NASA’s probe, the “Messenger”, will fly past planet Mercury for the second time since it was launched. It first passed the planet on the 14th of January, when it managed to photograph 20% of Mercury’s surface.

The data was sent back to Earth, where scientists were able to translate and map the data picked up by Messenger. This isn’t, however, the first visual information we have on Mercury. 45% of the planet’s surface was unveiled and mapped in 1974 and 1975, due to NASA’s ship - the “Mariner 10”, who passed by the planet a total of three times. Although the Messenger was launched in 2004, it only passed Mercury once so far. Its mission also includes collecting samples of space matter around the planet.

It is estimated that the Messenger’s second flight past Mercury will offer the highly coveted 1,200 photos of another 30% of the planet’s surface. The new pictures will be taken from the opposite side of Mercury than the one mapped on the Messenger’s first flight.

Upon analyzing the received information, scientists have come to the conclusion that Mercury has been shrinking over the years. The surprising part is that Mercury’s shrinking rate is higher than previously estimated, and it’s apparently due to volcanic activity. The pictures also revealed an enormous crater, thought to be the result of an impact. NASA also concluded that Mercury’s molten iron core is responsible for the planet’s magnetic field.

Mercury’s position and its proximity to the Sun have hindered its viewing and analyzing from our own planet. Thus, a space probe is vital to unearthing the mysteries of the battered, undulating planet. As Pluto is now considered to be a “dwarf planet”, Mercury receives the title of our system’s smallest planet. It’s only a third of the Earth in size (with a diameter of 3,032 miles), but it is slightly larger than our Moon.