Featured Research

from universities, journals, and other organizations

Dwarf Planet Formerly Known As Xena Officially Named 'Eris'

Date:
September 15, 2006
Source:
California Institute of Technology
Summary:
The International Astronomical Union has announced that the dwarf planet known as Xena since its 2005 discovery has been named Eris, after the Greek goddess of discord. Eris's moon will be known as Dysnomia, the demon goddess of lawlessness and the daughter of Eris.

Artists concept of the view from Eris with Dysnomia in the background, looking back towards the distant sun.
Credit: Robert Hurt / IPAC, Caltech

The International Astronomical Union (IAU) has announced that the dwarf planet known as Xena since its 2005 discovery has been named Eris, after the Greek goddess of discord.

Eris's moon will be known as Dysnomia, the demon goddess of lawlessness and the daughter of Eris.

The names are those suggested by the discoverers of the dwarf planet--Mike Brown, a professor of planetary astronomy at the California Institute of Technology, Chad Trujillo of the Gemini Observatory, and David Rabinowitz of Yale University, and by the discoverers of the moon--Brown and the engineering team of Keck Observatory where the observations were made.

"Eris is the Greek goddess of discord and strife," explains Brown. "She stirs up jealousy and envy to cause fighting and anger among men. At the wedding of Peleus and Thetis, all the gods were invited with the exception of Eris, and, enraged at her exclusion, she spitefully caused a quarrel among the goddesses that led to the Trojan War.

"She's quite a fun goddess, really," Brown adds. "And, for the Xena fans out there who are sad to see the name go, Eris appeared in her Latin version of Discordia as a recurring character on Xena: Warrior Princess."

True to its name, the dwarf planet Eris has stirred up a great deal of trouble among the international astronomical community, most recently last month when the question of its proper designation led to a raucous meeting of the IAU in Prague. At the end of the conference, IAU members voted to demote Pluto to dwarf-planet status, leaving the solar system with eight planets.

However, the ruling effectively settled the year-long controversy about whether Eris would rise to planetary status. Somewhat larger than Pluto, the body was formally announced to the world on July 29, 2005. With the August IAU ruling, Eris is the largest dwarf planet.

Eris, about 2,400 kilometers in diameter, was discovered on January 8, 2005, at Palomar Observatory with the NASA-funded 48-inch Samuel Oschin Telescope. A Kuiper-belt object like Pluto, but slightly less reddish-yellow, Eris is currently visible in the constellation Cetus to anyone with a top-quality amateur telescope.

Eris is now about 97 astronomical units from the sun (an astronomical unit is the distance between the sun and Earth), which means that it is some nine billion miles away at present. On a highly elliptical 560-year orbit, Eris sweeps in as close to the sun as 38 astronomical units. At present, however, it is nearly as far away as it ever gets.

Pluto's own elliptical orbit takes it as far away as 50 astronomical units from the sun during its 250-year revolution. This means that Eris is sometimes much closer to Earth than Pluto--although never closer than Neptune.

Dysnomia, the only satellite of Eris discovered so far, is about 250 kilometers in diameter and reflects only about 1 percent of the sunlight that its parent reflects. The name is both a nod to Lucy Lawless, the actress who played Xena on the TV show, and to the astronomical tradition of naming the first satellites of dwarf planets.

Based on spectral data, the researchers think Eris is covered with a layer of methane that has seeped from the interior and frozen on the surface. As in the case of Pluto, the methane has undergone chemical transformations, probably due to the faint solar radiation, causing the methane layer to redden. But the methane surface on Eris is somewhat more yellowish than the reddish-yellow surface of Pluto, perhaps because Eris is farther from the sun.

Brown, Trujillo, and Rabinowitz first photographed Eris with the Samuel Oschin Telescope on October 31, 2003. However, the object was so far away that its motion was not detected until they reanalyzed the data in January of 2005.

The search for new planets and other bodies in the Kuiper belt is funded by Caltech and NASA. For more information on the program, see the Samuel Oschin Telescope's website at http://www.astro.caltech.edu/palomarnew/sot.html.

For more information on Mike Brown's research, see http://www.gps.caltech.edu/~mbrown.

To learn more about Eris, see http://www.planeteris.com.


Story Source:

The above story is based on materials provided by California Institute of Technology. Note: Materials may be edited for content and length.


Cite This Page:

California Institute of Technology. "Dwarf Planet Formerly Known As Xena Officially Named 'Eris'." ScienceDaily. ScienceDaily, 15 September 2006. <www.sciencedaily.com/releases/2006/09/060914155305.htm>.
California Institute of Technology. (2006, September 15). Dwarf Planet Formerly Known As Xena Officially Named 'Eris'. ScienceDaily. Retrieved September 20, 2014 from www.sciencedaily.com/releases/2006/09/060914155305.htm
California Institute of Technology. "Dwarf Planet Formerly Known As Xena Officially Named 'Eris'." ScienceDaily. www.sciencedaily.com/releases/2006/09/060914155305.htm (accessed September 20, 2014).

Share This



More Space & Time News

Saturday, September 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

MIT BioSuit A New Take On Traditional Spacesuits

MIT BioSuit A New Take On Traditional Spacesuits

Newsy (Sep. 19, 2014) The MIT BioSuit could be an alternative to big, bulky traditional spacesuits, but the concept needs some work. Video provided by Newsy
Powered by NewsLook.com
Boeing, SpaceX to Send Astronauts to Space Station

Boeing, SpaceX to Send Astronauts to Space Station

AFP (Sep. 17, 2014) NASA selected Boeing and SpaceX on Tuesday to build America's next spacecraft to carry astronauts to the International Space Station (ISS) by 2017, opening the way to a new chapter in human spaceflight. Duration: 01:13 Video provided by AFP
Powered by NewsLook.com
East Coast Treated To Rare Meteor Sighting

East Coast Treated To Rare Meteor Sighting

Newsy (Sep. 16, 2014) Numerous residents along the East Coast reported seeing a bright meteor flash through the sky Sunday night. Video provided by Newsy
Powered by NewsLook.com
Space Race Pits Bezos Vs Musk

Space Race Pits Bezos Vs Musk

Reuters - Business Video Online (Sep. 16, 2014) Amazon CEO Jeff Bezos' startup will team up with Boeing and Lockheed to develop rocket engines as Elon Musk races to have his rockets certified. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins