As far as I can tell, the two levels don't have any true difference other than price. If the planet has say, expert metal miners, there's an equal chance of finding it on either the first or second.

Being that the chance of finding anything at all on a planet is on the lower end of the scale, the odds of finding *two* such goodies is even lower.

This means that if you find nothing on the first go, it's very possible you singly got the short straw and missed the goodie. However, if you do find something on your first try, doing the second exploration is gambling on weather or not your planet has double bonuses.

This means that if you find something the first time, the second upgrade will be statistically less effective.

I think its based on whats on the planet usually you'll find resources at 50% and artifacts at 100% but i have gotten resources at 100% as well. if you get a resource off a planet i think it boosts your asteroid rate when getting crystal and/or metal.

if you find a planet with heavy neutral defense you can usually find artifacts on them.

Like someone else said, unless the second has a lower probability you are true, if not you are mistaken.

You are saying basically that once you roll a 1 on a dice, on the second roll you have a lower chance to get a 1 ...

True but what he said is false, he (Quinburger) said that if you find something on a planet, you have a lower chance to find something else on your second try ...

The only reason you should not explore a second time, is that it is more expensive, so you could explore another planet for cheaper ... Although if you did explore all your planets, you could go for this second try ...

Mothership (-60% development cost at lvl 3 colonization) plus tech (-40% cost for searching for artifacts) will give you free artifact search

I'll admit, i've gone and upped the percentage of bonuses in my games.