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It most certainly does. Check your facts.

> and why it wasn't placed in a geosync

Geosync is the most crowded orbital position we have. This is the last place you want to be if you are trying to avoid junk. Check your facts.

> or a higher circular orbit.

As it stands the shuttle is strained to the limit to get to the station. Infact Columbia (the heaviest of the four shuttles) can't reach the station where it is. Move it any higher, and you wouldn't be able to get to it. Check your facts.

Okay, most of the folks here seem to be bashing NASA and jumping to conclusions that the probe is lost. No damn way. They'll come up with a solution soon enough - for one thing, a similar incident occured with the Stardust probe earlier this year. Just take a look at the status reports.

Start at somewhere aroud May 4,2001 and go backwards (by that report, the problem had been fixed). I bet the glitch on Cassini will be fixed just as easily. Note that the problem occured just before christmas, so they probably just tried a "quick fix" to see if it just went away. Like said, they have until 2004(!) 'till Cassini is at its destination to try a number of things. They'll probably get rid of the contamination just by turning on the heaters for a couple of months, but they don't want to start the operation and immediately leave for a christmas vacation (in case something comes up).

Okay, most of the folks here seem to be bashing NASA and jumping to conclusions that the probe is lost. No damn way. They'll come up with a solution soon enough - for one thing, a similar incident occured with the Stardust probe earlier this year. Just take a look at the status reports.

Start at somewhere aroud May 4,2001 and go backwards (by that report, the problem had been fixed). I bet the glitch on Cassini will be fixed just as easily. Note that the problem occured just before christmas, so they probably just tried a "quick fix" to see if it just went away. Like said, they have until 2004(!) 'till Cassini is at its destination to try a number of things. They'll probably get rid of the contamination just by turning on the heaters for a couple of months, but they don't want to start the operation and immediately leave for a christmas vacation (in case something comes up).

There is a "management shakeup" occurring right now. Daniel Goldin, the longtime administrator of NASA, has retired (see what he's up to and his new computers at the L.A. Times Celebrity Setup).

Dr. Daniel Mulville is the current Acting Administrator while Sean O'Keefe is waiting for confirmation.

The BBC article refers to the "Stardust" project as though everyone knows about it...

Stardust project, which had a similar problem that was much worse. In that case, Stardust's team were able to completely remove the contamination

You can read more about that mission at http://stardust.jpl.nasa.gov.

What a name.

Worryingly, the origin of the contamination is unknown

here

Ozone only screens UV radiation, not heavy particles (protons etc.).
Take a look at The Solar Wind at Mars.

Other theories suggest that the absence of a Martian magnetosphere may explain the lack of water on Mars - without a shield from a planetary magnetic field, the solar wind would dissociate large amounts of water vapor in the atmosphere - raising the amount of free oxygen. The hydrogen would be lost into space, especially on a planet as small as Mars.

Mars Observer has found, firstly, evidence that a substantial (possibly planetary-scale) magnet field existed in geological time - in the form of fossilised magnetic fields, interestingly in stripes of alternating polarity, like on earth either side of crustal spreading zones such as the mid-Atlantic ridge, which implies a tectonic conveyor built was going for a while early in Martian history;

and secondly, regional mini-magnetospheres, big enough to have effects on the density of the atmosphere and (IIRC) weather patterns. (Haven't got an URL to hand, but it would have been somewhere on the JPL Global Surveyor site.

It'll be interesting to see what the regional distribution of this hydrogen looks like, once higher resolution data comes out. Er, in.

"the ice caps of Mars are believed to be frozen carbon dioxide"

No, the frozen caps are condsidered to be somewhat of a "slop" of dirt, CO2 ice (dry ice), and water ice. In addition, every summer, some of this water sublimes (we're below the triple point, for those chemists out there) and evaporates into the atmosphere. Mars isn't as completely dry as a lot of people think. The problem is that we haven't found water yet that is easily accessible. More can be found at

More can be found at the Mars Global Surveyor Homepage

So why don't they have news about this on the offical 2001 Mars Odyssey page?

http://mars.jpl.nasa.gov/odyssey/

>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... ;)

>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... ;)

Don't forget Io - there's plenty of internal heat there!

Io's surface is molten rock with continuous active volcanos. There is so much geological activity on Io, it's almost impossible to spot craters from foreign bodies. Io's too small to have stored the heat itself, it gets it from the tidal pull of Jupiter's gravity continuously deforming its shape.

Europa is the next closest moon after Io (about 150% the distance from Jupiter), and has liess mass (roughly 50%) - so it should have less tidal disruption. However, observations from Gallileo have shown that the surface of Europa is changing quite rapidly (APOD pic of Europa changing), so there is almost certainly some internal heat there. Europa is almost certainly the best candidate for life in our solar system.

One of the big reasons we're hearing more of this is that since the fossil bacteria mars meteor find there has been a lot more focus on Astrobiology. NASA Ames has a Astrobiology Academy that is sort of a Space Camp for the 18 to 25 year old crowd that grew up wanting to go to Space Camp (that's us).
There are also a lot of Collegiate program's like Penn State's and some new peer reviewed astrobiology journals.
Sort of a case of we find what we look for. Makes you wonder what the SETI people could do with more funding.

Here is the same in English from NASA

NASA has a great article about Geminid meteors. The number of meteors has increased greatly since first they first appeared in the mid-1800's. NASA also provides a video taken from a man in CA, December 13, 1998.

NASA has a great article about Geminid meteors. The number of meteors has increased greatly since first they first appeared in the mid-1800's. NASA also provides a video taken from a man in CA, December 13, 1998.

NASA has a great article about Geminid meteors. The number of meteors has increased greatly since first they first appeared in the mid-1800's. NASA also provides a video taken from a man in CA, December 13, 1998.

I thought this might be an appropriate place to say that the compostion of the martian atmosphere is (from NASA):

CO2: 95.3% (Earth= 0.03%)

N2: 2.7% (Earth= 78%)

Ar: 1.6% (Earth= 1%)

O2: 0.13% (Earth= 21%)

I would actually be most concerned about the amount of nitrogen. I think that plants generaly need some nitrogen, which they generally get from the air (martian soil isn't very nitrogen rich, either), and, considering that the surface pressure of Mars is 6 milibars (1/200 the surface pressure of Earth), I don't think that there would be an adequate amount of nitrogen in the atmosphere.
Also, there is the issue of whether organic matter is viable on Mars at all. Mars doesn't have the protection from UV radiation that Earth does. On Mars, water molecules are cleaved by the radiation which produces radicals, which would either react directly with organic molecules, or produce hydrogen peroxide, which isn't too friendly, either.

More information can be found here: Basics of Spaceflight Section I

BY YOUR COMMAND,
Anonymous Coward

Here are some "cool" animations where you can see the ice caps melting. Also, here's a JPL press release which is a little more level headed than the news coverage.

This graph from this report shows a striking correlation between the length of solar cycles and mean temperature over the last hundred years (interesting that the length of the cycle should give the best correlation - the authors suggest the shorter solar cycles correspond to higher solar output).

Also, there is considerable historical evidence that the current change in climate is really pretty small beer compared to what has happened in the past:

"The Norwegian farmer Folke Vilgerdson made the first attempt to settle in Iceland in about 865 AD... He lost his cattle in a severe winter and disappointed went back to Norway after having seen a fjord filled up by sea ice. Therefore he called the country Iceland. Only a few years later, in 874, Ingolf Arnason succeeded. He was followed by many others, and settlement was completed in 930 AD... In 982, Erik the Red discovered new land West of Iceland. He called it Greenland; according to the Greenlander Saga this was only to persuade people to follow him... But the O(18) curve suggests that the name described a reality... So the drastic climatic change [warming] late in the ninth century may be part of the reason why Iceland and Greenland did not get the opposite names." (Dansgaard: Palaeo-Climatic Studies on Ice Cores, in Oeschger, Messerli and Svilar, 1980).

Here is another account, also suggesting that Greenland had a suprisingly comfortable climate at the time.

1997-98 EL NIÑO EVENT INCREASED LIGHTNING ACTIVITY

"The 1997-98 El Niño Event and Related Wintertime Lightning Variations in the Southeastern United States" was selected as one of the "Highlight" articles appearing in the February 15 issue of Geophysical Research Letters. The paper describes the increase in lightning activity in the northern Gulf of Mexico Basin in response to the 1997-98 El Niño event. The authors use two data sets to obtain this information. One data set was a 10-year (1989-99) database of U.S. cloud-to-ground lightning activity. The NASA Lightning Imaging Sensor on the Tropical Rainfall Measuring Mission (TRMM) Observatory was also used. The LIS gives the total (in-cloud and cloud-to-ground) lightning activity data recorded from space. Results showed that during 1997-8 a 100-150% increase in lightning days year-to-year and a nearly 200% increase in lightning hours (compared to 1996-7 and 1998-9) in the basin. They attribute these changes to an enhanced synoptic-scale forcing associated with ENSO and a stronger than normal upper-level jet stream. They also find good agreement between most of the recent warm ENSO events and cyclogenesis within the basin.

Cyclogenesis: Process of initiation or intensification of a cyclonic circulation in the atmosphere (source)

ENSO event: ENSO is the term currently used by scientists to describe the full range of the Southern Oscillation that includes both SST increases (a warming) as well as SST decreases (a cooling) when compared to a long-term average. (source)

http://liftoff.msfc.nasa.gov/temp/StationLoc.html
works fine on Netscape under Tru64 UNIX as well as Linux!

It is true that everything is moving away from everything else on a large scale (and ignoring the peculiar motion caused by local gravity, like that between Andromeda and teh Mikly Way).

My biggest problem with modern science (physics and astrophysics in particular) is this truly inane method of making "conjectural" observations

No, your biggest problem is reading about modern science on Slashdot. C'mon, people! Jeez, I understand when Terri Gross screws up her science interviews, but we ought to be able to do better. These commments (even the highly rated ones) are the worst description of cosmology I've seen in a long time. Bleah.

Okay, so let's start with this one.

Doesn't it make a LOT more sense to think that dark matter is just the stuff floating around that doesn't have any light bouncing off of it?

That's one possibility. In fact, that is exactly the MACHO (Massive Compact Halo Objects) hypothesis. Okay, quick primer on dark matter: First, there are two kinds of dark matter:

• The stuff that must be in galaxies to explain their rotation curves
  
• The stuff that would have to be there to make the universe flat
  

The first kind really has to be there, because we can measure its gravitational effect directly. But it ain't stars (we can see them), and it ain't dust or gas, because we can "see" that when we look through it. So that leaves large agglomerations of regular matter (MACHOS) or weakly interacting massive particles (WIMPS). WIMPS could be massive neutrinos, but the best estimate for neutrino mass probably isn't enough to account for it. And yes, the term MACHOS was chosen in response to the term WIMPS.

As for the second kind, the only "evidence" for that has until recently been theoretical. If the inflationary hypothesis is correct, the chances of the universe being as flat as we see it but not exactly flat are very very small. That of course is pretty limited evidence.

However, recent measurements of several separate parameters are starting to converge on a cohesive picture. The universe is flat, but has a term (referred to as "Dark Energy", "cosmological constant", or sometimes "quintessence") which accounts for about a third of the energy of the universe and will cause it to expand forever.

Here are some useful URLs:

• Cosmological constant
  
• Cosmology primer
  
• Ned Wright's Cosmology Tutorial
  

Hope that clears up some of the confusion.

My biggest problem with modern science (physics and astrophysics in particular) is this truly inane method of making "conjectural" observations

No, your biggest problem is reading about modern science on Slashdot. C'mon, people! Jeez, I understand when Terri Gross screws up her science interviews, but we ought to be able to do better. These commments (even the highly rated ones) are the worst description of cosmology I've seen in a long time. Bleah.

Okay, so let's start with this one.

Doesn't it make a LOT more sense to think that dark matter is just the stuff floating around that doesn't have any light bouncing off of it?

That's one possibility. In fact, that is exactly the MACHO (Massive Compact Halo Objects) hypothesis. Okay, quick primer on dark matter: First, there are two kinds of dark matter:

• The stuff that must be in galaxies to explain their rotation curves
  
• The stuff that would have to be there to make the universe flat
  

The first kind really has to be there, because we can measure its gravitational effect directly. But it ain't stars (we can see them), and it ain't dust or gas, because we can "see" that when we look through it. So that leaves large agglomerations of regular matter (MACHOS) or weakly interacting massive particles (WIMPS). WIMPS could be massive neutrinos, but the best estimate for neutrino mass probably isn't enough to account for it. And yes, the term MACHOS was chosen in response to the term WIMPS.

As for the second kind, the only "evidence" for that has until recently been theoretical. If the inflationary hypothesis is correct, the chances of the universe being as flat as we see it but not exactly flat are very very small. That of course is pretty limited evidence.

However, recent measurements of several separate parameters are starting to converge on a cohesive picture. The universe is flat, but has a term (referred to as "Dark Energy", "cosmological constant", or sometimes "quintessence") which accounts for about a third of the energy of the universe and will cause it to expand forever.

Here are some useful URLs:

• Cosmological constant
  
• Cosmology primer
  
• Ned Wright's Cosmology Tutorial
  

Hope that clears up some of the confusion.

Nonetheless, amateur built CCD's can do pretty amazing things - they can go deeper with a with a couple of minutes of exposure time then the 200-inch Hale Telescope could using film in 1970. Here's a good example, look at these images of extremely faint Globular clusters taken with a homemade telescope and CCD camera.

Some of these objects weren't recorded on the Palomar Sky Survey!

Understand, ground based telescopes aren't a replacement for space based telescopes, if not just because of the bandwidth issues ground based scopes face. Nonetheless, ground based professionals and amateurs are recording data that was believed to have been the sole terrority of space based telescopes when HST was designed, built and launched.

NASA's smart by building NGST to primarly work in the IR ranges.

Oh, BTW, Jupiter and the moon are easier to image then Saturn because they are brighter and larger... :-)

I hope it's got a towel!

We miss you Douglas.

Check out the mission summary.

Here it is, in full:
UF-1
Launch Date: Dec. 5, 2001
Launch Vehicle: U.S. Space Shuttle Endeavour: STS-108
Elements: Multi-Purpose Logistics Module (MPLM), Photovoltaic Module batteries

1. Provides for research work by delivering experiment racks for the U.S. Laboratory and two storage racks.

Glad to know that NASA is spending their $600M well on this shuttle launch instead of sending three probes to Mars, something to Pluto, or researching a new technology.

Seriously, can't this stuff be delivered on unmanned craft? (Well, obviously not the new crew, but they could catch a Russian Soyuz for a quarter of the cost)

The experiments include: STARSHINE-2, the Prototype Synchrotron Radiation Detector, Collisions Into Dust Experiment-2, Capillary Pump Loop, and Space Experiment Module-11.

STARSHINE 2 will be the third satellite of Project Starshine -- the Student Tracked Atmospheric Research Satellite for Heuristic International Networking Experiment -- to be deployed. More than 25,000 students from 26 countries will track STARSHINE 2 as it orbits Earth for eight months. The students will use the information that they collect to calculate the density of the Earth's upper atmosphere. Starshine will fly into space in a Hitchhiker canister in the payload bay of Endeavour and will be deployed 240 miles (387 kilometers) above the Earth.

I invite you to check for ISS/shuttle sightings on the nasa website. Also Heavens above might be updated with the shuttle orbital information within the next few hours.

For example, I see there will be a nice pass almost straight above San Francisco, Thr Dec 06, 05:26 PM for ISS, and 11 minutes later (05:37 PM) the shuttle catching up with it! So I suspect similar opportunies for other US cities in the coming days, weather permitting of course.

Don't expect to see more than a moving point of light, but it is still quite cool.

Please don't believe that we'll be able to do away with space-based observing because of this innovation. Our atmosphere absorbs an awful lot of interesting wavelengths.

Actually there were 2 congressmen that were space tourists before Glenn:

Senator Jake Garn on STS-51D

Bill Nelson on STS-61C

This is from some previous /. comments: 1 2 3

Actually there were 2 congressmen that were space tourists before Glenn:

Senator Jake Garn on STS-51D

Bill Nelson on STS-61C

This is from some previous /. comments: 1 2 3

Actually there were 2 congressmen that were space tourists before Glenn:

Senator Jake Garn on STS-51D

Bill Nelson on STS-61C

This is from some previous /. comments: 1 2 3

As I recall Andromeda is supposed to collide with us in 200 million years, give or take a couple million. Because the outer regions of galaxies are rather sparse I suspect other than the light show in the sky we (or whatever might be looking up at the sky 200 million years from now) will probably be relatively unaffected.

Re: super-telescopes, I cannot wait for the NASA Origins programs' second and third generation telescopes, the planet finders. The goal by 2020 is to put high-power optical interferometers in space, so we can not only infer the presence of planets, but image them.

As I recall Andromeda is supposed to collide with us in 200 million years, give or take a couple million. Because the outer regions of galaxies are rather sparse I suspect other than the light show in the sky we (or whatever might be looking up at the sky 200 million years from now) will probably be relatively unaffected.

Re: super-telescopes, I cannot wait for the NASA Origins programs' second and third generation telescopes, the planet finders. The goal by 2020 is to put high-power optical interferometers in space, so we can not only infer the presence of planets, but image them.

IANAA, but I have a few comments neverthe less :)

First of all, visible light just isn't the best spectrum to do astronomy in for a lot of things, especially not the detection of extrasolar planets. Infrared radiation, unhindered by most space dust, and lower in energy, is clearly superior for studying things that are not giant balls of gas. The Next Generation Space Telescope and the Terrestrial Planet Finder both use infrared radiation to study objects of great interest that are difficult to study with something like the HST.

Interferometry, the technology you refer to that allows telescopes to combine their phase information to generate an image with angular resolution of that of a single larger telescope (through something known as apature synthesis) is only one of the many uses of intereferometry. Perhaps much more exciting than that is the ability of the Terrestrial Planet Finder to use nulling interferometry to selectively block out the radiation from a star, without blocking out the much fainter (millions of times less) glow of a circling planet.

Unfortunately the earth's atmosphere is mostly opaque to infra-red light, and room temperature objects (like most of the surface of the earth, and the telescopes on it) generate so much infra-red radiation that it makes it nearly impossible to do any far-infrared studies from the ground. The Darwin Project web site has a good explaination about the reasons terrestrial planet hunting should be done in space.

Ground based observatories will always have a place, however eventually it will be a matter of cost and convenience rather than any technical superiority.

Not saying this isn't cool, but it's mostly postponing the inevitable day when very little new astronomy can be done inside the confines of an atmosphere....

IANAA, but I have a few comments neverthe less :)

First of all, visible light just isn't the best spectrum to do astronomy in for a lot of things, especially not the detection of extrasolar planets. Infrared radiation, unhindered by most space dust, and lower in energy, is clearly superior for studying things that are not giant balls of gas. The Next Generation Space Telescope and the Terrestrial Planet Finder both use infrared radiation to study objects of great interest that are difficult to study with something like the HST.

Interferometry, the technology you refer to that allows telescopes to combine their phase information to generate an image with angular resolution of that of a single larger telescope (through something known as apature synthesis) is only one of the many uses of intereferometry. Perhaps much more exciting than that is the ability of the Terrestrial Planet Finder to use nulling interferometry to selectively block out the radiation from a star, without blocking out the much fainter (millions of times less) glow of a circling planet.

Unfortunately the earth's atmosphere is mostly opaque to infra-red light, and room temperature objects (like most of the surface of the earth, and the telescopes on it) generate so much infra-red radiation that it makes it nearly impossible to do any far-infrared studies from the ground. The Darwin Project web site has a good explaination about the reasons terrestrial planet hunting should be done in space.

Ground based observatories will always have a place, however eventually it will be a matter of cost and convenience rather than any technical superiority.

Not saying this isn't cool, but it's mostly postponing the inevitable day when very little new astronomy can be done inside the confines of an atmosphere....

Bwahahaha! Someone please moderate this +1, Funny, or -1, Troll. Or maybe IHBT IWHAND IHL

Thanks a lot, now I have to go figure out the conversion...
Visit http://www.athena.ivv.nasa.gov/curric/weather/fahr cels.html to see for yourself.

But you already are. It's called the hydrologic cycle. Sure there are a few bugs to work out, but its extremely stable!

The reason other spacecraft could not track Venus before is that Venus is so close (angularly) to the Sun (the angular seperation never exceeds 48 degrees). Most telescopes are not designed to withstand that kind of brightness or radiation.

Excerpt from http://chandra.harvard.edu/about/spacecraft.html:
The sunshade door is one of the most basic and important elements of the spacecraft system. This sunshade door remained closed until Chandra achieved pointing control in orbit. Now that it is opened, it shadows the entrance of the telescope to allow it to point as close as 45 degrees to the sun.

Looks like a safety margin of three degrees! Also, when you point a spacecraft at or nearly at the sun, you may be heating the spacecraft in places it was not designed for. This can be especially bad for some optics, especially if they are thermally controlled.

Other spacecraft, like SOHO are designed to point at the sun.

Disclaimer: I work on SOHO

Actually, most of the data used by astronomers is publicly available. Try the following:

HST data archive: every HST image. Also has other mission data.

Astronomical Data Center: archive of data tables published in peer-review astronomy journals

NASA/IPAC Extragalactic Database: index of known data for other galaxies. You can get redshifts here, for example.

The software used by astronomers is also generally publicly available. For example, Debian Linux ships with IRAF, the image reduction software that most of us use (the ones who can't afford IDL anyway).