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NASA's $73 Million Water-Finding Trick
An anonymous reader writes "The folks at NASA, obviously looking for new ways to explore the universe, are planning to crash a two-ton probe into the moon. The goal? To find water." From the article: "NASA plans a series of robotic precursor missions including the Lunar Crater Observation and Sensing Satellite, or LCROSS, which will plow into the crater, and the mapper, called the Lunar Reconnaissance Orbiter. When LCROSS strikes the crater, it is expected to create a hole 16 feet deep and send up a 2.2 million-pound (998,000-kg) plume of debris for sensors and cameras stationed on a second spacecraft to monitor. Dozens of ground-based telescopes, as well as possibly space observatories, such as the Hubble telescope, will be trained on the plume as well."
They used to crash the upper stages of the Saturn 5 to gain scientific data from the Moon. Learned a lot that way.
Hard to say if this will work though. The theoretical plume size has a lot of unknowns involved. To date, they have never directly observed water on the Moon, but have only identified a certain amount of hydrogen, which would correspond to a certain amount of water, if that hydrogen was bound in water molecules. If the hydrogen is hydrated minerals, that plume will be much, much smaller than projected.
"... it is expected to create a hole 16 feet deep and send up a 2.2 million-pound (998,000-kg) plume of debris"
I think they're most likely ballpark figures for a 5 metre deep crater, and 1000 tonnes of debris. Convert these to imperial measurements and back again without thinking too much, and you gain many significant figures of accuracy!
Tedious Bloggy Stuff - hooray?
NASA tried this impact project with Lunar Prospector in 1999. But it did not lead to any substantial ejection of water vapor off the impact point. No water vapor was observed with the Hubble/STIS (spectrograph). I believe (have not RFTA) that NASA wants to do it right with a proper impactor at this time.
Is this maybe what you're referring to? From the linked article:
There is also a very old historical account that could also be explained by a meteor hitting the Moon. This was recorded by Gervase of Canterbury who, in 1178, along with five other monks, saw a very bright flash on the Moon:
"There was a bright New Moon, and as usual in that phase its horns were tilted towards the east. Suddenly, the upper horn split in two. From the midpoint of the division, a flaming torch sprang up, spewing out fire, hot coals and sparks."
Some astronomers believe that the crater Bruno, one of the youngest on the lunar surface, may have been formed in this event.
More information in this article. Hope this helps.
The higher the technology, the sharper that two-edged sword.
Your analogy is bad since the mass of wyoming is not easily determined. Furthermore, since the impactor is 2 orders of magnitude less than the empire state building, that would imply that since
impactor:moon
that wyoming is approximately 2 orders of magnitude less mass than the moon.
doubtful.
I'm more curious of why they want to do it at all. Isn't the moon covered with craters? Many of which are a lot more than 16 ft deep? Can't they observe the dust and debris around those craters?
Good question. Unfortunately, the dust around those craters aren't glowing from heat, allowing you to use emission spectroscopy. The article doesn't say that's what they're doing, but that's the only thing I can imagine they'd be doing it for.
It would probably be satisfactory if a normal asteroid would be polite enough to smash itself at our leisure and on a schedule (although the asteroid would contaminate the results by adding an unknown quantity to the system; we know what our machine is made out of and can "subtract" it), but that doesn't seem to be in the cards.
Though to be fair, the Soviet space program was far more efficient; they achieved more fatalities per accident.
Blank until
let me be the mass of earth
let mw be the mass of wyoming
let se be the surface area of earth
let sw be the surface area of wyoming
you can get an approximation for mw with:
mw = me*sw/se
Of course this makes a lot of assumptions (which are approximately true hence the approximate value for mw).
Silly peasant. Witches burn, and what also burns? Wood. Wood also floats (along with very small rocks). So, if she drowns, then she isn't made of wood, and wouldn't burn, thus isn't a witch.