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122 votes
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What will be the effect if we stand on Jupiter?

(*) Jupiter, for all intents and purposes, doesn't have a solid surface to stand on. Not any more than you could say that Earth's atmosphere has it, before you hit Terra Firma. It's an enormous ball ...
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55 votes
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Why does this image of Jupiter look so strange?

As @Hobbes mentioned it is not an image of an entire hemisphere but it has been distorted to allow for wide angle vision. That's why it looks so strange. The image is a composite made by Kevin M. ...
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46 votes
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Why is Jupiter called a "Gas Giant"?

Jupiter being a gas giant is not about its appearance, as another answer stated. It's only about the mass distribution of a planet. Jupiter's mass is 320 Earth masses, while we know from the Juno ...
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34 votes
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Why are we interested in visiting the giant planets' icy moons?

The icy moons are of interest for exploration as part of the overall "follow the water" strategy of exploration that NASA (and others) have been exploring for some time. The "where else can water be ...
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27 votes

What are these features on this moon of Jupiter?

The image is of Jupiter's moon Io The image is of course a composite, massively contrast-enhanced, and color adjusted to be both clearer and more visually appealing. The red dot is a volcanic eruption ...
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24 votes
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How much longer would New Horizons take to reach Pluto without the Jupiter slingshot?

It was said in here that the time to reach Pluto was shortened by 3 years. It's also said that after the Jupiter flyby the probe gained ~ 4 km/s accelerating to the speed of 23 km/s relative to the ...
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  • 1,674
24 votes

If colonists burrowed far enough under the ice on Ganymede or Europa, would the ice provide adequate protection for them from Jupiter's radiation?

Yes, it absolutely would! The radiation on Europa is about 5.4 Sv (540 rem) of radiation per day. Looking at this guide, and assuming you want to meet OSHA standards of 5 rem per year, you would need ...
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  • 118k
22 votes
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Why does NASA's Juno spacecraft only have a one year primary mission?

While many missions have been able to continue beyond their design lifetimes (Cassini and the Mars Exploration Rovers being prominent examples), the type of mission and orbit Juno must undertake to ...
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20 votes

How long does it take for a signal to travel between Earth, and Juno at Jupiter?

Using NASA's Eyes measuring the distance from Jupiter to Earth at this moment (5th Jul 2016, 11:50 CEST) is 48 light minutes, 21.39 light seconds, and that would be the time Juno's communications ...
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18 votes
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How is JunoCam different from a normal CCD camera?

JunoCam used different technologies than does the typical framing camera one buys at a store. A typical digital color camera uses a Bayer filter pattern, a row of alternating tiny blue and green ...
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18 votes
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How unreachable are Jupiter's moons from Mars with the technology developed for going to Mars?

Let's go back our old friend the Pork chop plotter. Earth to Jupiter using minimum fuel takes around 2 years and you get one opportunity per year, more or less, to get there. You can shorten the ...
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  • 18.9k
17 votes

How long does it take for a signal to travel between Earth, and Juno at Jupiter?

EDIT: based on @Beska's comment, I went back and calculated the difference including light time. In other words, you have to use Jupiter's position roughly 48 minutes ago to state the travel time. ...
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  • 148k
16 votes

Why are we interested in visiting the giant planets' icy moons?

The motivation is the growing understanding, from the Voyager, Galileo and Cassini probes, that these icy moons (I'd throw in Enceladus) are geologically active with sub-surface oceans of liquid water,...
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15 votes

What would happen if an Earth-sized body encountered Jupiter?

If you saw the video of the Shoemaker-Levy collision you will see that although that was a collection of smaller objects, there is very much a collision, rather than a gas engulfing a solid. Once the ...
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15 votes
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Will Dragonfly flyby Jupiter en route to Saturn?

Here is a paper which among other things includes the results of a trajectory search. They say Gravity assists of Earth, Venus, and Mars were included with a patched conics assumption. Jupiter was ...
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  • 18.9k
14 votes

Why is Jupiter called a "Gas Giant"?

One reason they are called gas giants is because they are mostly composed of elements that are gaseous at Earth like temperatures and pressures. Jupiter is primarily composed of hydrogen with a ...
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13 votes
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Why does the Juno spacecraft flyby Earth on the way to Jupiter?

No, the Atlas 551 is not powerful enough to send Juno to Jupiter. From this article on NASA's website: The Juno spacecraft was launched from Kennedy Space Center in Florida on August 5, 2011. ...
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13 votes

How much longer would New Horizons take to reach Pluto without the Jupiter slingshot?

Depending on the time of launch, there were 4 different major plans for the NH mission profile. The first 3 involved Jupiter flybys, and would have an arrival date of 2015, 2016, or 2017. The last was ...
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  • 118k
12 votes
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How strong is the Sun's gravity at the distance of Jupiter's orbit?

Acceleration due to gravity is given by $$ a = \frac{GM}{r^2} $$ where G is the universal gravitational constant, M is the mass of the central body and r is the distance between the bodies' centers. ...
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12 votes

What are the gravitational assist effects on the inclination of a probe's trajectory, from passing by Jupiter at different latitudes?

Yes, Jupiter can make a trajectory perpendicular to the ecliptic, which is exactly what it did for Ulysses, which observed the poles of the Sun: The function is just vector addition. It depends on ...
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  • 57.6k
12 votes
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Will Juno record its deorbit?

You won't see Jupiter's atmosphere from the "inside". The entry and destruction of the vehicle is very fast, and occurs relatively high in the atmosphere. Way, way above any clouds. There would not be ...
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  • 57.6k
12 votes

Would a Europa lander need radiation shielding similar to Juno?

A Europa lander would need much more shielding, and/or more radiation tolerant components. Juno's orbit avoids the main radiation belt, but Europa is right in the middle of it.
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  • 57.6k
12 votes
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How did Voyager 1 avoid crashing into Jupiter?

Voyager was continually pointing its camera towards Jupiter, while passing alongside it, with its closest approach being 349,000 km. With no visible fixed references behind the planet, it's not ...
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12 votes

Are any electrically propelled missions to the outer solar system being planned? If not why not?

No, there are no planned missions using an Ion drive to the outer solar system. The reason is something that you haven't taken in to account. Sunlight drops significantly as one goes further from the ...
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  • 118k
12 votes
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Why did Pioneer 11 use a gravitational assist to swing above the ecliptic plane... twice?

According to NASA's history on the mission, Pioneer 11's goals included both investigation of the solar wind outside of the ecliptic, and a look at the polar regions of Jupiter, which appeared to have ...
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11 votes
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When can we (public) expect to see the first optical images of Jupiter from the Juno spacecraft?

There's an interesting Planetary Society article about this: What to expect from Junocam We won't be able to see spectacular views of Jupiter's belts and zones from Jupiter orbit until the very end ...
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  • 5,168
11 votes

A Jupiter-sized star?

Jupiter is about as large as a planet can get, physically. Suppose we slowly add hydrogen and helium to Jupiter, so slowly so as to keep it at more or less its current temperature. Surprisingly, it ...
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  • 64.2k
11 votes

How unreachable are Jupiter's moons from Mars with the technology developed for going to Mars?

I whomped up a spreadsheet to compare scenarios like this: Hohmann.xls. Typing Earth into departure planet cell and Mars into destination planet I get Launch windows open each 2.14 years (synodic ...
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10 votes
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How long did New Horizons take to upload all of its data from the Jupiter encounter?

According to NASA's NH Jupiter press kit: Closest approach was on February 28, 2007 Download began on March 14 After the Jupiter encounter, the first hibernation mode cycle started on June 28, 2007. ...
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  • 121k
10 votes

Is the far side of the tidally locked Europa moon safe from Jupiter's radiation?

The radiation that causes problems near Jupiter is not emitted by Jupiter. Jupiter has radiation belts, like Earth's Van Allen belts, but much more intense. This radiation doesn't consist of photons, ...
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