Skip to comments.Scientists discover moon orbiting so-called 10th planet (nicknamed 'Xena')
Posted on 10/01/2005 5:10:46 PM PDT by NormsRevenge
LOS ANGELES - The astronomers who claim to have discovered the 10th planet in the solar system have made another intriguing announcement: it has a moon.
While observing the new, so-called planet from Hawaii last month, a team of astronomers led by Michael Brown of the California Institute of Technology spotted a faint object trailing next to it. Because it was moving, astronomers ruled it was a moon and not a background star, which is stationary.
The moon discovery is important because it can help scientists determine the new planet's mass. In July, Brown announced the discovery of an icy, rocky object larger than Pluto in the Kuiper Belt, a disc of icy bodies beyond Neptune. Brown labeled the object a planet and nicknamed it Xena after the lead character in the former TV series "Xena: Warrior Princess."
By determining the moon's distance and orbit around Xena, scientists can calculate how heavy Xena is. For example, the faster a moon goes around a planet, the more massive a planet is.
But the newly discovered moon, nicknamed Gabrielle after Xena's faithful traveling sidekick in the TV series, likely will not quell the debate over what exactly is a planet and whether Pluto should keep its status. The problem is there is no official definition for a planet and setting standards like size limits potentially invites other objects to take the "planet" label.
Possessing a moon is not a criteria of planethood since Mercury and Venus are moonless planets. Brown said he expected to find a moon orbiting Xena because many Kuiper Belt objects are paired with moons.
The moon is about 155 miles wide and 60 times fainter than Xena, the farthest-known object in the solar system. It is currently 9 billion miles away from the sun, or about three times Pluto's current distance from the sun.
Scientists believe Xena's moon was formed when Kuiper Belt objects collided with one another. The Earth's moon formed in a similar way when Earth crashed into an object the size of Mars.
The moon was first spotted by a 10-meter telescope at the W.M. Keck Observatory in Hawaii on Sept. 10. Scientists expect to learn more about the moon's composition during further observations with the Hubble Space Telescope in November.
Brown planned to submit a paper describing the moon discovery to the Astrophysical Journal next week.
The International Astronomical Union, a group of scientists responsible for naming planets, is deciding on formal names for Xena and Gabrielle.
On the Net:
California Institute of Technology: http://www.caltech.edu
W.M. Keck Observatory: http://www2.keck.hawaii.edu
What? Not Xenu?
Since they have started naming "new" planets after television characters, I guess the next planet can be named MacGyver. How about Cartman? Kramer?
Robert Hurt (IPAC)
Artists concept of a view of the planet, looking back toward the distant sun.
A partial moon maybe...
A new planet and other strangers (Santa, Easterbunny, and Xena.)
Caltech professor of planetary astron-omy Mike Brown and his colleagues announced a startling discovery on July 29: a new planet larger than Pluto in our solar system. But they also found two other objects, and all three are oddities that could revolutionize our understanding of the solar system.
The discoverers have nicknamed the objects Santa, Easterbunny, and Xena. Brown, along with former Caltech postdoc Chad Trujillo, who is currently at the Gemini Observatory in Hawaii, and David Rabinowitz of Yale, detected the three objects with the 48-inch Samuel Oschin Telescope at Palomar Observatory.
All three objects are nearly Pluto-sized or larger, with Xena large enough to be called the tenth planet. The three also have odd elliptical orbits, and are members of the Kuiper belt, a region beyond Neptunes orbit that for decades was merely theoretical. When astronomers began detecting Kuiper-belt objects in the mid-1990s, the region suddenly became reality.
Xena, which is currently about 97 astronomical units away (one AU equals the distance between the sun and Earth, or approximately 93 million miles), is at least the size of Pluto and probably much larger. The researchers hope that infrared data returned by the Spitzer Space Telescope in late August, plus recent data from the 30-meter IRAM telescope in Spain, will help nail down Xenas size. Brown predicts that Xena will be highly reflective, because spectrographic data gathered by Trujillo show the surface composition is similar to that of Pluto. If, like Pluto, Xena reflects 70 percent of the sunlight reaching it, then it is about 2,700 kilometers (over 1,600 miles) in diameter.
The second object, nicknamed Santa because it was found on December 28, 2004, is one of the more bizarre objects in the solar system, according to Rabinowitz. His observations from a small telescope in Chile show that Santa is a cigar-shaped body whose length is about the diameter of Pluto. No large body in the solar system comes close to rotating as fast as Santa, which has a four-hour period. Observations by the team at the W. M. Keck Observatory have shown that Santa also has a tiny moon, nicknamed Rudolph, which circles it every 49 days.
Easterbunny, so named because of its discovery last March, is 52 astronomical units away, and like Santa is probably about three-quarters the size of Pluto. Moreover, Easterbunny is now the third Kuiper belt object, after Pluto and Xena, known to have a surface covered in frozen methane. For decades, Pluto was the only known methane-covered object beyond Neptune, but now we suddenly have three, in a variety of sizes at a variety of distances, and can finally try to understand Pluto and its cousins, says Kris Barkume, a PhD student working with Brown.
I vote we name it Kucinich.
They named a planet after these two? What's next? Mulder and Scully?
The Earth's moon formed in a similar way when Earth crashed into an object the size of Mars.
Do we know this as fact?
What object was it?
A cigar-shaped body? Wouldn't a better name be...ah nevermind.
Did Xena and Gabrielle ever,well you know what.
Should we search hard enough we'll probably find several of these objects. I think Pluto's demotion has become inevitable. I sure don't consider it a planet anymore.
BumP into each other,,, ?
In yur dreams .. ;-P
That's neither funny nor cute and whoever's doing it needs to have a little sit-down chat with an adult.
It's considered pretty certain based on analysis of rock and dust samples brought back from the Apollo missions.
We are apt to imagine that we could discover these effects by the mere operation of our reason, without experience. We fancy, that were we brought on a sudden into this world, we could at first have inferred that one billiard ball would communicate motion to another upon impulse, and that we needed not to have waited for the event, in order to pronounce with certainty concerning it. Such is the influence of custom, that, where it is strongest, it not only covers our natural ignorance but even conceals itself, and seems not to take place, merely because it is found in the highest degree. But to convince us that all the laws of nature, and all the operations of bodies without exception, are known only by experience, the following reflections may, perhaps, suffice. Were any object presented to us, and were we required to pronounce concerning the effect, which will result from it, without consulting past observation, after what manner, I beseech you, must the mind proceed in this operation? It must invent or imagine some event, which it ascribes to the object as its effect, and it is plain that this invention must be entirely arbitrary. The mind can never possibly find the effect in the supposed cause, by the most accurate scrutiny and examination. For the effect is totally different from the cause, and consequently can never be discovered in it. Motion in the second billiard ball is a quite distinct event from the motion in the first. nor is there anything in the one to suggest the smallest hint of the other. --David Hume
So the moon is made up from earth and some other body,
but which one? Mars? or something else?
And if earth where on earth did it come from?
Inquiring minds want to know, this is not something
you would discover in Weekly World NEws.
Or maybe it IS ! At least if alien cross dressers are involved.
You mean the mother ship has launced a probe? Maybe Louis Fairy-Khan's days are numbered after all.
Cisco & Pancho. Panch has to be the planet, though, since he is the fat one.
At least Xena and Gabby set an example of TV characters that look like healthy women and not emaciated heroin waifs.
I think they should stick with Roman mythology though.
Who's left among the Olympians?
Juno (too far away from Jupiter?)
Vesta (I think there already is an asteroid)
Apollo (no -- associated with the Sun)
Diana (maybe...the huntress and all)
Vulcan (would make people think of Star Trek)
Ceres (already an asteroid)
Also, does the position of this new planet contradict Bode's law?
While the debate is meaningless, the continuing discovery of planets or whatever they are called out beyond Pluto/Neptune, way beyond, probably means there are planets all the way to the next star. It is possible a starship might go directly to the next star, but it is more likely that the Kuiper objects and Oort objects present a natural evolution--stepping stones--in the same direction.
regarding supposed impact origin of the Moon:
She can't a whole moon!
A partial moon maybe...
As a poet I once knew said, "... her ass
looked like the bottom of heaven!"
Why is there no difinition of 'plantet'?
I would think that anything massive enough to shape itself into a shpere would be a good definition.
there is a huge ring of debri between earth and mars- they think that may have once been a planet
I read somewhere that it had been named “Eris”.
Today we call the resulting post crash debris by the unimaginative names, "Earth" and "Moon".
Facts are elusive and science does often produce absolutes, but the crash hypothesis explains why the Earth's spin axis is titled so profoundly with respect to its orbital plane and that huge gash west of California called the Pacific Ocean, and why the Earth-Moon system is the closest thing to a double planet in the solar system, inter alia.
Right — but this is the Greek name. The Roman equivalent is “Discordia.” It’s not an attractive name for a planet, though.
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