Early Exploration1609 - 1976

Early ExplorationFrom Galileo until the mid-1960s, scientists were restricted to ground-based observations of Mars

What are its limitations?

Galileo Galilei observed Mars in 1609 and wrote in 1610: “…if I am not mistaken, I believe that I have seen it is not perfectly round.”

Early Exploration

Giovanni Cassini calculated a rotational period of 24 hrs, 40 min; first noted the southern polar cap in 1666

Early Exploration

Giovanni Schiaparelli popularized the straight lines he called “canali” (channels), though no one else mapped such features until later

Percival Lowell misinterpreted “canali” to mean canals (artificial); mapped 437 “canals” in 917 sketches; took the idea of canals to the grave

Early Exploration

Early Exploration Changing features on the Martian surface, interference from

Earth’s atmosphere, and observers’ physiology led to observations with interesting interpretations:

Canals brought water from the polar regions to the equatorial region

With an atmosphere, climate should be warm enough for beings on the planet

Dark patterns change with seasons on Mars; plant life growing and dying

Early Exploration“This carrying of water from pole to pole, and melting of ice over such large areas, might give rise to uncomfortable currents in ocean and air; but very likely an inhabitant of earth might be transported to the surface of Mars, and be no more surprised at what he observed there than if he went to some point on the earth to him unknown.”

- Henry White Warren, 1879

Early Exploration“A third presence on Mars indicates a living world: vegetation. The evidence is in the blue-green areas and the changes in their appearance. Vegetation would present exactly the appearance shown…. The seasonal change that sweeps over them is metabolic; that is, it shows both growth and decay….”

- Earl C. Slipher, 1962

Early Exploration“A third presence on Mars indicates a living world: vegetation. The evidence is in the blue-green areas and the changes in their appearance. Vegetation would present exactly the appearance shown…. The seasonal change that sweeps over them is metabolic; that is, it shows both growth and decay….”

- Earl C. Slipher, 1962

Early Exploration

Prior to the mid-1960s, scientists viewed Mars as a place with an environment not too unlike Earth, though intelligent life probably did not exist.

In 1965, Earth takes a closer look…