7/26-28/2006 - John Loves Mary

Mary's Violet Eyes Make Crazy John Stay Up Nights Pondering. Chad, Too.

An august body of astronomical talent has set their eyes on taxonomy.  On August 24th, there will be a vote on a set of planetary definitions.  Until this week, there has never been an iron-clad definition of just what a planet is.  The problem is that, almost any reasonable definition of planet must either [a] exclude Pluto or [b] include something other than our famous 9.  Not wanting to rely on Greek Mythology, the commission has finally laid out a definition that would immediately welcome 3 newcomers into the club: Ceres, Charon and the aptly named 2003 UB313.

Starting from us and working our way outwards, the first new planet is Ceres.  Currently thought of as the largest asteroid in the belt between Mars and Jupiter, Ceres meets all the criteria.  What interests me most about Ceres is that it is the closest of the new potential planets, which means that we will likely increase our efforts to study it.  Who knows what that will yield, but I am very interested at the thought.  By the by, I thought that I heard that there are two other very large asteroids in the belt.  I wonder whether they are potential candidates for future planethood?

The next closest of the early candidates is Charon, better known as "Pluto's moon."  It might sound odd Pluto's moon would get planetary consideration while our own (which is bigger) would not.  The deal is that "moon" as opposed to "planet" is to be defined as being a function of relative size.  So our moon is much smaller than Earth, while Charon is close in size to Pluto.  That would make Pluto and Charon binary planets.  Pretty cool.  We have sent a probe to Pluto, which should arrive in 2015.  It would be fantastic if we also got some shots at Charon at the same time.

Our final new candidate is 2003 UB313, a.k.a. Xena (but, pneumonically, what the heck was I supposed to do with that?).  Xena is 50% farther away from us than Pluto, which makes it a lot harder to study than the other 2.  What we do know about Xena is that it is similar in make-up to Pluto, and considerably larger.  Xena is the real problem child here.  If Xena is not a planet, then how can Pluto be a planet?  I also thought I heard that Xena had a non-planular orbit around the sun, like Pluto.  I wonder whether studying the two in concert will give us any insights into gravity and its impacts on orbits?  Alas, I worry that the distance will keep us from garnering much from Xena for quite some time.

But lest you think the show ends there, there are plenty more potential planets in our solar system!  The next 12 likely candidates would be:

• 2003 EL
• 2005 FY
• Sedna
• Orcus
• Quaoar
• 2002 TX
• 2002 AW
• Varuna
• Ixion
• Vesta
• Pallas
• Hygiea

What are we going to do with that?

Elvis fearfully sees others quietly taking away various investments via parliamentary heckling?

38,000 heavenly steps today.  Cheers,