The Mariner 10 probe photographed Mercury in 1973. The MESSENGER spacecraft flew by Mercury in January 2008, and revealed previously unseen details in high resolution photographs. Both of these spacecraft were launched by the US. As far as is known to the public, no manned missions and no astronauts have ever been anywhere near Mercury.
No one has every been to Mercury. The furthest man has been is to the Moon. Probes have been sent to Mercury
No human explorations has been nor can be on Mercury.
The US has never been to Mercury.
Mercury is a relatively rare element, it has not been found on Mercury the planet but theoretically it can be detected.
No natural satellites of Mercury have been discovered.
there were about 7 missions to mercury
There have been no manned missions to Mercury.
Yes, there have been probes sent to Mercury. Messenger and Mariner 10.
no one has ever been to mercury because there is not enough oxygen and it is too hot.
Mercury is about 4.6 billion years old.
No.
Mercury has no atmosphere to speak of, and therefore it has no weather.