Now we weren’t going to leave out everyone’s favourite dwarf planet, were we?!
- Small but Mighty!
Pluto is named after the Roman god of the Underworld, who coincidentally was also the god of wealth as diamond and other jewels supposedly came from the Underworld. It’s ironic that such a tiny member of our solar system family was named after such a powerful god! But how did it get its name?
Pluto’s naming process was very democratic. Percival Lowell has begun the search for a planet he predicted should have existed in 1905 – something was pulling on Uranus and it has to be a planet. Sadly, Lowell never found Pluto before his death in 1916. In 1930, 23 year-old Clyde Tombaugh finally found the mystery planet after a year of painstaking work to find it. It was the Lowell Observatory in Arizona that had the right to name this planet instead of the IAU. They Observatory asked for suggestions from the world over (according to the Library of Congress they received around 1,000). The winning offer was from 11 year-old Venetua Burney from Oxford, England – she picked Pluto to keep with the trend of naming planets after characters from classical mythology. Pluto, in mythology, had a habit of making himself invisible which Pluto the planet had seemed to have been able to do for years to evade its own discovery! “Pluto” also honours Percival Lowell, whose efforts for over a decade ended up in Pluto’s discovery; the first two letters of Pluto are his initials.
- A Lonely Life
Pluto has only been visited on one occasion – in 2015 we got our first good look at our tiny, icy neighbour thanks to the New Horizons probe. We finally got to see Pluto’s heart shaped planes, its very thin atmosphere and its icy cliffs. It took 10 years to get from Earth to our distant dwarf planet travelling at a whopping 84,000 kilometres per hour. Here are some of the beautiful images yielded from this probe:
- Not a Planet!
The International Astronomical Union made it most controversial decision to date in 2006 when they demoted Pluto from a planet to a dwarf planet. Why? There are three criteria that must be met by an object in space to be granted planetary status: 1. It’s in orbit around the sun, 2. It’s roughly round in shape and 3. It has cleared its neighbourhood of surrounding objects. Pluto didn’t meet the last one. Planets need to gravitationally dominant in order to clear its little pocket of space of other objects – Pluto hasn’t done this as it’s too small! Eris, discovered in 2005, is a dwarf planet too! The discovery of Eris is often blamed for the eventual downfall of Pluto; one of the astronomers credited with discovering Eris now proudly goes by the handle @plutokiller on Twitter. A bold choice!
If you are still annoyed about this decision, you aren’t alone. Alan Stern, leader of NASA’s new horizons mission, said he was embarrassed for the field of astronomy for making this decision considering that only 5% of the world’s astronomers voted on the issue. It remains highly controversial and new proposals are made every few years in an attempt to reinstate Pluto. Maybe in 5 years it’ll be a planet again! Until then, it remains a dwarf planet.
- Moons, moons, moons!
While Pluto certainly doesn’t boast the 82 moons of Saturn, or the 79 of Jupiter, it does have quite a few moons given its tiny 2,360km diameter. Pluto has 5 moons; Charon, Nix, Styx, Hydra and Kerberos. Charon is the largest of the moons – with half the diameter of Pluto itself! Charon gets its name in relation to Pluto as Charon in greek mythology was a ferryman who transported the souls of the dead to the underworld.
- It’s Cold – Very Cold
The New Horizons probe gave us information about Pluto we did not have before, we are now able to understand what life on the dwarf planet would be like. Firstly, the sun from Pluto is not a familiar sight as it resembles a large star in the night sky rather than our familiar friendly ball of yellow warmth. As the sun is roughly 6 million km from Pluto it doesn’t do an overly good job of heating the little planet – if you were holidaying on Pluto you would experience a crisp -233 Celsius (and we complain about the weather here!). Pluto is very scenic as it has beautiful mountain ranges of frozen Nitrogen and Methane formed on a bedrock of water ice. There is one major upside to Pluto though! Due to its tiny size it has much less gravity and therefore is an ideal location to perfect your basketball dunk! If you can dunk at 10ft high on Earth, you can do the same at 150ft high on Pluto – Michael Jordan who?!