Went there, never saw the Remans, never saw this mythological crater, and never got this so-called button to scan. YES! This is a SERIOUSLY bugged mission. Four goes, an hour each time, and no crater, no scan, no fight with the Remans. I did however, see the Unidentified Vessel sitting under the moon on my second go round, as I was leaving, though. But, no. This mission is seriously SNAFUed.
I didn't have any problems with this. The crater is right there on the planet. Your first scan is supposed to be interrupted. You turn away, see the Iconian ship, it momentarily disables you and disappears. Scan again. ta-da