The Official Space and Astronomy Thread v. Well, this is weird.

[El Barto]

Three videos from ESA (European Space Agency):

Journey to the ISS Part 1: The Soyuz launch sequence explained (Length 00:11:29)

Journey to the ISS Part 2: Soyuz rendezvous and docking explained (Length 00:21:06)

Journey to the ISS Part 3: Soyuz undocking, reentry and landing explained (Length 00:20:44)

Lots of cool technical details including orbital mechanics and rendezvous.

I've seen the launch sequence vid. I DL'd about 75 various space docs a few months ago. Most of what you get are basic overviews, but NASA and a couple of other agencies would put out some great stuff back in the 60's and early 70's that's definitely geared towards a pretty bright audience.

It's particularly interesting to learn up on the early NASA programs, Vanguards through to Skylab, and then see that the Soviets were doing the exact same things, just different. An understanding of the differences, and the different approaches they led us each to, is pretty fascinating. Those Soyuz rockets they're using today are essentially the same ones they were blasting off 50 years ago and it's a fine approach. As exemplified in many things, we took to spending more money on nicer, more technological tools while they went for quantity over quality. A good approach for military hardware, but in the space arena it never panned out for us.

And I believe that we just purchased all of the unused engines from the N1 rockets the Rooskies never used. By many accounts the finest rocket motor ever built, and when they no longer had use for the N1 the motors just got stashed in some Kazakhstan warehouse somewhere.

[Kotowboy]

New Page Fail


Nobody will see my outstanding joke.

[MrBoom_shack-a-lack]

Apparently The Andromeda Galaxys actual seize, were it more brighter and visible from Earth:



Had no idea. Imagine having that to look up to every night.

[Fiery Winds]

[ThatOneGuy2112]

^

Kinda disappoints me that they didn't come up with a cooler name than "Milkdromeda" for when our galaxies collide. But who knows if humanity will still be around in 4 billion years to stick with that name.

[El Barto]

Apparently The Andromeda Galaxys actual seize, were it more brighter and visible from Earth:



Had no idea. Imagine having that to look up to every night.

Turns out it is visible from Earth. NASA's photo of the day:
https://apod.nasa.gov/apod/image/1508/AndromedaAlps_Dunchi_4677.jpg

[MrBoom_shack-a-lack]

Apparently The Andromeda Galaxys actual seize, were it more brighter and visible from Earth:



Had no idea. Imagine having that to look up to every night.

Turns out it is visible from Earth. NASA's photo of the day:
https://apod.nasa.gov/apod/image/1508/AndromedaAlps_Dunchi_4677.jpg

[Chino]

I wonder what kind of exposure was needed or that photo.

[BlobVanDam]

I wonder what kind of exposure was needed or that photo.

Here's the info from the photgrapher
https://www.flickr.com/photos/md88/19664596953/

[Phoenix87x]

So the bright light in the center is light being sucked into a super massive black hole right?  not a massive star or anything?

[faizoff]

That NASA pic of the day of Andromeda is breathtaking.

[Chino]

I found this to be pretty interesting.

https://www.scienceworldreport.com/articles/29101/20150820/nasa-raids-museum-endeavor-space-shuttles-spare-parts.htm

NASA may be cannibalizing museum pieces for space shuttle parts. In order to meet budget goals, NASA is turning to museums to find the parts that it needs for the International Space Station.

In this case, NASA engineers are working to remove four tanks from the old space shuttle Endeavor for use as potable water storage on the International Space Station. The tanks measure about 3 feet by 1 foot and weight about 40 pounds each while empty. They're from deep inside the orbiter, so museum patrons won't notice that they're actually gone.
This isn't the only shuttle that had its tanks removed. The shuttle Atlantis had its water tanks removed in May for future use on the ISS.
It seems as if even old parts are getting a makeover when it comes to the space agency. Because of the limited budget, NASA is thinking of creative ways to make things work and to successfully complete future space missions.

[BlobVanDam]

It doesn't sound like the kind of thing that would cost much, relatively speaking. It's kind of sad that NASA has to raid museum pieces to meet their current budget, over something that seems so basic.

[Chino]

It doesn't sound like the kind of thing that would cost much, relatively speaking. It's kind of sad that NASA has to raid museum pieces to meet their current budget, over something that seems so basic.

That's what I was thinking as well, but then I remember it's for space. I feel like anything, no matter what it is, must cost a small fortune. These tanks are probably made of some crazy material that prevents even the smallest amount of vapor from escaping the container, and there's probably some funky stuff required for micro gravity.

I too think it's sad, but even if NASA's budget was strong, I still don't think I'd hate this. Let's say these tanks cost $75,000 a piece (I'm basing that estimate on nothing). The money they just saved could higher two quality engineers for a year that they otherwise might not have been able to bring on board.

[BlobVanDam]

As I said, relatively speaking. I assume everything has to be engineered to a much higher standard from better materials for use in space, and a lot of it is custom or specialized stuff, so would cost a lot to have made.
I have nothing against them doing it, I just wish they weren't in a position where they had to do it to stretch their budget further.

[Chino]

I feel you.

[jasc15]

I too think it's sad, but even if NASA's budget was strong, I still don't think I'd hate this. Let's say these tanks cost $75,000 a piece (I'm basing that estimate on nothing). The money they just saved could higher two quality engineers for a year that they otherwise might not have been able to bring on board.

That's not a bad guess for cost.  My company makes tanks, and has made some for the shuttle and ISS (not this particular one).  The major cost is engineering development and qualification test programs.  It can cost half a million dollars or more to develop and qualify a new tank.  As for materials, it's probably nothing exotic; likely stainless steel or maybe titanium.

[Jarlaxle]

I'll ask this here since I'm likely to get an answer much faster than if I were to try to google it. If a planet had two moons (let's just use earth), one in the northern skies, the other in the southern, yet both were visible at the same time across the planet, and one was much larger than the other, would they have the same or different moon cycles? For simplicity, if the moon were twice as large would it then take twice the time to complete a lunar cycle? Is there any way that the moons would operate on different cycles?

Why I'm asking is Ive created a fantasy world with two moons. They have the same conditions I already included (one is much larger, in the opposite "sky"), and I wrote that one was waxing while the other was waning. I know very little on the subject, and want to have my facts a little more straight before I proceed any further.

[Chino]

It would really depend on a lot of factors.

How big are they?
What are their distances from Earth? Are the similar, or does one have an orbit far outside the other?
What do their orbits look like?
How long do they take to do a full orbit?


Fun fact. Many scientists believe that we did have two moons at one point in our history. The theory is that they eventually collided and formed the single moon we have today.

Cool/related article;
https://www.universetoday.com/92148/what-if-the-earth-had-two-moons/

[Jarlaxle]

It would really depend on a lot of factors.

How big are they?
What are their distances from Earth? Are the similar, or does one have an orbit far outside the other?
What do their orbits look like?
How long do they take to do a full orbit?

Mars has two moons, but they are small enough where they don't seem to effect each other. Then you have gas giants with dozens of moons, and they heavily influence each other.

Fun fact. Many scientists believe that we did have two moons at one point in our history. The theory is that they eventually collided and formed the single moon we have today.

Cool/related article;
https://www.universetoday.com/92148/what-if-the-earth-had-two-moons/

Let's say moon one is more or less identical to ours in every way.

Moon two is 5 times as large, is a quite a bit further away than M1 (making it appear to be about 3 times larger) with a similar shaped orbit that is obviously larger with it being further away.

My initial thoughts are that with a larger orbit the lunar cycles would be different. With M2 being further away would the phases of each moon just last proportionately longer? One of the big reasons I ask this is not only to be correct with the logic of it, but because I had the idea of "what if they were both were either full or new at the same time?" We have all our phenomena that occur on one full moon, wouldn't the world go crazy during a double full moon? Especially since it's occurance would be extremely rare.

[Chino]

I don't think it would be possible to technically have two full moons. You might have two moons that to the naked eye appear to be full, but one would be receiving more light than the other as they are not at the same point in space. I think.

[Jarlaxle]

Thanks Chino! That article was an interesting read as well.

[jasc15]

The orbital period is independent of the size of the moon(s), so you could make the periods anything you like in your fantasy world just by changing their distance.

The period is related to the 3/2 power of the distance from the planet:
https://en.wikipedia.org/wiki/Orbital_period#Calculation

For example, if M2 is 1.59 times further from the planet as M1, its period will be twice that of M1: 1.59^3/2 = 2.

[Chino]

The orbital period is independent of the size of the moon(s), so you could make the periods anything you like in your fantasy world just by changing their distance.

I'm not saying you're wrong. I'm curious. I can understand how orbital periods would be independent of size given one moon, but wouldn't multiple moons throw that off? Pending their proximity and orbits, wouldn't that have an effect on their periods?

[jasc15]

Well, yeah, but that's a 3-body problem for which there are no good analytical solutions.  It would be interesting to see if this matters for a planet like Jupiter or Saturn, where the central body is so much more massive than the moons and the moons likely have little effect on eachother.

[Chino]

Well, yeah, but that's a 3-body problem for which there are no good analytical solutions.  It would be interesting to see if this matters for a planet like Jupiter or Saturn, where the central body is so much more massive than the moons and the moons likely have little effect on eachother.

Jupiter's moon effect each other quite a bit, no?

[El Barto]

It doesn't sound like the kind of thing that would cost much, relatively speaking. It's kind of sad that NASA has to raid museum pieces to meet their current budget, over something that seems so basic.

That's what I was thinking as well, but then I remember it's for space. I feel like anything, no matter what it is, must cost a small fortune. These tanks are probably made of some crazy material that prevents even the smallest amount of vapor from escaping the container, and there's probably some funky stuff required for micro gravity.

I too think it's sad, but even if NASA's budget was strong, I still don't think I'd hate this. Let's say these tanks cost $75,000 a piece (I'm basing that estimate on nothing). The money they just saved could higher two quality engineers for a year that they otherwise might not have been able to bring on board.

I'll occasionally pop down to the local Pick&Pull to grab a minor part for a car, not to save money but because I feel like taking care of something right then and there. It's possible NASA was approaching it from the standpoint of turnaround time just as much as cost. My hunch is that ISS water tanks are probably not an off the rack item, so new fabrication could be time consuming.

[Chino]

I'm disgusted that I spelled hire as 'higher' in that prior post.

[jasc15]

Jupiter's moon effect each other quite a bit, no?

Indeed.  Never thought about this before.

[Jarlaxle]

The orbital period is independent of the size of the moon(s), so you could make the periods anything you like in your fantasy world just by changing their distance.

The period is related to the 3/2 power of the distance from the planet:
https://en.wikipedia.org/wiki/Orbital_period#Calculation

For example, if M2 is 1.59 times further from the planet as M1, its period will be twice that of M1: 1.59^3/2 = 2.

Awesome, thanks!

[jasc15]

This is another useful point:

Basically, when you have several bodies orbiting a much larger body, the length of the orbits of the smaller bodies will tend to settle into simple-fraction (1/2, 2/3, 1/3, etc.) multiples of each other.  1 to 2 to 4 for Io, Europa, and Ganymede.  The slight ellipses of any real-life orbits cause the gravitational force of the moons, to “pulse” (becoming slightly stronger or weaker) along another moon’s orbit.  As a result (this is not at all obvious right off the bat) if the other moon slows down it gets pushed a little faster at regular intervals, and if it gets too fast it gets slowed down at regular intervals.

[Chino]

Siiiick

https://www.gfycat.com/CrispFavorableDuckbillplatypus

[jasc15]

Probably using this:

https://www.nowykurier.com/toys/gravity/gravity.html

I think that may have been posted here before.

[gmillerdrake]

Probably using this:

https://www.nowykurier.com/toys/gravity/gravity.html

I think that may have been posted here before.

Yeah, this is fun!

[El Barto]

Probably using this:

https://www.nowykurier.com/toys/gravity/gravity.html

I think that may have been posted here before.

Quite entertaining and a great time waster at work. What it needs most is the ability to zoom out. A nice touch would be the ability to manually input velocity and vector.