If you've recently looked at the night sky, you've probably seen Mars because the planet is almost impossible to miss.
Because of a cosmic coincidence, Mars outshines almost everything else in the sky, and now is the best time in years to look at the red planet. The orbits of Earth and Mars periodically bring them together relatively close, but this year the two planets are the closest they have been since 2003.
Mars and Earth orbit the Sun at different speeds, but every two years or so planets are in a straight line with the Sun, an alignment known as opposition. Since Earth and Mars are on the same side of the Sun at this time, they are relatively close.
This year the resistance will take place on July 27th. Mars will rise in the sky when the sun goes down and then rises again when the sun rises. But this contrast is special because Mars is also close to the perihelion.
Perihelion refers to the point in the orbit of a planet when it is closest to the sun. Planets do not have perfect circular orbits, but rather elliptical ones that lead them closer and further away from the sun during the year.
Since Mars is so close to perihelion this year, when it is in opposition to Earth, it is even closer to us than usual, an alignment called perihelion opposition. It was a similar situation in 2003, but everything went even better, bringing Mars closer than it did almost 60,000 years ago. According to NASA, it will not get closer to Earth than it did before August 28, 2287.
The closer Mars is to Earth, the brighter it appears in the night sky. Do not believe these online memes claiming that Mars will be as big as the Moon, but it will be the fourth brightest object in the sky, behind the Sun, Moon and Venus. During this time span of a few weeks, Mars will even outshine Jupiter.
If you have a telescope, it is a good time to look at Mars, though you may not be able to select many surface details. Since this summer, a global dust storm is raging, and although it seems to be dying, there is still enough dust in the atmosphere that makes it hard to spot any of the planet's features.