The misconception might stem from the fact that our understanding of Mercury's surface has significantly improved in recent decades. Here's why:
* Early observations: Early observations of Mercury were limited to ground-based telescopes, which could only see a small portion of the planet's surface. This led to a limited understanding of its features.
* The Mariner 10 mission: The Mariner 10 spacecraft in the 1970s provided the first close-up images of Mercury, revealing its heavily cratered surface. However, Mariner 10 only mapped about 45% of the planet's surface.
* MESSENGER mission: The MESSENGER mission, which orbited Mercury from 2011 to 2015, provided detailed global maps of the planet's surface. MESSENGER's high-resolution images and other data allowed scientists to create comprehensive maps of Mercury's topography, geology, and composition.
* BepiColombo mission: Currently, the BepiColombo mission, a joint mission by the European Space Agency and the Japan Aerospace Exploration Agency, is orbiting Mercury and is providing even more detailed data.
So, while Mercury's surface was only partially mapped before the MESSENGER mission, thanks to this and subsequent missions, we now have a fairly comprehensive understanding of its surface features.
It's important to keep in mind that scientific exploration is an ongoing process, and we continue to learn more about Mercury and other celestial bodies.
