1840   Johann Maedler publishes the first detailed map of the surface of Mars.

1965   American space probe Mariner 4 takes the first detailed photographs of the southern hemisphere Mars and measures the atmospheric pressure of the planet.

1969   American space probe Mariner 6 takes high resolution photographs of the equatorial region of Mars

1969   American space problem Mariner 7 takes high resolution photographs of the southern hemisphere.  The photos help determine that the planet's polar ice caps are composed of frozen carbon dioxide

1971   Soviet space probe Mars 2 crashes on the surface of Mars before sending its data to Earth.

1971   American space probe Mariner 9 successfully orbits the planet.  It sends thousands of images of the planet.

1971   Soviet probe Mars 3 lands of Mars and successfully transmits the first television images of the planet's surface.

1973   Soviet orbiter probe Mars 4 is unable to achieve an orbital path around the planet.

1976   American space probe Viking 1 lands on the surface of mars and successfully transmits weather and soil data.

1975   American space problem Viking 2 completes 706 orbits of the planet and returns over 16,000 images.  Its lander also successfully transmits high-resolution photos of the planet's surface.

1988   Contact is lost with Soviet probe Phobos 1 before it is able to transmit useful data.

1988   Soviet probe Phobos 2 sends data while orbiting Mars but contact is lost before the deployment of its landers.

1993   Contact is lost with American space probe Mars Observer as it enters the planet's atmosphere.

1996   Russian probe Mars '96 is destroyed on launch.

1997   American probe Mars Pathfinder successfully lands on the planet's surface and transmits data collected from scientific instruments.

1997   American probe Mars Global Surveyor successfully transmits surface mapping data from orbit.  Contact is lost with the surveyor after 5 years in orbit.

1998   American probe Mars Climate Orbiter is destroyed when entering the atmosphere of Mars before sending data.

1999   American probe Mars Polar Lander is destroyed when entering the atmosphere of Mars

2001   American probe 2001 Mars Odyssey Martian orbit and transmits data intended to help search for evidence of water on Mars.  It remains in orbit today.

2003   American rovers Spirit and Opportunity successfully land on the surface of Mars and transmit geological data about the planet's surface features.

2004   Contact is lost with British space probe Beagle 2 as it enters the atmosphere of Mars.

2006   American space probe Mars Reconnaissance Orbiter attains Martian orbit and transmits data for analyzing landforms, minerals, and ice of Mars.