Though both dark matter and dinosaurs are independently fascinating, you might reasonably assume that this unseen physical substance and this popular biological icon are entirely unrelated. And this might well be the case. But the Universe is by definition a single entity and in principle its components interact.

My childhood books on geology had dramatic drawings of volcanoes belching steam into the atmosphere of a prehistoric and still-sterile Earth, suggesting that our planet was born with a subcutaneous reserve of water, waiting to be lanced to the surface by accommodating eruptions. As a kid, that sure seemed reasonable. But it's not true.

It will be fun to see what turns up in the Rosetta and Philae images and data from Comet 67P/Churyumov-Gerasimenko! Astronomy is always full of surprises when you see something at high resolution for the first time.