Thursday, June 28, 2018
Opposition of Saturn, tonight, June 28, 2018
Tonight is the opposition of Saturn, when it is biggest and brightest as seen from Earth. If you have clear skies (I don't) head out and have a look. If you have been wondering which of the brightish dot in the eastern evening sky is Saturn, tonight is a good night as Saturn is the brightest object just above the Full Moon. Take note of the stars nearby so that as the Moon moves away over the next few nights you can easiluy find it again.
Saturn is now visible the entire night long, and is highest above the northern horizon (and best for telescope observation and astrophotography) around local midnight. Saturn's rings are almost at their widest and will gradually close up after this, so they will be a worthwhile sight in even small telescopes.. Modest sized instruments will show the Cassini Division. For a few days around opposition you can see the Seeliger effect, where the planets rings brighten considerably as the Sun illuminates the rings from directly behind us. Australian amateurs have reported it as being quite noticeable this year.
As well as the rings the orbiting of the large Moon Titan can bee seen over successive days. ANd the pale equatorial band and darker polar caps are visible as well. The shadow of Saturn on the rings may be more difficult to see in modest instruments at this time, but will grow more noticeable over the coming days.
Even past opposition Saturn will be a worthwhile telescopic object for many weeks, so if you miss out tonight, you have plenty of chances over the next month or so.
In binocuars, you will see Saturn as a distinct oblong above the Moon tonight. Saturn is still within binocular range of the globular cluster M22, but tonight the light of the Full Moon drowns it out.