The First Dwarf Planet

when I was growing up we were taught that there were nine planets in our solar system while this number has since dropped to eight this does not diminish just how cool the former ninth planet is in fact I would wager that it is an even more interesting world to us now despite it being classified differently this is cup of science Joe and today I here to talk about Pluto covering everything from its Discovery to what we have learned from and about it now speaking of its Discovery this happened in the year 1930 by an astronomer named Clyde tomow at the time of his Discovery Clyde was working at the L observatory in Flagstaff Arizona he made this discovery using what I like to think of as an early form of astrop photog graphy he would take images of the patch of sky where Pluto was thought to be and these images were exposed onto large plates Clyde could then load two of these plates into a device called a blink comparator this would let him quickly swap between the two loaded plates and look for any movement or differences between them and when he discovered the small dot of Pluto moving consistently against the background Stars he knew he had discovered something after this discovery was made and confirmed and the observatory released it to be checked on by other people they started getting name suggestions from people around the world the name that they selected came from an 11-year-old girl named venisha Bernie who selected the name based off of the Roman god of the underworld and as of this time our solar system had gained its ninth planet Pluto but as I hinted at earlier this classification would not last forever but we will get into that one later for now let's talk a bit about Pluto itself it is rather small in size having a radius of 715 miles making it about 16 the width of Earth for another point of comparison our moon is around 1,79 miles so the Moon is bigger than Pluto it has a larger radius and it has roughly six times more mass as well Pluto is also very far away from us and from the Sun it is on average 39 astronomical units away from the Sun or around 3.7 billion miles reaching it would be like driving around the earth roughly 148,000 times it even takes light 5.5 hours to make this trip and it is moving rather quickly this distance means that the sun is dark there but it's not as dark as our night if you were to stand on Pluto at noon and look towards the sun it would be about 300 times as bright as our full moon there is a moment each day near sunset here on Earth where the light is the same as it would be if you were looking at the sun midday on Pluto now for me it's around 7:57 p.m. but if you're curious to find your Pluto time there there's a NASA link that brings you to this page here I'll leave it in the description and you basically come down and provide it with your location and this will tell you roughly what time of day for you on Earth is the light going to match what Pluto would be receiving at about noon or midday for it Pluto has an unusual orbit around the sun when compared to the planets it is both elliptical and it is tilted the time it takes it to orbit around the Sun is 248 years during this long oval-shaped orbit it can be as far away as 49.3 astronomical units or as close as 30 astronomical units from the Sun an interesting thing this causes is that during its parah helion which is when it's the closest to the Sun it is closer than Neptune so it's like it's inside of Neptune's orbit during that point for its rotation one day on Pluto takes 153 hours its axis of rotation is tilted by 57° with respect to its plane of orbit around the sun this means it's almost spinning on its side and like Venus and Uranus it exhibits a retrograde rotation this means it is spinning from east to west as opposed to west to east like say the Earth does Pluto's also got some moons five to be exact they are Karen NYX Hydra karos and sticks this Moon system may have formed by a collision of Pluto in another similar sized object in the past during the formation of the solar system the most notable Moon of these is Karen it is by far the biggest of Pluto's moons coming in at about half the size of Pluto itself it is very close to it as well orbiting it only 12,200 Mi away so they're like about to be kissing because of how close they are to each other and how close they are in size Pluto and Karen are tidally locked to each other only ever showing the other the same side as if in an endless Waltz and as far as I know they're the only that's the only planetary system or where the main body and one of its moons are both tidally locked to each other at least in our solar system for the longest time we did not know anything about what Pluto looked like it remained a speck until we got our first images from Hubble in 1994 which still did not reveal much aside a gray sphere with some surface details it would not be until 2015 with the flyby of New Horizons that we would get a true look at the beauty of Pluto for now though let's turn our attention to 2006 when Pluto was re classified as a dwarf planet this happened for a couple of reasons one is that we discovered another astronomical body called ays that had traits very similar to Pluto more similar to Pluto than either of them were to the other eight planets and so unless we were just going to start expanding the number of planets in the solar system this meant that new criteria needed to be set there were three criteria selected for this it is in orbit around the sun it has sufficient Mass to be rounded by its own gravity and it has cleared the neighborhood around its orbit Pluto clears the first two criteria but because it shares its orbit with the rest of the Kyper Bel objects it does not pass the third criteria and so it along with other known objects that are similar such as ays were then classified as dwarf planets instead there's like I think five or six dwarf planets now another one is series but the three examples I'll have here are Pluto series and and ays you know what though this does not mean Pluto is any less of a majestic World regardless of our classification of it and as I mentioned earlier with the flyby of the New Horizon spacecraft we really learned and got a visual of this this flyby showed us that Pluto has mountains valleys Plains and craters its tallest mountains are between 6,500 and 9800 ft tall and are made of Big Blocks of water ice which are sometimes coated with frozen Gases such as methane the large troughs valleys found on Pluto can be as long as 370 Mi and to add more to the interesting features of this far away dwarf planet my favorite thing is called Sputnik plena which is a large partially glaciated Basin that has formed into part of the heart-shaped topography that we've called tomow Regio you may also notice a red coating on a good part of Pluto this is caused by what we call tholin tholins are a wide variety of organic compounds which are formed when carbons are struck by solar ultraviolet or Cosmic radiation and if we look here at Pluto and Karen we can see that some of these tholin have escaped Pluto's gravity and fallen on onto Karen and because these two are tily locked the tholin always fall roughly onto the same spot now there is surely even more that we know about Pluto and have discovered that I have not covered in this video which only goes to show the takeaway that I would like to end on which is regardless of what we as humans May classify something as many of the astronomical objects out there are still beautiful a inspiring and have the ability to teach us even more about our solar system and maybe even our universe I hope you've learned something and I implore you to step outside tonight and look towards the Stars

Channel: Cuppa Science Joe

Views: 189

Keywords: space, science, astronomy, pluto, nasa, solar system, astronomer

Id: 92D6gWGkYuQ

Length: 11min 26sec (686 seconds)

Published: Mon Apr 29 2024