What Is the Milky Way? Our Galaxy, Seen From Australia
On a clear, dark night away from city lights, a pale, glowing band stretches right across the sky. I saw it properly for the first time on a camping trip…
Once in a Blue Moon: The Surprising Origin of the Phrase
We use “once in a blue moon” for something that happens very rarely. My parents said it all the time when I was growing up, and I always wondered what…
What Is a Barycentre? Why the Moon Does Not Just Orbit Earth
What is a Barycentre? A barycentre is the centre of mass of two or more objects orbiting each other, the point around which they actually move as a system. (In…
When Will the Sun Die? Its Age, Its Future and Our Fate
The Sun has been rising every morning for longer than there has been anyone to watch it, so it is easy to think of it as permanent. But like every…