FAKULTI PENDIDIKAN TEKNIKAL

ASTRONOMI & FIZIK

WILL PRESENT :

ERIS, THE LARGEST DWARF PLANET

PREPAIRED FOR : DR. ARIF AGAM

BY :ROSHALIZA BINTI RAHMAT

DB100017SAINS GROUP 2 (TUTORIAL 2)

ERIS THE LARGESTLARGEST DWARF

PLANET

WHAT IS A PLANET ?

A ball of gas, liquid or solid, orbiting a star, whose size is neither

too big or too small for a planet.

Who Is Eris?

• Eris is a dwarf planet which lies at the edge of our solar system. Eris has one moon named Dysnomia.

• Eris is a tenth planet that found in orbit around the Sun, since the discovery of Neptune and its moon Triton in 1846.

• Eris was discovered on 5th January 2005 using Samuel Oschin Telescope at Palomar Observatory, when they were having a close look at some images of the outer Solar System taken in 2003.

• It is also one of a member of the Kuiper Belt.

• Eris was known as the largest dwarf planet, larger than Pluto, discovered by Clyde Tombaugh in 1930

• Eris is almost 10 billion miles from the Sun and takes 557 years to complete its orbit around the Sun.

• Eris was known as the largest dwarf planet.

• What are the dwarf planets ?

Physical of Eris• Size : 2400km in diameters (2340km in year 2010 by Occultation)• Surface and atmosphere : The presence of methana ice, indicating that the

surface may be similar to Pluto. The surface temperature is estimated to vary

between about 30 and 56 kelvin (−243 and −217 degrees Celsius, it is cold enough for methana ice to persist ).

• Even though Eris can be up to three times further from the Sun than Pluto, it approaches close enough that some of the ices on the surface might warm enough to sublimate.

• Eris appears almost grey.

Naming • Eris has known with the earlier name called Xena, after

the main character of the television series Xena “The Warrior Princess.

• Eris also known as 2003 UB313. This name based on the date it was first seen.

• However, there is a rule stating that all objects orbiting outside Neptune’s orbit have to be named after a creation of mythology. Then, it was officially named Eris on 13th September 2006.

• Eris is named after the goddess of strife, discord, contention and rivalry in Greek mythology.

ERIS’S MOON• Eris has one moon that is officially named as (136199)

Eris I Dysnomia.

• ‘Dysnomia’ is taken from the mythological daugther of Eris. It is the daemon spirit of lawlessness.

• Dysnomia takes 16 days to go around Eris.

• By using the Hubble Space Telescope, the image of the Dysnomia is the only the moon around Eris.

• Size : About 22 times smaller in diameter than Eris.

Dysnomia

Dysnomia(Gabrielle)

ErisThe name is pronounced

EE-ris. (2003 UB313 / Xena)

Current orbit of Eris

The orbit of Eris is odd. The orbit is not a circle, so Eris moves closer to and further from the Sun as it goes around. It takes Eris 557 years to go around one time. The orbit of Eris is also tilted,so, it doesn't move in the same plane that the other planets orbit in.

Current sky position from Segamat (22nd April 2011) :

This information was taken from website :

http://www.wolframalpha.com/input/?i

=eris+planet

Orbital properties:

AU(Astronomical Unit) is the

average distance of the planet from the Sun

Eris Discovery Image

Eris

Animation showing the movement of Eris on the images used to discover it. Eris is indicated

by the arrow.

Samuel Oschin Telescopeat Palomar Observatory

Hubble Space Telescope

Astronomers Discovered Eris• Eris was discovered by the three

astronomers below :

Dr. Micheal E. Brow (Mike Brown)Professor of Planetary Astronomy

Caltech

Chad Trujillo(An astronomer at

Gemini Observatory, Hawaii)

David L. Rabinowitz(A researcher at Yale

University)

Pluto and ErisWhen is a planet or not a planet?

(Opinion from Martina Redpath – Armagh Planetarium)

• After much discussion the International Astronomical Union (IAU) decided to reclassify Pluto, as it no longer fulfilled the criteria to be a regular planet.

• Discussion and debate regarding Pluto’s fate split opinion for years, after all, its orbit was different to the other planets being tilted by nearly 20 . The final straw in ⁰the decision to demote Pluto occurred in 2005 when Mike Brown, an astronomer from the California Institute of Technology and his team announced they discovered an object in 2003 beyond Pluto that was larger. The object (2003UB313) was suitably named after the Greek goddess of strife and discord, Eris.

• The IAU gathered and decided Pluto’s fate, they redefined what the term planet really meant.

• The criteria to be classed as a planet are as follows;

• A planet must :

1.       Be in orbit around a star eg. the Sun.

2.       Have enough mass and gravity to be a

sphere.

3.       Must have enough mass to dominate its

orbit, ie. have cleared any objects out of its

path.

• It was this final requirement that caused Pluto to lose planetary status. Pluto is located in the Kuiper Belt so therefore has not cleared its orbit.

• Eris is no longer Pluto’s twin, but a totally different world. These two planets seem to have similar surfaces yet different internal make-up.

• This has opened up many queries regarding these two world’s history and why they are so different.

• Perhaps when the spacecraft New Horizons arrives at Pluto in 2015 we’ll gain a much better understanding about the dwarf members of our Solar System.

SOURCES

• http://en.wikipedia.org/wiki/David_L._Rabinowitz• http://en.wikipedia.org/wiki/Chad_Trujillo• http://en.wikipedia.org/wiki/Michael_Brown• http://en.wikipedia.org/wiki/Eris_(dwarf_planet)• http://en.wikipedia.org/wiki/Dysnomia_(moon)• http://www.armaghplanet.com/blog/pluto-and-eris-when-

is-a-planet-not-a-planet.html• http://www.wolframalpha.com/input/?i=eris+planet

THANK YOU