Life's most vital elixir may have formed within 200 million years of the Big Bang, new research suggests. Conditions for producing water were thought to be lacking this early on because heavier ...

BRAVAIS, in his great memoir 1 on this subject, divides circumzenithal arcs into two classes, ordinary and extraordinary. “Les arcs circumzenithaux ordinaires sont les arcs tangents aux halos de ...

Similarly, galaxy clusters are suffused inside vast haloes of dark matter, which we can detect indirectly. Scientists are ...