Escape the ordinary
PHYSICA
Landing on Mercury
Mercury, the planet closest to our sun and the second hottest in our solar system is still unknown landing rovers. Much of our knowledge about the planet comes from radars and imaging flyby probes. Landing a spacecraft on mercury has been a challenge for some time now due to its proximity to the sun. Can we do it?
Let us start with some well known figures about Mercury. It takes 88 days to orbit the sun at a distance of about 58 million kilometers with a surface temperature that reaches as high as 430 degrees Celsius and low as -180 degrees. The intensity of sunlight it receives is about 7 times larger than that received by earth and this is responsible for raising its temperatures to astoundingly high levels during day. It’s atmosphere is extremely thin in nature and consists of mostly oxygen, sodium, hydrogen and helium. Due to lack of a thick atmosphere, there are no gases to trap considerable heat making Mercury’s night time temperature go freezingly cold. Towards the poles where sunlight is limited, patches of frost can be observed. Small amount of water or rather ice can also be found. This is because the proton’s from solar wind collide with surface metal oxides to form H2O molecules.
Can we ever land on Mercury?
The key reason why we don’t attempt to land on Mercury is because of its high temperature difference and lack of atmosphere. However despite all of that, there still technically a chance we could walk on the planet’s surface.
Mercury has a very slow rotation period, taking about 60 days to rotate fully and since it has a short revolution period of 88 days as well, we can deduce that under 176 days it should be able to complete a single cycle of day and night. Terminator line is a slowly shifting twilight zone that moves with the downward movement of sun and following that moderate zone, it is technically possible to avoid both scorching heat and biting cold after landing.
However even after figuring out a place to land, the process of landing itself poses a problem to tackle. Mercury’s lack of atmosphere would mean no friction induced breaking to aid us during landing and that would force us to rely more on heavy fuels. The last obstacle we’ll need to face would be the journey. As we approach the Sun increasing amounts of radiation would make travel harder. This is just on top of the seven years we’ll need to navigate the trajectory necessary to interpret the planet.
As we said, travel is possible but only technically. With current technological developments, sending a lander without human crew alone would be a great feat. Nevertheless, sending a lander to Mercury could offer us a new perspective on the Solar System's smallest planet and help us unravel some of its mysteries.