THIS column comes to you from a very different place 鈥� Australia, where I have been accompanying a New Scientist Discovery Tour to see the hybrid solar eclipse visible from the west of the country. I have had two weeks of stargazing here, getting to know the sky from a new perspective.
No matter where you live in the world, Mars is taking a little stroll through Gemini this week, so it is a great time to get to know this lovely constellation with its prominent twin stars, Castor and Pollux, and take a look at the Red Planet at the same time. Each night Mars will appear to be in a slightly different place, but throughout the end of April and until around 14 May, when it starts to move into Cancer, it will be near Castor and Pollux in the sky.
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There are a few ways to find these stars, but one of the simplest is using the nearby constellation of Orion and its two brightest stars, Betelgeuse and Rigel. Betelgeuse is the red giant that makes up Orion鈥檚 left shoulder. It appears in the top left of the constellation from the northern hemisphere, or in the bottom right as seen from the southern hemisphere. On the opposite side of Orion鈥檚 belt sits Rigel, the blue-white supergiant. This makes up Orion鈥檚 right foot 鈥� so again, it will be in the bottom right of the constellation in the northern hemisphere, but at the top left for those in the southern hemisphere.
To find Gemini, draw a line from Rigel to Betelgeuse, then keep that line going about the same distance again. You will see two bright stars: Castor and Pollux. If you are looking at the end of April or the beginning of May, a bright red 鈥渟tar鈥� will appear near the twins 鈥� this is Mars. Take a look through binoculars to make the rusty hue of the planet a little clearer.
Those who live in the northern hemisphere might think of Orion as a northern constellation, since we are familiar with the upright figure of a mythical hunter that we ascribe to it there, but it is important all over the world.
During my trip to Australia, we were given a fascinating talk on Indigenous astronomy by Peter Swanton at Mount Stromlo Observatory near Canberra. He told us how the Kokatha people of Australia鈥檚 Great Victoria Desert have a story about this constellation. They describe it as a hunter called Nyeeruna who tried to woo the seven sisters, or Yugarilya, the stars that make up what is also known as the Pleiades.
The sisters wanted nothing to do with him. Nyeeruna got angry and used fire magic 鈥� he lit his fire and it got brighter, and this caused the star we know as Betelgeuse to become more vivid and then dim. This story, which also talks about the dimming of the star Aldebaran as one of the sisters faced up to Nyeeruna to fight him off, represents one of the oldest human records of stars such as Betelgeuse that display variable brightness.
What you need
Binoculars
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