Too Fast

One of the reasons why NASA don't send probes to land on the surface of Mercury is because the planet is moving too fast. Mercury is traveling at 48 kilometres per second. It is the fastest moving planet in the solar system. The closer you are to the sun the faster you have to move to stop yourself cascading into the star. It is very hard to get probes to travel at close to 48 kilometres per second

image generated by artificial intelligence (chatGPT) 

Earth is traveling slower than mercury but it is still moving fast, 30 kilometres per second. It is possible to meet the planet in it's path but the sun's gravity would interfere in the rendezvous. Mercury is 3 times closer to the sun than Earth although it has a highly elliptical orbit and can be as far as 70 million kilometres from the sun. 

Sources : 

Book: The Planets by Professor Brian Cox

Website: https://science.nasa.gov/mercury/

Website: Wikipedia