Old Views

From an old encyclopedia c 1940. In just 25 years space missions made a mockery of such views. Beginning in 1965, a plethora of rocket ships reached Mars and many other places. Men landed on the moon.

There are lessons in this today. Some people dismiss predictions of voyages to the stars, or UFO reports, claiming that interstellar distances make them impossible. Numerous UFO cases make a mockery of that. Ample experience shows it is unwise to underestimate the possibilities spawned by technological advances.

The planetary data in the old work also requires comment (click for better view). The info on Mercury's density and gravity is erroneous. The innermost planet is not 17% denser than our world. Its density is slightly less, or 98% that of Earth. Likewise, Mercury's gravity is lower than 44% of ours; it's just under 38%.

In contrast to the Mercury data, that for Mars is fairly accurate. Mars has long been the best known planet in the solar system. It is easier to study than Mercury, which is smaller, never gets as close as Mars does occasionally and is too close to the sun for proper observation. The Red Planet also has satellites, enabling researchers to accurately calculate its mass and gravity. It's not surprising the astronomers of a century ago erred about the innermost planet.