Friday Headlines, October 10, 2014
THE LATEST IN THE GEOSCIENCES
Today’s round-up:
Slump takes out a house. Eek!
Is Pluto a planet again, or what?
Rock fall video!
North Salt Lake home being demolished after landslide
This actually happened 0n August 5, but I only first saw this footage in the last week. It’s definitely worth watching.
This is in the category of Earth processes called “mass wasting.” I put these processes in four categories:
- So slow you can’t see it happen (but you see the evidence): Creep and solifluction
- Fast enough to see, but you can easily escape (like walk away): Slumps
- So fast that you can’t get out of the way, but you do have time to see it coming: mud and debris flows and slides, including avalanches.
- So fast that you never know what hit you: Rock falls
The above event is a slump. You can see people standing and watching it, and casually walking away.
Alas, homes are not able to walk away, so they are often destroyed in such events. The linked article tells more about the aftermath of this particular slump event.
Wait, what? Pluto a planet again?
What makes a planet a planet? According to the International Astronomical Union (IAU), a planet is defined by possessing the following three criteria:
- Is in orbit around the sun
- Is round
- Has cleared the neighborhood around its orbit
Pluto fails the third criterion, because several ‘dwarf planets’ near its orbit, and because it sometimes crosses the orbit of Neptune.
In a debate between two big-wigs in the IAU and the director of the Harvard Origins of Life Initiative, there was an audience vote about whether or not Pluto should be a planet. The vote was “yes.” But this is hardly cause to celebrate.
Officially, Pluto still a dwarf planet unless and until the IAU votes it back to ‘planet’ status. Because no astronomers have asked the IAU to review the planetary status of Pluto, it’s not likely to be voted on.
So yeah. Pluto is still not a planet. And it will probably remain not-a-planet for the foreseeable future.
China: a new rockfall video from Guiyang, Guizhou…
As it seems to be the week of mass wasting, here’s another event that happened just yesterday. This one is a rock fall. As I noted above, rock falls tend to be so fast, you probably won’t know what hit you.
Luckily, in this case, police had just closed the road, so no cars were in danger when this rock wall went down.
Penny Higgins - Storyteller • Artist • Scientist 
Forget the IAU; they came up with that silly definition just to please the bolometricists and annoy the planetologists. Notice that their definition has nothing to do with how the planet forms or what happens inside, just with how long it has been in a given orbit. If a Pluto-sized planet had formed at Mercury’s distance from the Sun, it would have cleared its neighborhood long ago.
As a proud planetologist, I go with the original definition: If it is big enough to be round under its own gravitational forces but no so big that it is in fusion, then it is a planet. (Or “planemo” if you want to appease the IAU.) That gives us some 400 or so planets in this solar system alone, which is more than enough to start learning some very cool things!
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