Dark Skies September Update

September Sky Map
5 years 11 months ago

I’m sure that you’ve all noticed the nights starting to draw in after the long summer days. Not really surprising since September brings the autumn equinox of equal length day and night time. In the skies, we’ve lost Jupiter and Mercury in the west, with only Venus clinging onto the bright twilight zone, some couple of degrees high at sunset. The other planetary double act featuring Saturn and Mars continues in the SSW skies, although Saturn is steadily dropping, with Mars slowly dimming in magnitude or brightness as the month progresses.

The other gas giants of our Solar System, Uranus and Neptune, are visible if anyone is interested, although binoculars or a telescope will be needed to find these blueish points of light. For any early risers amongst you, Mercury will make a reappearance in the morning skies in the last week of September, with a wafer thin moon close by on the 29th.

Speaking of the Moon, there is also a lunar eclipse on the 16th, although it is only a faint penumbral version. The moon will rise in eclipse, with the weak shadow leaving the lunar surface around 21.55 BST. To be honest though, most people wouldn't notice a penumbral eclipse unless it was actually pointed out to them! It’s that faint.

From our nearest neighbour in space, how about trying for an object outside of our own galaxy, indeed how about the next nearest Galaxy to our own. At an “astronomically close” distance of 2.5 million light years, the Andromeda Galaxy, is also the most distant object you can see with the naked eye – remember that factoid for the next pub quiz you go to. To put that distance into perspective, a light year is the distance light can travel in a year, which is 186,000 miles per second (x60 seconds / minute, x60 minutes / hour,  x24 hours / day and x365 days per year) = roughly 6 million million miles per year. Now multiply that by 2.5 million- the number of light years Andromeda is distant – and you discover that the unaided human eye can see as far as 15 million, million, million miles. Wow!! Use the map to help you see that far!! 

Coming back to earth with a slight bump then, and ending with some meteor showers active during the month. There are several showers active over the next couple of months, although nothing really major. The Taurids probably represent the pick of the crop displaying long, slow meteors, although not particularly numerous. That said, given there are several active showers , your chances of spotting the odd meteor or two are pretty good. 

Clear skies until next month.