The last such event was in 2003 when Mars and Earth came the closest they had in almost 60,000 years - touching within 34.6 million miles (55.7 million kilometres) of each other.
The best view of Mars happened early Tuesday morning, but you can still see it Tuesday night, from anywhere in the world, if you simply look up.
Mars which is already brighter than usual, will shine even more and will appear to be bigger on Tuesday.
NASA estimates the 2003 "opposition" was the closest approach by Mars in nearly 60,000 years. Additionally, gravitational pull of the planets within our solar system constantly affects the shape of their orbits, moving Mars' orbit even closer to the Earth. Since the orbits of the two planets are of different lengths, they come close to each other once every two years.
That year also marked the closest that Mars had come to Earth since the Stone Age - and on Tuesday, it will come the closest it has since then.
The phenomenon takes place whenever the red planet reaches its position of "opposition", when Earth is between Mars and the sun.
This proximity interprets that the Earth is in "opposition" with Mars - meaning that it is sitting directly between the Sun and the planet.
Now's the time to catch Mars in the night sky.
Earth's neighboring planet, Mars, is closer than it has been in the past 15 years, offering unusually bright views of the Red Planet's auburn hues.
If the weather co-operates tonight - and it's not looking very good right now - the planet will easy to spot. In fact, Mars will remain brighter than Jupiter in the night sky until about September 7.
One of the proposed methods of pumping more Carbon dioxide into the Red Planet's atmosphere is by bombing the planet's poles.
Mars will next be close to Earth in October 2020.
As for novice astronomers who might be a little bummed they missed the 3:50 a.m. wake up call, NASA streamed Mars' close encounter with Earth live from the Griffith Observatory.
Astronomers say we should be able to see it throughout early August.