Other Objects in Our Solar System

Comets, Meteors, Asteroids, and Kuiper Belt Objects (KBOs)

Halley’s Comet 1910

Comets • • • • Halley’s Comet takes 76 years to orbit the sun. It was last seen near Earth in 1986.

A comet is a “dirty ice-ball”.

It is made of ice, rock, methane, and ammonia.

There is a large cloud of comets beyond Pluto. They are called the “Oort Cloud”.

Comets

• • • Comets show “tails” which point away from the sun.

The tails are caused by the ice becoming gas.

The “coma” is a bright cloud of gas that forms around the solid core of the comet.

Asteroids Asteroid Ida and its moon

Asteroids • • • Asteroids are pieces of rock and mineral.

There is an asteroid belt which orbits the sun between Mars and Jupiter.

There are pieces which are basketball size to 940 Km (580 mi.) for the dwarf planet Ceres.

Meteoroids, Meteors, Meteorites An iron meteorite A mineral meteorite

Meteoroids • • • Meteoroids are pieces of moons, planets, and asteroids which are relatively small.

Some meteoroids are small enough that they burn up as they enter Earth’s atmosphere. These are meteors.

Some are large enough that they land on Earth. They are meteorites.

Sedna

Sedna

Trans- Neptunian Objects (TNOs) • • • • Objects in the solar system which are farther than Neptune. Some cross Neptune’s orbit. TNOs include KBOs, SDOs, and comets KBO = Kuiper Belt Objects SDOs = Scattered Disk Objects

Kuiper Belt Objects- 30 AUs out to 50 AUs • • • • There are very large objects found beyond Neptune Quaoar is an 800 mile wide KBO.(43AU) Quaoar was found in June 2002 by Chad Trujillo and Mike Brown at Caltech in Pasadena.

N ASA WEB

TNOs •

Where are TNOs?

•

New TNOs or new dwarf planets?

• • • • • • Ixion , 650 mi wide, 3.7 Billion mi out.

2002 UX25, 580 mi., 4 Billion mi. out.

Varuna , 560 mi., 4 billion mi. out.

2002 TX300, 540 mi. , 4 billion mi.

2002 AW197, 550 mi., 4.4 billion mi.

2004 DW, 1,000 miles wide, 4.4 billion miles from the sun, discovered 2/17/04.

New Dwarf Planets •

New Planets Or TNOs… IAU • • • • • • • • Xena 1600 mi 2003 Now Eris (8/06) Sedna 930 mi 2003 Orcus 930 mi 2004 Quaoar 800 mi 2002 Easter Bunny 775 mi. 2005 Santa 744 mi. 2003 Buffy 720 mi. 2005 Ixion 660 mi. 2001

Dwarf Planets August 24,2006 • • • The IAU has declared several TNOs to be “dwarf planets” This is why Pluto was demoted in Aug., 2006. It is smaller than several TNOs.

Xena was officially named Eris on Sept. 13, 2006

Eris : The New Dwarf Planet (SDO) •

The SDOs and the Oort Cloud • • • • Scattered Disk Objects are KBOs that have been scattered by the gravity of Neptune. They have irregular orbits.

The Oort cloud is located 50,000 AU to 100,000 AU or about 1 light year out.

The Oort Cloud is made of millions of comets.