/sci/ - Science & Math

[Anonymous No.2569435]

>To gain interplanetary momentum while already in flight, the trajectory of the Cassini mission included several gravitational slingshot maneuvers: two fly-by passes of Venus, one more of the Earth, and then one of the planet Jupiter. The terrestrial fly-by was the final instance when the Cassini space probe posed any conceivable danger to human beings.

>Had there been any malfunction that caused the Cassini space probe to collide with the Earth, NASA's complete environmental impact study estimated that, in the worst case (with an acute angle of entry in which Cassini would gradually burn up), a significant fraction of the 32.7 kg of plutonium-238 inside the RTGs would have been dispersed into the Earth's atmosphere so that up to five billion people could have got radiation poisoning,

>NASA willing to risk the lives of 5/6 of the Earth's population to speed up a mission to Saturn

Okay, not your biggest fan anymore NASA

[Anonymous No.2569447]

I doubt that was a very likely event

[Colonel Coffee Mug !phJ7yIcs.Q No.2569458]

Holy mother of Jesus tapdancing Christ in rollerblade Heaven.

That's the mother of all AWESOMEs.

[Anonymous No.2569468]

NASA astrophysicist here

Don't worry, we're VERY precise with these calculations. It's pretty much guaranteed that nothing will happen unless the laws of physics change.

On a completely unrelated note, is it "soh-cah-toa" or "coh-sah-toh"?

[Anonymous No.2569482]

I still think the NASA make up this annoucements just to get attention. It's a good commercial move.

Yet... it's disappointing because nothing like this would happen.

Fucking universe. It's so slow it fucking bores me sometimes.

[Colonel Coffee Mug !phJ7yIcs.Q No.2569483]

>>2569468

hurr durr I reference Randall Munroe who also worked at NASA I so witty

[Anonymous No.2569646]

NASA confirmed for first feasible creation of a planet-killer

[Anonymous No.2569671]

You just KNOW NASA's gonna hold this one above our heads to get more funding.

[Anonymous No.2569715]

>>2569671

I can't wait for life under the iron boot of the nasa hegemony

[Anonymous No.2569805]

Accelerating objects to sufficient speeds to see parts of our own solar system in a reasonable amount of time and then crashing them into the earth would have negative consequences?

shocker.

i never would've known.

[Anonymous No.2569807]

that entire 32kg is likely only a _tiny_ fraction of the crap we put into the atmosphere in above ground nuclear testing.

yawn.

[Anonymous No.2570028]

>>2569807

Nope

>In April 1964, a U.S. Navy Transit navigation satellite with a radio-isotopic generator onboard failed to reach orbit and disintegrated in the atmosphere, spewing out over 950 grams of plutonium-238. This was more than the total amount of plutonium released during all nuclear explosions by 1964.

http://en.rian.ru/analysis/20091111/156797969.html

[Scientist No.2570047]

>>2569435
>5 billion people could get radiation poisoning from 32.7 kg of plutonium-238
Going to want some citations on this one. Sounds like a pure scare tactic to me.

[Anonymous No.2570078]

>>2570047

>From the Cassini Final Environmental Impact Statement, NASA 1995, pages viii-ix:

>“During the interplanetary portions of the mission, postulated short-and long-term inadvertent
reentry accident scenarios could result in releases of plutonium dioxide to the environment.
However, NASA is designing the mission to avoid the potential for such accidents. The mission’s
design ensures that the expected probability of an inadvertent reentry would be less than one in a
million. If such an accident were to occur, plutonium dioxide could be released in the upper
atmosphere and/or scattered in indeterminate locations on the Earth’s surface. Within the exposed
population of 5 billion people, approximately 1 billion people (i.e., 20 percent or 1/5 of the
population) would be expected to die of cancer due to other causes. The estimated fatalities that
could result from an inadvertent reentry with release would represent an additional 0.0005 percent
above the normally observed cancer fatalities [500,000 deaths in addition to the estimated 1
billion cancer deaths].

http://scholar.lib.vt.edu/theses/available/etd-120899-134345/unrestricted/06chapter_3.PDF

[Scientist No.2570091]

>>2570078
Really? Only 32 something kg enough to kill a billion people? Someone double check that please with a different source. That just seems... extraordinarily high.

[Anonymous No.2570098]

>>2570091
They didn't say kill.

[Anonymous No.2570101]

>>2570091

The original source is god damned NASA

I think the billion is normal cancer deaths though, the wording claiming only a 0.0005% increase slightly confuses me

[Anonymous No.2570106]

>>2569435

>32.7 kg of plutonium-238
>65.4 nanograms each person
>poison billions of people

I don't think so.

[Scientist No.2570118]

>>2570098
Reading comprehension bitch.

>1 billion people (i.e., 20 percent or 1/5 of the
population) would be expected to die of cancer due to other causes

[Anonymous No.2570146]

>The estimated fatalities that
could result from an inadvertent reentry with release would represent an additional 0.0005 percent
above the normally observed cancer fatalities [500,000 deaths in addition to the estimated 1
billion cancer deaths].
>an additional 0.0005 percent

herp derp, sure is a scary "absolutey everything possible goes wrong in the worst possible way" scenario

[Scientist No.2570156]

I'm a retard who lacks reading comprehension. Ignore me. Sorry.

[Anonymous No.2570169]

>>2570146

half a million from one bad probe, still a cool high score

[quietpinkyimpondering No.2570180]

>>2569468
>>NASA astrophysicist here

Don't worry, we're VERY precise with these calculations. It's pretty much guaranteed that nothing will happen unless the laws of physics change.

On a completely unrelated note, is it "soh-cah-toa" or "coh-sah-toh"?

NASA astrphyst here? I'm honored, sir

[Anonymous No.2570188]

>>2569468
What do you think of the movie 'Sunshine?' Regarded as one of the most scientifically accurate scifi film, at least in the past few years it is.

[Anonymous No.2570209]

>>2570188
I find it's concept and solution pretty realistic, as well as the way it handles it's events and conflicts, but the rest seems to be accurate in what people expect from science fiction only.

[Anonymous No.2570210]

>>2570188

>flying huge amounts of fissile material into the sun to 'restart it'
>Scientifically accurate

Pick one.

[Anonymous No.2570217]

>>2570210
>>flying huge amounts of fissile material into the sun to 'restart it'
Actually this is very possible to perform, but you'll need billions of them in order to pull it off.

[Scientist No.2570226]

>>2570188
If one ignores the freezing in space in under a minute incident, /maybe/.

[Anonymous No.2570232]

>>2570188
>most accurate science fiction film?
No.
>most accurate science fiction film in recent years?
Yes.

[Anonymous No.2570285]

>>2570226

freeze in vacuum

i dont think so

[Anonymous No.2570305]

>>2570285

Why would the liquids inside your body and on your skin not freeze in the coldness of space? (Unless you're facing the sun or something)

[Anonymous No.2570306]

>>2570285
ahhh his body will sublimate if he freezes

[Anonymous No.2570314]

>>2570305
Because in order to feel "cold" (or freeze) there has to be matter (air, water, solids) to transfer energy to.

[Anonymous No.2570324]

>>2570314

matter like your body?

[Anonymous No.2570330]

>>2570285

ain't you never heard of radiative cooling?

ain't you never heard of Earth? ain't you heard that Earth is in space? ain't you never heard of winter?

[Anonymous No.2570336]

... yes, your body is going to freeze itself.

[Anonymous No.2570337]

>>2570305
They wouldn't "freeze" because they would evaporate.

[Anonymous No.2570363]

>>2570285
>>2570330

Radiative cooling is commonly experienced on cloudless nights, when heat is radiated into space from the surface of the Earth, or from the skin of a human observer. The effect is well-known among amateur astronomers, and can personally be felt on the skin of an observer on a cloudless night. To feel the effect, one compares the difference between looking straight up into a cloudless night sky for several seconds, to that of placing a sheet of paper between one's face and the sky. Since outer space radiates at about a temperature of 3 kelvins (-270 degrees Celsius or -450 degrees Fahrenheit), and the sheet of paper radiates at about 300 kelvins (room temperature), the sheet of paper radiates more heat to one's face than does the darkened cosmos.

wikipedia

[Anonymous No.2570384]

>mfw temperature confuses people

Basically, state of matter is determined by two things: temperature is one, and pressure is the other. -40 C water in a vacuum is going to evaporate because the surface pressure of the water is larger than the 0 pressure of the vacuum.
Even if that weren't the case, your body has no means of transferring its thermal energy away because there's nothing to transfer it to. Basically the only thing causing you to lose energy will be your natural blackbody radiation. You'll freeze to death much faster in Antarctica than you will in the ~2.5 K vacuum of space.