New 10th Planet Discovered

[Turtle]

http://science.nasa.gov/headlines/y2005/29jul_planetx.htm

 

This is very cool! I have to see what name it gets.

[Chacmool]

Very exciting indeed! Any guesses on the new name? I hope the follow the naming pattern of the other planets, and give it the name of a Roman god/goddess.

[Tormod]

Thanks for posting that, Turtle.

 

I have posted the entire release here along with an illustration.

[Turtle]

___It seems naming this planet is a little harder than it may seem; moreover, is it a "planet" at all? This question of what constitutes a planet is rather a large debate now, & a key argument is that "planet" is a cultural term & not a scientific one. Read more here:

http://space.com/scienceastronomy/050802_planet_definition.html

[Aki]

Is this new 10th planet the same as Planet X?

[CraigD]

I think Mike Brown’s right, and we'd best get out of the habit of counting planets beyond Neptune. Pluto/Charon, 90377 Sedna, 2000 CR105, 90482 Orcus, 50000 Quaoar, 20000 Varuna, and now 2003 EL61, 2005 FY9, and 2003 UB313, AKA planetx – more and improved astronomy is almost certain to find even larger Kuipier belt / Oort cloud objects on a fairly regular basis.

 

:) I’ve got a whimsical proposal for the definition of “planet”: An object orbiting the sun that is in turn orbited by at least on moon massive enough that a unaided human being couldn’t put themselves into orbit around it. Of course Mercury and Venus would be out by this definition, and possibly Mars, which hardly seems fair, Venus being nearly the equal of Earth, but part of the charm of whimsy is that it’s rarely fair. :)

 

Seriously, Brown’s “big enough to be round” definition seems the way to go, provided there’s a rule against gravel piles, which can be pretty spherical under their own gravity, yet hardly seem proper planets.

[CraigD]

Is this new 10th planet the same as Planet X?

No. "Planet X" is a result of inaccuracies in the 19th century math and astronomy accounting for the gravitational effect of Neptune. They thought there was one more big planet, and hunted for it 'til they found Pluto, which wasn't nearly big enough.

[emessay]

Who is going to discover next 11th planet ? And when ?........

[CraigD]

Who is going to discover next 11th planet ? And when ?........

Some think we’re up to about 25 already. In the last few years, discoveries of object close to the size of Pluto have averaged 3 or so a year.

[Jay-qu]

10th planet? did anyone hear about that rock they named sedna? i thought that was gonna be classed as a planet, i guess not...

[Tormod]

The distinction between Sedna and other objects is basically the orbits, I think. AFAIK this "tenth" planet has a more standard orbit than previous objects.

 

Even Pluto's orbit is "abnormal" considering that it passes inside Neptune's orbit and also the inclination of Pluto's orbit is off quite a bit IIRC.

[Turtle]

___Besides Pluto's elliptical eccentricity, its orbit is inclined to the ecliptic 17 degrees.

This paragraph is exerpted from the article I linked to in post#4:

 

"Pluto is small, its orbit very noncircular, and it travels 17 degrees outside the main plane of the solar system where the other planets roam. In recent years, several other round worlds at least half as big as Pluto have been found on similar offbeat paths, including two announced last week in addition to 2003 UB313, whose orbit is inclined a whopping 45 degrees."

___Why not "planetoids" for those below a certain mass threshold? :)

[maddog]

Being this latest object is at about 97 AU, it is farther than the Kuiper belt and is likely a

reminant of it. Given Pluto's inclination to the Ecliptic of about 7 Degrees (relative to the

orbit of the Earth's orbit), it is even possible that Pluto and Charon came from there as

well (though likely separately). The nebular hypothesis would have most gases freeze

out by this distance except near cores (like metalic Hydrogen of Jupiter). So Neptune

may be the last Gas Giant for star the size of our sun (G2 V). It is with the discovery of

Sedna that people have begun to rethink whether Pluto is even a planet.

 

maddog