Monday 26th July to Sunday 1st August 2021

At the beginning of August, Saturn reaches opposition.  This astronomical term means that the planet appears in the opposite side of the sky to the Sun and from a practical point of view, light from the Sun will brighten Saturn's rings.  In other words, it's a good time to get your telescope out from next week and aim it towards the south east at about 11pm when Saturn will have risen above the horizon!


Saturn's prominent rings are made from mainly ice crystals, which reflect sunlight really well.  Getting technical, this is known as the Seeliger Effect, when light originating from behind an observer is reflected by the rough surface of an object or from many particles.


The planet itself is one of the gas giants and the second-largest planet in our Solar System.  Saturn is known to have at least 82 moons orbiting around it and the largest of these, Titan, will be to the right of the planet.


Please remember that star charts show what you would see with the naked eye or binoculars - if you like, a "true" view.  If you are using an astronomical telescope, then the view is reversed, so Titan will appear to be to the left of Saturn.  Astronomers live with this reversal as it would need extra lenses in the telescope to correct the image and that would waste light in the process.


If you aim your telescope towards Jupiter's moons at about 11pm on Sunday 1st August there is the chance to see the occultation of Europa by Ganymede - Ganymede will appear to cover part of Europa and then move away from it again.




Monday 19th to Sunday 25th July 2021

Saturday 24th sees a Full Moon.  You'll need to be looking towards the south east and the Moon will have risen above the horizon from 11pm.  At the same time, Saturn will be located slightly above the Moon, with Jupiter a little to the left.


The gas giant planets in our Solar System look like very bright stars because they are relatively close to us and they reflect light from our own Sun, which is a very powerful source.  Stars always appear fainter because they are much further away from us and are generating their own light.

If you stay up until 1am and aim your telescope towards Jupiter, there is an excellent chance to observe the famous Red Spot.  This is a huge storm in Jupiter's atmosphere, about twice the size of the Earth, with wind speeds up to 425 miles per hour.  The storm has lasted for at least 150 years.  Very often you will not see the spot as Jupiter rotates very fast on its axis and where a day on Earth lasts 24 hours, on Jupiter it is only 10 hours long.  If you can't see the Red Spot, it will be because at the time you are looking, it is round the other side of the planet!

There are several good opportunities to observe the International Space Station next week.  Monday 19th from 11.36pm, Tuesday 20th at

10.49pm and Wednesday 21st from 10pm.  The ISS will appear in the west and spend about 7 minutes passing overhead, before disappearing to the east.



Monday 12th to Sunday 18th July 2021

Just after sunset on Monday 12th there is an opportunity to view the planet Venus together with a thin Crescent Moon.  At about 9.15pm, the Moon will be towards the west, with Venus slightly to the right of it and closer to the horizon.

You will be able to see them with the naked eye, but if you are using binoculars or a small telescope to improve your view, please remember never to aim directly towards the setting Sun as this would cause instant and permanent blindness!


On Saturday 17th, one of Jupiter's Galilean moons, Ganymede, transits (or moves across) the face of the planet and in doing so, casts a shadow on the gas giant's surface.  You will need to be pointing your telescope south east towards Jupiter from about 11.45pm.


Ganymede is the largest moon and overall ninth-largest object in our Solar System.  It is actually bigger than planet Mercury!  Galileo, pioneer of the astronomical telescope, first observed Ganymede in 1610 along with three other Jovian moons - Io, Europa and Callisto.

Galileo was also the first person to observe Saturn's rings and you could do the same with your telescope when you have finished watching Ganymede's transit as Saturn will be located a little to the right of Jupiter.