Jupiter has a stormy, banded atmosphere with oval vortices and storms which encircle the entire planet. Photo: Znith Observatory http://znith-observatory.blogspot.com

Look nearly overhead after sunset and you will see a very bright star – which in reality is no star at all – but rather, the planet Jupiter.

Our solar system’s ruling gas giant shines brightly in the constellation Gemini. However, it will start fading somewhat as the earth races away from it in its orbit around the sun, after our closest approach in the first week of January.

With the naked eye we see it only as a point of light; however, a pair of 10x50 binoculars will reveal four smaller and closer points of light around Jupiter. These are its four largest moons (out of a total of 68 moons) and are the same moons seen by Galileo Galilei when he first observed them in 1610. Each one of them is a distinct world – some covered by water ice, others volcanically active .

It is only through a telescope that Jupiter is revealed in all its glory. The light-gathering power of this instrument allows astronomers to view fine details on planets’ surface or atmospheres.

For example, a few weeks ago, Charles Galdies photographed Jupiter through his telescope in Naxxar. The photo, combined from the averaging of individual frames out of a video recording, also shows Jupiter’s Great Red Spot, which happened to be facing the earth at the time of the observation.

The Great Red Spot is a massive anti-cyclone, similar to a hurricane on the earth – but in line with Jupiter’s gigantic status, this hurricane is three times the size of the entire earth and has been raging on Jupiter for at least the last 400 years.

Post your images of the night sky on the society’s Facebook page www.facebook. com/groups/maltastro.

Alexei Pace is president of the Astronomical Society of Malta.

Astronomical events this month