Astronomy & Space Exploration

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It’s officially ranked the second-largest black hole known; estimates on the current record holder span a wide range, from 6 to 37 billion solar masses. The black hole makes up 14 percent of its galaxy’s mass, versus the usual 0.1 percent.
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http://voices.nationalgeographic.com/2012/11/30/is-this-the-biggest-black-hole-ever/



:nervous:
 
Fair play mr Trump. Did he do one for the 50th anniversary of the Apollo 1 fire?
 
cesc's_mullet said:
Conspiracy theories board
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Is it a conspiracy theory? I thought it was along the lines of string theory/multiverse etc which I believe has some backing in the scientific community. I know nothing about it though so it may well be some nutjob theory which is what it sounds like.
 
If Nasa had the budget of the US army we could probably explore moons like Titan and Europa within a few years. I bet we find some kind of fish in the lakes there
 
Macern said:
If Nasa had the budget of the US army we could probably explore moons like Titan and Europa within a few years. I bet we find some kind of fish in the lakes there
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My money is on squid like creatures.
 
Macern said:
If Nasa had the budget of the US army we could probably explore moons like Titan and Europa within a few years. I bet we find some kind of fish in the lakes there
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The DoD has a bigger space budget than NASA does, if memory serves.
 
What do you guys think of transposition, docking and extraction? I became very interested in the Apollo programme and missions after watching Apollo 13. It was one of the safest orbital maneuvres and docking techniques ever tried. All the T, D & E's passed off without any incidences. Also, it just seems and looks so cool.
 
Nikhil said:
What do you guys think of transposition, docking and extraction? I became very interested in the Apollo programme and missions after watching Apollo 13. It was one of the safest orbital maneuvres and docking techniques ever tried. All the T, D & E's passed off without any incidences. Also, it just seems and looks so cool.
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Never really heard about this. Is there a way to learn about it a bite-sized chunk? Say, a youtube video?
 
rcoobc said:
Never really heard about this. Is there a way to learn about it a bite-sized chunk? Say, a youtube video?
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T, D & E is now widely regarded as one of the reasons we were able to go to the moon in the 60s, even with computers that are now considered not powerful at all for a mission of that complexity. It was the reason the Apollo missions had a CSM (command/service module) and a LEM (lunar module)

This wiki article explains things on a basic level. Not very good, but it's the basics.

 
The Cassini–Huygens mission has thus far cost a little over $3bn. For a multi-agency, multi-national effort, it isn't a prohibitive sum. Admittedly, you'd need to throw in the cost of a submersible for a trip back to Titan, but that's not going to increase the total beyond means.
 
Nick 0208 Ldn said:
The Cassini–Huygens mission has thus far cost a little over $3bn. For a multi-agency, multi-national effort, it isn't a prohibitive sum. Admittedly, you'd need to throw in the cost of a submersible for a trip back to Titan, but that's not going to increase the total beyond means.
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There was a proposal to put a small boat on one of the lakes there at a cost of about $0.5bn (not including the launch), unfortunately lost out to another Mars mission though.
 
A well publicised mission (or two) sounds just like the sort of thing that Trump might want to do. I mean, you can imagine him standing there in mission control on launch day, cameras flashing.
 
Just seen an article about the Dipole repeller and the Shapley attractor.

Had a bit of a read about them, but still cant quite figure out in my mind what they are.

It says on wiki the Shapely attractor is a supercluster with a shitload of gravity thats pulling us toward it. (or at least i think it says that)

Wiki also says that the dipole repellent is a region in a cluster that is repelling things away from it. It goes on to mention stuff about flows and stuff I dont really understand.

The two together seem to be acting in tandem with us in the middle and the diagram showing these flows look just like we see in a diagram of how a magnet works with the line shooting from the dipole repeller into the shapely attractor.

Ive probably got the wrong end of the stick as my technical understanding of scientific terminology is somewhat limited.

Can anyone try explaining to me whats what with these things?
 
Nick 0208 Ldn said:
A well publicised mission (or two) sounds just like the sort of thing that Trump might want to do. I mean, you can imagine him standing there in mission control on launch day, cameras flashing.
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It's definitely going to happen. He tweets about space quite a lot and has Elon's (and isn't someone else related to space industry?)

He could actually be really good for space exploration, but then so would have John McCain and Obama's plan would have been okay eventually
 
rcoobc said:
It's definitely going to happen. He tweets about space quite a lot and has Elon's (and isn't someone else related to space industry?)

He could actually be really good for space exploration, but then so would have John McCain and Obama's plan would have been okay eventually
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But what is going to happen though? The Cassini mission is something which has lived in my memory for years, yet as such, it doesn't bring an endgame within the span of a presidency.

Do you think he might opt for a return lunar mission? By way of a warm-up for Mars, we'll be walking on the moon once again.
 
Nick 0208 Ldn said:
But what is going to happen though? The Cassini mission is something which has lived in my memory for years, yet as such, it doesn't bring an endgame within the span of a presidency.

Do you think he might opt for a return lunar mission? By way of a warm-up for Mars, we'll be walking on the moon once again.
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The problem is, if he only lasts 4 years, it's not going to matter much what he says (in terms of future missions).

Short of going full Apollo/Mars Direct and trying to get people to whatever celestial body as quickly as possible at a decent expense
 
How far away do you all think we are from creating artificial gravity units for space ships? That will surely be the game changer for space exploration.
 
Garethw said:
How far away do you all think we are from creating artificial gravity units for space ships? That will surely be the game changer for space exploration.
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You mean like centrifuges? Nothing engineering wise preventing it from being done tomorrow, just the money and political will that's lacking.
 
This is a great tool for calculating the centripetal acceleration in a centrifuge.

http://www.artificial-gravity.com/sw/SpinCalc/

To get 1G, I think once you have a radius of about 1km, it would be very difficult to even realise you where in space. At about 50-100m you probably couldn't have any windows.

To get 0.8G, you could probably get away with a 20 meter radius doing 6 rotations per minute.

Anything less than 20 meters and you start running into problems, even when dropping the desired centripetal acceleration: If the "tangential velocity" is too low, then someone running in one direction would experience a lot less "gravity" than in the other. If the rotations per minute are too high, everyone will get dizzy. And if the radius is too low, peoples heads will have less gravity than their feet.

But the ISS is about 100m wide so it's easily doable. Or use the "tether to a lower stage" idea.
 
~28 meters, 3.5 rotations per minute would give you Mars gravity and work well though
 
Ubik said:
You mean like centrifuges? Nothing engineering wise preventing it from being done tomorrow, just the money and political will that's lacking.
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To create centrifugal force wouldn't they need to have the ship spinning continuously?
 
Garethw said:
To create centrifugal force wouldn't they need to have the ship spinning continuously?
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Yeah, but that doesn't expend any fuel at all (if the whole ship is spinning) once it's started. Or have only one section of it spinning like the Hermes in the Martian.

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Also, children on Mars. Will growing up in a Low-G environment cause elongated limbs? Under performing organs? An under performing heart? Under performing muscles (especially leg muscles). And eyes that can't focus properly?

I think a lot of those would unfortunately happen. But children being born and growing up on Mars is the only way to make colonisation manageable.

So, whilst having kids sleeping at an angle might help slightly, the best option will be for kids to spend a good amount of their time in a 1G environment...

So centrifuges even on Mars.



1G=sqrt((x^2)+(0.38^2)). We need a 0.925G centrifuge to get 1G, if the centrifuge is at 90 degrees to the ground. (Mars doesn't help at all!)

But you could either use a train going 100 miles an hour in a 200 meter circle, or something swinging around like in space.

Or we could use a pendulum-cradle that creates a 0.5-1.5G acceleration at the bottom of the swing, but it also creates a 0G environment at the top of each swing
 
Nick 0208 Ldn said:
The Cassini–Huygens mission has thus far cost a little over $3bn. For a multi-agency, multi-national effort, it isn't a prohibitive sum. Admittedly, you'd need to throw in the cost of a submersible for a trip back to Titan, but that's not going to increase the total beyond means.
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The Huygens probe landing on Titan was one of the greatest scientific achievements of all time IMO. Too bad the plan of sending a submarine to explore the oceans of Titan now seems to be put on hold. We would have learnt so much about Saturn's moons. Cassini-Huygens was such a path breaking mission. Well worth the money spent on it.
 
The children of mars thing has got to be the biggest problem with Mars that no one talks about.

Plasma shielding is comparatively easy to solve (two-three meters of water above you will virtually eliminate it). Oxygen can be created just by compressing the atmosphere and growing some plants (although there are much more efficient ways). There is already water on mars.

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Have 2-3 meters of water in between the sheets of the domes. Water is an excellent at absorbing plasma. It will also absorb most electromagnetic rays thrown at it, outside the visible spectrum. Note there are probably much better ways to do it using transparent plastics, or easier ways to do it by building underground, but if you want to live outside and have only the technology we have today, build a dome with a water filling.

But the lack of gravity is a problem for children born on mars. Probably for a Earth-grown person, they could spend a lot longer in Martian gravity with few ill-effects, because people have already spend years on the ISS and we are slowly getting to grips with a lot of those issues.

The easiest solution seems to be a 1.2km Maglev/high speed train going in a big circle at 200 miles an hour, tilted at an angle. We already have trains that are designed to do this on earth:



But that's a lot of work, just to allow kids to grow up with 1G. Alternatively, just let them grow up in Martian gravity and never send them back to earth?
 
The TV series "The Expanse" deals with the issue (being born in Mars or even farther).

Details like that elevate it to the Mount Olympus of current Sci-Fi tv shows.
 
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George Owen said:
The TV series "The Expanse" deals with the issue (being born in Mars or even farther).

Details like that elevate it to the Mount Olympus of current Sci-Fi tv shows.
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Yeah I'm still only 3 episodes in. No spoilers! Seems quite well reviewed.
Will Absolute said:
:smirk:

You don't think that might constitute....you know.....child abuse?
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It's definitely a problem. I can't think of an obviously *cheap* solution based on our current level of tech.

The best solution is probably the train going round a 1.2-3 km track (200-500 m radius) at 100-150 mph. We already have 1500 mile long high-speed rail tracks, trains that go 600 km/h and trains that are kilometers long (although maybe not high-speed trains). We could also make use of the thin atmosphere and low martian temperature to help. On Earth, we could build this with no problems whatsoever.

But shipping a train from Earth to Mars is (probably) not going to happen. The Martian colonies need to get to the point where they can make everything required to make a high speed train on mars, and then make it. Then they still need to make sure the environment is pressurised, that it's safe, and that they can power it.

If they had to produce a centrifuge as quickly as possible, they could probably find away to do it.
 
That's a fantastic chart. Distributions are really interesting. Wonder if the huge difference between the number of hot super-earths and gas giants (at a Jupiter-esque distance from the star) discovered by Kepler is a real thing or just an artefact from the detection technique.
 
I'd imagine some are easier to detect during transit due to proximity to the parent star (Kepler's accuracy diminishes after a Sol-Mars range for detection). The relative orbital plane has to align, too. Still an imperfect system, so no wonder it produces so many false positives that need to be weeded out:

https://arxiv.org/pdf/1605.02825.pdf
 
For reference, our Solar System is inclined at an angle of ~65° relative to the core galactic plane of the Milky Way:

Panoramic+zodiacal+light.jpg
 
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