable zones are more about the net amount (and to a degree, the concentration) of solar radiation on a planet, not between two fixed radii out from the star.

I did read somewhere that planets could travel in a much less circular orbit and still meet the requirements for habitability, maybe that's what's happening here.  It just seems a little far-fetched that something that close to a star could sustain liquid anything, and I really don't know how life would evolve from solid rock.

[karajorma]

Exactly. Silicon isn't quite as good a choice but silicon analogues can be made of many simple carbon chemicals.

Besides there is no reason why you can't make complex molecules that react in liquid methane as long as they are non-polar and don't require metal ions the way our bodies do.

Sure you might not get complex life in liquid methane that often but I'm talking about life not intelligent life.

[Grey Wolf]

jdjtcagle, it's actually a bit more limited than that. Elements that could potentially form the macromolecules required for life are basically restricted to Group 14.

[jdjtcagle]

Didn't know that...

[karajorma]

Originally posted by StratComm
Mercury, for example, is not a candidate for life in any form, because our sun has not only fried the surface by its proximity but quite possibly cooked much of the surface rock away over the past 5 billion years.  

You're right because we now know that mercury's rotational period is different from that of it's orbit but until recently Mercury was thought to be a one face planet which rotated as quickly as it orbited the sun.

Now it follows that if the planet is blisteringly hot on one face and freezing cold on the other there must be a region between the two extremes.

 I doubt Mercury does have life since it has no atmosphere and since it's now proven that it isn't a once-face planet but if it was the possibility existed that there might be life on the planet.

See what a load of crap habitable zones are now? Basically all that is needed is energy. This doesn't even have to come from the star. It doesn't in the case of Europa after all.

[Flipside]

However, iirc, even on Earth we are constantly finding different pressures, temperatures etc in which to make carbon and oxygen molecules react in different ways, so the possibilities aren't as limited as it seems

[jdjtcagle]

Kara: Yep, the radiation from Jupiter is enough...

[Grey Wolf]

You don't need the sun at all, actually. Take a look at deep-ocean vents. The energy for those ecosystems is all geothermal and chemical.