Stories by Fred L. Whipple

Puzzling changes in the orbital period of Comet Encke, which circles the sun every 3.3 years, can be attributed to the rotation of its icy nucleus and the thrust of gases evaporated from it

Although Comet Kohoutek was a disappointment to visual observers, it provided a good opportunity for the study of one of the objects that may be relics of the cloud from which the sun and the planets formed

The artificial satellites are man's first venture into experimental celestial mechanics. An account of how the first satellite's orbit was determined, and how our knowledge of this orbit can be applied

Astronomers have recently constructed some plausible theories about the composition and origin of these periodic visitors to the center of the solar system

The vast distances of interstellar space are filled with huge amounts of dust and gas, the study of which has led to a new theory accounting for the origin of stars and planets