PUBLISHED: 16:32, Tue, Oct 13, 2020 | UPDATED: 20:11, Tue, Oct 13, 2020
Every 26 months or so, Mars, Earth and the Sun form a straight line in the heavens. In astronomical terms, this alignment is known as an opposition. And although opposition can happen at any point in Mars's orbit, this year's event comes just six days after the planet's closest approach to Earth.
This means the planet is still exceptionally big and bright at night and will remain so until November.
Astronomer Tom Kerss said on his weekly podcast Star Signs: Go Stargazing: "Last week we talked about Mars reaching its closest approach to the Earth for some time to come - about 15 years.
"It was around 62 million km away from us at its closest point, which sounds like a lot but it's just a stone's throw in interplanetary terms.
"And it's now beginning to slip away from us again ever so slowly, but this week Mars will actually be at its brightest when it reaches what's known as opposition in the sky on Tuesday."
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Mars tonight: Find out when and where to look for the Red Planet at night (Image: STAELLARIUM/GETTY)
Mars tonight: Mars at opposition is very bright when seen from Earth (Image: NASA)
During opposition, the Red Planet will appear directly across from the Sun with our planet in the dead centre.
When a similar alignment happens with Mars on the other side of the Sun, we call this event conjunction.
Mr Kerss said: "On Tuesday, the Earth comes directly between Mars and the Sun.
"The difference in the apparent size of Mars from last week to this week is absolutely tiny - just a fraction of an arc second, which itself is a tiny fraction of a degree.
"So by seeing the full face of Mars at opposition we will see it at its very brightest".