I believe I know what he's trying to talk about, but Lori will explain it a lot better and more accurately than I.That's pretty much how I figured it, but he's absolutely not willing to listen to any views but his own, even those of real astronomers and astrophysicists.
Protip: think oceans from comet water instead of Earth forming in the belt.
Lorizael, I've got a question related to the asteroid belt. There's a guy on CFC who is obsessed with convincing us that Babylonian mythology and Genesis are accurate descriptions of how the solar system and Earth were formed. He keeps insisting that Earth was formed in the asteroid belt because our water and Vesta's water are identical.
I can't find anything online anywhere that states even the possibility of Earth forming in the asteroid belt. Do you know of any theory or even a hypothesis by a reputable astronomer that talks about this?
...I wonder how the Theia impact may have informed all that. It had to be a somewhat low-energy event as two planets colliding goes, but it can't have not affected the orbit...
Lorizael, I've got a question related to the asteroid belt. There's a guy on CFC who is obsessed with convincing us that Babylonian mythology and Genesis are accurate descriptions of how the solar system and Earth were formed. He keeps insisting that Earth was formed in the asteroid belt because our water and Vesta's water are identical.
I can't find anything online anywhere that states even the possibility of Earth forming in the asteroid belt. Do you know of any theory or even a hypothesis by a reputable astronomer that talks about this?
The current best model for how the planets got to where they are is the Nice model (https://en.wikipedia.org/wiki/Nice_model), according to which the inner planets haven't really moved much at all. The best theory we have for why the asteroid belt is the way it is is that Jupiter (which astronomers think migrated inward and then back out at one point) prevented planetesimals from accreting into full-size planets because its gravity made things a little too exciting. Accreting requires relatively low velocity impacts. Too high a velocity and little planets just shatter instead.
Eventually, all the little planetesimals in what is now the asteroid belt were gobbled up or ejected, leaving behind what is in reality a very sparsely populated region. (The total mass of the asteroids is a tiny fraction of our moon, for example.) So from that it doesn't seem plausible that Earth formed in the asteroid belt, because it would have been subject to the same harsh gravitational influences, and a peaceful migration inward in response is way, way less likely than being destroyed or kicked out of the solar system entirely.
Additionally, much to Pluto's chagrin, the modern definition of a planet requires "clearing out" your orbit. This process isn't expected to take very long, only something in the range of tens of millions of years. If Earth had been inside the asteroid belt long enough to fully form before migrating inward, why didn't it clear out the asteroid belt?
Lorizael, I've got a question related to the asteroid belt. There's a guy on CFC who is obsessed with convincing us that Babylonian mythology and Genesis are accurate descriptions of how the solar system and Earth were formed. He keeps insisting that Earth was formed in the asteroid belt because our water and Vesta's water are identical.
I can't find anything online anywhere that states even the possibility of Earth forming in the asteroid belt. Do you know of any theory or even a hypothesis by a reputable astronomer that talks about this?
The current best model for how the planets got to where they are is the Nice model (https://en.wikipedia.org/wiki/Nice_model), according to which the inner planets haven't really moved much at all. The best theory we have for why the asteroid belt is the way it is is that Jupiter (which astronomers think migrated inward and then back out at one point) prevented planetesimals from accreting into full-size planets because its gravity made things a little too exciting. Accreting requires relatively low velocity impacts. Too high a velocity and little planets just shatter instead.
Eventually, all the little planetesimals in what is now the asteroid belt were gobbled up or ejected, leaving behind what is in reality a very sparsely populated region. (The total mass of the asteroids is a tiny fraction of our moon, for example.) So from that it doesn't seem plausible that Earth formed in the asteroid belt, because it would have been subject to the same harsh gravitational influences, and a peaceful migration inward in response is way, way less likely than being destroyed or kicked out of the solar system entirely.
Additionally, much to Pluto's chagrin, the modern definition of a planet requires "clearing out" your orbit. This process isn't expected to take very long, only something in the range of tens of millions of years. If Earth had been inside the asteroid belt long enough to fully form before migrating inward, why didn't it clear out the asteroid belt?
THANK YOU!!! :D
Would it be permissible to post a link to this post over at CFC? In any case, I will post the link you provided to the Nice model.
(and it's nice - no pun intended - to see references to the Oort Cloud; this guy thinks it's not real and accuses me of "believing" in it as though it's some kind of religious thing or fairy tale, even though I've posted links about it)
| The edge of the universe is closer than scientists previously thought (http://alphacentauri2.info/index.php?topic=18189.0) |
IRAS 19312+1950 (http://www.jpl.nasa.gov/news/news.php?feature=6607), why?
IRAS 19312+1950 (http://www.jpl.nasa.gov/news/news.php?feature=6607), why?
Stellar models are fiendishly complicated and not something I've studied in depth. The one thing I'll say, which the article talks about, it that the more distant a star is, the more difficult it is to tell if you're seeing the star or the star+interstellar medium of gas and dust in between. Disentangling the two often involves looking at a star in multiple EM bands (radio, optical, IR) and seeing what gets through.
Unlike the black and anti stuff in the Universe, this makes a lot of sense to me.
So gravey matter is concentrated in the mash? ;)
You're pretty good at this! I really hope you find a niche as an author or virtual university professor or planetarium director or something where you can find a broad audience.
Stellar models are fiendishly complicated and not something I've studied in depth.
Taking cosmology this semester, so I've seen the equations of MOND (Modified Newtonian Dynamics, the main dark matter alternative). They work well for that one thing dark matter was originally proposed to explain (galaxy rotation curves) but not anything else where dark matter seems to be having an effect.
For example, right now we're working through the formation of large scale structure in the early universe. If the early universe is composed only of regular matter, then it acts basically like a fluid. That is, it has pressure and doesn't want to be compressed (by gravity), which slows the formation of structure. If the universe is mostly dark matter, however, then matter collapses without any impeding force and structures do form (when we observe them to form).
SO...by turning to the Dark Side the Universe could unleash the power of The Force. ;-)
How goes the teaching part?
SO...by turning to the Dark Side the Universe could unleash the power of The Force. ;-)
Current models of dark matter say that (a) it's everywhere, (b) it can pass right through us, and (c) galaxies wouldn't exist without it. So then you could say it surrounds us, it penetrates us, it binds the galaxy together...QuoteHow goes the teaching part?
I'm enjoying it. Grading is a hassle and kind of nerve-wracking. But getting up in front of a class and breaking down complex topics and answering questions and trying to share a little bit of what I'm passionate about... it's stimulating and fun.
QuoteHow goes the teaching part?
I'm enjoying it. Grading is a hassle and kind of nerve-wracking. But getting up in front of a class and breaking down complex topics and answering questions and trying to share a little bit of what I'm passionate about... it's stimulating and fun.
Suppose Dark Matter is simply the gravitational shadow of particles moving at the speed of light. You can't detect them by other means because they no longer exist in that time and place.
We'd fry from the radiation. That would put Earth inside Jupiter's huge Van Allen belts, and they are INTENSE.
If it passed that close, wouldn't we lose our Moon, atmosphere, and oceans? Wouldn't that alter our orbit, too?
We'd fry from the radiation. That would put Earth inside Jupiter's huge Van Allen belts, and they are INTENSE.
I meant within...
-And I suspect that at that very closer range, the heat Jupiter radiates might be non-trivial, too.
I'm trying to write blog posts more frequently, especially now that I'm not busy and have no excuses. To that end, if you guys have any questions about astronomy (and to a lesser extent, math and physics), fire away. If it's a quick question, you'll get a quick answer here. But if it's a question for which the answer can involve a story and some terrible MS Paint illustrations and maybe a bit of math (and I think it would be a fun thing to write about), I'll put together a blog post to answer it. I'll try to get posts out within a week or so, because my hope is that the pressure of someone asking me a question will nudge me into writing.
If this doesn't appeal to anyone here, oh well. If it does, cool, and thanks.
As the best of our instruments have become far more refined in the last few decades, have there been any significant advances in the range of parallax measurements? ISTR observations six months apart being good for measuring distance on the order of something 11lyrs. Is that anything like it currently stands?
I've never quite gotten why astronomy/cosmology thinks our observations tell us anything relevant about the mass of the universe within several orders of magnitude. Stands to reason that there's a distinctly non-trivial amount of cosmic gas/dust and other non-radiating matter out there making estimations nothing but poorly-informed guesses...
But there is a spacecraft in orbit right now--Gaia--which will get us to the galactic core, which is roughly 30,000 light years distant.Orbiting Earth - or further out from the Sun?
As the best of our instruments have become far more refined in the last few decades, have there been any significant advances in the range of parallax measurements? ISTR observations six months apart being good for measuring distance on the order of something 11lyrs. Is that anything like it currently stands?
The first star for which we accurately measured the parallax--61 Cygni--is 11 light years away, and that was in 1838. We've been able to do about 1000 light years for awhile. But there is a spacecraft in orbit right now--Gaia--which will get us to the galactic core, which is roughly 30,000 light years distant.
Another complication is that the radial velocity and transit methods work best for systems that are edge on to us, but the astrometric method works best for systems that are face on to us. So it's difficult for one method to be used to confirm the results of the other.
A couple questions on Lagrange point matters. So this Gaia probe has a roughly 10% better baseline with the Sun-Earth L2 point only being 1% of the Sun-Earth distance further out (1,5 million km)?
On another note, it is known that a couple other planets in our system have small objects orbiting in their respective L4-L5 points. Especially Mars and Jupiter. I kinda wondered why, over the eons, these objects didn't clump to bodies large and massive enough to become roughly spherical. Think Vesta-sized. Is there some peculiarity on how those objects move around in any particular L4-L5 points that precludes the formation of larger bodies? I read about Lissajous orbits around those points, but with a sufficient number of objects I expected encounters to be common.
Okay. Here's one for you. It may or may not be cosmic. Is all energy the same in that it travels in waves, and we just perceive it differently as light or heat or sound or earthquakes, ( as examples) depending on frequency and amplitude? Or is it particles, particles traveling in waves, or some of each ?
The other problem is that there's just not enough material. Accretion into a planetesimal is a runaway process, but if you don't have enough mass packed densely enough, that runaway process never starts. Additionally, there's not a lot of gas left in interplanetary space, which causes drag that slows material down, increasing the likelihood of objects eventually colliding and making those collisions softer. Softer collisions are better for objects sticking together rather than blowing apart.
I was hoping for something other than another black hole-black hole merger this time, but apparently detecting this many in so short a period of time has some scratching their heads. That is, stars and other dots in space rarely ever collide, because space is so big compared to the size of gravitationally collapsed objects, unless those objects basically started out next to each other anyway. And if these black holes started out next to each other, why did it take until they had both lived their entire lives as stars and then collapsed into black holes before they merged?
I read it and think that there's some kind of kernel for a Larry Niven story. Weaponized gravity wave communication transmitters in a Pak Protector war or something.
Be glad you didn't start with lissajous curves/orbits then. :)You had to make me look, didn't you? ;)
Be glad you didn't start with lissajous curves/orbits then. :)You had to make me look, didn't you? ;)
https://en.wikipedia.org/wiki/Lissajous_orbit
No problem. And of course, that all ties into eclipses. About a billion years ago, the apparent size of the moon was maybe 5% larger, so the moon would always cover up the sun if it passed between the earth and it. In another billion years, as the moon gets farther away, it will never be able to totally eclipse the sun. We're so special.
Haumea is an interesting object: it rotates around the Sun in an elliptic orbit which takes it 284 years to complete (it presently lies fifty times further from the Sun than the Earth),
and it takes 3.9 hours to rotate around its axis, much less than any other body measuring more than a hundred kilometers long in the entire Solar System. This rotational speed causes it
to flatten out, giving it an ellipsoid shape similar to a rugby ball. The recently published data reveal that Haumea measures 2,320 kilometers in its largest axis -- almost the same as Pluto --
but lacks the global atmosphere that Pluto has.
First Trans-Neptunian Object With a Ring
According to the data obtained from the stellar occultation, the ring lies on the equatorial plane of the dwarf planet, just like its biggest satellite, Hi´iaka, and it displays a 3:1 resonance
with respect to the rotation of Haumea, which means that the frozen particles which compose the ring rotate three times slower around the planet than it rotates around its own axis.
Is there a likelihood that Haumea, instead of being a single body, is two 'lobes' connected somewhat like 216 Kleopatra, but closer?
It's just that I find it odd Haumea pulls a Jinx-like object on us like in Larry Niven's Known Space novels.
Assuming that the longest axis of Haumea also lies in its equatorial plane, I wonder if this ring would orbit the dwarf planet in an ellipsoid shape as well instead of the usual circular one.
I mean, the orbital velocities needed to stay at a given distance of the surface are not 'circular' in respect to this world's equator.
A Moon crossing the Andes of Earth or the seams of Rugby shouldn't have a measureable effect on it's orbit, should it?
I imagined the actual earth shape was relatively smoother, but with more of an apparent belly bulge than that. A little less spherical.
So this has me wondering, what factors create a rugby planetoid, rather than the more familiar spherical ones?
For example, is this more likely to happen when the denser core of a moon/planet does an amoeba style complete separation while still travelling in the same orbit, resulting in a faster and slower Rugby? Or is it the lack of rotation, or rotation perpendicular to the axis of orbit that is the key factor? Or is it something else, more like a ball of playdough in orbit, collecting gravel and dust in it's path? Or maybe more of a giant teardrop of liquid gas gathering droplets of other gasses on it's leading bulbous end?
Again, no hurry on this one.
Dark Matter and Energy Don't Exist: Astronomer Claims to Solve Universe's Greatest Mysteries With New Model (http://alphacentauri2.info/index.php?topic=20194.0)
Astrophysical Journal article linked - something about scale invariance.
Thank you very much for that, Lorizael.
What of Dark Energy? Is it simply out of the light spectrum, or is it something weird?
A question I've asked concerning relativity/cosmology, that I think is probably crucial.
What is Space? The 300-Year-Old Philosophical Battle Still Rages Today
(http://alphacentauri2.info/index.php?topic=20207.msg108883#new)
Well Lorizael, I don't mean to impose on your time trying to explain the unknown. Then again, the nature of space itself is sort of the interesection of philosophy and cosmology and exactly the kind of thing you might like to talk and theorize and speculate about, but if so, do it when you have the time and inclination.
Is space elastic? Is it subject to distortion by force from things like gravity or the big bang? I guess black holes suggest that.
If so isn't it possible that stuff on the fringes of the universe is accelerating because it's entering normal, undistorted space, and our physics is based on our perspective, our world, where mass and weight seem the same at sea level, and adapted as we change altitude, get beyond our atmosphere, Earth's gravity, The Sun's etc., and yet hasn't adapted to the rules of "original space."
To the extent that we don't know what dark energy is, but it acts like a cosmological constant, it's starting to sound suspiciously like "ether."
I guess I can see your point on the aether thing. Isn't the Bell labs radio telescope discovery of the background noise from The Big Bang a similar example? Something ubiquitous that eventually had no other credible alternative explanation?
If you look at quantum physics, it says that the vacuum of space should have energy itself. And since most of space is a vacuum, that would seem to work as a candidate for dark energy. But when you try to calculate how much energy might be in the vacuum (there's not necessarily a definitively correct way to do this), it comes out to be ~120 orders of magnitude (that is, a 1 followed by 120 0s) more powerful than the observed effect of dark energy. So that's a pretty bad prediction.
http://iopscience.iop.org/article/10.3847/1538-4357/aa9789 (http://iopscience.iop.org/article/10.3847/1538-4357/aa9789)
http://aip.scitation.org/doi/full/10.1063/1.4964481 (http://aip.scitation.org/doi/full/10.1063/1.4964481)
Well my qualifications for that are... I understand the physics pretty well and played around with some oscilloscopes and circuit boards for a semester of E&M.
Well my qualifications for that are... I understand the physics pretty well and played around with some oscilloscopes and circuit boards for a semester of E&M.
I decided a long time ago maths is maths. Yeah, one specialty uses a different set of equations more than another, but it's all math.
Except finance. I don't think they are using math anymore.
Well my qualifications for that are... I understand the physics pretty well and played around with some oscilloscopes and circuit boards for a semester of E&M.
I decided a long time ago maths is maths. Yeah, one specialty uses a different set of equations more than another, but it's all math.
Except finance. I don't think they are using math anymore.
I just read this to my wife ( CPA/ Chief Accounting Officer ) when she asked what I was laughing about. She chuckled and said "Creative Writing. Seriously, we use a lot of creative writing."
I've changed my mind. It's nothing but clear that pro science writers read each other's stuff all the time. Have a look at that SciTech Daily article and party on with your own bad self.
Okay. Stumbled across this cool looking Mars terraforming video.Need a good Magnetic Field and Ozone layer so as to keep any real atmosphere that is released... But it will last for a few millennium or so without...
https://www.facebook.com/ScienceNaturePage/videos/1332147706917484/UzpfSTExNzM2NjM0MzkzNTIxMzk6MTk4MTYzNzg3NTIyMTM1NA/ (https://www.facebook.com/ScienceNaturePage/videos/1332147706917484/UzpfSTExNzM2NjM0MzkzNTIxMzk6MTk4MTYzNzg3NTIyMTM1NA/)
This doesn't square with my concept of terraforming Mars. The usual explanation is that my concept of science is stuck in the Space Age. Melting the icecaps would only result in two polar seas. Where are they getting the oxygen and hydrogen for oceans and atmosphere? Are they defrosting the perma-rust and then using plants to liberate the oxygen from the iron?
Don't get me wrong- I love the idea of terraforming Mars and always have, new worlds are full of possibility. But is this a possibility in want of commitment, or is it science fiction like the colonization project which hasn't worked out the critical problems yet?
Yeah, I know, I kind of buried the lede there. It's mostly a computer job. I'm working for my university, helping NASA organize and archive data on small solar system bodies.
I'll watch the video and comment when I get home from work...
But what about the new thing on the block, 2015 BZ509? (An asteroid in a retrograde co-orbital resonance with Jupiter, recently asserted to be of possible interstellar origin). NASA's site didn't return any results when I searched for it.
I'll watch the video and comment when I get home from work...
I lied. Anywho, the problem with Mars is that it's dry and cold and has a thin wisp of an atmosphere. The bad news is there's no good way to directly combat either the dryness or the coldness.
If you melt the ice caps or bombard the planet with icy comets or setup an interstellar bucket brigade, the extremely low pressure means any liquid water more or less instantly boils away.
You also can't really increase the temperature because, well, what is it you're heating up? Not Mars itself--it's way too large. You just want a higher surface temperature, but there's barely anything on the surface to have a temperature.
The good news is both these problems can be solved by introducing an atmosphere. There is dry ice (frozen CO2) in the polar caps and probably some other greenhouse gases stuck in rocks. And the solar system is full of ammonia and CO2 and hydrocarbons that could be used to trap heat. Throw a whole lot of atmosphere onto the planet, trap heat, warm it up, melt ice, produce water vapor which is an extremely potent greenhouse gas, get yourself a nice positive feedback loop going on.
If you establish any kind of water cycle, the ice in the polar caps will eventually "fall" into the low-lying areas on Mars. (We see something similar happen on Mercury and Titan, for example.) There are questions about how much water is tucked away on Mars. May need to import more.
And Mars' lower gravity means you need a lot more atmosphere than that present on Earth to get the same surface pressure. And Mars' distance from the sun means it's just plain colder. May want to setup giant space mirrors to direct more light at the surface.
And yes, there's the problem that Mars' low gravity and lack of a magnetosphere means its more susceptible to atmospheric escape. Timescale on this is pretty long, but still something to worry about.
It's all pie in the sky right now. Transporting that much material through the solar system doesn't seem to be physically impossible, but we currently have no experience with any of that. How do you build a planet-wide magnetic field? How do you create a biosphere from scratch? How do you make sure you don't accidentally create Venus? No solid answers to those questions right now.
Okay, that raises another stupid series of questions. I presumed atmosphere retention was strictly a function of gravity, but if it isn't does that mean that the less massive Mars requires a stronger magnetic field to retain an atmosphere?
If all planets don't have magnetic fields, why do some have them and others not? The dynamo effect of a molten core? The massive presence of nickel and iron ? A radiation belt ? Or is that a side effect of a magnetic field?
Thank you. So the practical approach at this time would still be the Total Recall method - do whatever you do underground?
So conservation of angular momentum is a variation of voodoo magic. Got it.
Thank you. So the practical approach at this time would still be the Total Recall method - do whatever you do underground?
But boring. I like the giant magnetic balloon(s) (https://phys.org/news/2017-03-nasa-magnetic-shield-mars-atmosphere.html).
Alright, so here's a really rough estimate. If the magnetic field is roughly the size of Mars + decent Martian atmosphere, and the strength is the same as Earth's (and uniform all the way through, which is probably a very bad assumption), and Mars is actually empty space... then you've got ~200 million gigajoules of energy stored in the field. Mars is really iron+nickel+rock, all of which are better at holding magnetic fields, so the answer may be lower by 2 or 3 orders of magnitude.
The largest nuclear plant in the US operates at ~4 Gigawatts, so you need to commander its output for a year and a half to produce your magnetic field. But if you do need less because you're dealing with the actual composition of Mars and not a vacuum, we're talking at most just a few days of that plant's output. It's honestly not an astronomical sum because Earth's magnetic field is in truth very weak (~50 microteslas, compared to the 5 milliteslas of a refrigerator magnet). It's only a lot because it's a huge volume of space.
Well, it starts with the plainly observable fact that everyone's artificial gravity is insanely reliable.
I conclude this: in the ST universe, there's stuff about how gravity works that was discovered by the mid 90's. Khan's ship had artificial gravity, and it wasn't spinning or accelerating. So there's a way to make, dunno, a gravity deck plating cheaply that works for a very long time with little or no power input. Every race discovers this application of the law of gravity pretty soon after they go into space. The same, or similar, techniques make for a nifty non-reaction gravity drive, which Starfleet calls "impulse". A slightly more sophisticated application involving the interaction of fields from two gravity generatorsdistortswarps space-time and makes for a nifty FTL drive. Thus, everyone and his mother has a FTL starship with two drive pylons of some sort. Both types of drive take a lot more juice then the deck plates because the gravity fields, by the nature of the thing, are not static, but have to expand and contract and vary in intensity. That Warp is probably by an order of magnitude more power-hungry than Impulse naturally follows.
But if impulse relies on a gravity generator producing thrust somehow, then your momentum needs to come from somewhere.
-though it has to be low/no power, or they'd lose gravity in emergencies roughly every episode
Try a web search for "levitating frog" to see how it's done
Has to be some sort of self-contained or at the very least rechargeable system, otherwise the gravity would falter for sure each time the warp core is ejected. ;lol
And, there have been questions about ejectra from the impact (or lack there of, but most could be currently under existing ice - some conjectures about side glance hit, but still), would the rapid melt/vaporization have any possible effect of how that might get distributed?
How much would that change (or muddy up if you will) the calculations of the probable size and energy of the impacting object?
If ice was present and its thickness was comparable to the impactor’s diameter, then a more energetic projectile is required to produce a crater of the observed size, and the fraction of non-ice debris in the ejecta would be smaller than if the impact hit ice-free land (19).
The presence of an icy layer significantly modifies the cratering mechanics. Observable features demonstrated by the modeling include variations in crater morphometry (depth and rim height) and icy infill of the crater floor during the late stages of crater formation. In addition, an icy layer modifies the velocities, angles, and volumes of ejecta, leading to deviations of ejecta blanket thickness from the predicted power law. The dramatic changes in crater excavation are a result of both the shock impedance and the strength mismatch between layers of icy and rocky materials.
If dark matter and dark energy are negative mass fluid and the fluid is continuously created, where does it come from?
Farnes also introduces a creation term for the negative masses so he gets something akin dark energy. A creation term is basically a magic fix by which you can explain everything and anything. Once you have that, you can either go and postulate an equation of motion that is consistent with the constant creation (or whatever else you want), or you don’t, in which case you just violate energy conservation. Either way, it doesn’t explain anything. And if you are okay with introducing fancy fluids with uncommon equations of motion you may as well stick with dark energy and dark matter.
Yeah, was disappointed by that presser. Yesterday they said we should get composition data today, but instead they mostly just talked about what they didn't find and then showed off the 3d stuff. Not sure what that means, exactly.
But on the neat side, the younger woman on that panel, Silvia, is a former colleague of mine. Among other things, we were both involved with archiving the Pluto flyby data. But then around this time last year she got a job at SwRI as a scientist on the New Horizons team.
Heh, that's not really my thing.
...to get your answers.
Regardless, I hope that 2019 is your best year ever.
...to get your answers.
Well, as I said, my group is involved with the archival effort for New Horizons data. So I do have some contacts. But, well... :-X
Thanks! I got a promotion and retroactive raise at the end of the year, so I'm hoping to move into my own apartment (rather than living with stranger roommates) some time this spring.
Thanks! I got a promotion and retroactive raise at the end of the year, so I'm hoping to move into my own apartment (rather than living with stranger roommates) some time this spring.
That's great news. Maybe someday you can get a Space Force Commission and double dip.
All told, it will take about 20 months for all the data currently trapped on the probe to be sent back down to Earth. That data includes "literally hundreds of images and spectra and other data types," Stern promised.
https://www.space.com/42903-new-horizons-ultima-thule-flyby-data-intermission.html (https://www.space.com/42903-new-horizons-ultima-thule-flyby-data-intermission.html)
https://www.space.com/42903-new-horizons-ultima-thule-flyby-data-intermission.html (https://www.space.com/42903-new-horizons-ultima-thule-flyby-data-intermission.html)QuoteAll told, it will take about 20 months for all the data currently trapped on the probe to be sent back down to Earth. That data includes "literally hundreds of images and spectra and other data types," Stern promised.
Gonna be a while before we get the high res pics. Kinda makes me wonder if they shouldn't have held onto the news for a while so they had a more steady stream of info.
Am I the only one who had good seeing for the eclipse?
Am I the only one who had good seeing for the eclipse?My wife and elder son stayed up to watch it together. Laz said it wasn't worth staying up so late, but he spent the whole time reading, which he would do every night if we let him.
Nice shot, Uno.
Could y'all edumacate me about why they don't wrap something like a Faraday cage -or maybe just a silvered mylar envelope- around the ISS -or one whole module, anyway- and run a current through it for a radiation shield? Same for traveling crew capsules, though I see that's a considerably greater engineering challenge...ANYone?
Like, the big short-term threat is solar flares, right? And that's a particle radiation problem, right? And a large/intense enough magnetic field will handle particle radiation -if not the x, gamma, etc., wave radiation- nicely. So, this is an obvious enough thing that I figure, with fair confidence, that there were pretty definitive theoretical/engineering studies done by the time I was born in the mid-sixties, and either the power requirements are prohibitive to do that for three days or so, or there's too much wave radiation in a flare - or both. Help me out here, if you can...
Yeah, but Who ordered a Magnitude?
When they did that power generation test with a conductive tether, the one that melted from all the juice it produced, any idea how much drag? I never heard anything about that in the reporting...
Yeah, on that end... they measured a voltage of 3500 V and a current of about half an amp, so that's ~1750 W (Joules/second) being generated, which is drained from the shuttle's kinetic energy. Shuttle's mass was 10,500 kg and moving at like 7-8 km/s, which gives it roughly 300 billion joules of energy. So I think it would take a long time to slow it down appreciably by this method, unless there's some other factor I'm missing.Y'know, it strikes me at this late date that there's a useful idea in there, if the engineering could be worked out - just, I was thinking about emergency power, when several orders of magnitude greater drag would be very valuable for leaving orbit w/o all that scary/dangerous reentry stuff, or at least less of it.
Lori, what's going on with your space career these days?
Can anyone tell me anything about the very bright light that looks like an airplane running light that's currently, roughly, SSE almost 45 degrees up after sunset? Two, three weeks ago, it was ESE, maybe 10 degrees above the horizon. It's visible before anything but the moon, last week, and it more flashes than twinkles.
Before you say "Elon Musk disco ball" to me, no. Those are in LEO, and have something like a half hour to cross the sky; I'd see motion.
It's hard to believe, but some sites I googled are trying to tell me it's just Sirius.