Don't Miss Tonight's 'Opposition Of Mars' An Event That Only Happens Every Two Years

NASAAn illustration of Mars Opposition and the relative 'tilt' in the orbits of Earth and Mars.

Mars and the sun will be on directly opposite sides of the Earth on Tuesday, April 8, an event that happens roughly every two years.

The "opposition of Mars" means that skywatchers will be able to see Mars throughout the night as it rises in the eastern sky at sunset, moves nearly overhead at midnight, and sets at sunrise, according to NASA.

The Red Planet will be really easy to see with the naked eye, shining 10 times brighter than some of the brightest stars in the sky, NASA said.

The alignment happens because Earth and Mars orbit the sun at different distances. Earth is closer to the sun, so it takes around half the time to complete one trip around the sun. Every 26 months, the gap between Earth and Mars narrows - the sun, Earth, and Mars converge in a nearly straight line.

NASAMars will be easy to see in the clear night sky throughout out the month of April. On the date of opposition it will shine brighter than Spica, the brightest star in the constellation Virgo.

If both Mars and Earth had circular orbits, then both planets would be at their minimum distance from each other on the date of opposition, NASA explains. But that's not the case. The orbits are elliptical so that Earth is closest to Mars one week later, on April 14, when the distance between the two bodies is 92 million kilometers (that seems far but it's relatively small on an astronomical scale).

Although April 8 and April 14 are both good dates to see Mars in the night sky, NASA says that you should be able to spot the blazing bright-orange planet on any night in April, provided there's a clear sky.