Andy Briggs
A telescope view of a section of space, containing many galaxies.

What is a galaxy?

We live in a galaxy called the Milky Way. But there is so much more to know about these grand and glorious star islands in space! Click in here, and prepare to have your mind expanded.

A ball of stars: globular cluster M13

What is a globular cluster?

Unlike the open star clusters – containing sibling stars, scattered through the disk of our galaxy and presumably other galaxies – globular clusters are big, symmetrical and old, like an earthly city’s oldest and most staid citizens.

A horn-shaped graphic depicting the various epochs of the universe.

What is the Big Bang?

In the view of modern cosmologists, the Big Bang is the event that marked the birth of our universe.

What’s a constellation? What’s an asterism?

Both constellations and asterisms are patterns of stars. What’s the difference?

A bright star next to a starry cloud.

A mystery solved? Fast Radio Burst detected within Milky Way

Fast Radio Bursts are very mysterious bursts of radio waves – perhaps just a thousandth of a second long – coming from all over the sky. This new discovery of one in our own galaxy is a stunner!

A man in a white coat and mask, bending over a machine.

What are gravitational waves?

First postulated by Albert Einstein in 1916 but not observed directly until September 2015, gravitational waves are ripples in spacetime.

What are exoplanets?

Exoplanets are worlds orbiting distant stars. The history of our knowledge of exoplanets, the various types of exoplanets, how astronomers find them, and more, here.

Three connected boxes with what looks like different configurations of galaxies and voids inside.

What is dark energy?

Dark energy is one of the great unsolved mysteries of cosmology. It’s now thought to make up 68% of everything in the universe.

Airy-looking, cosmic-looking painting, dotted with round holes of various sizes.

What is dark matter?

Dark matter doesn’t emit light. It can’t be directly observed with any of the existing tools of astronomers. Yet astrophysicists believe that it and dark energy make up most of the mass of the cosmos. What dark matter is, and what it isn’t. here.

A white ball representing a star, with distorted-looking lines around it.

What is a neutron star?

Neutron stars are born in supernova explosions. They are stars with a couple of times our sun’s mass, squeezed into a sphere the size of an earthly city.