The scientists are worried because of 4-part helium molecules that are only seen in ancient times. Regular helium is 1 part. The idea is that where ancient molecules are identified, you're looking at some pretty old issues returning. At least that's what I gather by some reading and some looking at science-based you-tube explanations. If I'm mistaken it's because I misunderstood some very scientific language known efficiently by chemistry majors. I only took Chem 101 in premed, and that was long, long ago. I had to stop school in the 80s because I was worried about my kids' behaviors while I was studying 90 hours a week. They deserved to have a caring parent around when they may have opened the wrong door in their young lives. It was worth it. Both of them retired from their jobs recently, one was a top cop, the other a beloved computer consultant to large companies.