Astronomy – Changing skies

As the seasons change, so do our night skies. We start saying goodbye to Matariki and Orion as they disappear over the horizon, and start saying hello to the constellation of Scorpio and a number of other interesting objects. Many of these objects can only be viewed from the Southern Hemisphere.

Most people believe that the only objects that we can see in the night skies are contained in our Milky Way galaxy. This is not true. In March we start to see two other galaxies with the naked eye: The Large Magellanic Cloud (LMC) and the Small Magellanic Cloud (SMC). Maori referred to them as, Nga Patari-Kaihau, or Te Reporepo, and they were used to aid navigation, as well as to predict winds.

The Magellanic Clouds are dwarf galaxies which orbit the Milky Way galaxy. The LMC is about 160,000 light years away and the SMC is around 200,000 light years away. A light year is the distance that light travels in a single year, which makes both objects very far away. Both galaxies contain stars, clusters of stars and nebulae – much like our own Milky Way.

The two Clouds are clearly visible to the naked eye. If you go outside at around 10pm or so and face the south, you will see the start of the Milky Way on the horizon. Follow it up until about 40 degrees and look to the right. You should see two wispy cloud-looking objects. These are the two Magellanic Clouds. To many people they look like real clouds in the sky.

Another interesting object to see in March is Omega Centauri found in the constellation of Centaurus, about 16,000 light years away from us.

Omega Centauri is what we call a globular cluster. This is an object where a large group of stars orbit the galactic core. Because of the gravity of these stars, the cluster appears round in shape, or globe-like. Viewing Omega Centauri is a little more difficult than the Clouds. Some people with very good vision can see Omega Centauri with the naked eye.

The rest of us need binoculars to see the glowing ball. At around 10pm, you will need to go to a dark spot, with a view to the south. Look up the Milky Way until you see the Southern Cross. Find the two bright ‘pointers’. Almost directly to the left of the pointer closest to the Cross is where you will find the Omega Centauri globular cluster.

Another easy way to find these objects is to download an astronomy app on your smart phone. Google Skymap is a great app for Android and SkyView Lite is a fantastic app for your Apple device. Both apps are free and very easy to use.