What’s a safe distance from a supernova for Earth?

What's a safe distance from a supernova? To survive a supernova, recent data says Earth would have to be at least 160 light-years away from the exploding star.

How many red dwarf stars in nearby space?

Astronomer Guy Ottewell uses 2 charts - showing 2 different volumes of space - to contemplate and question the density of red dwarf stars in our Milky Way.

A deep penumbral lunar eclipse overnight tonight

A penumbral lunar eclipse happens tonight, May 5-6, 2023. It's visible from eastern Europe, Africa, Asia, Australia, New Zealand, Antarctica and Indonesia.

What are white dwarf stars? How do they form?

A white dwarf is the incredibly dense core of a dead star, left behind when the star exhausted its fuel. Our sun will become a white dwarf one day.

Hybrid solar eclipse: An annular-total on April 19-20

A hybrid solar eclipse will cross Australia, Timor-Leste and Indonesia on April 20, 2023. Surrounding areas will see a partial eclipse. Find maps and more here.

What is a neutron star? How do they form?

A neutron star is born from a supernova explosion. They contain a couple of times the mass of our sun, squeezed into a sphere the size of a city on Earth.

The attitude of the Swan and the Northern Cross

Guy Ottewell answers the question: Since the Northern Cross is vertical as it sets in the west, why is it not also vertical as it rises in the east?

Green comet passes Aldebaran on February 14 and 15

The green comet - Comet 2022 E3 (ZTF) - will pass near the bright star Aldebaran on February 14 and 15. Find maps and guidance on how to see the pair.

Comets and asteroids: What’s the difference?

Comets and asteroids both orbit our sun, but usually reside in different parts of our solar system. And except for a few, they're different materials.

Asteroid close encounter January 26: How to watch online

Asteroid close encounter today! Near-Earth asteroid (2023 BU) will pass safely 2,174 miles (3,500 km) away from Earth. Details here on how to watch online.