From the 17th to the 19th of August, comet 2P/Encke will appear to pass within a hair’s breadth of Mercury in the early evening sky. When it reaches the nearest point, at about 11pm on the 18th, it will be only 45′ (or about one and a half Full Moons) away from Mercury, although it will be far below the horizon that late at night. It is also just too faint for the human eye to detect without assistance, so you’ll need to break out the binoculars. As soon as you can see Mercury (directions below) after sunset, centre it in your binoculars and start looking. I’m quite looking forward to seeing my first comet in years!
* How to find Mercury: Even though Mercury is very bright, because it’s so well lit by the Sun, it’s one of the hardest planets to see. This is because it’s so close to the Sun that it’s usually dipped below the horizon before twilight ends. However, Mercury is luckily near it’s highest point in the sky which makes our task easier. As soon as the first stars appear in the sky, locate Venus. Venus is absolutely unmistable – it is in the sky above where the Sun just set and blazes so brightly that it frequently gets reported as a UFO!. If you then cast your gaze below Venus, look for a pinkish “star” which is quite low above the Horizon, and compare with the picture below. Because of the favourable conditions it shouldn’t be too hard to find, but if it’s not there, try again after about 20 minutes when the sky is darker. The later it gets, the brighter it shines, but be careful not to leave it too long, because it will eventually set an hour or so after the Sun. This event is listed on Urban Astronomer’s Calendar, or you can add it to your own calendar by clicking the button below: