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.
Kepler also found the first Earth-size planet that orbits in a star's habitable zone, the area around a star where a planet could exist with liquid water on its surface. The Kepler mission builds upon the stalwart Hubble Space Telescope, which launched in 1990 and was the first of its kind to be placed in space.