Adrian Dening's Stars Over Somerset

Monday 14th to Sunday 20th February 2022

On the morning of Wednesday 16th, planet Mercury reaches its greatest western elongation from the Sun. What on Earth does that mean? In practical terms, Mercury appears the furthest it ever gets away from the Sun and can be viewed popping up over the south east horizon a hour before sunrise.

If you look towards the south east around 6.30am you will see Venus shining brightly, with Mars a little below it and Mercury to the left of Mars very close to the horizon. Please don't be tempted to use binoculars or a telescope to obtain a better view as if you accidentally catch a glimpse of the Sun in the eyepiece, it will cause instant and permanent blindness.

The evening of 16th sees a Full Moon rising in the east after dark and for the following few evenings, a bright Gibbous Moon. You might think that it's ideal time to aim your telescope that way, but in reality the amount of sunlight being reflected from the lunar surface washes-out many of the interesting lunar features.

If astronomers are looking at such a bright Moon, they normally use a special filter in their eyepiece to lose most of light that their telescope has collected! This is called a Neutral Density filter and it prevents your eyes from being temporarily burnt - the same as if you have accidentally stared at a light bulb - afterwards there is a black spot in your vision for a while. Please don't try it!

To safely observe the Sun, astronomers use a totally different type of filter that is far more complex and expensive than the Neutral Density ones.

Screenshot courtesy of Stellarium
Copyright Adrian Dening and Radio Ninesprings 2022