"Life" on planets? How is it measured/counted?

[Alcator]

When life evolves on a planet, the planet gets a shield and 4 indicator arcs (each 90 degree wide) inside - initially "dark". Then, as time progresses, these start filling in. Also, defensive laser cannons appear on the surface. Furthermore, the planet starts producing spaceships.

Which of the things is a representation of how much life is there on the planet? I'm asking in regards to the "Maximum life in your system" achievement.

[impending_zombie_apocalypse]

it's in regards to how many planets around your star support life, i think the total planets you can have is 10 and thusly 10 life planets, i could be wrong though, i got the achievement but it was a long while ago.

[mat.duf]

I personally have a system with 10 life planets and didn't get the achievement.


Edit : OK just got it.
Basically what you need is a system with at least 2 suns + 10 life planets with max XP (max XP gives 4 turrets on the surface of the planet).

I got luck because I get more than 5 almost maxed life planet by stealing some to the system you need to defeat in the 3rd part of Duel.

[Alcator]

Thank you, gentlemen!

[MORKITE=GREEN(52,127,126)]

i always thought that the higher the exp bar is, the more ships + turrets you have on that planet. the normal arrow ships are like fighters, theres one that shoots missles, and one thats purely anti planet/sun.