Mercury is the smallest planet in our solar system and often looks similar to the moon; however, this cratered world boasts an iron core with evidence of past tectonic activity and volcanism.
Telescope observations made from Earth indicate that Mercury could contain water ice in its polar regions, with evidence provided by MESSENGER for supporting this hypothesis.
Temperature
Due to Mercury’s shorter year span than Earth days, its surface temperatures fluctuate drastically between extreme heat and cold. Spacecraft engineers must design thermal control systems capable of handling these fluctuations while keeping both their craft and scientific instruments within safe operating temperatures.
The MESSENGER mission revealed that induction currents that power Mercury’s magnetosphere are constantly reconfiguring it, leading to daily variations in its inner magnetic field structure. BepiColombo will allow a more complete picture of these processes underlying this dynamic dynamic.
Radio waves reflected off Mercury’s ice reflect in ways not observed here on Earth, providing scientists with a shock when using the Messenger spacecraft to study this unique phenomena. Ice at low temperatures acts as an excellent reflector for radio waves – similar to water ice on Mars and Jupiter/Saturn moons – suggesting a large quantity may exist within Mercury’s permanently shadowed craters.
Atmosphere
The atmosphere plays an integral role in Earth’s environment. It transports solar heat from equatorial regions to the poles, producing regular wind patterns that bring moisture from oceans onto Earth’s surface and providing protection from cosmic radiation and reflection of ultraviolet rays from the Sun.
Scientists are fascinated with studying Earth’s atmosphere for understanding its dynamics and effect on climate systems.
Earth’s atmosphere can be divided into four layers. The troposphere contains gases that make up our air we breathe; in contrast, the stratosphere contains the ozone layer which absorbs UV radiation from the Sun; at high altitudes temperatures increase again and form regions such as mesosphere and thermosphere that extends outward from here; when combined together they form the ionosphere which provides shortwave radio communication as well as providing aurorae such as northern and southern lights.
Surface
Mercury’s ever-shifting temperatures (176 Earth days of day and night) require thermal control systems capable of managing extremes in both heat and cold. They must also absorb and reflect solar radiation and X-rays effectively while still permitting instruments to function effectively.
MESSENGER data have demonstrated how solar energetic particle events (SEPs) can significantly alter Mercury’s magnetosphere and magnetotail, producing dipolarisation fronts and flux ropes with significant dawn-dusk asymmetry (Liljeblad et al. 2019).
These phenomena and currents interact to shape Mercury’s magnetic field, with induction currents playing a critical role in shaping its size and shape. bepiColombo will explore Mercury’s large-scale structure and dynamics of its magnetosphere to gain more insight into these mechanisms by using electron in situ observations and global model simulations in combination with different geometry, pointing, resolutions, operational timing capabilities of its instruments to conduct large-scale magnetosphere measurements – it will also investigate predicted and observed hemispheric asymmetries between observations made from spacecraft orbiting Mercury.
Landing
Mercury differs significantly from Earth in that it lacks an atmosphere, instead boasting only a thin “exosphere” consisting of atoms blasted off by solar radiation, solar wind, and micrometeoroids. As these vapors quickly escape space they form an atmospheric tail of particles which helps carry away much of Mercury’s heat-soaked surface.
Mercury, with its sunlit side blazing away during the daytime hours, can reach temperatures hot enough to melt lead. But during nightfall it gradually cools off significantly to temperatures well below freezing point.
United States President Dwight Eisenhower eagerly pursued plans for sending men into space after Soviet Russia launched Sputnik into orbit unexpectedly on Oct 4, 1957. Congress passed the National Aeronautics and Space Act of 1958 establishing the National Advisory Committee for Manned Space Flight (NACA), followed by a joint NACA/Advanced Research Projects Agency Manned Satellite Panel draft specific plans for such program; eventually this body merged into NASA in 1959 as the Mercury program brought astronauts aboard and cemented NASA’s future while simultaneously cementing astronauts into pop culture icons.