The University of Salamanca
The University of Salamanca
September 13, 1966 — Gemini 11 astronaut Dick Gordon takes a walk at approximately 160 nautical miles above the Earth’s surface. (NASA)
600 Million Years and Counting…
I was pretty bored so I decided to make some GIFs of the last 600 million years of our planet’s plate tectonics.
The first GIF is a global mollewide projection. The second one is of the Colorado Plateau and the North American Southwest. The next GIF is of the entire formation of the North American Continent. The fourth GIF is of geologic and tectonic evolution of Europe. And finally the last one is the same as the first except in rectangular format.
I obtained the images from Global Paleogeography and them compiled them one by one into Photoshop with the end result being the above GIFs.
The color of the Aurora depends on the altitude and the atom being struck by solar radiation (causing excitation). At higher altitudes, there is more Atomic Oxygen than Nitrogen, leading to the common color stratifications you see.
500-200 km altitude
— Atomic Oxygen — Red
— Atomic Oxygen — Greenish-Yellow
— Ionized Nitrogen — Blue/Purple
— Nitrogen (N2) — Crimson
Oxygen only emits red at higher altitudes because once it’s excited, it takes a longer time to emit red than it does green. Why is that important? Well, at lower altitudes there is more Nitrogen for the Oxygen to bump into and absorb that excitation-energy before it gets a chance to emit red light. In this case, where the collision occurs, the Oxygen will emit Green and at low enough altitudes the Nitrogen-Oxygen collisions eventually prevent Oxygen from emitting any light at all.
During stronger storms, high energy solar particles will reach lower in the atmosphere and cause the Crimson emission from Nitrogen, creating a deep-red band at the lower edge of the aurora. Other elements emit light too, like Hydrogen (Blue) or Helium (Purple) which are at higher altitudes.
“So you’re made of detritus [from exploded stars]. Get over it. Or better yet, celebrate it. After all, what nobler thought can one cherish than that the universe lives within us all?”
―Neil deGrasse Tyson
These photos are on the shortlist for Astronomy Photographer of the Year 2014, a competition and exhibition run by the Royal Observatory Greenwich. The winning images will be posted here on September 18.
The Midnight Planétarium watch was a collaboration between Van Cleef & Arpels and Christiaan van der Klaauw. The watch is made of 396 separate parts and features the six closest planets orbiting the sun in real time (Uranus and Neptune were left out because you probably won’t live long enough to see either one complete a full orbit).
Where can I buy this??! I don’t know if anyone knows but doesn’t hurt to ask.