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I had an interesting experience just this morning. I have been a firm believer in a few things:

• Proprietary UNIX operating environments like Solaris and AIX are, in all aspects, the best platform for back office services ... i.e. data warehousing, CRM, etc.
• Linux based operating environments are the best platform for front tier platforms like web servers, app servers, file & print, etc. (especially using SAMBA, RH puts Win2K to shame!)
• Windows, especially Win2K (XP isn't worth the $$$ to upgrade) is the best choice for the typical office user and home user.

So, I downloaded RH 7.3 iso's from NASA (blazing download speeds, over 1.7 Mbps) and burned the install CD's. I then popped CD #1 in my laptop and rebooted. In less than 1 hour my laptop was a functional dual-boot machine. I let RedHat make all the install decisions, rather than customizing like I would do on a server. I allowed GRUB to be my boot loader. It boots both Win2K and RH beautifully, no issues. RH runs great AND I didn't have to download one single driver to get my system to work with Linux. Win2K doesn't include support for my 2 year old network card, so I have to have that driver downloaded before attempting a Win2K install on this laptop, no such problem with RH.

I'm a believer now. RH 7.3 is definitely ready for the average end user's PC. The installation is no more difficult than Windows, if you set it to boot to graphical logon mode life is easy. And once in Gnome (or KDE) all the tools that a typical end user might want are there. With about the same amount of effort that it takes to install Office XP that same user can download, install and use Open Office (that took me about 30 minutes).

Best of all, I didn't have to use knowledge gained in 10 years of implementing and administering UNIX servers. It was pretty damn easy. To get the same easy installation with Win2K on a laptop I need to get the OEM version of Win2K appropriate to my laptop OR I can just get the generic RH distro. No issues, no worries, no compatibility problems.

Bottom line, MS OS is no longer superior in the consumer market based on what I just saw, and the Linux price is hard to beat. For the user who doesn't want to deal with creating their own CD's they can pick up the boxed set of RH for a low price down at Best Buy. Within an hour they can have a functioning system that is equal to Windows. The only thing keeping it from going mainstream is games. Come on game developers. Get those games running on Linux and MS is in big trouble.

There is no way in hell that anybody could anything significant with 40ft or less. I'm not a pilot or even terribly proficient with physics, but I don't imagine it would take much to demonstrate that the output necessary to provide enough airflow over 40ft of even the most promising surface to attain sufficient lift would be beyond human ability, even if three 80lb Armstrongs were behind the yoke. And I'm assuming this is a vertical limit as well as a horizontal one, so that rules out things like balloon assist.

Some examples of the state of HPV flight include:

Velair
Daedelus
Musculair
Light Eagle
Sakuzo

40ft. Give me a break. Literally.

Would the same thing help jets fly faster/quieter? The way I see it is that if the jet moves through the air easier, less kinetic energy is wasted making a sonic boom.

And now, for your viewing pleasure... some really cool images! (that last one's a big + slow, but worth it)

Ali

Would the same thing help jets fly faster/quieter? The way I see it is that if the jet moves through the air easier, less kinetic energy is wasted making a sonic boom.

And now, for your viewing pleasure... some really cool images! (that last one's a big + slow, but worth it)

Ali

Make sure to check out the details of the EJ-22 turbofan. It contains technology which will forever change the face of civilian (and military) aviation.

Among its innovations, this engine uses foil air bearings with PS-304 high-temperature lubricant developed by NASA.

It's two years old, but here is a really nice composite of world light polution, and a "brief explanation written by a professional astronomer."

according to NASA the mean torque strength for their astronauts is 13.73 Nm. That would be comparable to the 1.5Nm that this robotic hand can do. i think.

NASA has pressure-time graphs of dust devils as well as their patterns on their website.
Interesting findings from the Mars Pathfinder are also shown and detailed there.

Since we're talking figures, I did some quick digging to compare to NASA. NASA's FY2000 budget was $13,578.4 million, which was about 2 times the ESA EUR7,066M budget for the same year. After some quick math, France and Germany contributed EUR1,862.5M and EUR1,726.3M (26.4% and 24.4%) respectively of the total ESA budget. This makes their total space spending about 14% and 13% respectively of US spending. These calculations were made without first converting the FY2000 EUR7,066M ESA budget to dollars (or vice versa), assuming a very rough 1:1 equivalence, so actual figures will be off a bit.

Gomez's Hamburger is featured today (August 7, 2002). I check this site out daily; they frequently post some really tasty pics. http://antwrp.gsfc.nasa.gov/apod/astropix.html

If any of you had read the explanation on the excellent APOD site, you'd have seen that this thing had already been found in 1985 by Arturo Gomez. This is hust a new Hubble picture of it.

Check it out on APOD

That's not the least bit interesting, and you know it.

You can't dismiss the fact that people are vain. Expensive luxury items start paying you back immediately in terms of self-satisfaction and social status, whereas the solar panels are out of sight for the most part, and won't payback anything for 10-20yrs; and for the trouble of going solar you'll still get most people rolling their eyes at you.

As much as I'd like it to be, solar just isn't that cost-effective... especially in the face of other power generation that isn't taxed for the pollution that we'll all end up paying for anyway.

(My bet for our future of clean renewable energy is the combination of Solar Power Stations with a hyrdogen economy.)

--

The following excerpt is from Gibson, E.K. Jr., McKay, D.S., et al. Life on Mars: evaluation of the evidence within Martian meteorites ALH84001, Nakhla, and Shergotty", Precambrian Research 106:15-34.

The lines of evidence which indicate possible biogenic activity in the martian meteorite ALH84001 (McKay et al., 1996) are: (1) the presence of carbonate globules which had been formed at temperatures favorable for life, (2) the presence of biomenerals (magnetites and sulfides) with characteristics nearly identical to those formed by certain bacteria, (3) the presence of indigenous reduced carbon within Martian materials, and (4) the presence in the carbonate globules of features similar in morphography to biological structures. Each of these phenomena could be interpreted as having biogenic origins but the unique spatial relationships indicated that, collectively, they recorded evidence of past biogenic activity within the meteorite.

See also NASA's astrobiology news page and my earlier comment.

The following excerpt is from Gibson, E.K. Jr., McKay, D.S., et al. Life on Mars: evaluation of the evidence within Martian meteorites ALH84001, Nakhla, and Shergotty", Precambrian Research 106:15-34.

The lines of evidence which indicate possible biogenic activity in the martian meteorite ALH84001 (McKay et al., 1996) are: (1) the presence of carbonate globules which had been formed at temperatures favorable for life, (2) the presence of biomenerals (magnetites and sulfides) with characteristics nearly identical to those formed by certain bacteria, (3) the presence of indigenous reduced carbon within Martian materials, and (4) the presence in the carbonate globules of features similar in morphography to biological structures. Each of these phenomena could be interpreted as having biogenic origins but the unique spatial relationships indicated that, collectively, they recorded evidence of past biogenic activity within the meteorite.

See also NASA's astrobiology news page and my earlier comment.

SPIE-The International Society for Optical Engineering captured the bulk of Dr. Hoover's presentation in an interview published in their December '96 magazine. This September 1998 article offers pictures of the fossils found, as does a July 1997 article. Another story announces a fossil find in another meteorite that fell on Murchison, Victoria, Australia.

Many people question the science, but it would seem people should question the scientific community which has held its hands over its eyes when faced with the prospect of life on other planets. The community is just now peeking between its fingers and beginning to accept that there might be life elsewhere. In the presentation I attended, Dr. Hoover noted that NASA set up rules in advance of the Viking missions - that any one of the several (4?) tests coming back positive would be indicative of life on the red planet, but once some of the tests came back positive, they decided that all of the tests had to be positive to confirm the existence of life on Mars. Such has been the distinctly non-scientific approach of the community when confronted with the distinct possibility of life on other planets.

More links:

• Evidence of Biomarkers and Microfossils in Ancient Rocks and Meteorites abstract.
• A collection of NASA (and other) news releases pertaining to evidence of extraterrestrial life.

SPIE-The International Society for Optical Engineering captured the bulk of Dr. Hoover's presentation in an interview published in their December '96 magazine. This September 1998 article offers pictures of the fossils found, as does a July 1997 article. Another story announces a fossil find in another meteorite that fell on Murchison, Victoria, Australia.

Many people question the science, but it would seem people should question the scientific community which has held its hands over its eyes when faced with the prospect of life on other planets. The community is just now peeking between its fingers and beginning to accept that there might be life elsewhere. In the presentation I attended, Dr. Hoover noted that NASA set up rules in advance of the Viking missions - that any one of the several (4?) tests coming back positive would be indicative of life on the red planet, but once some of the tests came back positive, they decided that all of the tests had to be positive to confirm the existence of life on Mars. Such has been the distinctly non-scientific approach of the community when confronted with the distinct possibility of life on other planets.

More links:

• Evidence of Biomarkers and Microfossils in Ancient Rocks and Meteorites abstract.
• A collection of NASA (and other) news releases pertaining to evidence of extraterrestrial life.

SPIE-The International Society for Optical Engineering captured the bulk of Dr. Hoover's presentation in an interview published in their December '96 magazine. This September 1998 article offers pictures of the fossils found, as does a July 1997 article. Another story announces a fossil find in another meteorite that fell on Murchison, Victoria, Australia.

Many people question the science, but it would seem people should question the scientific community which has held its hands over its eyes when faced with the prospect of life on other planets. The community is just now peeking between its fingers and beginning to accept that there might be life elsewhere. In the presentation I attended, Dr. Hoover noted that NASA set up rules in advance of the Viking missions - that any one of the several (4?) tests coming back positive would be indicative of life on the red planet, but once some of the tests came back positive, they decided that all of the tests had to be positive to confirm the existence of life on Mars. Such has been the distinctly non-scientific approach of the community when confronted with the distinct possibility of life on other planets.

More links:

• Evidence of Biomarkers and Microfossils in Ancient Rocks and Meteorites abstract.
• A collection of NASA (and other) news releases pertaining to evidence of extraterrestrial life.

In the press release we read " new evidence confirming that 25 percent of the magnetic material in the meteorite was produced by ancient bacteria on Mars. ... This means that one-quarter of the magnetite crystals ... in Martian meteorite ALH84001 require the intervention of biology to explain their presence. "

The words "confirm" and "require" are very strong, indeed.

However, in the abstract of the scientific report we read something quite different: " On Earth such ... magnetites are known to be produced by magnetotactic bacteria. We suggest that the observation ... are [sic] both consistent with, and in the absence of terrestrial inorganic analogs, likely formed by biogenic processes."

So, the scientists suggest that something is consistent with a proposition, and the press-releasers convert that into confirmation of the proposition.

Sure, scientists' language often needs to be modified for public consumption, but here we have a case of changing the entire thrust of the story.

This sort of mistake would be unacceptable from a high-school science student, and that makes me wonder whether this exaggerating rewriting might have been deliberate. I remember a story of crying "wolf" ...

In the press release we read " new evidence confirming that 25 percent of the magnetic material in the meteorite was produced by ancient bacteria on Mars. ... This means that one-quarter of the magnetite crystals ... in Martian meteorite ALH84001 require the intervention of biology to explain their presence. "

The words "confirm" and "require" are very strong, indeed.

However, in the abstract of the scientific report we read something quite different: " On Earth such ... magnetites are known to be produced by magnetotactic bacteria. We suggest that the observation ... are [sic] both consistent with, and in the absence of terrestrial inorganic analogs, likely formed by biogenic processes."

So, the scientists suggest that something is consistent with a proposition, and the press-releasers convert that into confirmation of the proposition.

Sure, scientists' language often needs to be modified for public consumption, but here we have a case of changing the entire thrust of the story.

This sort of mistake would be unacceptable from a high-school science student, and that makes me wonder whether this exaggerating rewriting might have been deliberate. I remember a story of crying "wolf" ...

• Satellites Reveal a Mystery of Large Change in Earth's Gravity
  Satellite data since 1998 indicates the bulge in the Earth's gravity field at the equator is growing, and scientists think that the ocean may hold the answer to the mystery of how the changes in the trend of Earth's gravity are occurring.

and don't forget to check out the Natural Hazards

• Satellites Reveal a Mystery of Large Change in Earth's Gravity
  Satellite data since 1998 indicates the bulge in the Earth's gravity field at the equator is growing, and scientists think that the ocean may hold the answer to the mystery of how the changes in the trend of Earth's gravity are occurring.

and don't forget to check out the Natural Hazards

• Satellites Reveal a Mystery of Large Change in Earth's Gravity
  Satellite data since 1998 indicates the bulge in the Earth's gravity field at the equator is growing, and scientists think that the ocean may hold the answer to the mystery of how the changes in the trend of Earth's gravity are occurring.

and don't forget to check out the Natural Hazards

Regarding jet engines: got a link? Regarding scramjets: so you mean this technology they've spent billions of dollars on is further along than the one that got virtually no funding at all? What a surprise.

Terrier-Orion sounding rockets (from surplus military stocks) can be obtained on a university budget

Can you get to orbit in them?

The dev costs on scramjets are easily in the billions

And, what, orbital rockets were developed in someone's backyard on a shoestring budget? They spent billions on them, too.

Finally, who cares how much is tanking. Fuel costs are negligable compared to the rest.

What we're interested in here is mass. To get to orbit, a rocket has to take thousands of tons of oxidizer along with it. A scramjet could leave most of it behind.

(hint: they weren't. Scramjets will be subject to the same guidance problems).

What, you mean the guidance problem of having all your thrust at the very bottom of the vehicle, which is basically a requirement for rockets?

As was pointed out != as has been proven. Please point me to your real-world proofs or stop presenting "I hope" as "It has been proven".

Oh, I do apologize. Shuttle engines specific impulse in a vacuum of 452. And let's see, here's an experimental air-breathing jet engine with a specific impulse in the atmosphere of around 2000. Or this one, from NASA themselves. In particular note the specific impulse of ion engines at 20000 which, if I'm not mistaken is higher than 400. Also it specifically states, "The chemical rocket engine is a fairly lightweight device. However, the specific impulse is not high. Solid and liquid propellants in present use deliver an impulse of around 250 seconds. The best liquid propellants so far conceived and evaluated yield an impulse of about 350 seconds." And of, course, there's this one, also at NASA, stating that Scramjets' specific impulse varies over the Mach range from 1000 to 1500. Want more?

Before stating that scramjets can accelerate to mach25 in the atmosphere you are going to have to solve the materiels problem

Gee, I seem to recall saying that very same thing. How kind of you to tell me what I already knew and act like you are all-knowing in the process.

scramjets by definition cannot [throttle back]

Eh? They have to accelerate constantly the whole time? Can't slow down, can't cruise, can't do anything except go faster? Do explain to me where you learned this.

Until then, kindly refrain from proposing theoretical yet unachievable limits.

You're the one proposing limits pal, not me.

Regarding jet engines: got a link? Regarding scramjets: so you mean this technology they've spent billions of dollars on is further along than the one that got virtually no funding at all? What a surprise.

Terrier-Orion sounding rockets (from surplus military stocks) can be obtained on a university budget

Can you get to orbit in them?

The dev costs on scramjets are easily in the billions

And, what, orbital rockets were developed in someone's backyard on a shoestring budget? They spent billions on them, too.

Finally, who cares how much is tanking. Fuel costs are negligable compared to the rest.

What we're interested in here is mass. To get to orbit, a rocket has to take thousands of tons of oxidizer along with it. A scramjet could leave most of it behind.

(hint: they weren't. Scramjets will be subject to the same guidance problems).

What, you mean the guidance problem of having all your thrust at the very bottom of the vehicle, which is basically a requirement for rockets?

As was pointed out != as has been proven. Please point me to your real-world proofs or stop presenting "I hope" as "It has been proven".

Oh, I do apologize. Shuttle engines specific impulse in a vacuum of 452. And let's see, here's an experimental air-breathing jet engine with a specific impulse in the atmosphere of around 2000. Or this one, from NASA themselves. In particular note the specific impulse of ion engines at 20000 which, if I'm not mistaken is higher than 400. Also it specifically states, "The chemical rocket engine is a fairly lightweight device. However, the specific impulse is not high. Solid and liquid propellants in present use deliver an impulse of around 250 seconds. The best liquid propellants so far conceived and evaluated yield an impulse of about 350 seconds." And of, course, there's this one, also at NASA, stating that Scramjets' specific impulse varies over the Mach range from 1000 to 1500. Want more?

Before stating that scramjets can accelerate to mach25 in the atmosphere you are going to have to solve the materiels problem

Gee, I seem to recall saying that very same thing. How kind of you to tell me what I already knew and act like you are all-knowing in the process.

scramjets by definition cannot [throttle back]

Eh? They have to accelerate constantly the whole time? Can't slow down, can't cruise, can't do anything except go faster? Do explain to me where you learned this.

Until then, kindly refrain from proposing theoretical yet unachievable limits.

You're the one proposing limits pal, not me.

As part of the same program for which the packbots were developed, NASA's JPL has worked with iRobot on adding sensors and software to make more autonomous versions of these same platforms. My small company (Rossum Technologies) has been part of this effort for several years. Our 'urbie' version has stereo vision, omnidirectional cameras, laser range finder, infra-red cameras and more. Besides basic obstacle avoidance the robot is capable of autonomous stair climbing, visual-based navigation, leader-follower and others. Read more on JPL's web site

"Flybys like this happen every 50 years or so," says Don Yeomans, the manager of NASA's Near-Earth Object Program office at JPL. The last time (that we know of) was August 31, 1925, when another 800-meter asteroid passed by just outside the Moon's orbit.

Actually, asteroids pass even closer to the Earth every year; most of them are just smaller than 800 meters. In many cases, we don't detect the objects until after they've gone past.

Here's a list of objects which have come closer to the Earth than 2002 NY40 in the past decade or so. The final column shows the closest approach in terms of the Lunar Distance (between Earth and Moon). For 2002 NY40, that's about 1.3.

Name or Nominal Date +/- Nominal
Designation YYYY-mmm-DD HH:MM D_HH:MM (LD/AU)

1994 XM1 1994-Dec-09 18:54 00:02 0.3
2002 MN 2002-Jun-14 02:02 00:02 0.3
1993 KA2 1993-May-20 20:38 00:01 0.4
1991 BA 1991-Jan-18 17:18 00:01 0.4
1994 ES1 1994-Mar-15 17:16 00:01 0.4
2001 BA16 2001-Jan-15 20:29 00:01 0.8
1999 VP11 1965-Oct-21 18:47 19:28 0.9
2002 GQ 2002-Mar-31 03:31 00:01 1.1
1995 FF 1995-Mar-27 03:30 00:01 1.1
1996 JA1 1996-May-19 16:35 00:01 1.2
1991 VG 1991-Dec-05 09:22 00:01 1.2
2002 EM7 2002-Mar-08 00:58 00:02 1.2
2002 CU11 1925-Aug-31 00:42 05:33 1.2
2002 CB26 2002-Feb-08 19:11 00:01 1.2
2000 LG6 2000-Jun-02 21:38 00:07 1.3

You can generate such lists yourself at The NEO Program's list of Near Earth Objects.

It's a bleeding edge technology, that you could build at home. Here are some examples and references:
JPL - NASA progress report on a fresnel zone lens.
Zone Plate (reflecting) Fresnel Antennas for Amateur SETI -- Part 1
You'll have to dig, but also use Google to find it.

You should be able to design a flat antenna from solid foam insulation with foil on both sides by removing the foil at the right places. There are design programs to do the math. Aiming is going to be tricky, but should be no more difficult than any other installation.

Good luck.

--Mike--

Stellarium is an impressive piece of free software for Linux and Windoze that renders the sky at any given time given your coordinates.
I bet it will make it much easier for the untrained people to find the asteroid in the sky (considering its trayectory.

answer: 1. sound is much slower than radio waves, so the electronics can be slower and simpler (and therefore cheaper). To "slow down" a radio signal, you'd need a large diameter ring of sensors -- something that may not fit on top of a launch tower

Thanks for the feedback! It prompted me to do some calculations and further investigation. Apparently, there are TWO different SOLLO systems: SOLLO 1 and SOLLO 2. (Note: There's an error in the HTML for the SOLLO2 page where a less-than-symbol can be mistaken as the start of an HTML element.) Here's the description for SOLLO 2:

The basic concept of SOLLO 2 is the estimation of the distance of a lightning strike from the difference between the time of arrival of the visible flash and the audible thunder. SOLLO 2 locates lightning strikes to within a meter radius. The single receiving station includes an electric-field sensor at the center of a horizontal circle of 1- or 2-meter radius, four microphones placed on the circle at 90-degree intervals, and a fifth microphone 1 or 2 meters above the center. A nearby lightning strike causes the electric-field sensor to put out a pulse that is used to start the timer and to trigger the digitization and recording of microphone outputs as functions of time. The differences between times of the arrival of thunder at the five microphones range up to a few milliseconds. These differences are determined with[in] 10 s, from real-time digital cross-correlation among the microphone outputs. The direction from which the thunder came (thus the direction to the lightning strike) is computed by finding the set of direction cosines of the sound-propagation vector that yields the least squares best fit to the time-of-arrival differences, given the known speed of sound.

So, to answer my own question of why not use just RF? The speed of light is approximately 900,000 times the speed of sound; let's just call it one million (10^6) to make the calculations easier. Then, the differences between times of the arrival of thunder at the five AM receivers would range up to a few nanoseconds and the differences would need to be determined within 10 picoseconds. Ouch! I'm no electrical engineer, but that looks like terahertz to me. Getting it back down to gighertz would require expanding the baseline by a factor of 1000. That implies arranging the RF receivers around the perimiter of a circle 2 km in radius. SOLLO 2 would fit in the back of a pickup truck; mine wouldn't be quite so portable. =)

answer: 1. sound is much slower than radio waves, so the electronics can be slower and simpler (and therefore cheaper). To "slow down" a radio signal, you'd need a large diameter ring of sensors -- something that may not fit on top of a launch tower

Thanks for the feedback! It prompted me to do some calculations and further investigation. Apparently, there are TWO different SOLLO systems: SOLLO 1 and SOLLO 2. (Note: There's an error in the HTML for the SOLLO2 page where a less-than-symbol can be mistaken as the start of an HTML element.) Here's the description for SOLLO 2:

The basic concept of SOLLO 2 is the estimation of the distance of a lightning strike from the difference between the time of arrival of the visible flash and the audible thunder. SOLLO 2 locates lightning strikes to within a meter radius. The single receiving station includes an electric-field sensor at the center of a horizontal circle of 1- or 2-meter radius, four microphones placed on the circle at 90-degree intervals, and a fifth microphone 1 or 2 meters above the center. A nearby lightning strike causes the electric-field sensor to put out a pulse that is used to start the timer and to trigger the digitization and recording of microphone outputs as functions of time. The differences between times of the arrival of thunder at the five microphones range up to a few milliseconds. These differences are determined with[in] 10 s, from real-time digital cross-correlation among the microphone outputs. The direction from which the thunder came (thus the direction to the lightning strike) is computed by finding the set of direction cosines of the sound-propagation vector that yields the least squares best fit to the time-of-arrival differences, given the known speed of sound.

So, to answer my own question of why not use just RF? The speed of light is approximately 900,000 times the speed of sound; let's just call it one million (10^6) to make the calculations easier. Then, the differences between times of the arrival of thunder at the five AM receivers would range up to a few nanoseconds and the differences would need to be determined within 10 picoseconds. Ouch! I'm no electrical engineer, but that looks like terahertz to me. Getting it back down to gighertz would require expanding the baseline by a factor of 1000. That implies arranging the RF receivers around the perimiter of a circle 2 km in radius. SOLLO 2 would fit in the back of a pickup truck; mine wouldn't be quite so portable. =)

This is really awesome. I'm totally impressed! By the way, this was on Astronomy Picture Of The Day on July 24.

APOD July 24th

Gives the usual detailed information.

Here are the risk reports from JPL's Sentry system. Until yesterday 2002 NT7 was still at the top of the chart, but the probability of a collision has dropped a couple of orders of magnitude. It won't hit in 2019, but it might be possible in 2060. Incidentally, the most likely to hit (1 in 600 that it hits between 2068 and 2101) is only 40m across, but it'll still hit like an atomic bomb.

The page for the asteroid has lots of interesting numbers. How much damage would a trillion tons of TNT do?

Here are the risk reports from JPL's Sentry system. Until yesterday 2002 NT7 was still at the top of the chart, but the probability of a collision has dropped a couple of orders of magnitude. It won't hit in 2019, but it might be possible in 2060. Incidentally, the most likely to hit (1 in 600 that it hits between 2068 and 2101) is only 40m across, but it'll still hit like an atomic bomb.

The page for the asteroid has lots of interesting numbers. How much damage would a trillion tons of TNT do?

Here are the risk reports from JPL's Sentry system. Until yesterday 2002 NT7 was still at the top of the chart, but the probability of a collision has dropped a couple of orders of magnitude. It won't hit in 2019, but it might be possible in 2060. Incidentally, the most likely to hit (1 in 600 that it hits between 2068 and 2101) is only 40m across, but it'll still hit like an atomic bomb.

The page for the asteroid has lots of interesting numbers. How much damage would a trillion tons of TNT do?

Yup - sort of.Studies have shown that less than 20 percent of the total thrust used to fly at Mach 3 is produced by the basic engine itself. The balance of the total thrust is produced by the unique design of the engine inlet and "moveable spike" system at the front of the engine nacelles and by the ejector nozzles at the exhaust which burn air compressed in the engine bypass system.

That link is a quick overview of the Blackbird, including a bit of info about the engines. Ram air definitely plays a big part. Anyone know if those "ejector nozzles" are what I'd call an afterburner, or is the afterburner included in the "basic engine itself?" It sounds like they're the ramjet portion, but...

Another source is waste heat from air conditioners. One article a while ago pointed out that all those fscking airconditioning units radiating into the street raise urban temperatures. I think it was 3 F or 5 F.

If you look carefully at the whole of the a
without the additional worries that we had
without. Viz: (from here)
"
With the processing of a few more observati
asteroid 2002 NT7 through July 28, we can n
out any Earth impact possibilities for Febr
2019. While we cannot yet completely rule o
impact possibility on February 1, 2060, it
very likely that this possibility will be s
ruled out as well as additional positional
observations are processed. Because the SEN
system tracks a multitude of test particles
effort to map the uncertainties of the aste
future positions, some of these test partic
take slightly different dynamical paths. He
there are currently two entries for 2060 in
IMPACT RISK table. The entry with the highe
(larger Palermo Technical Scale) would be t
that would then take precedence.
"
Really, the whole thing seems like it's som
lay money on it, if you know what I mean.

Robert Falker

• Changing Our Weather One Smokestack at a Time
• Thunderstorms are affected by Pollution (May 2002)
• Tiny Particles of Pollution May Carry Large Consequences for Earth's Water Supply (December 2001)

I realize these links have a bias for NASA but NOAA is also actively researching this area.

• Changing Our Weather One Smokestack at a Time
• Thunderstorms are affected by Pollution (May 2002)
• Tiny Particles of Pollution May Carry Large Consequences for Earth's Water Supply (December 2001)

I realize these links have a bias for NASA but NOAA is also actively researching this area.

• Changing Our Weather One Smokestack at a Time
• Thunderstorms are affected by Pollution (May 2002)
• Tiny Particles of Pollution May Carry Large Consequences for Earth's Water Supply (December 2001)

I realize these links have a bias for NASA but NOAA is also actively researching this area.

• Changing Our Weather One Smokestack at a Time
• Thunderstorms are affected by Pollution (May 2002)
• Tiny Particles of Pollution May Carry Large Consequences for Earth's Water Supply (December 2001)

I realize these links have a bias for NASA but NOAA is also actively researching this area.

• Changing Our Weather One Smokestack at a Time
• Thunderstorms are affected by Pollution (May 2002)
• Tiny Particles of Pollution May Carry Large Consequences for Earth's Water Supply (December 2001)

I realize these links have a bias for NASA but NOAA is also actively researching this area.

A lot of evidence points to asteroid impact likely being the biggest actual threat to mankind

Oh come on, what for evidence? Compared to other threats?

Lots of civilization ending threats face us. Race ending threats face us. Life on Earth ending threats face us. For most of them the odds are basically impossible to calculate. Will we end civilization? Render the human race extinct? Render the Earth unfit for anything but the most primitve life through poisoning the Earth with our waste? It is incalculable, because it depends on making a subjective judgement of whether we can learn to be wise, instead of clever. We are clever enough to build things that could kill us as a side-effect. Are we wise enough not to? That is incalculable.

Astronomical disasters are ones about which we can make reasonable, defensible judgements, and start to enter into actuarial calculations.

...I say there are dozens dangers far more likely ... and additionally asteroids is not the only astronomical accident that may happen, there are far more, just not spectaluar enough to make movies from. How about a supernova in our quater of the galaxy? We will be ripped away.

Yes, a close enough Supernova burst could destroy civilization. Slashdot has discussed this recently, and again here. 160 to 200 light years was suggested to be the distance beyond which civilization would be safe from a supernova. NASA's picture of the day site has half a dozen articles about eta carinae, a large variable star that they state is a good candidate for the next supernova in our neck of the woods. It is well beyond that 200 ly limit.

There were in fact 5 missions that landed on the moon.
Apollo 11, 12, 14, 15, 16, and 17.

Landing Coordinates:
Apollo 11: 0.71 degrees North, 23.63 degrees East
Apollo 12: 3.04 degrees South, 23.42 degrees West
Apollo 14: 3.65 degrees south, 17.48 degrees West
Apollo 15: 26.08 degrees North, 3.66 degrees East
Apollo 16: 8.97 degrees South, 15.51 degrees East
Apollo 17: 20.16 degrees North, 30.77 degrees East
http://science.ksc.nasa.gov/history/apollo/flight- summary.txt

-always look up the facts before posting-

This may be feeding the trolls, but ...

There were several moon missions. Apollo 11 was the first one to land; all the subseequent ones (the program ended with Apollo 17) also landed on the moon, except for Apollo 13, which suffered a meteor collision enroute and had to return to Earth. Check out this site:

Project Apollo Program Overview

Like I said, I may be feeding the trolls, but it sounds to me like you genuinely didn't know this, so ...

Why do you believe that?

I decided to look for myself and found no mention of contact with Venus or Mars in the mission description for Pioneer 10 or 11, or Voyager 1 or 2. I am not an astro-physicist, but it sure seems to me that risks associated with a slingshot off Venus would outweigh the gains to be made in speed. If you can show me a link, I would be grateful.

This looks like an even grander attempt than the X-33 and the now-defunct Venturestar project. Venturestar was cancelled because it was too ambitious, wasn't it? Looks like some NASA vaporware...er vaporplane.

Based on the information here, if it doesn't hit us, this thing's gonna be flying by awefully close. Might be quite a show!

Surely close enough for the naked-eye at night. Maybe even during the day?