Administration: Individual. The DAB-4 is a revision of one of the most popular individual achievement tests available. Its 8 subtests identify studentsâ strengths and weaknesses across important areas of school achievement. A supplemental manual shows how to probe student responses to obtain information about studentsâ thinking processes and problem-solving strategies.
In 1992, the first evidence of a planetary system other than our own was discovered, orbiting the pulsar PSR B1257+12. Three years later, 51 Pegasi b, the first extrasolar planet around a Sunlike star, was discovered.
Beyond the Planets - the discovery of Pluto. Key points: How Pluto was discovered. Mercury, Venus, Earth, Mars, Jupiter, and Saturn have all been known since ancient times. Uranus was discovered by chance by Herschel in 1781. Neptune was discovered in 1846, ostensibly as a result of calculations to explain deviations in the position of Uranus, but substantial luck was involved.