55
votes
Accepted
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. ...
- 2,501
48
votes
Accepted
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
Accepted
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 ...
- 2,506
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 ...
25
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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24
votes
Accepted
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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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
Accepted
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 ...
- 73.2k
18
votes
Accepted
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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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. ...
- 149k
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,...
- 1,073
15
votes
Accepted
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 ...
- 19.3k
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 ...
- 149
14
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 ...
- 121k
13
votes
How does the James Webb space telescope measure wind shear?
The team determined how quickly the winds vary with altitude and produce wind shears by comparing the currents detected by Webb at high altitudes to those observed by Hubble at deeper layers
https://...
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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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12
votes
Accepted
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.
...
- 10.1k
12
votes
Accepted
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 ...
- 58.5k
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.
- 58.5k
12
votes
Accepted
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 ...
- 167k
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 ...
- 121k
12
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 ...
- 15.6k
12
votes
Accepted
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 ...
- 167k
11
votes
Accepted
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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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 ...
- 73.2k
11
votes
Why are Jupiter's trojans even remotely stable?
I'm answering my own question here based largely on the comment from @CuteKItty_pleaseStopBArking
Saturn's influence can be separated into a radial component (near Saturn's conjunction with the ...
- 3,844
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, ...
- 10.2k
9
votes
How was Juno's arrival set up to be on the evening of July 4th?
There have been four major US planetary probe events on (or scheduled for) 4th July. This compares to approximately a hundred "major events" for US planetary probes. At least one (Viking) was somewhat ...
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9
votes
Juno to Jupiter Budget
Was that option considered in detail?
Almost certainly not. This question is based on the false assumption that staffing levels remain more or less constant across all phases of flight. This is not ...
- 73.2k
9
votes
The plane of the orbit of Juno around Jupiter is not the ecliptic plane. How did it get into this plane?
The plane of the orbit around the Sun is not directly related to the planet-relative plane of the hyperbola on approach to Jupiter, or correspondingly the orbit around Jupiter after orbit insertion. ...
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Only top scored, non community-wiki answers of a minimum length are eligible