Early Exploration Mariner 3 & 4 “…these missions are being undertaken because Mars is of physical and geological interest and offers the best opportunity in our solar system for shedding light on the possibility of extraterrestrial life. (They)…, however, are not designed to provide answers to the question of life on Mars.” Mariner 4 Press Kit, October 29, 1964

Early Exploration Mariner 4 Launched November 24, 1964; closest approach occurred on July 14, 1965 Took 22 pictures w/ a TV camera viewing through a reflecting telescope

Early Exploration Mariner 4

Early Exploration Mariner 4

Early Exploration Mariner 4 Notable observations from Mariner 4 Images returned showed a Moon-like cratered terrain Surface atmospheric pressure of 4.1 to 7.0 mb (accepted values ranged from 10 – 100 mb) Daytime temperatures of -100° C (-148° F) were estimated No magnetic field was detected

Early Exploration Mariner 4 How did Mariner 4 advance scientific understanding of Mars? Mars looked more like the Moon Life far less likely IMPORTANT: Mariner 4 only imaged ~1% of the surface of Mars, mostly in the southern hemisphere What technological advance(s) did Mariner 4 carry? The Mariner 4 spacecraft

Early Exploration Mariner 6 & 7 “Study the surface and atmosphere of Mars to establish the basis for future experiments in the search for extra-terrestrial life and to develop technology for future Mars missions. The 1969 flights will not determine the presence of life on Mars but will help establish whether or not the Martian environment is suitable for life.” Mariner (6 & 7) Press Kit, July 18, 1969

Early Exploration Mariner 6 & 7 Launched February 23 (M6) & March 27, 1969 (M7) Close approaches occurred July 31 (M6) & August 5 (M7), 1969

Early Exploration Mariner 6 & 7 Two TV cameras – medium & high resolution, IR radiometer (surface temps, is southern cap CO2 or H2O?), UV spectrometer (atmospheric composition), IR spectrometer (surface & near-surface composition)

Early Exploration Mariner 6 & 7

Early Exploration Mariner 6 & 7

Early Exploration Mariner 6 & 7 Notable observations from the Mariner 6 & 7 missions report Temps range between -73° C (-100° F) & 15° C (60° F) The polar caps were crusted with frozen carbon dioxide… Features with a dimension of 900 (ft.) could be identified. The so-called Martian canals were not in evidence. At a location called Nix Olympica…was a huge crater 300 miles in diameter. No indications of volcanism were found. Mariner 6 & 7 imaged 20% of the surface of Mars, mostly in the southern hemisphere

Early Exploration Mariner 6 & 7 How did Mariner 6 & 7 advance scientific understanding of Mars? Temperature range South polar cap composed of CO2; temp reading of -123°C (-190°F) NO CANALS What technological advance(s) did Mariner 6 & 7 carry? Spacecraft with higher resolution cameras & spectrometers

CRATER BOXES!!!

Early Exploration Mariner 8 & 9 “Study the surface and atmosphere of Mars in detail, and over a period of time, to provide a broad picture of the history of the planet and natural processes currently shaping the Martian environment. To accomplish this, one spacecraft will map 70% of the planet and the other will repeatedly study selected areas on Mars to observe changes on the surface and in the atmosphere.” Mariner (8 & 9) Press Kit, April 30, 1971

Early Exploration Mariner 8 & 9 Launched May 8 (M8) & May 30, 1971 (M9) Mariner 8 failed 4.5 minutes after launch, Mariner 9 arrived at Mars on November 14, 1971

Early Exploration Mariner 8 & 9 Narrow-angle and wide angle TV cameras, IR radiometer (surface temps), UV spectrometer (composition of upper atmosphere), IR interferometer spectrometer (provide a picture of the circulation of the atmosphere & composition of the surface)

Early Exploration Mariner 9 Arrived at Mars only to find a global dust storm blanketing the planet Circular features peaking through the dust

Early Exploration Mariner 9

Early Exploration Mariner 9 Notable results from Mariner 9 Global mapping (imaging) of the surface of Mars The first detailed views of the Martian volcanoes, Valles Marineris, the polar caps, and the satellites Phobos and Deimos Provided information on global dust storms, the planet’s rugged gravity field, and evidence for surface aeolian (wind) activity.

Early Exploration Mariner 9 Olympus Mons 27 km tall (16.8 miles), 600 km (373 miles) wide Shield volcano composed of basalt Largest (known) volcano in the solar system

Early Exploration Mariner 9 Valles Marineris 4,000 km long (2,500 miles), 200 km (124 miles) wide, 7 km (4 miles) deep Large crack resulting from uplift of Tharsis bulge Named after Mariner 9

Early Exploration Mariner 9 Tharsis Bulge Credit: NASA/Goddard Space Flight Center

Early Exploration Mariner 9 How did Mariner 9 advance scientific understanding of Mars? Mars is more geologically diverse than had ever been presumed Evidence water once flowed on the surface, not in artificial canals, but natural river channels What technological advance(s) did Mariner 9 carry? Spacecraft orbited Mars, first unmanned planetary orbiter in history