Slashdot Mirror

Depends, are kids just a subset of adults? :)

Some moons are fairly boring chunks of rock (like, say, The Moon), others tell a story of an extremely violent past (like, they've been blasted to bits and only just managed to stay as one entity, like Miranda).

Others have thick atmospheres containing weird-ass chemicals (like Titan), others have vulcanism driven by processes we barely understand (like Triton, or Io)

Some may have oceans, others are small chunks of rock we would barely notice if they weren't orbiting some other body (like Phobos).

The planets may be more interesting in some respects, but there are a lot more moons to look at :)

Depends, are kids just a subset of adults? :)

Some moons are fairly boring chunks of rock (like, say, The Moon), others tell a story of an extremely violent past (like, they've been blasted to bits and only just managed to stay as one entity, like Miranda).

Others have thick atmospheres containing weird-ass chemicals (like Titan), others have vulcanism driven by processes we barely understand (like Triton, or Io)

Some may have oceans, others are small chunks of rock we would barely notice if they weren't orbiting some other body (like Phobos).

The planets may be more interesting in some respects, but there are a lot more moons to look at :)

Not just planets, but some moons too.

Some moons are extremely interesting:

• Europa and Callisto may have oceans, thus making them the most likely places that we will find extra-terrestrial life
• Titan has a nitrogen-rich atmosphere that is so thick that astronomers have not yet been able to see the surface.
• The Moon - as has been mentioned before on Slashdot, the Moon may have water at its south pole. It is important to confirm this initial observation. If water does exist there, it could be mined and used as fuel, thus acting as an inter-planetary refuelling point.

For an earlier image of a planet-like body orbiting a star: click here.

First off, NASA has produced thousands of spinoffs, and I guarantee you use several of them every day.

But even aside from that, NASA isn't a corporation and not everything should be run as one. You need some "blue-sky" research that isn't focused on a specific goal. You don't know what you'll find, but you'll find something.

Now, incompetence and dumb mistakes (why didn't they use a second intererometer to check?) need to be dealt with, but overall I'd keep NASA. What we really need is some revisions in space law so that private companies can do more space research and run their own launches. Then we get the best of both worlds (no pun intended).

This is the same tidal energy that causes Io to radiate excess heat in the form of volcanic eruptions. Certainly the effect is less near Europa, but according to this page your assertion is still up in the air.

>Not to mention the fact that one side of the
>moon faces the sun at all times! Any solar
>collectors on Earth are subject to day/night
>cycles. The moon would rarely be impacted, when
>the lunar eclipses happen.

Doh! One side of the moon always faces the EARTH! (synchronous rotation). We had never seen the far side of the moon until we sent something "back there" to take pictures.

So: that being the case, is it really possible that one side of the moon is always bathed in the light of the sun? If so, then how did we ever get visible pictures of the OTHER SIDE of the moon? Did we use a gigantic flashbulb, or something? ;)

Map of the entire surface including the far side

The Far Side of the Moon Consider how this picture would look if it had been taken during a "full moon:" since during a full moon the entire side of the moon that is facing the Earth is lit up, only the portion of the moon in this photograph that is said to be visible from Earth (see the pic's caption) would have any sunlight on it.

Far Side of the Moon, with animation showing the same side of the moon always toward the Earth. This doesn't show where the sun is in relation to the animation; but figure that the sun is way off the screen from the animation...the darkened part of the moon in the animation is representing the side of the moon we never see from Earth, NOT how the light hits the moon (the Earth does not illuminate the moon, although it does sometimes reflect a little of the sun's light onto the dark portion of the quarter moon...)

So, taking this into account, will it be useful to build these lasers on the moon, especially the power plant?

Apollo 11 Laser Ranging Retroreflector Experiment. "Laser beams are used because they remain tightly focused for large distances. Nevertheless, there is enough dispersion of the beam that it is about 7 kilometers in diameter when it reaches the Moon and 20 kilometers in diameter when it returns to Earth. Because of this very weak signal, observations are made for several hours at a time. By averaging the signal for this period, the distance to the Moon can be measured to an accuracy of about 3 centimeters (the average distance from the Earth to the Moon is about 385,000 kilometers)."

Add to this, the fact that the moon wobbles...

Ah yes, here's a thought... ;)

>Not to mention the fact that one side of the
>moon faces the sun at all times! Any solar
>collectors on Earth are subject to day/night
>cycles. The moon would rarely be impacted, when
>the lunar eclipses happen.

Doh! One side of the moon always faces the EARTH! (synchronous rotation). We had never seen the far side of the moon until we sent something "back there" to take pictures.

So: that being the case, is it really possible that one side of the moon is always bathed in the light of the sun? If so, then how did we ever get visible pictures of the OTHER SIDE of the moon? Did we use a gigantic flashbulb, or something? ;)

Map of the entire surface including the far side

The Far Side of the Moon Consider how this picture would look if it had been taken during a "full moon:" since during a full moon the entire side of the moon that is facing the Earth is lit up, only the portion of the moon in this photograph that is said to be visible from Earth (see the pic's caption) would have any sunlight on it.

Far Side of the Moon, with animation showing the same side of the moon always toward the Earth. This doesn't show where the sun is in relation to the animation; but figure that the sun is way off the screen from the animation...the darkened part of the moon in the animation is representing the side of the moon we never see from Earth, NOT how the light hits the moon (the Earth does not illuminate the moon, although it does sometimes reflect a little of the sun's light onto the dark portion of the quarter moon...)

So, taking this into account, will it be useful to build these lasers on the moon, especially the power plant?

Apollo 11 Laser Ranging Retroreflector Experiment. "Laser beams are used because they remain tightly focused for large distances. Nevertheless, there is enough dispersion of the beam that it is about 7 kilometers in diameter when it reaches the Moon and 20 kilometers in diameter when it returns to Earth. Because of this very weak signal, observations are made for several hours at a time. By averaging the signal for this period, the distance to the Moon can be measured to an accuracy of about 3 centimeters (the average distance from the Earth to the Moon is about 385,000 kilometers)."

Add to this, the fact that the moon wobbles...

Ah yes, here's a thought... ;)

>Not to mention the fact that one side of the
>moon faces the sun at all times! Any solar
>collectors on Earth are subject to day/night
>cycles. The moon would rarely be impacted, when
>the lunar eclipses happen.

Doh! One side of the moon always faces the EARTH! (synchronous rotation). We had never seen the far side of the moon until we sent something "back there" to take pictures.

So: that being the case, is it really possible that one side of the moon is always bathed in the light of the sun? If so, then how did we ever get visible pictures of the OTHER SIDE of the moon? Did we use a gigantic flashbulb, or something? ;)

Map of the entire surface including the far side

The Far Side of the Moon Consider how this picture would look if it had been taken during a "full moon:" since during a full moon the entire side of the moon that is facing the Earth is lit up, only the portion of the moon in this photograph that is said to be visible from Earth (see the pic's caption) would have any sunlight on it.

Far Side of the Moon, with animation showing the same side of the moon always toward the Earth. This doesn't show where the sun is in relation to the animation; but figure that the sun is way off the screen from the animation...the darkened part of the moon in the animation is representing the side of the moon we never see from Earth, NOT how the light hits the moon (the Earth does not illuminate the moon, although it does sometimes reflect a little of the sun's light onto the dark portion of the quarter moon...)

So, taking this into account, will it be useful to build these lasers on the moon, especially the power plant?

Apollo 11 Laser Ranging Retroreflector Experiment. "Laser beams are used because they remain tightly focused for large distances. Nevertheless, there is enough dispersion of the beam that it is about 7 kilometers in diameter when it reaches the Moon and 20 kilometers in diameter when it returns to Earth. Because of this very weak signal, observations are made for several hours at a time. By averaging the signal for this period, the distance to the Moon can be measured to an accuracy of about 3 centimeters (the average distance from the Earth to the Moon is about 385,000 kilometers)."

Add to this, the fact that the moon wobbles...

Ah yes, here's a thought... ;)

>Not to mention the fact that one side of the
>moon faces the sun at all times! Any solar
>collectors on Earth are subject to day/night
>cycles. The moon would rarely be impacted, when
>the lunar eclipses happen.

Doh! One side of the moon always faces the EARTH! (synchronous rotation). We had never seen the far side of the moon until we sent something "back there" to take pictures.

So: that being the case, is it really possible that one side of the moon is always bathed in the light of the sun? If so, then how did we ever get visible pictures of the OTHER SIDE of the moon? Did we use a gigantic flashbulb, or something? ;)

Map of the entire surface including the far side

The Far Side of the Moon Consider how this picture would look if it had been taken during a "full moon:" since during a full moon the entire side of the moon that is facing the Earth is lit up, only the portion of the moon in this photograph that is said to be visible from Earth (see the pic's caption) would have any sunlight on it.

Far Side of the Moon, with animation showing the same side of the moon always toward the Earth. This doesn't show where the sun is in relation to the animation; but figure that the sun is way off the screen from the animation...the darkened part of the moon in the animation is representing the side of the moon we never see from Earth, NOT how the light hits the moon (the Earth does not illuminate the moon, although it does sometimes reflect a little of the sun's light onto the dark portion of the quarter moon...)

So, taking this into account, will it be useful to build these lasers on the moon, especially the power plant?

Apollo 11 Laser Ranging Retroreflector Experiment. "Laser beams are used because they remain tightly focused for large distances. Nevertheless, there is enough dispersion of the beam that it is about 7 kilometers in diameter when it reaches the Moon and 20 kilometers in diameter when it returns to Earth. Because of this very weak signal, observations are made for several hours at a time. By averaging the signal for this period, the distance to the Moon can be measured to an accuracy of about 3 centimeters (the average distance from the Earth to the Moon is about 385,000 kilometers)."

Add to this, the fact that the moon wobbles...

Ah yes, here's a thought... ;)

Pluto is far and away the most boring of all of the planets. In fact, according to many scientists it isn't a planet at all, but rather an asteroid. Why are we wasting this much time and energy on a little rock in an eccentric orbit just because we (mistakenly) call it a planet? Pluto is SMALLER than EUROPA, less interesting, and a lot farther away. Let's go to Europa instead. Europa is one of the most interesting places in the solar system... A moon of ice with possible liquid oceans. It's truly an awesome place. I propose that NASA should bag the pluto mission and do this one instead.

Yeah, really fscking long ones; plus they've got this vertical oscillation. I think Sol's orbit is 200 MYears and the oscillation is 26 MYears. It's thought there may be some correlation between mass extinctions here on earth and when we go through the thickest part of galaxy.

The periodicity of the Sun's vertical oscillation is closer to 30Myr, but appart from that you're correct. See for instance Rampino (1997) in the Journal of Celestial Mechanics and Dynamical Astronomy, or Rampino et al. (1997) in the Annals of the New York Academy of Sciences.

For a more popular slant, and a slightly more famous name, you could also have a look at Shoemaker (1999) in the Annual Review Of Earth And Planetary Sciences (Yes, that Shoemaker, as in Comet Shoemaker-Levy 9).

This nebula is also known as the Tarantula Nebula, NGC 2070. It is located in the Large Magellanic Cloud; a supernova appeared nearby in 1987. Southern Hemisphere observers can see the nebula with binoculars.

A few years ago, astronomers announced that a dwarf galaxy in the direction of Saggitarius was colliding with the Milky Way. I'm not sure it's exactly within our galaxy's borders [I'd thought it was, but the only reference I could find after a minute of googling said otherwise], but it's orbiting (every billion years or so), and the galaxies have had an effect on each other. Check out this FAQ about the dwarf and the referred page. Key quote: "It [SagDEG] is apparently in process of being disrupted by tidal gravitational forces of its big massive neighbor in this encounter. "

It has certain benefits that PCs do not have (locked hardware, unified memory, etc.)

Locked hardware is a benefit?! For whom? Certainly not for the customer. Maybe for those that love control, such as the MPAA and the RIAA, but not us, the customers.

It seems you have already been assimilated into the Borg.

Makes me long for the day when PS2 meant PS/2 and not PlayStation 2. (Maybe we shouldn't abbreviate PlayStation 2 like that, look at CSS, is it Cascading Style Sheets, Content Scrambling System or C Styled Script?).

Anyway, the PS/2 was somewhat of a closed system (IBM had been overly tight-fisted about controlling use of the MCA bus technology - it hurt them and they have learned from their mistake), but it was far more open than the PS2 game machine.

P.S. I am wondering, what benefits can game consoles have over PCs anyway? PCs have TV out for those that want connections to TVs and the frame rates are nowadays faster than human perception and the scan rate of any monitor or TV out there. Please let me know what I am missing. Granted they are cheaper than PCs sometimes, but not by all that much it seems. And anything with a hard drive is getting close to being a PC anyway... Heck, GCC can be made to run on it I heard.

How do they name these things? 2001 KX76 - how boring! Charon is named - why not this? Don't these astronomers have any creativity left in them? Maybe they're waiting to name it - a 'Name That Planet' contest or something. Or if someone pays enough, they'll name it after them - money got a tourist into space.

The International Astronomical Union gets to set names, and their FAQ addresses the possibility of buying them (and the question of whether Pluto is a planet or not). There is a description here of how the IAU goes about naming various things.

Ok. All the cranks are coming out. I might as well join the party.

Let me start with a story about the planet that wasn't.

It seems at a lecture back on January 2nd, 1860, the French mathematician Urbain Le Verrier announced that the problem of observed deviations in Mercury's orbit could be resolved by assuming the existence of one or more intra-Mercurial planetoids. Over time, both before and after this announcement, various people claimed to have spotted such planetoids. One of them was named Vulcan, a name that was, about a century later, re-used in a well-known science fiction television show, which was how I got on to this damn story in the first place.

The planetoids, including Vulcan, were, in the end, proven fictional. Perhaps sunspots. Perhaps asteroids/comets on a near-sun trajectory.

In 1916, the General Theory of Relativity was put forth by Albert Einstein. E=MC. Energy and Mass are one and the same.

More precisely: The energy released by the sun causes a proven gravitational effect upon the orbit of Mercury.

My question, still unresolved, is:

When they took into account General Relativity with respect to these spacecraft, were they referring to time dilation effects, which makes sense given that they are dealing with a Doppler shift. Or, as wacky as it sounds, were they accounting for the gravitational effects of starlight?

Which also raises questions concerning "dark matter". Do scientists account for the gravitational effects of all the energy that has been radiated over the years?

After all, our piddling little sun puts out 3.86e26 Joules/second. E=MC&sup2 implies this is equivalent to 4.536e9 Kg/second. No offense, thats one heck of a lot of mass. Spread out over a very large spherical space. And the spacecraft is inside that sphere of energy, complicating the mathematics.

So: Anyone out there better with mathematics than I am want to take a crack at this? What effect does this sphere of radiated energy have upon the spacecraft? Complicating matters is that the energy in the vicinity of the spacecraft is proportional to the surface area of a sphere of radius r. The energy density increases as you go toward the sun, and decreases as you go away. Intuition makes it appear that there should be a small, but definite effect towards the sun.

What about the aliens who arranged the stars to look like a sea serpent, a bear, a hunter, or a virgin (obviously with a sense of humor -- it's amusing to conteplate the provocative pose she's taking).

They even signed (or at least initialed it. This is sometimes calle the coathanger cluster, but clearly it's a fancy letter "T").

Well, we could remove them with high-power lasers. This has already been proposed, and is quite feasible:

In-depth article on ORION space debris removal project
Photonics Spectra discussion of ORION project
ORION summary
ORION details
Military Discussion of LISK-BROOM
High power laser ablation conference

In a similar vain, this Zoom in to Europa is pretty cool. Europa is the satellite of Jupiter that may have have a liquid water ocean under its icy surface.

X-33 References

The Delta Clipper (DC-X) program which MD had proposed for NASA's X-33 effort competed with several other projects, including Lockheed's Venture Star. But the Clipper had a distinct advantage: a working prototype.

A collection of DC-X images

It's a shame Clinton, Gore, and NASA decided to go with the flash and dazzle promised by Lockheed instead of investing the time and energy in a simpler project that was much further along.

At least one asteroid does. But even so, Charon is awfully big for a moon. No other planet has a moon that's so large relative to it, and the two bodies are more or less in a position of orbiting each other. In any event, I don't see how any of this disqualifies Pluto from comet-hood.

... Yeah, but look at Io. Obviously Europa doesn't have that particular level of insane tidal forces, but there's probably enough to do something ...

That's true. Io is one weird place. But I seem to remember hearing that the four (or something) innermost moons of Jupiter are within its equivalent of our van Allen belts (the Jovian ones are HUGE because of its enormous magnetic field), peppering them with radiation enough to make them sterile if they had Earth-life on them. Perhaps some very hardy bacteria (like those that survive inside some nuclear reactors - talk about tough) could live there, but in my book this further lowers the chance of life ever forming on its own. But maybe the packice of Europa protects it from that - I don't know.

... I don't have enough info on Jupiter's moons' orbits to hazard a guess, though ...

Look here for more info on Jupiter and its moons. But Europa is VERY close to Jupiter - just 670000 km away according to the aforementioned website, just roughly four times the diameter of Jupiter. That'd put Luna at about 50000 km distance instead - talk about tidal waves! Besides, that would put the moon just inside the outer magnetosphere of Earth, giving Luna a good dose of radiation on its own.

Kinda reminds me of my first astronomy class. I hadn't even made it to my freshman year of high school and I had 4 credits of Astronomy from the local community college.

Many people have given good advice above. I'll mainly just second their comments. The order I'd proceed in is.

First item, a good beginners star atlas.

Second item, warm clothing.

Third item, many nights in the country just learning the stars and constelations.

After that go and get a good pair of binoculars or a good telescope.

Last, but not least. As your doughter is so young, you will need to be there as a source of infromation. You'll need to learn alot to help guide her in the early years.

Now for some Links. The first two have good beginners information. Some of the links below may be dead. I just quick cut and pasted them from the astronomy section of my Interesting Places page.

• Astronomy Mag. (www.astronomy.com/home.asp).
• Sky & Telescope Mag. (www.skypub.com).
• Minnesota Astronomical Society (MAS) (www.mnastro.org).
• The Telescope Shoppe (www.telescopeshop.com), 3402 Federal Dr., Eagan, MN, 651-688-7335. Yes this is a local Twin Cities telescope shop. They have a map on their site showing where they are. They are tucked in the lower level along the side of the strip mall they are in. The store is small and easy to miss. If your at the corner of Yankee Doodle RD and Federal Dr., park in the lot to the south east. They are a short stones throw from the intersection.
• Telescope making links
• • Many good links on making AltAz mounts (zebu.uoregon.edu/~mbartels/altaz/altaz.html).
  • ATM's resource List (www.freenet.tlh.fl.us/~blombard).
• Astronomy-Mall.com (www.astronomy-mall.com/Astronomy-Mall).
• Stellafane (www.stellafane.com).
• Terrestrial Planet Finder (tpf.jpl.nasa.gov).
• Many Images of the moon (www.seds.org/nineplanets/nineplanets/pxmoon.html) .
• Solar Views (www.solarviews.com).
• Planetary Image Atlas (www-pdsimage.JPL.NASA.GOV/PDS/public/Atlas).
• Hubble Space Telescope Archive (oposite.stsci.edu/pubinfo/pictures.html).
• Hummble Site (hubble.stsci.edu).
• StarStuff (www.starstuff.org).
• SpaceRef (www.spaceref.com), Your space refference.
• Astronomy Picture of the Day Archive (antwrp.gsfc.nasa.gov/apod/archivepix.html).
• SkyView (skyview.gsfc.nasa.gov) virtual observatory.
• 2MASS (www.ipac.caltech.edu/2mass/) and (pegasus.astro.umass.edu/GradProg/2mass.html) Two Micron All Sky Survey.
• Large Angle and Spectrometric Coronagraph Experiment (LASCO) (http://lasco-www.nrl.navy.mil/lasco.html).
• AAVSO Network to Search for Optical Counterparts of Gamma-Ray Bursts (www.aavso.org/grb.stm).
• High Altitude Observatory (www.hao.ucar.edu).
• Asteroid Comet Impact Hazards (impact.arc.nasa.gov).
• • Unusual Minor Planets (cfa-www.harvard.edu/iau/lists/Unusual.html).
  • Potentially Hazardous Asteroids (cfa-www.harvard.edu/iau/lists/PHACloseApp.html).& nbsp; Of particular interest to me are LB16 and AN10 which will pass at a distance closer than the moon's orbit. LB16 currently only has one opposition charted so it's predicted orbit will likely change as new data comes in. It's expected to swing by in 2004. In 2027 AN10 will visit earth. It's orbit is calculated with three oppositions meaning it't much more likely to really showup ontime and in place. With further data LB16 could either get closer or farther away. When AN10's orbit was first predicted (only one opposition at the time) it's error envelope included earth. With further data it was found to just pass within the moon's orbit and miss the earth.
  • Forthcoming Close Approaches To The Earth (cfa-www.harvard.edu/iau/lists/CloseApp.html).&nbs p; This is the document to look at when you want to know who will visit next and how far away. It has all close approaches to 0.2 AU away from earth or within 20% of the distance of between the sun and earth. On Sep 19th, 2000 we will have a visiter at 0.0477 AU and on Oct 31st anotehr one will pass at 0.07386 AU. LB16 and AN10 are expected to pass at around 0.25% of the distance between the sun and earth.
• Mars Global Surveyor (mars.jpl.nasa.gov/mgs/index.html).
• Mars Orbiter Laser Altimeter (MOLA) (ltpwww.gsfc.nasa.gov/tharsis/mola.html). There are full data on the shape of Mars including 1 degree and .5 degree elevation data sets.
• Planetary photojournal by JPL (photojournal.jpl.nasa.gov).
• NASA's Origins Program (origins.jpl.nasa.gov).

I'm not an astronomer, but if I recall correctly, most of the reasons scientists theorize the existence of a "Planet X" have to do with anomalies in the rest of the planetary orbits that aren't cleared up by factoring in the gravitational pulls of all the planets we know about. I think people knew that Pluto existed well before it was discovered because it was obvious something was affecting Neptune's orbit -- it was "just" a matter of finding it after that. However, Pluto proved not large enough to account for _all_ the irregularities in Neptune's orbit -- it didn't mass enough.

These anomalies disappeared when the Voyager spacecraft allowed astronomers to determine the mass of the outer planets more accurately. Planet X, the orbit disrupting gas giant that astronomers had searched for never existed. The following link tells the story of the search for Planet X:

http://www.seds.org/billa/tnp/hypo.html#planetx

Wow, that site is really cool. I remember going to it a long time ago, they certainly have kept it going.

Anyway, here's another great pic of 2 more galaxies collding.

And hell, I might as well borrow their html of the description:

Billions of years from now, only one of these two galaxies will remain. Until then, spiral galaxies NGC 2207 and IC 2163 will slowly pull each other apart, creating tides of matter, sheets of shocked gas, lanes of dark dust, bursts of star formation, and streams of cast-away stars. Astronomers predict that NGC 2207, the larger galaxy on the left, will eventually incorporate IC 2163, the smaller galaxy on the right. In the most recent encounter that peaked 40 million years ago, the smaller galaxy is swinging around counter-clockwise, and is now slightly behind the larger galaxy. The space between stars is so vast that when galaxies collide, the stars in them usually do not collide.

Check out http://www.seds.org/billa/tnp/mars.html& lt;/a> . No one is saying that there isn't water on Mars -- we know there is. This article is saying that the formations are not necessarily formed by liquid water. The northern polar cap has a layer of ice, the southern cap may have an ice layer, and there's a non-0 chance that there are aquifers under the surface.

Also, Neptune and Pluto are in a 3:2 resonance, which is another reason they won't collide.

http://www.seds.org/nin epl anets/nineplanets/plutodyn.html

And it's "bugger all" not "all bugger". :-&gt

What would have happened if the Tunguska event of 1908 had happened 2 hours later? Boom, in the middle of Moscow... Here's some statistics; whether they comfort you or scare you is all in how you look at things. There are probably about 1000 >1km asteroids that cross earth orbit. One of those hits us, on extreme average, every 300,000 years or so. You might be interested in reading this. Also, this place has a lot of good info and links about meteorites, impacts, and the like.

But you've gotta think... between airbursts and small impacts, we're bombarded pretty heavily already. All precautions allowed by our level of technology are being taken; if a meteorite hit us tomorrow, there's not a single damn thing we can do about it. Worrying about it is as pointless (even less so) than worrying about tripping over a sidewalk crack and breaking your neck. If you spend every spare minute thinking about it, yes, you'll be a paranoid wreck. So don't.

Of course, some people (Arthur C. Clarke among others) think it'll take a major impact in a populated area to unite the planet... The problem is it could happen tomorrow.. or 10,000 years from now. We just don't know. (of course, because I said that, and because today's Friday the 13th, I'll probably get hit by one on the way to work)

and look what happened to them!! There is also evidence that earth has been hit by cosmic debris (hehe ;) many times.

Am I the only one who gets the wrong idea when people talk about a PS/2?

I can't wait until the release of the new Dungeons and Dragons logic peripheral, the TSR-80!

Kevin Fox

So, for completness' sake:

• Mercury: 0
• Venus: 0
• Earth: 1
• Mars: 2
• Jupiter: 17
• Saturn: 18
• Uranus: 21
• Neptune: 8
• Pluto: 1

Also, I believe that all moons (except Luna) are named after Roman mythological figures, except those of Uranus, which are from more modern literature (Shakespeare and Pope). This is not a recent phenomena, the first discovered moon of Uranus was named in 1787 (by Herschel). So he's the visonary who bucked the trend. :-)

Not to be picky, here, but I believe that Saturn has more moons than Jupiter. Of course, the poster didn't say that, but I just wanted to be sure that nobody inferred incorrectly. :-)

[Thanks to Students of the Exploration and Development of Space (www.seds.org) for the reference. Check out for a list of all the named moons for both.]

Not to be picky, here, but I believe that Saturn has more moons than Jupiter. Of course, the poster didn't say that, but I just wanted to be sure that nobody inferred incorrectly. :-)

[Thanks to Students of the Exploration and Development of Space (www.seds.org) for the reference. Check out for a list of all the named moons for both.]

Not to be picky, here, but I believe that Saturn has more moons than Jupiter. Of course, the poster didn't say that, but I just wanted to be sure that nobody inferred incorrectly. :-)

[Thanks to Students of the Exploration and Development of Space (www.seds.org) for the reference. Check out for a list of all the named moons for both.]

In the interim we have managed to scrape together enough Pu-238 to meet NASA's needs by using the remaining stock from the cold war days and by purchasing it from Russia. Improvements in the efficiency of the RTG's have reduced the requirements for Pu-238. The recent Casini mission, however, required nearly 35 kg.

There are proposals on the table to produce Pu-238 in Department of Energy research and test reactors. Analysis has shown that they can produce up to 5 kg per year which NASA states is sufficient for future mission. Another alternative that is currently being considered it the restart of the Fast Flux Test Facility (FFTF) for isotope production, including Pu-238. DOE is expected to make a decision on FFTF in the near future. It's also possible to produce Pu-238 in commercial power reactors, but there is little support for this.

I sincerely hope that problems in procuring Pu-238 do not impact future NASA missions.

I had always thought it was an urban legend, but the Sea ttle Times and other sites briefly mention singer John Denver's attempt to do the same thing in the early 1990s. He was quite the space fan.

From SPACEVIEWS UPDATE, 1997:

• John Denver: Singer/songwriter John Denver, a longtime member of the National Space Society's Board of Governors, died in a light plane crash in California October 12. Although best known for his hit songs in the 1970s, he was a founding governing member of the National Space Institute in 1976, along with Isaac Asimov, Arthur C. Clarke, Bob Hope, Alan Shepard and others. He stayed on the board after the 1987 merger of the NSI with the L-5 Society, which created the National Space Society. "He personified the deep desire of many of our Society's members to someday travel in space," said Board of Governors chairman Hugh Downs. "We will miss his vision, his talent, his perseverance and his unique ability, through his words and music, to help others understand the fragility and beauty of this planet we call home."

As I recall, he asked NASA, who refused him. Not to be spurned, he then asked the Soviets in the same year, which didn't go over too well with American patriots. The jokes were talking about a real "Rocky Mountain High."

In reality there are many types of asteroids, grouped either by composition or surface spectra, or both. I quote from Bill Arnett's excellent The Nine Planets:

• C-type, includes more than 75% of known asteroids: extremely dark (albedo 0.03); similar to carbonaceous chondrite meteorites; approximately the same chemical composition as the Sun minus hydrogen, helium and other volatiles;
• S-type, 17%: (Stony) relatively bright (albedo .10-.22); metallic nickel-iron mixed with iron- and magnesium-silicates;
• M-type, most of the rest: (Metal) bright (albedo .10-.18); pure nickel-iron.
• There are also a dozen or so other rare types.

Admittedly, with launch costs as high as they are, it wouldn't matter if you could go to a type M asteroid and pick up sacks of minted gold coins. A reasonable payload wouldn't pay for launching the mission. That's where John Lewis' Mining the Sky comes in handy. Lewis has worked out how to return payloads that are entirely unreasonable by today's limited standards.

The first asteroid "gold strike" will probably be dirt. If you sent a robot probe out to the asteroid that has the cheapest return fuel cost. (It used to be Nereus, but I believe that an even cheaper one was discovered.) Have the robot scrape up some dust from the surface, bag it, then return to low Earth orbit. Sell the dirt to NASA as shielding for the space station. If the asteroid has enough metal in the dirt, extract it and charge extra for that. If the asteroid was a carbonaceous chondrite, roast the dirt in a solar oven and condense out the water and other volatiles released. Sell those seperately at a premium price. Sell the slag for radiation shielding.

Lewis claims that you could return from Nereus 20 to 50 kg of dirt for every kg you launch. That's not quite good enough to be profitable today, but with cheaper launchers....

Oh, and as everyone else has probably pointed out, we need to know what asteroids are made of in case we ever have to nudge one away from Earth. (Bruce Willis can go only if it is a one-way trip. 8-)
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There have been several hypothetical planets that did not turn out to be real, but none specifically between Earth and Mars. The term Planet X was used by Percival Lowell around a hundred years ago to refer to a specific mass beyond the orbit of Neptune that seemed to be causing its orbital inconsistencies. The search for Planet X took decades (really beginning in 1841), finally ending with the discovery of Pluto in 1930. To some extent, this search continues, with the discovery in the last decade of hundreds of so-called "Transneptunian" asteroids, representative of a great cloud of small rocks. While it's not impossible that there is still a large planet-sized body far out there, it's unlikely. There have been numerous non-scientific books and articles that have used terms like "Planet X" or "Planet Ten" to refer to other imagined planets, but these works aren't scientifically supported.
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You're absolutely right. I attended a seminar some years about this topic. The navy has researched this for sometime. He(3) is an isotope of Helium. Very rare. On earth is is produced during the natural decay of Plutonium. Very rare indeed.

If fused perfectly (assuming my memory holds) it releases heat + water + hydrogen.

What a great fuel for deep space travel. You get the energy from the fusion to propell your ship and as a byproduct water to drink and more fuel.

The talk I attended discussed mining it from the surface of the moon.
see this link . not sure if this is the same group but it is the same idea.

And again this link (gotta love google). This one discusses fusion with deutrium. The talk I saw was He3+He3.

Yeah...that probably IS the reason NASA doesn't want to crash Galileo on Europa...they fear retribution! I did a research paper on Europa not too long ago and I have some links about Europa if anyone is interested.

here
here
here
here
here
here
here
here
here
here
here
here
here
here
here
here
here
here
here
here
and here!
sorry if this drags on...some links may not be that great.

Hmm, a large, stable object already in Earth orbit.

Now where would we find something like that?

Too bad it'd be beyond our technology to get there.

Currently, there have been 33 missions to Mars from Earth, 8 of which have been mostly sucessful. Fully two thirds of the missions to mars have been 100% unsucessful, and most of those that have returned some useful data have failed at some point earlier than expected.

If you thought the navigation error (damn those English units...) that led to the demise of the Mars Climate Orbiter was embarrassing, just remember that the Viking landers 1 and 2 were both rendered useless far before the end of their operational lifetime when the Viking 1 lander, acting as a communication relay for the other lander, was mistakenly shut down.

I think the Smaller, Cheaper, Better paradigm is a commendable one, and deserves more of a chance. Why Mars seems to be such a difficult planet to get to deserves a closer inspection as well. Our success rate in every other space endeavor has been an order of magnitude higher, but it has nothing to do with NASA's attempts to make its new spacecraft more economical.

Check out the Nine Planets website... great for info about the solar system.

Here's the Pluto page.

The main problems with Pluto's status as a planet are:

• The mass is too small... only 1/6 as massive as Earth's moon. When originally discovered, Pluto was thought to be massive enough to exert a gravitational pull on Neptune, but now we know that's not the case. The discovery of Charon in 1978 helped pin down the combined mass of the Pluto-Charon system (basic astronomy... in a binary system, the orbital period is related to the sum of the masses).
• It's not unique... it turns out that there are hundreds, maybe thousands of Kuiper belt objects out there at roughly the same distance as Pluto, many in 3:2 resonance with Neptune's orbit (just like Pluto). The first of these was 1992 QB1 (as the name suggests, discovered in 1992).

So Pluto is just the biggest and brightest of a whole family of rock/ice "asteroids" out there beyond Neptune.

Perhaps calling Pluto a planet is just an accident of history, based on a wild over-guesstimate of its true mass. But why rock the boat? And after all, Pluto is a couple of orders of magnitude more massive than the biggest Mars-Jupiter asteroids (Ceres, Pallas, Vesta, etc).

PS, From the Nine Planets mass figures, Charon is 1/9 the mass of Pluto, not 2/3. But it's still pretty accurate to call Pluto-Charon a double planet.

Earth-Moon is really a double planet too (despite 1/80 mass ratio), if you go by visual appearance... the difference in radius is much smaller than the difference in mass (volume is proportional to radius cubed, and the Moon is less dense than Earth as well).

Check out the Nine Planets website... great for info about the solar system.

Here's the Pluto page.

The main problems with Pluto's status as a planet are:

• The mass is too small... only 1/6 as massive as Earth's moon. When originally discovered, Pluto was thought to be massive enough to exert a gravitational pull on Neptune, but now we know that's not the case. The discovery of Charon in 1978 helped pin down the combined mass of the Pluto-Charon system (basic astronomy... in a binary system, the orbital period is related to the sum of the masses).
• It's not unique... it turns out that there are hundreds, maybe thousands of Kuiper belt objects out there at roughly the same distance as Pluto, many in 3:2 resonance with Neptune's orbit (just like Pluto). The first of these was 1992 QB1 (as the name suggests, discovered in 1992).

So Pluto is just the biggest and brightest of a whole family of rock/ice "asteroids" out there beyond Neptune.

Perhaps calling Pluto a planet is just an accident of history, based on a wild over-guesstimate of its true mass. But why rock the boat? And after all, Pluto is a couple of orders of magnitude more massive than the biggest Mars-Jupiter asteroids (Ceres, Pallas, Vesta, etc).

PS, From the Nine Planets mass figures, Charon is 1/9 the mass of Pluto, not 2/3. But it's still pretty accurate to call Pluto-Charon a double planet.

Earth-Moon is really a double planet too (despite 1/80 mass ratio), if you go by visual appearance... the difference in radius is much smaller than the difference in mass (volume is proportional to radius cubed, and the Moon is less dense than Earth as well).

Check out the Nine Planets website... great for info about the solar system.

Here's the Pluto page.

The main problems with Pluto's status as a planet are:

• The mass is too small... only 1/6 as massive as Earth's moon. When originally discovered, Pluto was thought to be massive enough to exert a gravitational pull on Neptune, but now we know that's not the case. The discovery of Charon in 1978 helped pin down the combined mass of the Pluto-Charon system (basic astronomy... in a binary system, the orbital period is related to the sum of the masses).
• It's not unique... it turns out that there are hundreds, maybe thousands of Kuiper belt objects out there at roughly the same distance as Pluto, many in 3:2 resonance with Neptune's orbit (just like Pluto). The first of these was 1992 QB1 (as the name suggests, discovered in 1992).

So Pluto is just the biggest and brightest of a whole family of rock/ice "asteroids" out there beyond Neptune.

Perhaps calling Pluto a planet is just an accident of history, based on a wild over-guesstimate of its true mass. But why rock the boat? And after all, Pluto is a couple of orders of magnitude more massive than the biggest Mars-Jupiter asteroids (Ceres, Pallas, Vesta, etc).

PS, From the Nine Planets mass figures, Charon is 1/9 the mass of Pluto, not 2/3. But it's still pretty accurate to call Pluto-Charon a double planet.

Earth-Moon is really a double planet too (despite 1/80 mass ratio), if you go by visual appearance... the difference in radius is much smaller than the difference in mass (volume is proportional to radius cubed, and the Moon is less dense than Earth as well).

Imagine 1 trillion Bill Gateses standing in a circle (not a pretty picture, but play along for a moment). Now ask each one to convert his fortune into pennies and toss them in a collective pile.

OK, so I'm a math weirdo, but play along for a moment. If one trillion Bill Gateses were standing in a circle and threw all their pennies in, how tall would the pile of pennies be?

Actually, there wouldn't be a pile at all: the density would only be one penny per 2.5 square cm. Assuming three Gateses per linear meter. Evenly spread out, there's plenty of room to spare. 1*10^12 people -> (1/3)*10^12 m circumference -> 1.06*10^11 m diameter -> 2.5*10^21 m^2 area -> 2.5*10^13 cm^2 per Gates. Each Gates gets to throw his wealth of 1.06*10^13 pennies into a square 50 km on a side.

If all those Gateses were standing in a circle, light would take over five minutes to cross its diameter. The circle would be not quite the size of Mercury's orbit around the sun.

If each penny contained 1 trillion tiny computers and each computer had its own IP address, you'd still have used only a fraction of IPv6's potential space.

To be precise, about 2.9%.

But good luck rewriting the TCP protocol for your penny network -- its end-to-end space-time delay is ten minutes!

Jamie McCarthy