March made its closest appearance to earth in the past 11 years yesterday evening at 21:35 GMT. As a result, the red planet will be just 75 km away from the earth.
Earth and Mars make a close approach every 2 years and 2 months which is known as opposition. It takes place because our planet catches up with Mars and undertakes it, like a runner on the inside track. Some oppositions are closer than others because Mars follows an elliptical orbit and it depends on whether we catch up when Mars is close to the sun or far away.
Nevertheless, oppositions are the best time to launch rockets to Mars because the energy needed to fly there is at a minimum. This year the European Space Agency has taken advantage by sending a probe.
Launched in March, it will enter orbit in October. Known as the Trace Gas Orbiter, the probe's mission is to look for evidence of life.
There are tantalizing hints that microbial life could still be alive on the planet, almost certainly living below the surface. Underground, the microbes would be protected from the harsh ultraviolet light and cosmic rays that strike the surface. They would also be beyond the reach of the oxidizing chemicals found in the top layers that would attack living cells. But the gases produced by the microbes would leak into the atmosphere. And here's where it gets interesting.
However, if you miss the view this time, you need not to worry, there will be an even closer approach coming in 2018. Mars will be more than fifteen million kilometers closer to Earth, drawing to 58 million kilometers.