Mars 96 (sometimes called Mars 8) was an orbiter launched in 1996 by Russia and not directly related to the Soviet Mars probe program of the same name. The orbiter's intended destination was Mars, but its actual destination was the Pacific Ocean, due to problems with the launch vehicle. The Mars 96 spacecraft was based on the Phobos vehicles launched to Mars in 1988. They were of a new design at the time and both ultimately failed. But for the Mars 96 probe the designers believed they had corrected the flaws of the Phobos vehicle. Alas, they did not get to find out if they had produced a successful design this time due to the launch vehicle failure.
It was, however, a very ambitious mission and the heaviest (intended) interplanetary probe ever launched. It included a large complement of instruments such as the Penetrator, many provided by France, Germany, and other European countries (some of which have since been re-flown on Mars Express, launched in 2003), and the United States. It was made up of the Orbiter, two Surface Stations, and two Penetrators.
Percival Lawrence Lowell (March 13, 1855 – November 12, 1916) was a businessman, author, mathematician, and astronomer who fueled speculation that there were canals on Mars, founded the Lowell Observatory in Flagstaff, Arizona, and formed the beginning of the effort that led to the discovery of Pluto 14 years after his death. The choice of the name Pluto and its symbol were partly influenced by his initials PL.
The hole was discovered by chance on images of the dusty slopes of Mars' Pavonis Mons volcano taken by the HiRISE instrument aboard the robotic Mars Reconnaissance Orbiter currently circling Mars. The hole appears to be an opening to an underground cavern, partly illuminated on the image right. Analysis of this and follow-up images revealed the opening to be about 35 meters across, while the interior shadow angle indicates that the underlying cavern is roughly 20 meters deep. .