The sky is full of potential triangles. All you need is three stars that aren't in a line. We have large triangular asterisms – the Summer, Spring, and Winter Triangles. And there are also two triangle constellations. The northern one is Triangulum, and it has a surprisingly long history.

The year 2018 was a good one for astronomers. Mars, asteroids, and the outer Solar System had the spotlight more than once. Gaia is bringing the Milky Way into focus, and Hubble found the most distant star ever seen. Here are my choices for the top astronomy stories of 2018.

It's been a year of discoveries, celestial spectacles, and new developments, though tempered by some sadness, for those interested in astronomy and space. Here are my choices for the notable events in 2018.

Aurorae, Moon visitors, stars, planets, and more are in the astro countdown to Christmas. Here are the days from mid-Advent to Christmas Eve.

Northern lights, space probes, astronomers, astronauts, stars, planets and other interesting things in space and astronomy. All of these and more are in the astro countdown to Christmas that began on the Bellaonline Astronomy Forum.

There are several canines in the night sky, including a wolf and a fox. But the best known canine constellations are Canis Major (the Greater Dog) and Canis Minor (the Lesser Dog).

Here are 30 people who made contributions to astronomy and space. Ten of them were also born between Halloween and the Winter Solstice. Can you match them to their birthdays?

Haumea is a dwarf planet in the Kuiper Belt, a region of icy bodies beyond the orbit of Neptune. It's a bizarre little object whose discovery was controversial, has the shortest day of any known large body, and is one of family of objects produced by a massive collision in the early Solar System.

Barely visible to the unaided eye, Messier 8 (M8) – the Lagoon Nebula – lies about five thousand light years away in the constellation Sagittarius. It's over a hundred light years across, an enormous turbulent stellar nursery.

2018 was the 10th anniversary of the Astronomy Photographer of the Year awards. The Royal Observatory Greenwich first hosted them in 2009. But this year the event was in the National Maritime Museum, and the 2018 images - plus some great past winners - are on exhibition in a brand new gallery.