Astronomy – Many moons to see

Most people have only ever seen one moon – our own. But this month, we are going to look at how to use technology to find and observe the four largest moons of Jupiter (Galilean Moons) – Io, Europa, Ganymede, and Callisto.

June is the best time this year to observe Jupiter. Astronomers call it ‘being in opposition’. This mean that the Earth sits directly between the Sun and Jupiter. At that point, Jupiter is the closest it will be to the Earth for the year.
This makes it easier to see the details on Jupiter’s surface using a smaller telescope. Using good binoculars, you should be able to make out some of the moons around Jupiter.

Finding Jupiter is pretty easy. Look to the East just after sunset. The brightest star will be Jupiter. But how can we make sure? We can use our devices to find out.

On Android, I use the SkyMap app. I have heard good things about StarWalk 2 on iPhones. These apps are truly amazing. You point your phone to the sky, and the screen will show you what you are looking at.

For those with older phones, you may want to take a look at a free programme called Stellarium. This runs on Windows, Mac OSX and Linux. In my opinion, it is one of the best astronomy programmes out there.
What do we do once we have found Jupiter in the night sky? If you have a good pair of 10×40 or, even better, 10×50 binoculars, look up at Jupiter and adjust your focus. As your eyes get used to the glare, you will suddenly see small dots of light around Jupiter. Some of these dots are surprisingly far from Jupiter. These small dots are the Galilean Moons.

Luckily we can again turn to technology to help us in understanding what we are seeing. Sky and Telescope magazine has a very good app for iOS called JupiterMoons. On Android I use an app called: Moons of Jupiter.
Both these apps show us the exact positions of the moons around Jupiter at the moment of observation. Just match what you see on the screen to what you are seeing through your binoculars, and you will be able to name the moons.

In one night, you can see up to five moons in the night sky.

Also in June, we can attempt to spot Mercury. Mercury and Mars will be very close together on June 18 in the dusk sky. Many people never get to see Mercury, so this may be a good time to look for it.
Look for red Mars just after sunset in the west and slightly dimmer Mercury will be right next to it. Now that you know how to use the apps, use them to make sure of what you are seeing.
The Hibiscus Coast Astronomical Society meets every first and third Thursday of the month at Faithfull Funeral Services Hall, 35 Red Beach Road, 7.30pm. All are welcome.