Sources: NASA, Homemade Documentaries (YT Channel), ESA

Whenever you wish to see Mercury amongst Earth's shifting skies, it never strays far from the sun. Often does it hide amongst the blinding rays of golden light throughout its quick orbit. Be sure to catch it if you could.

In fact, after billions of years since its creation, it is still partly molten & responsible for generating a magnetic field weaker than Earth's but twenty times stronger than Venus'. It's enough to keep the ionizing solar wind at bay.

Said surface, alongside Mercury's mantle, is proportionally thin for a terrestrial planet. Thus, its iron & nickel core takes up 85% of the planet's radius.

Only a faint exosphere exists to contain potassium, sodium, oxygen & a few other chemicals - an invisible, rough reflection of the surface's makeup.

Throughout these long days, Mercury's rocky surface is heated to 427 C by the sun's unrelenting rays. Though, the planet's lack of an atmosphere allows nighttime temperatures to fall to -173 C.

However, in Mercury's case, the combined efforts of its highly eccentric or oval-shaped path & slow rotation make it so one day is over two Mercurian years. Also thanks to the orbit, the small body is within Earth's proximity for longer than Venus can be per orbit.

With its surface covered in pale scars from raw impacts & a smattering of cliffs, Mercury is often compared to the Moon by appearance alone. It doesn't help when both objects are, in a sense, tidally locked to the things they orbit.