When you’re headed toward the Moon or planets, there are no signposts to keep you on the right track. Fortunately, nature provides its own markers: the stars. Spacecraft orient themselves by sighting on the Sun and one or more other stars. In the early days of space exploration, the most popular of those stars was Canopus.
Canopus is a good navigational beacon because of a combination of brightness and location. It’s the second-brightest star in the night sky — only Sirius outshines it. And it’s far south in the sky, in a region with no other bright stars. That makes it an easy-to-find target.
Canopus is more than 300 light-years away. It looks so bright because it’s more than 400 times brighter than Sirius, and ten thousand times brighter than the Sun.
The star is eight times the mass of the Sun. So even though it’s billions of years younger than the Sun, Canopus is nearing the end of its life. It’s uncertain how its demise will play out. It straddles an important dividing line. On one side of the line, it would end as the Sun will — throwing off its outer layers, leaving a hot, small corpse known as a white dwarf. On the other side, it would blast itself to bits as a supernova — briefly providing an especially bright signpost for exploring the universe.
Canopus is so far south that you need to be south of about Dallas to see it. It’s due south about 9 or 10 p.m., well below Sirius — another bright beacon.