The "Messenger" mission to Mercury made a very close pass just last week. The Messenger probe should enter Mercury orbit on March 18, 2011.
You likely mean NASA's MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) program of 2007.
That is because it is so near to the sun. For more details, you will need to study Kepler's laws of planetary motion.
The Mariner 10 space probe was the last spacecraft in the Mariner program, and launched on 3 November 1973. Its mission was to measure the atmospheric, surface, and physical characteristics of Mercury and Venus. After taking some 4000 photographs of Venus, Mariner 10 then flew by Mercury, taking the first photographs detailed enough to reveal the planet's cratered surface and a faint atmosphere of predominantly helium.
The lander was used to land on planets and study the such as the moon and the orbiter was used to orbit the planet while studying it.
The mission of a Telescope is to study or see space.
They study mercury with high powered satellites from outer space. Of course if they got to close to it where it is so close to the sun it would fry in an instant. The closest planet they have been to the sun is venus and that satellite burnt up from venus's hot atmosphere. Anything closer than that would vaporize. The only planet or considered planetoid we have not taken a look at is Pluto where it is so far away and it is so small.
* Mariner 10 - USA Mercury/Venus Flyby - 526 kg - (November 3, 1973 - March 24, 1975) Mariner 10 was the first dual planet mission. It flew past Venus on February 5, 1974 for a gravity assist to the planet Mercury. Mariner 10 was the first spacecraft to have an imaging system. It flew past Mercury 3 times on March 29, 1974, September 21, 1974, and March 16, 1975. These three encounters produced over 10,000 pictures with 57% planet coverage. It recorded surface temperatures ranging from 187°C to -183°C on the day and night sides. A weak magnetic field was detected but it failed to detect an atmosphere. Mariner 10 is now in a solar orbit.* MESSENGER - USA Mercury Orbiter - 3 August 2004 The Mercury Surface, Space Environment, Geochemistry and Ranging (MESSENGER) mission is designed to study the characteristics and environment of Mercury from orbit.Sourcehttp://www.solarviews.com/eng/craft2.htm#mercury
The study of our planet
geology
The study of the planet Mars.
astronomy
Mercury