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.
âBut this is the first time in 150 years that we can say we have convincing evidence that the census of the solar system is incomplete.â. The discovery of the world that Brown and Batygin refer to in The Astronomical Journal simply as âPlanet 9â began in 2003, with the discovery of a far more modest object named Sedna.