Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Exploration of Jupiter wikipedia , lookup
History of Solar System formation and evolution hypotheses wikipedia , lookup
Scattered disc wikipedia , lookup
Planet Nine wikipedia , lookup
Formation and evolution of the Solar System wikipedia , lookup
Eris (dwarf planet) wikipedia , lookup
Late Heavy Bombardment wikipedia , lookup
Kuiper belt wikipedia , lookup
COVER STORY A spacecraft journeys I who study space, met in Europe. f you have a textbook with our The astronomers voted that there solar system in it, you've probwould be eight planets instead of ably crossed out Pluto by now. nine. Those eight "classical" The puny, icy object was kicked out planets include Mercury, Venus, ofthe planet family on August 24. Earth, Mars, Jupiter, Saturn, Planet or not, Pluto and its icy Uranus, and Neptune. mysteries are still the destinatioti of New Horizons. In January, the Why did astronomers give 1,054-pound spacecraft Pluto the boot? For blasted off toward starters, they came Pluto, which is up with a new akes 3 billion miles definition for a Planet? from Earth. planet. A planet :o meets only two of the must be nearly If all goes ttiree new requirements: round and must according to 1. It must orbit the sun. orbit, or circle, plan, the piano. It has to be nearly rbund. the sun. Its sized spacecraft 3. Its orbit should not cross orbit should not will fly by Pluto another planet's orbit cross the orbit of in 2015. The spaceanother planet. Pluto's craft will get an uporbit intersects, or crosses, close look at Pluto and other Neptune's path. objects in the Kuiper (KIGHper) belt. The Kuiper belt is a Since its discovery in 1930, wide band of icy and rocky astronomers suspected that Pluto objects on the outer edges of our was an oddball when compared solar system. with the other planets. New technology has shown that its orbit is New Horizons—the fastest oval-shaped. Pluto is also smaller spacecraft ever built—will than the other planets. Even Earth's investigate the former planet, moon is larger. measuring its atmosphere and temperature. The spacecraft will Orbit and size weren't the only also beam pictures to Earth. problems. Pluto is made up of material that is difFerent from that ofthe other planets. While the othNew Class System ers are made up of rocks or gases, As the spacecraft sped onward, Pluto consists mostly of ice. world astronomers, or scientists WR NEWS Edition 4 Pluto appears to be similar td other objects in the Kuiper belt. ItJ status as a planet began to look bleak when 2003 UB313 was discovered three years ago. Thai Kuiper belt object, nicknamec "Xena," is larger than Pluto. The discovery prompted astronomers tc begin thinking about reclassifyin^ the objects in our solar system. Dwarf Planets Don't pity Pluto, though. It still has a place in space. Pluto is now one of a group of smaller space objects called dwarf pianetsi To Pluto and Beyond Nine years and 3 billion miles after it left Earth, New Horizons.wM fly by Pluto. The siiper-speedy craft will gathc information from the Kuiper belt, a region at the edge of the solar system. January 2 Cape Canaveral, Florida. ird the new dwarf planet. One member is the largest asteroid, called Ceres (SIHR-eez). The other space object is 2003 UB313. I More dwarf planets are lexpected to be named as they are discovered. "These dwarf planets [are popping up everywhere," astronomer Alan Stern told \WR News. Stem is in charge of ithe New Horizons mission. |Fuil Speed Ahead lAs New Horizons races toward Pluto, scientists hope the craft :will offer clues to how our solar system was formed 4.6 billion years ago. Many scientists believe that objects in the Kuiper belt are leftovers from the formation of the solar system. Pluto's downgraded title isn't stopping scientists from learning more about the dwarf planet. "We will continue pursuing exploration of the most scientifically interesting objects in the solar system, regardless of how they are categorized," says NASA official Paul Hertz. © THINK CRITICALLY Not all astronomers agree wrth the decision to change Pluto's status. Why might some oppose it? Pluto's Discovery Pluto was discovered in 1930, long after the other planets, by American astronomer Clyde Tombaugh (1906-1997). He wasnt the person to name it, though. Venetia Burney, an 11-year-old British girl, gave Pluto its name. She thought the new planet should be named for the Roman god of the underworld www. wccklyrcadcr. com