Tuesday October 23, 2012 (Lunar History – The Formation of the Moon)

The Launch Pad Tuesday, 10/23/12 Identify the region of the Solar System where these objects are found. Top Row All Kuiper Belt Kuiper Belt Asteroid Belt

The Launch Pad Tuesday, 10/23/12 Label the four parts of the Solar System. planetary region Kuiper Belt Scattered Disk Oort Cloud

Announcements Happy Fall

Assignment Currently Open Summative or Formative? Date IssuedDate Due Date Into GradeSpeed Final Day Quiz 6S110/5 10/26 Quiz 7S210/12 10/26 WS – Dwarf Planets F310/1810/2210/24 Quiz 8S310/19 11/2 WS – Trans- Neptunian Regions of the Solar System F410/2210/26

Recent Events in Science Orionid Meteor Shower Wows Weekend Stargazers shower-weekend-stargazers-photos.html Read All About It! The Orionid meteor shower rained bits of the famed Halley's Comet on Earth last weekend to the delight of stargazers around the world. The 2012 Orionid meteor shower peaked early Sunday (Oct. 21), with forecasters predicting up to 25 meteors an hour for patient stargazers with clear skies well away from city lights. In Norway, photographer Tommy Eliassen captured a spectacular view of the Orionids and Earth's dazzling northern lights.

Earth’s Moon Mare Highlands

Earth’s Moon Lunar History The current hypothesis suggests that a giant asteroid collided with the Earth to produce the Moon. The older areas have a higher density. The younger areas are still smooth.

The Formation of the Moon The current preferred hypothesis regarding the Moon’s formation is the ‘collision’ theory. It is, so far, the best at explaining how compositions of rock from the Earth and rock from the Moon differ. According to the collision theory, at the dawn of the Solar System a heavenly body the size of Mars hit the young Earth. As a result, material from the rocky mantle of the heavenly body and of the Earth was hurled into space. This collected in the shape of a ring on a path closely orbiting the Earth where it then gradually ‘clumped together’ to form the Moon.

The Formation of the Moon

Earth’s Moon Lunar History The Moon evolved in three phases: 1.original crust (highlands) As the Moon formed, its outer shell melted, cooled, solidified, and became the highlands - about 4.5 billion years ago. 2.formation of maria basins Maria basins are younger than the highlands – they formed between 3.2 and 3.8 billion years ago. 3.formation of rayed craters The material ejected from craters is still visible as rays - e.g., Copernicus and Tycho (rayed craters).

Worksheet Our Solar System

What is the Kuiper Belt? The Kuiper Belt is a disk-shaped region beyond the orbit of Neptune that contains masses of ice and icy rock believed to be the source of comets with orbital periods of less than 200 years.

What is the Oort Cloud? The Oort Cloud is a hypothesized spherical cloud of comets which may extend to roughly 50,000 AU, or nearly a light-year, from the Sun. This places the cloud at nearly a quarter of the distance to Proxima Centauri, the nearest star to the Sun. The Kuiper belt and scattered disc, the other two reservoirs of trans- Neptunian objects, are less than one thousandth of the Oort cloud's distance. The outer limit of the Oort cloud defines the cosmographical boundary of the Solar System and the region of the Sun's gravitational dominance. Our Solar System

What is the Scattered Disk? The Scattered Disk is a distant region of the Solar System that is sparsely populated by icy dwarf planets, a subset of the broader family of trans-Neptunian objects. The scattered disc objects (SDOs) have orbital eccentricities ranging as high as 0.8, inclinations as high as 40°, and perihelia greater than 30 astronomical units. Our Solar System

What three characteristics does a Scattered Disk Object (SDO) have? orbital eccentricities ranging as high as 0.8 orbital inclinations as high as 40° perihelia greater than 30 astronomical units Our Solar System