I am spending an unexpected week up in the West Highlands of Scotland in a beautiful place called Arisaig, helping out with a supply for the parish. I am relishing the beautiful blue seas, white / silver beaches and a welcome re-acquaintance with the sun ( I just saw on the news Edinburgh only had 1.6hrs of sun shine the first 10 days of July!). Another great part of being up in the ‘remote’ highlands is that there is very little light pollution up here – so the nights can be very dark – perfect if you are an enthusiastic stargazer like me. There is nothing like spending an hour – in a comfortable spot, wrapped up warmly to gaze at the immensity of the heavens, counting shooting stars, identifying constellations, working out asterisms within the constellations, squinting and trying to split binary stars with binoculars. Planet spotting is great fun too – especially with the new apps on smartphones that effectively give you a portable planetarium. Of course the planets do not generate light (unlike stars) but reflect the light from our star, the Sun, back to us. I learnt that the technical term for the amount of light a celestial body reflects is Albedo and it is low for the Earth, as we reflect only about 0.36 percent of the light that comes in. The Moon is a bit better though and this week we can get the chance to see ‘Earth-shine’ reflected on the moons surface.
This week, everywhere, a new Moon is rising giving us a chance to bathe in this Earthshine, the light from the Earth that illuminates the Moon. Right now is the perfect time to look for this enchanting phenomenon. So if you look at the photo to the left – you will see a new moon with about 10% positioned so the sunlight hits it and bounces down to Earth (the bright bit).The rest of the Moon, however, is positioned just right for the light from the sun to hit the Earth, bounce to the Moon, and come back down to the Earth again (the greyer 90%). That’s why we see, “The Old Moon in the New Moon’s arms.” The best time to see it is just around sunset when the reflected Earthshine is brightest.
Happy moon spotting!