The first three Winking Cat Treasure Hunt challenges expire tomorrow. You will need an SRV hangar, a DSS (Detailed Surface Scanner) and whatever FSD you can afford. Land at the crash/cache sites and scan them with your SRV for the rewards. See u/Cmdr-Owl's
Tomorrow the first three caches expire, reducing awards to 120M and one free ship. The second three will last another week before expiring.
One final note about Mitterand Hollow: this moon orbits fast – really really fast. So fast that catching up to it in supercruise is difficult. Approach from in front of the moon and let it come to you. See