Andy Briggs

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.

A ball of stars: globular cluster M13

What is a globular cluster?

Globular clusters are spherical collections of up to perhaps a million stars, orbiting mostly in the star halo of spiral galaxies, containing some of a galaxy’s oldest stars.

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.

A black hole surrounded by magnetic fields and an accretion disk.

What is astrophysics?

Observational astronomy and astrophysics work together to further our understanding of the cosmos. Astrophysicists apply the laws of physics and physical theories to interpret the light gathered by observational astronomers.

Yellow-orange donut shape against a black background.

What are black holes?

Black holes are among the most bizarre and enigmatic objects in the modern universe. Click in for a black hole introduction.