There Should be a Change in How We Decide What's a Planet and What Is Not

Pluto and it's moon, Charon

The astronomical bigwigs are at it again - trying to decide whether or not Pluto's a planet. I think the wrong people are debating this. Regular folk should decide. This is too important to leave to mere astronomers and academics.

So, let me offer a definition of a planet from the viewpoint of a consumer of astronomy. To be a useful definition, let's make it more like the way the APA describes mental illnesses. It gives some options and the requirement is that the disorder (or planet in this case) meet 3 of 4 or 4 of 7 of the criteria to be that mental disorder or astronomical object. This leaves room for variation within a type. So here's my offering for a definition of a planet.

1. Is a celestial body moving in an elliptical orbit around a star.
2. Is spherical in shape and has a shape that is stable under its own gravity.
3. Is large enough to dominate its orbit having cleared neighboring space of debris.
4. Has at least a diameter of 2,000 km.
5. Has a satellite that orbits around it.
6. Has an atmosphere.

To be a planet, it must meet four out of six of the above criteria.

Pluto would be a planet (1,2,4,5,6)
Eris might be a planet (1,2,4?,5,6?)
Makemake would be a dwarf planet (1,2,)
Quaoar would be a dwarf planet (1,2,5)
Orcus would be a dwarf planet (1,2)
Sedna would be a dwarf planet (1,2,)
Ceres would be a planetoid or asteroid (1)

I might even make a further distinction.

1 criteria = asteroid (mostly because it's not spherical)
2 criteria = planetoid
3 criteria = dwarf planet
In which case Orcus, Makemake and Sedna would be only planetoids.

Just my own humble opinion. It just seems that the requirement that a planet meet every criteria in a list is too rigid. It doesn't allow room for something odd to be a planet even though everybody thinks it ought to be one because it looks like one. That's how things get named out in the real world.

Scientists should remember that before they go around willy-nilly making a kid's model solar system obsolete.

Yeah, it makes me mad. I'm getting too old to relearn the solar system.

© 2014 by Tom King

Why They Call Them the "Golden Years"

Being in fashion? Not a problem.

There are distinct advantages to being a sexagenarian and it's not what just flashed through your dirty mind.  I have compiled a list of some advantages to being of an elderly persuasion.

• You have more interesting conversations about surgeries with your friends in a week than the average doctor does with his colleagues in a month and you've finally learned what a prostate is and what it means when it's gone. 

•  No one wants to kidnap you. In a hostage situation, you'll probably be the first one released. People let you ahead of them in restaurant lines, stores give you 10% off just for being you and you can sing along with the elevator music without shame. 

• Your kids hold family meetings down at the I-Hop about what to do about you (and you don't have to go to them). 

• You've discovered how to use the Internet to find out what's really wrong with you so you can argue with your doctor more effectively. Besides that, all that health insurance you bought is finally beginning to pay off. 

• Everyone's happy now when you take a nap in the middle of the afternoon and they try not to wake you up.

• Your kids bring you presents now when they haven't come to visit in a long time because they feel guilty. You've learned to use that guilt to get better presents.

• You can predict the weather with your joints and you're more accurate than the National Weather Service so you don't have to watch television weather reports anymore, which gives you more time to watch Matlock reruns on Netflix.

• Sex is as rare and as much appreciated as it was when you were 13. You can even get along without it. What you can't get along without are your glasses. 

• You are no longer expected to run – anywhere! And people don't think you're a hypochondriac anymore.

• People don't call you lazy anymore - in fact, they keep telling you that you should slow down a bit. If someone calls after 9:00 pm, they ask if they woke you up and apologize for calling so late.

• You and your fellow retirees control 75% of all liquid cash assets in the United States and you still remember your children and relatives who weren't nice to you.

• You don't have to remember anything you don't want to. Nobody expects you to remember anything anyway.

© 2014 by Tom King