The Tenth Planet Shrinks Under Hubble's Gaze

starexplorer2001 writes "An object called the 10th planet by some astronomers is not as large as previously thought. New images of 2003 UB313 (aka Xena) were delivered by the Hubble Telescope and showed up as only 1.5 pixels! Now, some are calling to demote Pluto and kill Xena."

Comments

Xena

[Detritus]

Forget Xena, the planet should be named Marvin.

A planet by any other name....

[svunt]

Ah, I still remember fondly the first time I saw a slashdot thread climb to a few hundred posts of argument about 'what makes a planet a planet?'. If ever a term was crying out for a rigid, ostensive definition from astronomers, it's 'planet'. From the ancient greek word for "wanderer", if we don't tighten it up some, the argument will come trotting out every time someone finds a rock doing laps about the sun. Stays within 10 degrees of the ecliptic, say 3,000km across...that works for me.

what scale?

[alphakappa]

"New images of 2003 UB313 (aka Xena) were delivered by the Hubble Telescope and showed up as only 1.5 pixels! "

1.5 pixels on what scale? A pixel is not a unit of measurement for size, it just denotes the smallest distinct unit in a picture. Yes, it appears sensational to say that a 'planet' appeared to be 1.5 pixels (100 exclamation marks), but that's just as stupid as saying that my backyard appears to be 5 pixels wide on Google Earth. Gives no information unless you say that the resolution is 1 pixel = X metres.

Why is this so hard?

[jpatters]

I don't understand why this is so hard to understand. The only sensible definition for a planet is an object that is spherical due to its own gravity, orbits a star, and is not itself a star. But these bozos keep saying "But Pluto is so different from the other planets, we can't call it a planet!" Well boohoo. So it's freaking different! Earth and Jupiter are somewhat freaking different from each other, last time I checked, but we call both of those objects planets! "But then there will probably be a thousand planets in the solar system!" they say. I say, get over it! This is not a big problem unless you're an astrologer! I honestly don't give a rat's ass about Pluto's legacy as being called a planet, if we are going to continue calling it a planet then we also need to call this other object (and several others) planets as well. The problem is, we keep being told that this needs to be controversial because defining a planet is somehow difficult, what I think is happening here is that there are a group of scientists who have an emotional problem with there being a thousand planets in the solar system and are preventing the IAU from adopting the obvious definition.