At the XXVIth General Assembly of the International Astronomical Union, held in Praague in August 2006, a new set of three criteria were decided to define what is — and what is emphatically *not* — a planet. Infamously, Pluto fulfilled only two of the three criteria, and so was unceremoniously dumped from the planet club, and reclassified as a "dwarf planet". A decade later, the New Horizons spacecraft swung past this tiny, frozen rock on the outskirts of the Solar System and reported back that Pluto is actually a pretty fascinating place, with a loads of cool suface features and even a thin atmosphere capable of creating dunes of solid methane! Dwarf planet it may be, but Pluto is still awesome.
SHOW NOTES
Syzygy is produced by Chris Stewart and co-hosted by Dr Emily Brunsden from the Department of Physics at the University of York.
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Emily at the University of York: www.york.ac.uk/physics/people/brunsden/
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Some of the things we talk about in this episode:
The "Dunes on Pluto" paper: http://science.sciencemag.org/content/360/6392/992
A good article about the paper: https://cosmosmagazine.com/space/scientists-unlock-the-secrets-of-pluto-s-methane-dunes
All about Pluto from NASA: https://solarsystem.nasa.gov/planets/dwarf-planets/pluto/overview/
When I was your age, Pluto was a Planet! https://www.redbubble.com/people/kipstewart/works/3024944-when-i-was-your-age-pluto-was-a-planet?p=t-shirt
Why Pluto is no longer a planet: https://www.universetoday.com/13573/why-pluto-is-no-longer-a-planet/
How Pluto got its name: https://www.smithsonianmag.com/smart-news/how-pluto-got-its-name-180955912/
The Kuiper Belt: https://solarsystem.nasa.gov/solar-system/kuiper-belt/in-depth/
The New Horizons mission: https://www.nasa.gov/mission_pages/newhorizons/main/index.html
Images of Pluto, before and after New Horizons: https://blogs.nasa.gov/pluto/2016/08/04/pluto-what-a-journey/
Pluto ... or Pluto™? https://twitter.com/ekaschyk/status/620967219934154752
Images of the Dunes on Pluto: http://science.sciencemag.org/content/360/6392/992/tab-figures-data
Astronomer Sir Patrick Moore: https://en.wikipedia.org/wiki/Patrick_Moore