Pluto The Pup

Pluto, formal designation 134340 Pluto, is the second-largest known dwarf planet in the Solar System (after Eris) and the tenth-largest body observed directly orbiting the Sun. Originally classified as a planet, Pluto is now considered the largest member of a distinct population called the Kuiper belt.[note 9] Like other members of the Kuiper belt, Pluto is composed primarily of rock and ice and is relatively small: approximately a fifth the mass of the Earth’s Moon and a third its volume. It has an eccentric and highly inclined orbit that takes it from 30 to 49 AU (4.47.4 billion km) from the Sun. This causes Pluto to periodically come closer to the Sun than Neptune. From its discovery in 1930 until 2006, Pluto was considered the Solar System’s ninth planet. In the late 1970s, following the discovery of minor planet 2060 Chiron in the outer Solar System and the recognition of Pluto’s very low mass, its status as a major planet began to be questioned.[6] Later, in the early 21st century, many objects similar to Pluto were discovered in the outer Solar System, notably the scattered disc object Eris, which is 27% more massive than Pluto.[7] On August 24, 2006, the International Astronomical Union (IAU) defined the term “planet” for the first time. This definition excluded Pluto as a planet, and added it as a member of the new category “dwarf planet” along with Eris and Ceres.[8] After the reclassification, Pluto was added to the list of minor planets and given the number …

Frontiers/Controversies in Astrophysics (ASTR 160) Class begins with a review of the first problem set. Newton’s Third Law is applied in explaining how exoplanets are found. An overview of the Solar System is given; each planet is presented individually and its special features are highlighted. Astronomy is discussed as an observational science, and the subject of how to categorize objects in the Solar System is addressed. The Pluto controversy is given special attention and both sides of the argument regarding its status are considered. 00:00 – Chapter 1. Review of the Problem Set 06:22 – Chapter 2. Conservation of Momentum in Exoplanets 14:02 – Chapter 3. Inner and Outer Solar System Objects 29:47 – Chapter 4. Kuiper Belt Objects and Oort Cloud 35:13 – Chapter 5. Classification and Interpretation of Celestial Objects Complete course materials are available at the Open Yale Courses website: open.yale.edu This course was recorded in Spring 2007.

The lonely planet.