Space and Astronomy Megathread (MERGED) - Part 1

[Micromind]

NASA's Parker Solar Probe captured this astonishing prospect of Earth swimming in a sea of stars over the course of ten days in April 2019. Earth is the first bright round spot that shows up and moves to the right of the frame before the Milky Way is seen. The Moon was too close to Earth to be resolved. The background star near Earth is Spica. Mercury is seen in transit across the Milky Way core. Venus is the very bright spot at the end. Jupiter and Saturn are also seen. The stripes are cosmic rays hitting the camera sensor. By the time Parker Solar Probe imaged Venus it was traveling at 95km/s (~213,000mph).

NASA Raw Data Source (Filtered L3 Earth Encounter):

 

[Dr.]

SpaceX “launch escape” test scheduled for 9am 10am 10:30am EST today (weather permitting). Apparently, the Falcon 9 booster will be intentionally exploded - - a minute or so into the flight to simulate a catastrophic failure. Whereupon, the (un-crewed) Dragon capsule will rocket away and splashdown to safety.

CREW DRAGON LAUNCH ESCAPE DEMONSTRATION | SpaceX

 

[Dr.]

^^ I got a detail wrong. Falcon wasn’t detonated during the test. Rather, its engines were shut down to simulate a malfunction. Then, after Dragon was jettisoned, the unpowered Falcon began to tumble (as expected). Eventually, it did explode.

 

[Micromind]

SpaceX “launch escape” test scheduled for 9am 10am 10:30am EST today (weather permitting). Apparently, the Falcon 9 booster will be intentionally exploded - - a minute or so into the flight to simulate a catastrophic failure. Whereupon, the (un-crewed) Dragon capsule will rocket away and splashdown to safety.

CREW DRAGON LAUNCH ESCAPE DEMONSTRATION | SpaceX

^^ I got a detail wrong. Falcon wasn’t detonated during the test. Rather, its engines were shut down to simulate a malfunction. Then, after Dragon was jettisoned, the unpowered Falcon began to tumble (as expected). Eventually, it did explode.

 

[KRYPTON INC.]

A mystery radio signal from deep space appears to be following a 16-day cycle

 

[Micromind]

Astronomers to sweep entire sky for signs of extraterrestrial life

 

[terry78]

NASA: Massive asteroid close to Earth on Saturday

 

[Dr.]

Astronomy 101 : solar vs. sidereal day

A solar day uses the position of the Sun to define one complete rotation of the Earth on its axis. A solar day is 24 hours long.

A sidereal day uses the position of distant stars to define one spin. A sidereal day is 23 hours, 56 minutes long.

A solar day is longer because the Earth’s orbit around the Sun causes the apparent position of the Sun to change. This means that the Earth has to rotate for an extra four minutes in order for the Sun to return to the same position in the sky. By comparison, stars are so distant that Earth’s orbital movement makes no difference. (The stars are a more “objective” frame of reference.)

The above applies to other planets as well. For instance, a solar day on Mercury is 176 Earth-days long . A sidereal day is 59 Earth-days.

Grammar trivia: “sidereal” is from Latin and means “of, or relating to, the stars.” And it’s pronounced with four syllables - sy-dee-ree-al.

 

[C. Lee]

NASA's $1 Billion Jupiter Probe Just Sent Back Dazzling New Photos of the Giant Planet and Its Great Red Spot

 

[Dr.]

Phil Plait explains leap years:

 

[Iceman]

Astronomers to sweep entire sky for signs of extraterrestrial life

One day they’ll find something!

 

[C. Lee]

Physicist Freeman Dyson dies at age 96 The man behind the sphere, Freeman Dyson, is dead at 96

 

[KRYPTON INC.]

 

[Micromind]

Ladies who launch: the women behind the Apollo Program

 

[Apollo]

Beam me up Scotty!

 

[Micromind]

Gravity, Interstellar, Armageddon, Apollo 13, Ad Astra, First Man, Passengers, Hidden Figures, 2001 A Space Odyssey, Wall E, Sunshine.

 

[Dr.]

Gravity, Interstellar, Armageddon, Apollo 13, Ad Astra, First Man, Passengers, Hidden Figures, 2001 A Space Odyssey, Wall E, Sunshine.

Hadfield’s critique of the artificial gravity in Passengers is well taken. But he could have gone further. Even after the spaceship’s spin resumed, stuff that was floating in midair would remain weightless. The only way for people and things to reacquire “gravity” is to be in physical contact with the spinning surfaces of the ship.

 

[Dr.]

Also, re: Interstellar. Hadfield says people or objects near a black hole would be torn to pieces (so-called “spaghettification”) due to extreme tidal forces. This is true of stellar mass black holes. But with supermassive black holes (which is what Gargantua was), the tidal forces are much gentler - and passage across the event horizon would be survivable. (Survival within the event horizon is a different story. )

 

[:eek:]

Trump signs executive order to support moon mining, tap asteroid resources | Space

An Avatar-situation in a distant future suddenly feels more than plausible, if we humans ever finds habitable planets/moons and manage to get there somehow. Hopefully we will never do.

 

[BrollySupersj]

With this you'd think Saturn would be just a few thousand miles away from the Moon. That is quite awesome.

 

[Dr.]

Launch date set: first crewed NASA mission since 2011.

 

[Marvolo]

Trump signs executive order to support moon mining, tap asteroid resources | Space

An Avatar-situation in a distant future suddenly feels more than plausible, if we humans ever finds habitable planets/moons and manage to get there somehow. Hopefully we will never do.

We'd be crazy not to mine the moon and asteroids. They're rich with resources and unlike on earth the moon and asteroids arent supporting life. It's literally the most eco friendly form of mining that humans could do.

Unfortunately an Avatar situation is inevitable given enough time. Humans are territorial and resource hogs. If there are habitable planets rich in resources, and humans can ever get to them some human will try to take those resources.

 

[Micromind]

Extensive Moon mining is not a good idea, Moon is already drifting away from Earth, mining will decrease Moon mass and make gravitational force between Earth and Moon weaker, if Moon goes away faster than it currently is... it will have a direct effect on seasons, ocean tides and weather on Earth, and some effects that we cannot predict in advance.

Asteroid mining, though expensive, could be alternative to Moon mining.

 

[RetrogradeOrbit]

Launch date set: first crewed NASA mission since 2011.

For those of us that don't tweet...
Nasa to launch first crewed mission from US in decade

 

[KRYPTON INC.]

Don't look down...