SPORE Space Mission SOS!!?

I'm in the Space stage and well, I'm doing this mission (You gotta find three pieces of a grail artifact and deliver them back to the planet) and they give you a list of the three planets you can find the pieces and I got the first two and on the third planet (Rayle) I found an artifact (a tablet piece) and it had nothing to do with the mission but the radar wasn't picking anything up. I went back through all three of the planets with no luck. I just can't find that third piece! Does anyone know what I'm talking about and can help me? Thanks!SPORE Space Mission SOS!!?
This happend to me as well. On one of those missions, I apparently picked up a wrong artifact. I ended up going back to all the planets and found it. All I can say is try checking again. Make sure that you don't confuse the lines pointing at the artifact planets with the lines pointing at the planet you need to delive them to. The planets with the lines that have arrows in them are pointing toward the artifacts. It's sometimes hard to see if you're zoomed out.SPORE Space Mission SOS!!?
This kinda happened to me too, the farthest planet to the left is the one you are supposed to take the artifact to. The three on the right are the ones that the artifacts are on, if the radar doesn't pick up the artifact fly around the planet and it should eventually pick up the signal, if it doesn't then I guess you'll have to find it yourself, but try going to the planet your trying to take it to and see if you really do have it or if you have to go back and find it again.