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First Results From Deep Impact Mission
jdoire wrote to mention a Physicsweb piece revealing some of the first bits of data from the Deep Impact mission. From the article: "Based on data from the flyby spacecraft and the impactor, Michael O'Hearn of the University of Maryland and colleagues say that Tempel 1 belongs to the Jupiter family of comets, although its overall shape and surface features are quite different from the nuclei of the two other comets that have been studied in detail -- Wild 2 and Borelly. They also report that Tempel 1 consists largely of extremely fine particles that seem to be very loosely bound together: in other words, the comet is more like a pile of powder than a solid rock." Looks like the Electric Universe folks were a bit off.
and their advertising application masquerading as a "website"
http://www.nasa.gov/mission_pages/deepimpact/medi
The same way the Shuttle on reentry 'impacts' the atmosphere, or the way a suicie from the Golden gate Bridge 'impacts' the water.
If you're moving fast enough, it's sure gonna feel like an impact.
____
~ |rip/\/\aster /\/\onkey
Well dang, if that's all it is, c'mon in for a landing buddy. Man, we had you comets all wrong.
Won't be a planet killer...more like a planet tickler...cute little fella.
There's nothing Intelligent about Intelligent Design.
The comet becomes terribly afraid whenever anything is about to hit it. This natural "tensing up," it what allows us to study it effectively.
Also, moving at many thousands of kilometers per second means that you can impact almost anything and cause an explosion. If the probe gently touched down, it might well have settled into the comet very ently.
When I saw the article (YESTERDAY!!) I thought about this also but came up with what I hope is a good analogy.
If you have ever been to the beach or played in a really deep sandbox, you know that the top layer of sand moves about easily. You can dig your toes in without any effort. The sand is loosely bound together.
However, if you drop a bucket (or anything else) onto the sand, that object will only sink in a small bit. Why? Other than the fact that there isn't much force behind dropping whatever onto the surface of the sand the sand itself compresses slightly from the impact.
'But Deep Impact was the size of a washing machine and travelling at a bajillion miles an hour when it hit. You can't compare that to dropping a bucket on the beach!' I hear you say.
Actually, you can compare the two. If you take the size of a bucket compared to the size of the beach, there is a huge difference. Even if you were to take a replica of Deep Impact and fire directly onto the beach at a speed approximating the impact speed on the comet I can guarantee you would get a similar result.
The impact would produce a nice big explosion of particles and the copper impactor would probably disintegrate. However, the beach would still be there albeit with a nice big hole in it.
Hope this long-winded explanation helps.
We will bankrupt ourselves in the vain search for absolute security. -- Dwight D. Eisenhower
I think its cool that we are all ready at the point where we can crash probes into comets and examine them. I wonder how long it will be until we can actually pull a comet into earth orbit and mine it for resources.
The comet seems to have survived:i media/addscolor90605.htmli media/1118923Fig7-90605.html
http://www.nasa.gov/mission_pages/deepimpact/mult
http://www.nasa.gov/mission_pages/deepimpact/mult
Procrastination -- because good things come to those who wait.
10101110
Does this mean that using an significantly large explosive device is almost a feasible scenario for specific types of comets.
I mean, I can understand not using that approach for something make of rock and ice, but with fine particles one would think that sufficient force would break it apart like a cue ball.
Obiviously this is just fuzzy thinking, but does anyone have any scientific input to why this would or would not be an emergency solution to be put on the table for this specfic type of comet?
How does it feel to be potential parents to an alien species?
Like a Scientologist?
(rimshot!)
"Rocky Rococo, at your cervix!"
...how is that there were an impact at all? Wouldn't the probe just sunk into the comet?
I'm guessing that what you're really asking is why any debris was thrown from the surface of the comet instead of the impactor just uneventfully sinking into the surface. Think of it like this: If you take a bowl and fill it with talc powder or flour (a very loosely bound together substance) and shoot a projectile into it with a slingshot, would it just sink in without producing any debris (a small puff of powder or flour)? Add to this the fact that there's far less gravity holding the comet together than there is holding the powder down/together (in the bowl). Does that visualization help?
It's an easy experiment. Try it. I might suggest a coffe can instead of a bowl though so that 1. you don't break the bowl and 2. you minimize the risk of the projectile flying back up and hitting you or someone/something else. Also use plenty of powder or flour as to slow the projectile enough that it can't hit the bottom and bounce back up and of course you want to wear safety glasses. Alternatively you could just view the images sent back from the mission (included in TFA) and trust that it's not all just a hoax.
If you can't just be yourself, then be more like me, ok?
http://en.wikipedia.org/wiki/Tunguska_event
e nt_040812.html
There have been a wide range of theories about this, but a puffball comet explains a lot about what happened there. From Aliens;
http://www.space.com/scienceastronomy/tunguska_ev
to Victorian Era Superweapons testing ala League of Extraordinary Gentlemen (the Comic book, not the movie). I have tried to find the site on Google Earth but have not been lucky.
Sorry about the writing. Robot fingers, you know? Cliff Steele in DOOM PATROL #23
Hard to believe that Neil Armstrong was not familiar with Lunar Surveyor. See http://nssdc.gsfc.nasa.gov/planetary/lunar/survey
John Sauter (J_Sauter@Empire.Net)
You've got many many metric tons of snowdrift, floating through space.
You ram a refridgerator size probe REAL fast into one side of it.
The 'snow' right where the fridge hits is going to move inward, but the many many metric tons of snow on the other side of it is going to want to stay right where they are (a body at rest tends to stay at rest). The movement inward of the snow under the probe's impact against all that 'resting mass' will cause the compression of the 'snow' in that area.
it might well have settled into the comet very ently.
Harrrooomm! Harruummmmm! My, but you are a hasty comet. Very hasty, indeed. Harrooooooomm!
I watched C-beams glitter in the dark near the Tannhauser gate.