Think of Mercury as a metal ball a bit larger than our Moon, with a rocky crust on top. more about Mercury at #365DaysOfAstro with @blackrockcastle
The Fermi Paradox: Given the size and age of the universe there should be extra terrestrial life but how come we can find no sign of it.
Bayer names, Flamsteed numbers and the Henry Draper catalogue – how to name falling star.
Daily sunspot records have been kept by most major observatories since the mid-1800s and there are records going back thousands of years of these dark areas on the Sun’s face.