31 Days of Planets: Pluto

Day 10

Pluto is still a planet. I know everyone was so upset when Neil DeGrasse Tyson fought to "de-planetize" Pluto, but that's not what really happened. What really happened is that Pluto became special. Pluto became a dwarf planet - one of only two others (maybe). Of course, there are probably billions more dwarf planets, but Pluto gave us the deliberate ability to classify small planetary bodies as "not Earth-sized" and "not-gas giants." Instead of wandering around saying, "well, I guess we should call it a planet because it orbits the sun even though it's super small and different and doesn't really meet the criteria for a planet" we were able to definitively say: "Pluto is a dwarf planet."

It's like saying, "well, I guess we'll call you a hippie because you eat organic food and don't like war and ride bicycles, but your hair is too neat and your clothes are too carefully chosen," instead of "you are a hipster."

Pluto is in fact smaller than Eris and composed primarily of rock and ice. In fact, Pluto may host a hidden ocean. This means, if we run out of water because we humans are good at making bad decisions, we can mine Pluto. But then imagine the price of water! We'll be watching it like we watch the price of gas. 

"8.57 a gallon! Good heavens!" 

"Well that's what you get when you have to mine it from Pluto."

Pluto's atmosphere plays host to nitrogen, methane, and carbon monoxide. There may even be wind on the surface of Pluto.

In conclusion, just remember: Pluto is still a planet - just a dwarf planet.

Image from zmescience

31 Days of Planets: Eris

Day 5: Eris

Eris is a real planet inside our solar system. Not a myth. Not some suddenly-appearing planet made up by crazy people. Some people claim that the planet Nibiru is actually Eris. This is not true.

Eris is a dwarf planet, probably bigger than Pluto. It resides past Neptune, and is known as a trans-Neptunian dwarf planet. It is the farthest known natural body in our solar system. It has one moon, Dysnomia, and the two were discovered in 2005. Eris was originally known as Xena, or Planet X.

Eris played an important role in modern astronomy - it forced scientists to differentiate between a planet and a dwarf planet. Many people were very upset when Pluto got "downgraded" from a planet - but in truth Pluto is still a planet, just a dwarf-planet. This is an important distinction because as we continue to discover more and more objects out in space, each with unique characteristics, we will have to have some way to classify them - just as scientists classify species and rocks and everything else imaginable. Then our human obsession with organizing everything will slowly be fulfilled in the arena of giant rock-like objects in space.

So what is a planet? you ask. Well, a planet orbits the sun, is massive enough for its own gravity to make it round, and has cleared its neighborhood of smaller objects around its orbit. This definition currently only applies to our solar system, but I'm sure eventually they'll expand it to "orbits a star" and then name everything else differently. Dwarf planets orbit the sun, is massive enough that its shape is controlled by gravitational forces, but hasn't cleared the neighborhood. Dwarf planets are like kids that like to play with other kids. Big planets are like grownups that build giant fences around their yard and call the cops if anyone cuts across the grass.

This is photo taken by the Keck telescope in Hawaii: 

This is an illustration of what Eris and Dysnomia might look like:

In conclusion, Eris is the first of many (planets, but not necessarily in our solar system). I can't wait to see what else is out there!

Pictures from NASA.

The Day the Sun Got Littler

This morning I couldn't see the sun because a dull cover of grey clouds ensconced the chunk of landmass where I live. But there I sat, still contemplating the sun and her magnificent death rays and reading her online dating profile, when I surprised myself by thinking, "well, that's not very big!" To put it in context, consider the two freaking gigantic black holes recently discovered by some astronomers in California. The article states, "Both encompass regions or 'event horizons' about five times the distance from the sun to Pluto." 


So I decided to do some math.


Math can be quite inspiring.


The distance from Pluto to the Sun is 3.67 billion miles*. 3.67 billion miles times 5 is 18.35 billion miles across, a number that is impossible to grasp. For help understanding big numbers, ask xkcd. Basically, the span of the biggest black hole's event horizon stretches for this number of miles:

18,350,000,000 miles

My next step involved finding out the size of the sun, because the sun is the biggest thing I know and can see and with which I mayhaps have some sort of understanding. So I read about the sun... heat... fire... solar system... moon... mass... distance... earth...

diameter: 864,938 miles.

And I thought to myself, "well, that's not very big."


Of course the Earth is smaller than the sun, and the continents and oceans are smaller than the Earth, and you could keep going like this until you get to quarks, but compared to the vastness of the universe, the sun isn't very big. Neither are we.


But who cares? Because we have great big minds which try ever so hard to encompass great big ideas which are mind boggling and socket blowing and bubble popping all at the same time; and despite our desperately diminutive state of existence, we will continue to build whopping big robots that explode from the surface of the earth in search of life on other planets, we'll still jump in front of trains to save a little girl's life, and we'll still continue to fight with each other, just to prove that we're right.


*Speaking of Pluto, the probe which is set to reach the not-quite planet in 2015, moved closer to Pluto than any probe before it three days ago.)