Have you noticed Mars rising in the east yet? It rises after 8pm and the red planet is at its brilliant best this month because it will be close to Earth.
Every 26 months, Mars is at “opposition”. More on that below, but what it means is that Mars is as close to Earth it gets during that time and appears brighter in our night sky. Why every 26 months?
The key to understanding this is to know that Earth goes around the Sun faster than Mars and it takes 26 months for us to catch up and be close together again! This year, Mars has its closest approach to Earth on 7th October and the red planet will be at opposition on the 14th.
Mars is as close as it gets to Earth all year and it won’t be this close again until 2033. The distance between Earth and Mars varies when we catch up to each other in orbit. That’s because we both have elliptical (or oval shaped) orbits around the Sun. Sometimes we’re closer to each other than other times. 2020 is a particularly close approach. Mars will look brilliant in the night sky.
When to look: Any time after 8pm from the start of December. Mars reaches opposition on the 8th of December at midnight.
Which direction to look: East
Mars will look better through telescopes if you wait for it to get higher up in the night sky. You’ll be looking through less atmosphere. See if you can pick up any detail on its surface when you look at it through a telescope. This may be difficult for smaller telescopes, but if you have access to a medium sized telescope or larger, hopefully you’ll be able to see some darker and lighter areas of the different features on the surface of Mars. No matter which telescope you have, it’s always worth having a look at Mars!
“Opposition” is a word that astronomers often use. A planet is said to be in “opposition” when it is on the opposite side of Earth to the Sun.
“Opposition” only occurs for planets that are further out from Earth’s orbit around the Sun. Mercury and Venus can never be in “opposition” because their orbits are closer to the Sun than Earth’s. Earth can never be in between these planets and the Sun!