Jupiter during National Astronomy Week 2014

Because Jupiter rotates very quickly, in about 10 hours, its appearance changes almost from minute to minute. Even a small telescope (50–100 mm aperture) will show its two major belts and a little detail within them. To see the planet well, you need a telescope of 75 mm aperture or preferably more, with a magnification of about 100.  With this you should be able to see the famous Great Red Spot, and the shadows of some of Jupiter’s satellites moving across the disc.

Have a look at our guide to choosing a telescope for more information.

 The Great Red Spot

The Great Red Spot lies in Jupiter’s South Equatorial Belt. It can be seen in this view taken by Simon Kidd, which  includes the moon Io.

Everyone wants to see the Great Red Spot (GRS) – but when will it be visible during NAW? It crosses Jupiter’s central meridian – the line down the centre of the disc from pole to pole – at the following dates and times during NAW between dusk and midnight.

  • 1 March 22:00

  • 2 March 17:52

  • 4 March 19:30

  • 6 March 21: 09

  • 7 March 17:00

Note: The GRS can normally be observed for a period some two hours before, as it approaches the central meridian and two hours after.

Shadow Transit
Transit of Europa and its shadow, photographed by Dave Tyler

Shadow transits

Jupiter’s four Galilean moons or satellites are constantly shuttling back and forth. From time to time you can see a black spot on the planet as the shadow of one of them crosses the disc, known as a shadow transit. This is not always very close to the satellite itself – it depends on the angle of the Sun at the time.

Here are the available shadow transits of the moons of Jupiter during NAW between dusk and midnight.  You should see a small black dot moving very slowly across the disc from one side to the other.

  • 2 March – Io from 18:31 to 20:46

  • 6 March – Europa from 20:47 to 23:39.

Which one’s which?

Jupiter’s four large satellites are in different positions each night. So which one is which? Take a look at these diagrams from  Sky Map Pro 11 to identify which satellites you can see on each night of National Astronomy Week at 8 pm. The sky background on some diagrams is blue as there is moonlight on those nights. These views have north at the top, as you’d see them through binoculars, but most astronomical telescopes give an inverted image with south at the top.

The satellites do move slowly, so at times other than 8 pm they will be in slightly different positions.

1 March at 8 pm

2 March at 8 pm

3 March at 8 pm

4 March at 8 pm

5 March at 8 pm

6 March at 8 pm

7 March at 8 pm

8 March at 8 pm