Space
Technology
29 rabbit holes · 17 people exploring
Common starting questions
- Was the Pioneer anomaly ever explained?
- What's on the Voyager Golden Record?
- How does a helicopter fly on Mars?
- How much memory did the Apollo guidance computer have?
- If the universe is full of stars, why isn't every direction bright?
Rabbit holes
- the NASA space pen myth is backwards
Clara Novak · 4 sources
- the Pioneer anomaly turned out to be heat
Dev Malhotra · 6 sources
- the voyager golden record has playback instructions written in hydrogen
Started wondering what aliens would even do with a record player. The cover explains how to play it using hydrogen's hyperfine transition as the clock. Unhinged in the best way.
Dmitri Kuznetsov · 6 sources
- tunguska flattened 80 million trees and left no crater
An object exploded in the air over Siberia in 1908 and flattened about 2,000 km² of forest. No crater because it never hit the ground. Chelyabinsk in 2013 was the same thing but smaller, and on dashcams.
Theo Martin · 4 sources
- Venera: the Soviet probes that landed on Venus and sent back photos
Venera 13 lasted 127 minutes on the surface of Venus, at roughly 470°C and 90 atmospheres. Its photos (and Venera 14's) are still the only color images from the surface. Nobody talks about this enough.
Nikolai Volkov · 5 sources
- space shuttle tiles could be held by their corners seconds after heating
The silica tiles were so good at not conducting heat that you could hold one by the edges while the center glowed. Then the Columbia part of the trail, which was a lot heavier.
moth · 4 sources
- Ingenuity was supposed to fly 5 times. it flew 72.
Omar Haddad · 5 sources
- There are probably tardigrades on the moon
They were in a 'lunar library' on the lander. A later experiment suggests they probably didn't survive the impact, but they're still up there, dehydrated, forever.
Dev Malhotra · 4 sources
- How did Apollo get to the moon with ~4KB of RAM
Kaito Morimoto · 6 sources
- why is the night sky dark?
Dev Malhotra · 5 sources
- what happens to astronauts' bodies after a year in space
Dev Malhotra · 5 sources
- Starlink streaks and the astronomers who hate them
Dev Malhotra · 5 sources
- Why do rockets launch from Florida and not, like, Maine
Dev Malhotra · 5 sources
- aerogel started as a bet about jelly
Kistler supposedly bet a colleague that he could replace the liquid in a jelly with gas without it shrinking. The result, around 1931, was aerogel.
Matteo Rossi · 6 sources
- the wingnut that kept flipping on a space station
Spin a rigid object around its axis with the middle moment of inertia and it periodically flips over; the other two axes are stable. Toss your phone spinning end over end and you'll see it.
Dev Malhotra · 6 sources
- why the ISS orbit is tilted 51.6 degrees
Carlos Mendoza · 4 sources
- how GPS has to correct for relativity
Alistair Grant · 5 sources
- the moon is drifting away by about 3.8 cm a year
Ethan Cole · 4 sources
- the sun's core makes less heat per cubic meter than a compost heap
The core produces apparently a few hundred watts per cubic meter, roughly like a compost pile or a lizard's metabolism. The sun is bright because it is unimaginably big, not because each bit is intense.
Arash Mohammadi · 6 sources
- a cosmic ray might have helped a Mario 64 speedrunner
A runner got teleported upward in Tick Tock Clock in 2013 and nobody could reproduce it. The leading explanation is a single bit flip in Mario's height value. Same thing that happens to satellites and that ECC memory protects servers from.
Ludovica Ferri · 5 sources
- why reusable rockets took so long
The Shuttle was technically reusable, but refurbishing it cost so much it never got cheap. The DC-X was doing vertical landings in 1993 and then got cancelled. Lots of 'we almost had this' in this one.
Lin Chen · 5 sources
- the moon trees
Seeds that went around the moon in a smokejumper's personal kit in 1971 and got planted all over the US. Some of them are still alive and people have lost track of where a lot of them are.
Dev Malhotra · 4 sources
- NASA probably taped over the original moon landing footage
Daniela Ruiz · 6 sources
- What the Saturn V actually burned per second
Five F-1 engines burning through more than 12 tonnes of propellant a second. And they solved combustion instability partly by detonating explosives inside running engines.
Ethan Cole · 6 sources
- in 1991 one particle hit the atmosphere with the energy of a thrown baseball
It was seen by the Fly's Eye detector in Utah, roughly 3×10^20 eV. That's tens of joules carried by one subatomic particle. Nobody knows what accelerates them that hard, and the sources should be relatively nearby, which makes it weirder that nobody can point to them.
Arash Mohammadi · 6 sources
- how old is the light from the stars I can actually see
Ethan Cole · 5 sources
- cosmonauts carried a triple-barreled gun because of wolves
Voskhod 2 landed off-course in the Siberian forest in 1965 and the crew spent a cold night there. Afterward cosmonaut survival kits included the TP-82 until 2007.
Dev Malhotra · 4 sources
- Kessler syndrome is less sci-fi than I thought
Went in thinking it was a Gravity plot device. Came out checking how many tracked objects are in LEO right now.
Haruto Sato · 6 sources
- how the James Webb telescope stays cold enough to work
Theo Martin · 6 sources