How NASA Will Bomb the Moon To Find Water

mattnyc99 writes "A few weeks ago we got first word of NASA's plan to crash a spacecraft into the moon next February. The new issue of Popular Mechanics has an in-depth look at the Lunar Crater Observation and Sensing Satellite and its low-cost, lightning-fast mission prep — even if delays have pushed it to late February or early March. Quoting: 'Andrews had no budget for an expensive lander to seek water, and conditions in the eternally dark polar craters would kill rovers, with temperatures close to minus 300 F. Instead, Blue Ice and its partners at Northrop Grumman came up with a concept to bring the lunar floor out in the open.... Since engineering precision hardware would break the budget, the LCROSS team had to make existing components work together.'"

Bomb what?

Next they'll bomb Uranus in order to find it's filled with gas.

Re:Bomb what?

I'm still waiting for them to rename that planet to Urectum to stop the stupid jokes.

percussion engineering!

I hit stuff to fix it all the time, why shouldn't they?

Re:percussion engineering!

"Percussive maintenance"

That Old Mr. Show bit

"The United States can, should, and will BLOW UP THE MOON!"

http://www.youtube.com/watch?v=kHpX5aa5Lz4 [youtube.com]

Bombing the Moon for water?

You mean liberate the Moon, don't you?

And I find the 'water' reason to be pretty transparent. We all know that there's oil up there and this is yet another neo-con plan that's going to suck us into another war to boost Bush's ratings. But when images of those poor Amazon women up there start coming back, it's jut going to blowup in their faces like Iraq did, and further depress our economy.

Risk of retaliation

The good news is that the Loonies can't do anything about it. I mean, all they could do is throw rocks at us, and what good would that do?

This is Awesome

Somehow, this mission strikes me as one of the coolest things NASA's done in a while. It's a struggling unit of the organization, working with spare parts from scrapped projects, jury-rigging a satellite together that will tow the spent upper stage of a rocket to the moon and smash the chunk of metal otherwise slated to be space debris into the closest heavenly body to send an Earth-visible (with a decent telescope) plume from one of its poles. Finally, it will analyze the plume to figure out if there's ice there.

Totally. Awesome

Re:

Well all mass exerts a gravitational pull on all mass, so yes they affect each other.

Are you afraid this will affect the Earth's orbit around the Sun? The change will be negligible --- the energy we'd need to mess up the orbits dangerously is far beyond us.

Re:Earth's Orbit?

Are you afraid this will affect the Earth's orbit around the Sun? The change will be negligible --- the energy we'd need to mess up the orbits dangerously is far beyond us.

I though it was well within our current power to fuck up the Earth's orbit. Given that the whole time I was growing up we were constantly told we could "blow up the Earth 20 gazillion times over" I was under the impression that we could fairly easily knock it off kilter.

When people say we could blow up the entire Earth, they really mean we could cover the surface of the Earth in nuclear explosions. It would kill all of us, but the Earth wouldn't care. It would just keep trundling along as ever.

Some maths: Suppose we wanted to increase the speed of the Earth by 1m/s. Kinetic energy = mass * speed^2, so (as the mass of the Earth is 5.9736*10^24 kg) we'd need 5.9736*10^24 joules. A megaton explosion is 4.184*10^15 J, so we'd need the equivalent of about a billion megatonnes of TNT. That's about one hundred million pretty big nukes (assuming all the energy of the nukes goes into the Earth's movement, which it wouldn't). And that's just to accelerate the Earth by 1m/s. And when you add to that the fact that the Earth's orbit is stable (so we need a lot of movement to do any real damage), you can see how little we could really do.

Hope that makes sense!

Re:Earth's Orbit?

the "bomb" weighs 5,000 pounds (2200 kg). It's most certainly been hit by heavier objects in its lifetime. The mass of the moon is ~ 7e1022 kg. Would you notice if a fly farted on you?

Re:Earth's Orbit?

African or European fly?

Re:Earth's Orbit?

The mass of the moon is ~ 7e1022 kg

I think you're mixing up 7x10^22 and 7e22 there; the Moon's mass most certainly is not 7e1022 kg. Estimates for the mass of the observable universe, for example, are around 2e52 kg [wikipedia.org].

That said I agree with your point - this will have an utterly negligible affect on the orbital dynamics of the Moon.

Re:Earth's Orbit?

Virtually all of the mass of this mission, except for maybe a little rocket propellant, will stay within the Earth-Moon system, so the center of gravity of the two won't change. In other words, no, this won't affect Earth's Orbit thanks to CONSERVATION OF MOMENTUM!!

Re:Earth's Orbit?

> Isn't Earth's orbit intimately mingled with it's moon?? How precise can the potential impact be measured in relation to this fact? I think Earth's orbit is fine where it is...

Sigh. I blame public schooling.

Re:The Time Machine

In that movie, construction was starting on the moon. To kick off the construction, a large bomb was set off. The result, the moon cracked in half and people eventually started to eat each other.

Geez, a plot like that'd make me crack the DVD in half and eat it.
     

Re:Wasn't this the plot of that Time Machine Remak

My God. Has the IQ of Slashdot dropped twenty points in the last fifteen minutes?

Re:Wasn't this the plot of that Time Machine Remak

My God. Has the IQ of Slashdot dropped twenty points in the last fifteen minutes?

It's a bit hard to tell but I'm afraid you're on to something. We seem to be getting more "whoosh" posts before the joke.

Re:Wasn't this the plot of that Time Machine Remak

You obviously don't know much about the science behind how they invented the moon. Because there isn't gravity on the moon, any small knock, no matter how small, could send it flying off into outer space. This ACTUALLY HAPPENED in a TV series called Space 1999 [wikipedia.org].

Look up gravity on the internet, if you don't believe me. I don't like the idea of loosing the moon just for sake of an experiment.

Re:Have they exceeded their authority?

Should NASA really be pursuing things that could ultimately fuck all of humanity up by breaking our tide?

If you are indeed worried about this, perhaps a remedial course in physics is in order. You might start a couple of books before the ones on orbital mechanics.

If you're funn'in us - well, sorry - not quite enough caffeine here.

Re:is that a good idea?

Simple physics tells us that bombing it with any bomb we currently have or are likely to have in the forseeable future will make no measurable difference and probablly a lot less difference than the various natural rocks that have hit the moon over the centuries.

Re:is that a good idea?

Granite contains Uranium. Get a geiger counter and test the nearest granite countertop and be amazed!

Of course, it's not *dangerous*, but it is definitely radioactive.

Re:is that a good idea?

Most of the radioactivity in stone and ceramic building materials is from potassium 40 decay, not uranium.

Re:Fahrenheit?

You know, while I'm generally in favor of the metric system over imperial, I've never cared nearly so much about the Celsius v. Fahrenheit debate.

Fahrenheit makes more sense in day to day contexts. 0 is very cold, 100 is very hot (both from a human experience point of view), and you have more precision on the temperatures in between. Now in this particular case it's so cold that it doesn't really matter; if I told you it was -184 C, or -300 F it wouldn't really change the fact that you can't conceive of the temperature as anything but "really, really cold".

Besides, who are you trying to chastise? The temperature was given in a quote from the article. Would you prefer Slashdot editors mangle quotes to conform to your prejudices?

Re:Fahrenheit?

"what will happen to water today?"

Before or after the salt trucks come through?

"what can fall from the sky today?"

Because it's not possible for different layers of air to be at different temperatures?

"Same with 100, also very hot, and usefull even in the kitchen."

No, it's not. When was the last time you stuck a thermometer into a liquid on the stove in the process of cooking? Does your range have temperatures on the burner controls? Boiling water isn't useful in the kitchen because it's "exactly 100 degrees Celsius" (which it isn't), but because it's at a constant temperature, regardless of what number you chose to associate with it. And even then, stovetop recipes have to be adjusted for altitude ("How high am I above sea level?" is a question asked more often than "What temperature is this boiling water?")

"(and both 0 and 100 can be easily calibrated on Earth)"

No, they can't. Celsius is defined as a linear offset to kelvin, period. At a "standard" atmospheric pressure of 101 325 Pa, water boils at about 99.974 C (and this is a mathematical approximation [iapws.org] based on experimental data). So even if you had a barometer that was accurate to 1 Pa absolute, arbitrarily declaring the saturation temperature in the room at the time as "100 C" is no more accurate than declaring it to be "212 F" (and at least there the approximately 180 F temperature difference between freezing and boiling is easier to subdivide geometrically).

As a linear offset to thermodynamic temperature, no mere mortal has the equipment to properly calibrate their thermometer (Celsius or Fahrenheit) in their kitchen.

"And no, 100 Fahrenheit isn't very usefull medically - it's a temperature of somebody with severe fewer;"

With respect to measuring human body temperature, Fahrenheit is useful medically by simple virtue of being more granular. Assuming a normal body temperature of 98.6 F (37 C), a fever of 100 F is still less than 1 C above normal. 38 C is 100.4 F.

"BS, even Celsius scale has way more precision than we need in day-to-day life"

Then the adjustments on your thermostat are marked only to the nearest 5 C? If it's more granular than you need, then put your money where your mouth is and set your thermostat up another 2 C.

"it's just above zero", "it's around 5", "a bit below 10"

So the "metric" temperature scale is one that people "feel" in units of 5 rather than 10? In Fahrenheit, that would be "in the 30's," "in the 40's" and "in the 50's," respectively.