13.7 bln years old:

http://www.nytimes.com/2003/07/11/national/11PLAN.html?ex=1058500800&en=376db8d91712a12f&ei=5062&partner=GOOGLE

The discovery of the oldest and most distant planet yet--it's 13 billion years old and is twice the size of Jupiter--has astronomers reeling because it could change their theories about when planets formed and when life could have first evolved. Alan Boss, an astronomer at the Carnegie Institution in Washington, told The Associated Press that finding such an ancient planet is a "startling revelation" because it means that planets could have formed within a billion years after the Big Bang, far earlier than most theories have stated. "This means that 13 billion years ago, life could have arisen and then died out," he explained to AP. "This has immense implications."

Interesting.... :eek:

Just because of its sheer age I would look there first for artifacts of civilization. (ie: spacejunk) Of course it is so far away that the planet wouldnt necessarily even be there when a probe reached it.

how can they determine how old it is?

Originally posted by Datura
how can they determine how old it is?

I'd guess by estimating how old the star around it are.

and that would beg the question, how do they know that?

This planet was found in a globular cluster; the stars of all globular clusters are about the same age, around 12-14 by, estimated from their positions in the Hertsprung Russell distribution; see
http://www.seds.org/messier/glob.html
as the most accurate age for the universe we currently have is 13.8 by old the clusters must be all very early stars, and any planets would need to be of a similar age, as planets are created at the same time as their stars (though I wonder if this is necessarily true.)
-----------------------------------
SF worldbuilding at
http://www.orionsarm.com/main.html

It is merely an assumption. The planet could have been captured from another system independent of the cluster. The cluster is in orbit around our galaxy and is constantly disrupting the orbits of millions of systems as it makes its fat way through the galaxy.

Yet it seems to me that the creation of sub brown dwarf objects, namely jovian planets with out a parent star is very likely and that these dark planets came about at the same time as the first stars appeared. Maybe their just as numerous as stars???

here's a better article on the subject, tells everything much more detailed
really advice to read it, because the history of that planet is much more intriguing
nytimes is hardly a good place to look for space info ;)
Then the planet was booted from its stellar orbit and captured by the gravity of another star that was well into its death throes........
http://www.space.com/scienceastronomy/oldest_planet_030710-1.html

Early planets YES, early life NO

Keep in mind these first generation planets are likely all hydrogen gasgiants, rocky planets like the earth formed after the first stars burnt out and produced heavy elements, wouldn't be much carbon based lifeforms without the supernova death of a few stars.

But one interesting thought is that there could be really many many many of these orbiting gas-giants or even rogue planets (without a central star) , maybe even enough to make up for some signifivant portion of the missing dark matter ???

I haven't seen mass counts that include the average planetary mass of solar systems.....