By Richard Harvey
With Mars at its closest approach since 2003, and the prospect of a clear sky to view it, a last-minute observation session was hastily arranged for Thursday 13th September at our Trysull observation site. I took the society’s 12” dobsonian reflecting telescope (the Tom Collier Telescope), and several other members turned up, all hoping to get a fine display of planets.
The Moon was a waxing crescent in the west as we arrived, lit around 20%. Once the scope was set up, we all enjoyed fine views of the shimmering lunar landscape. I was particularly interested in the small craters in Mare Crisium, which were very noticeable. Crater Picard is 21 miles across, and Pierce is only 12 miles across, we could see them quite clearly. They will soon be washed out with sunlight and not viewable for another month. Quite distinct tonight, on the edge of Mare Crisium, was the distinct dramatic rises of Cape Cape Lavinium and Cape Olivium.
To the left of the Moon, lower, just heading towards the trees, we saw Jupiter. With the sky not yet dark, the cloud belts were faint, but three of the moons were visible. The brightest, Ganymede, to the telescopic left. Although we could see only three moons, checking later with the Jovian Moon chart in Astronomy Now, all four should have been visible. Dimmer Callisto must have been lost to the twilight sky.
Read moreTrysull Observation Session Thursday 13th September 2018