Monday 25th April to Sunday 1st May 2022
Mercury is the closest planet to the Sun and is always a bit tricky to spot because it appears near dawn or dusk. It's also dangerous to use binoculars or a telescope to help as the planet will be near the rising or setting Sun.
On Friday 29th April, Mercury will be located just below the familiar open cluster of stars known as the Pleiades around 10pm local time. You will find the Pleiades towards the north west horizon. On 29th, Mercury will be at its greatest eastern elongation which, for an observer on the Earth, means that it is at its greatest separation from the Sun and will be quite easy to spot with a magnitude of +0.4 that evening.
Mercury is the smallest planet in our Solar System - only slightly larger than our Moon. Because it is so close to the Sun and it orbits so fast, a year on the planet only lasts 88 days. We are further away so our year lasts 365 days.
If you are observing the planet, you are looking at a place where the surface temperature varies from -173 degrees Celsius at night to +427 degrees during the day because it has no atmosphere to protect the planet and act as a blanket! To make matters worse, Mercury spins very slowly on its axis and a day on Mercury lasts 59 earth days, so if you were visiting, you'd be alternately frozen and cooked for long periods of time!
Confusingly, Mercury is not the hottest planet in the Solar System - that title goes to Venus because its thick atmosphere traps heat!
Screenshots courtesy of Stellarium
Copyright Adrian Dening and Radio Ninesprings 2022