Bath Astronomers

June Night Sky

June has the shortest, and least dark, nights, and therefore is generally not a good time for observing. This June, however,we have two planets at or near opposition. Mars came to opposition late in May, and Saturn reaches it in early June. This is good, and bad, news. The good news is that planets, or at least the brighter ones, are easy to see in twilight, and can be seen better than in a fully dark sky when they are almost blinding through a telescope. The bad news is that if they are at opposition at this time of year they will be very low in the sky – they are opposite the sun, and therefore in the same place that the sun was 6 months ago in December. This in turn means you will need a good south horizon to see them at all, and you will be looking through a lot of atmosphere to do so, and therefore  can expect wobbly images and colour fringes (from differential diffraction by the Earth’s atmosphere).

The especially frustrating thing about Mars is that the planet’s eccentric orbit means these oppositions in our southern sky are also when it is at its closest to the Earth, and therefore in other respects very well placed to view. We live in the wrong hemisphere! A casual glance to the southern horizon if it is clear after 11pm or so will show this as Mars is currently very bright – as bright as Jupiter – and of course markedly red. You won’t mistake it.

Saturn is simply on its slow trek around the sun, taking 29 years in total. It will be several years hence before it is well placed for us again.

But both planets are worth a look over the next month, and if you get still atmospheric conditions you may get good views. With a reasonable telescope you should see dark markings on Mars, and Saturn’s rings, in any event. The map below shows you where to find them. It is slightly confusing;Mars is much the brightest object in that part of the sky.

Mars and Saturn June 2016