Stargazers can marvel at Mars at its biggest and brightest this week, as the Red Planet moves closer to Earth than it will be for the next 15 years.
The planets briefly align every 26 months during their orbits around the Sun.
In the early hours of Wednesday – about 2.20 am Bahrain time – they will be in what astronomers call opposition, when Mars and the Sun will be in a straight line as observed from the Earth.
The phenomenon occurs as Earth takes roughly half the time to orbit the Sun at 365 days compared to 687 days for Mars.
Scientists said Mars will be visible without the use of a telescope during this time.
“Earth and Mars are like runners on a track. Earth is on the inside, Mars is on the outside,” US space agency Nasa’s October blog said.
“Every 26 months, speedy Earth catches up to slower Mars and laps it. Opposition occurs just as Earth takes the lead.”
The distance between the two during opposition differs because of the planets’ elliptical orbits.
They can be up to about 100 million kilometres apart, but Mars made its closest approach to Earth in almost 60,000 years in 2003 at 56m km.
This year, the distance is around 62m km.
It will be another 15 years until Earth and Mars pass by each other as close again.
The planets’ proximity every 26 months offers scientists an opportunity to launch more cost-effective missions to Mars.
The point just before the planets are closest takes the least amount of time to reach Mars from Earth.