Friday Four

Call this the "Weird Geography Edition"...

1. Jules Verne and H.P. Lovecraft seems to have had decent guesses, but it wasn't until 1992, after the advent of modern computing, that we could discover its exact location. "Point Nemo" is the spot in the ocean farthest away from land:

Point Nemo is so remote that it is doubtful whether anyone has ever consciously visited it yet. The participants in the 2015 Volvo Ocean Race, on the leg from Auckland, New Zealand to Itajai, Brazil, came closer than most. As they passed by Point Nemo, it was noted that the ships were closer to the occupants of the [International Space Station], circling overhead at an altitude of around 250 miles (app. 400 km) on one of its 15 daily orbits around the globe, than to the rest of humanity. [link omitted]

And speaking of spacecraft, the major practical application of this new knowledge is that Point Nemo serves as the center of the world's space graveyard. Space agencies guide dying craft with the goal of them splashing down in this remotest part of the ocean in order to avoid casualties during descent.

2. Do you hike or fly? If so, you may have encountered any of a long chain of giant, concrete arrows that point all the way across America. In case you were wondering, these were air navigation aids:

The Postal Service solved the problem with the world's first ground-based civilian navigation system: a series of lit beacons that would extend from New York to San Francisco. Every ten miles, pilots would pass a bright yellow concrete arrow. Each arrow would be surmounted by a 51-foot steel tower and lit by a million-candlepower rotating beacon. (A generator shed at the tail of each arrow powered the beacon.) Now mail could get from the Atlantic to the Pacific not in a matter of weeks, but in just 30 hours or so.

Just before World War II, the towers from most of these Transcontinental Air Mail Route markers were scrapped for the war effort, having already been made redundant by improved technology.

3. Or, perhaps, somewhere in Arizona, you have found a large, mysterious concrete X in the middle of nowhere. There's an entire grid of these:

The CORONA satellites orbited 100 miles above Earth with the objective of taking spy photographs of the Soviet Union and China.

Spy photos were flooding in -- but the pictures were blurry. That's what the concrete X's were for. That grid out in the Arizona desert was used to calibrate the cameras on board the satellites.

As a close-up shows, the markers themselves supply a clue as to their purpose, but that makes the story no less interesting.

4. Despite being unable, so far, to directly observe the possibly habitable planet nearest to Earth, we have some basis to guess what Proxima Centauri b might be like:

Eyeball Earth: it sounds weird and it is weird. Tidally locked with its sun, an Eyeball Earth consists of three extreme climatic zones -- scorchingly hot on the permanent day side, icy cold on the permanent night side. In between, ringing the planet: a thin, potentially habitable strip.

This setup gives the planet the appearance of an eyeball. Permanently staring into the sun.

It is because Proxima Centauri, a red dwarf star, is so small that this scenario is likely: To be warm enough for life, the planet would have to orbit so closely that the star's gravitational field will cause tidal locking.

-- CAV