Hubble Spies Pluto
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The Hubble map of Pluto from 1994 (upper) and the latest one below. Be sure to click the image for a larger version. Image credit: NASA, ESA, and M. Buie (Southwest Research Institute)
Pluto has a surface temperature of something like 35 to 45 K (-378oF to -396oF). I sort of always thought of Pluto as a pretty static place, but not so.
The little world’s northern hemisphere is getting brighter and it is becoming redder as a result. Hubblesite described it as an icy and dark molasses-colored world.
Here are some of the other Hubble images: 90 degs / 180 degs / 270 degs. The images don’t give us a lot of detail as far as the surface features go, still a lot can be learned from these pictures. We do have a spacecraft on the way to Pluto and in 2015 it will finally arrive – Pluto is a LONG ways away, heck those are Hubble pictures and we still can’t resolve the surface!
Ok before I get all carried away, Pluto has a diameter of 2,390 km and if you are thinking that’s smaller than our moon, you’d be right. Our moon happens to be the 5th largest moon in the solar system, but that’s another story. The other thing about Pluto’s size is Eris (yeah, the one that caused the hub-bub) is maybe even a little larger than Pluto. Pluto’s whole orbit is tilted 17 degrees relative to the ecliptic and it’s also very elongated.
I’m not going to go into the whole planet, dwarf planet debate. I will say I’ve come to my own conclusion. Suffice it to say, Pluto is very strange place.
Head on over to Hubblesite for the full press release, more images and even video.
Did either of the Voyagers take any pictures of Pluto? I in my heart still call it a planet. I also didn’t realize our moon was the 5th largest.
Thanks again for the info
Trudy
Not to usurp Tom here, Trudy, neither of the Voyagers made it to Pluto. One, I believe Voyager I made it to Jupiter, Saturn, Uranus and Neptune coming close to the long sought “Grand Tour” of the outer planets. Voyager II was shot out of the plane of the Ecliptic (path of most of the planets) during its Saturn encounter and never made it to Uranus or Neptune.
In terms of our moon, it may be only 5th largest, however, it might rank even higher in mass relative to the other moons, since the larger moons of the outer giant planets are mostly spheres of ices (water, ammonia, methane, etc.), which means lower densities overall, while our moon is mostly rock.
Yup Yup, Thanks JohnD.
Thank You John.
Trudy
I, for one, like Pluto’s demotion. It is, however, the king (I know, not in size but …) of all the grand stuff that is happening in the Oort cloud. A long time ago, I read a science fiction story or something about the expansion of humanity creeping out and colonizing the Oort cloud and thereby getting about 1/4 of the way to the Centauri system(s). Supposedly they then jumped to the Oort of Proxima Centauri since they were living in a environmental system that didn’t matter about the time needed to sneak on over. Do any of you know that story or article?
Editus
It was Voyager II, not Voyager 1, that flew by Uranus and Neptune. Also, Pluto is not in the Oort Cloud. It is both a Kuiper Belt Object and a planet. Pluto is one of a new class of PLANETS in our solar system, the dwarf planets that are planets because they are large enough to be in hydrostatic equilibrium but of the dwarf subcategory because they are not large enough to gravitationally dominate their orbits. In fact, these pictures that show Pluto to be a dynamic world reinforce its similarities to the larger planets. Most asteroids and KBOs do not have geological processes and weather.