The next approach is on Oct 6, 2020.
The two planets will be just 35.8 million miles (57.6 million kilometers) apart next Tuesday.
"It hasn't been this close since 2003 and won't be again until 2287", said Kelly.
Mars is already brighter than usual and will shine even more- and appear bigger - as Tuesday nears.
Mars will be visible in the sky this week as it makes its closest approach to Earth in 15 years.
If you've looked outside anytime after sunset recently, you've probably thought Mars looks a bit bigger than you remember it.
The planet's closest approach to Earth occurred in 2003 when the two planets drew within 34.6 million miles, the closest approach in almost 60,000 years.
Every 26 months or so, Mars swings by Earth at varying distances as both planets make elliptical orbits around the sun. These two planets do come nearly this close after every 15 to 17 years. By mid-August, Mars will become fainter as the planet and Earth travel farther away from each other in their orbits around the Sun. This is why you will often see Mars missions launching every two years.
"From its retrograde motion in the sky and its blood red color to the question of whether Mars has or had life, it is a planet that has never failed to make us wonder".
Mars will be easily visible with the naked eye - weather permitting. The sun, moon and Venus are usually the top three brightest objects.
Hubble, one of the largest space telescopes, captured images of dust storms on the Red Planet this summer. In 1877, Italian astronomer Giovanni Schiaparelli claimed to have seen canals on Mars, suggesting there could be possible civilization, or Martians, on the red planet. That same day, parts of the world will see a total lunar eclipse.
For the best views of Mars, you'll want to wait until after midnight - or closer to 1 a.m. - when the planet is at its maximum height in the sky.
The blood moon will be the longest total lunar eclipse of the 21st century and will occur just after 9pm United Kingdom time on Friday July 27.
Nasa has said that there is now a dust storm which is affecting the whole planet, so this may make seeing details on Mars a little more hard for astronomers.