The Messenger probe to Mercury is currently further from the Sun than the Earth is. That however is about to change for the last time. In the next few days, Messenger's path will take it inside the Earth's orbit for a reverse-slingshot encounter with Venus (144 days from now) which will take energy from it's orbit and drop Messenger's perihelion significantly.

Messenger is intended to be the first probe to orbit Mercury.

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Forming opinions as we speak