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Re: The Astronomy Thread

Posted: Fri Mar 28, 2014 9:06 pm
by icekatze
hi hi

They could undoubtedly reach it with contemporary propulsion (Dawn has ~10km/s of delta v) but it would still take forever. :P

Re: The Astronomy Thread

Posted: Sat Mar 29, 2014 3:50 pm
by GeoModder
icekatze wrote:They could undoubtedly reach it with contemporary propulsion (Dawn has ~10km/s of delta v) but it would still take forever. :P
Welcome to our "space age". :lol:
Does it matter if it takes a decade, or even half a generation, to arrive? And I say "arrive" on purpose, because flyby missions are a bit of waste IMO. Those just return a snapshot of a continous changing situation.
The benefit of a mission to Chariklo is that a probe going there could have gravity assist from 3 outer planets if necessary and alignments fit (not likely, but I thought I should mention it) the flight trajectory. Or even four if a mission would be launched along Uranus with the purpose of breaking velocity instead of increasing it before continuing to Chariklo.

Re: The Astronomy Thread

Posted: Sat Mar 29, 2014 7:03 pm
by Arioch
GeoModder wrote:
icekatze wrote:They could undoubtedly reach it with contemporary propulsion (Dawn has ~10km/s of delta v) but it would still take forever. :P
Welcome to our "space age". :lol:
Does it matter if it takes a decade, or even half a generation, to arrive? And I say "arrive" on purpose, because flyby missions are a bit of waste IMO. Those just return a snapshot of a continous changing situation.
It would probably take 10-20 years for a Dawn style spacecraft to achieve orbit around Chariklo. 20 years is a lot of time for something to go wrong with the spacecraft; the odds of being fully functional on arrival probably aren't great. It's also probably a challenge to secure funding from politicians who won't be in office (or might not even still be alive) when the thing arrives.

I am excited about New Horizons' flyby of Pluto in July of next year. It is a shame though that after 9.5 years of travel it will only be in the system for about a day. I'm concerned about responding to problems during the encounter when the lightspeed lag to Earth and back will be something like 10 hours.

Re: The Astronomy Thread

Posted: Sat Mar 29, 2014 10:49 pm
by Nemo
I have to question the value of a Chariklo mission when it would be easier and I'd argue more productive to go after Saturn or Jupiter. Sure there is some novelty to it, but the mission would be better served elsewhere. Especially given the constraints on RTG fuel.

Re: The Astronomy Thread

Posted: Sun Mar 30, 2014 7:20 pm
by GeoModder
There's a bit more then novelty to it. It would give (at the moment) unique insight in ring formations of smaller bodies.
While I agree that probes orbiting the jovian planets return more data because the region is more 'crowded' with objects, Saturn and Jupiter each had their share of probes already. So Uranus or Neptune would likely return more new data then a Jupiter/Saturn orbital probe would.
And a mission to land on Europa doesn't really count, it would also be a one-target mission then. :lol:

Arrival time depends largely on fuel mass respective to total probe mass, so if politicians really want their name&fame attached to a deep space mission, they should simply set more money aside for it.
There are probes outthere which already outlived the funding politicians and still return data. And both Galileo and Huygens likely saw the retirement of some of their funders, so I don't think that should be a reason to bar a project.

Personally, I'm more excited about the Dawn probe arriving at Ceres next year. :mrgreen:

Re: The Astronomy Thread

Posted: Thu Apr 10, 2014 10:48 pm
by Keter
Ceres might be a wetter and much more accessible Enceladus. Anyone know of a reason to send probes to Europa or Enceladus if Ceres turns out to have at least as much of an underground ocean as Enceladus and Europa?

Re: The Astronomy Thread

Posted: Thu Apr 10, 2014 11:39 pm
by Arioch
Keter wrote:Ceres might be a wetter and much more accessible Enceladus. Anyone know of a reason to send probes to Europa or Enceladus if Ceres turns out to have at least as much of an underground ocean as Enceladus and Europa?
That's a big if, but we'll know soon.

Re: The Astronomy Thread

Posted: Thu Apr 17, 2014 11:50 am
by Smithy
I don't have much time these days so I don't think this has already been posted, most I assume would of picked this up already, but for those that haven't.

Saturn might be birthing a new moon...

I'll peg the the BBC article also.

Image

Re: The Astronomy Thread

Posted: Thu Apr 17, 2014 4:59 pm
by GeoModder
Yeah, I read it today.
I think it's a stark opinion to say Saturn's rings can't produce a new 'moon' anymore.

Re: The Astronomy Thread

Posted: Thu Apr 17, 2014 9:47 pm
by Suederwind
NASA's Kepler Telescope Discovers First Earth-Size Planet in 'Habitable Zone'
Source

Re: The Astronomy Thread

Posted: Fri Apr 18, 2014 6:20 pm
by icekatze
hi hi

This one is sorta old news, but it seems like NASA is planning on capturing a small asteroid and pulling it into Earth orbit. Which I think is really cool.

Even if we'll probably never build a space elevator, and we won't need it for an anchor, there's still a vast amount of mineral wealth in them asteroids.

(Also, this gives me an excellent opportunity to link this video from Kerbal Space Program. The Kerbal Space Slam!)

Re: The Astronomy Thread

Posted: Mon Apr 28, 2014 1:23 pm
by Suederwind
NASA's Spitzer and WISE Telescopes Find Close, Cold Neighbor of Sun
Source

Re: The Astronomy Thread

Posted: Mon Apr 28, 2014 6:36 pm
by Arioch
Yeah, that's two brown dwarf systems within 7 light years. If brown dwarf systems are as common as red dwarfs (as seems likely), or perhaps even more common, then that's an awful lot of mass that's been completely unaccounted for.

Re: The Astronomy Thread

Posted: Mon Apr 28, 2014 8:22 pm
by GeoModder
I'm starting to wonder how many rogue planets they'll start discovering in Sol's neighbourhood say in a decade or so.

Re: The Astronomy Thread

Posted: Mon Apr 28, 2014 9:49 pm
by Arioch
GeoModder wrote:I'm starting to wonder how many rogue planets they'll start discovering in Sol's neighbourhood say in a decade or so.
Actually that's an important element of the recent WISE surveys: the fact that they're able to detect cool brown dwarfs 7 light years away is making it less and less likely that there are still undiscovered large planets poking around the edges of our own system.

Re: The Astronomy Thread

Posted: Tue Apr 29, 2014 12:40 am
by fredgiblet
Arioch wrote:Yeah, that's two brown dwarf systems within 7 light years. If brown dwarf systems are as common as red dwarfs (as seems likely), or perhaps even more common, then that's an awful lot of mass that's been completely unaccounted for.
Isn't that what Dark Matter was theorized for? IIRC Relativity wasn't working quite right because things were behaving as if there was a lot more mass than we could see, hence Dark Matter was theorized to fill the gap. An abundance of brown dwarfs could solve that.

Re: The Astronomy Thread

Posted: Tue Apr 29, 2014 3:25 am
by Arioch
fredgiblet wrote:
Arioch wrote:Yeah, that's two brown dwarf systems within 7 light years. If brown dwarf systems are as common as red dwarfs (as seems likely), or perhaps even more common, then that's an awful lot of mass that's been completely unaccounted for.
Isn't that what Dark Matter was theorized for? IIRC Relativity wasn't working quite right because things were behaving as if there was a lot more mass than we could see, hence Dark Matter was theorized to fill the gap. An abundance of brown dwarfs could solve that.
Yes, that's what I was referring to. I have the feeling that astronomers have grossly underestimated the mass of unseen systems (like brown dwarfs), interstellar gas and dust, and black holes.

Re: The Astronomy Thread

Posted: Tue Apr 29, 2014 5:04 pm
by GeoModder
Arioch wrote:
GeoModder wrote:I'm starting to wonder how many rogue planets they'll start discovering in Sol's neighbourhood say in a decade or so.
Actually that's an important element of the recent WISE surveys: the fact that they're able to detect cool brown dwarfs 7 light years away is making it less and less likely that there are still undiscovered large planets poking around the edges of our own system.
Oh, I meant with "Sol's neighbourhood" lightyears outthere, not in say the Kuiper -or Oortbelt of our system.
Personally, I don't think the changes of detecting a jovian-mass planet on Sol's outskirts are high. Not with the current record of detecting dwarf planet candidates in the same areas.

Re: The Astronomy Thread

Posted: Fri May 09, 2014 4:14 am
by Keter
I've got a vague memory of recently reading (on ArsTechnica, I think) an article that mentions near-consensus among at least one group of scientists that there's probably something Earth sized or bigger beyond main Kuiper belt but probably not as far as Oort cloud distance. Something about a recent finding making this more likely.

Re: The Astronomy Thread

Posted: Sat May 10, 2014 1:49 am
by Nemo
fredgiblet wrote:Isn't that what Dark Matter was theorized for? IIRC Relativity wasn't working quite right because things were behaving as if there was a lot more mass than we could see, hence Dark Matter was theorized to fill the gap. An abundance of brown dwarfs could solve that.

Oh I hope so. It would take an awful lot of stuff out there, like implausibly high values of "lots", but oh the schadenfreude. From memory dark matter is supposed to be like 80% of the mass of the universe. Think I said before how dark matter flags my phlogiston filter.