Word: comets
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Dates: during 1970-1979
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Such data may help clear up the mystery of the asteroid belt itself. For a long time astronomers suspected that it was made up of the remnants of a small planet that was blown apart, perhaps in a collision with a comet. Now astronomers are leaning to the idea that the asteroid belt consists of primordial matter that failed to coalesce into a full-fledged planet. If so, that could make an asteroid an even more valuable prize than any moon rock-assuming some far-ranging space traveler could bring it home. It would be a piece of material largely...
...Brady of the Lawrence Livermore Laboratory gave a description of the long-sought tenth planet, complete with its distance from the sun and its current position in the heavens. His "discovery" was made, not by scanning photographic plates, but by analyzing the erratic behavior of Halley's Comet, which comes into view every 76 years (next appearance: 1986), as it nears the sun in its elliptical and far-ranging orbit...
Checking historical observations dating back nearly 1,700 years, Brady found a peculiar irregularity: on each approach to the sun, Halley's Comet shows up as many as four days earlier or later than its predicted arrival date. That variation seemed to indicate that some unknown force must be influencing the comet's motion. Could it be the gravitational tug of a planet beyond Pluto...
...four years, Brady fed into a computer mathematical models of a ten-planet solar system, seeking the characteristics of a still undiscovered planet that would cause the irregularities in the comet's orbit. Gradually the description of Planet X emerged: it would be three times as massive as Saturn (second largest of the planets) and nearly 6 billion miles from the sun (more than half again as far as Pluto). It would take 464 years to complete a single trip around the sun, and the plane of its orbit would be tilted an angle of approximately 60° from...
...invisible women" whose achievements have been largely forgotten: Dorothea Dix, whose exposes revolutionized conditions in mental institutions a century ago; Sojourner Truth, a former slave and influential abolitionist who was received by Abraham Lincoln and later appointed "counselor to the freed people"; Maria Mitchell, who discovered a new comet in 1847; Belva Lockwood, activist lawyer and candidate for President on an equal-rights platform in 1884. In analyzing the bias that has ignored such figures, the women's studies courses frequently focus on economic exploitation and other forms of oppression. At Buffalo, a course on the Politics of Health...