Early ExplorationMariner 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 ExplorationMariner 4Launched November 24, 1964; closest approach occurred

on July 14, 1965Took 22 pictures w/ a TV camera viewing through a

reflecting telescope

Early ExplorationMariner 4

Early ExplorationMariner 4

Early ExplorationMariner 4Notable 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

estimatedNo magnetic field was detected

Early ExplorationMariner 4How 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 ExplorationMariner 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 ExplorationMariner 6 & 7Launched February 23 (M6) & March 27, 1969 (M7)Close approaches occurred July 31 (M6) & August 5 (M7),

1969

Early ExplorationMariner 6 & 7Two 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 ExplorationMariner 6 & 7

Early ExplorationMariner 6 & 7

Early ExplorationMariner 6 & 7Notable 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 ExplorationMariner 6 & 7How 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 ExplorationMariner 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 ExplorationMariner 8 & 9Launched 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 ExplorationMariner 8 & 9Narrow-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 ExplorationMariner 9Arrived at Mars only to find a global dust storm blanketing

the planetCircular features peaking through the dust

Early ExplorationMariner 9

Early ExplorationMariner 9Notable results from Mariner 9

Global mapping (imaging) of the surface of MarsThe 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 ExplorationMariner 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 ExplorationMariner 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 ExplorationMariner 9

Tharsis Bulge

Credit: NASA/Goddard Space Flight Center

Early ExplorationMariner 9How did Mariner 9 advance scientific understanding of

Mars?Mars is more geologically diverse than had ever been

presumedEvidence 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