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44

In the extreme energy of a large impact, the rock behaves like a liquid (It isn't actually completely melted, though some is. The extreme forces cause the rock to flow). As the impactor hits the moon, rock is pushed out, and since it is surrounded by relatively solid rock, it is pushed up. Then gravity takes over as the rock that has been pushed up now ...


11

Not in any way, no. The December solstice is the moment when the Sun reaches its southernmost point in its daily path in the sky (the June solstice, when the Sun reaches its northernmost point). It only depends on the tilt of the Earth on its orbit and the Sun. On the other hand, Jupiter and Saturn being in conjunction is a phenomenon that doesn’t depend at ...


10

I certainly don't know the details of these kinds of calculations, but as my thought is a bit too long for a comment I'll write it up as an answer. If you measure the flattening of a planet due to rotation (e.g. by measuring its rotation period) and the gravity (measured while keeping the orbiter at constant height above the planet), then you have everything ...


7

Yes, on one of the final orbits it took some pictures of the rings while crossing the ring plane: More details of that image are here, and this page show some still images. Here’s another one: though it’s hard to interpret without reading the description. All the science done during the “Grand finale” orbits is described here.


5

This can easily be tested using software such as Stellarium, where you can visualize the field of view with given focal length. If you have the software installed, click on "ocular view" (the most left button in the upper right corner). The following view is what you culd expect on December 21 with a 10mm eyepiece and a focal length of 1000mm: And ...


5

Telescopes magnify, they don't bring you closer. So if from Earth Jupiter has an apparent radius of 0.01 degrees (measured as an angle because it is the apparent size) And if Saturn has an apparent angle of 0.005 degrees, then if you magnify 100x then Jupiter will have an apparent size of 1 degree, and Saturn would have a size of 0.5 degrees. Magnification ...


4

Our eyes are not good enough to see the difference; Jupiter has an angular diameter of 29.8" to 50.1", while Saturn's is 14.5" to 20.1"; with rings, which are about 2.25 times as wide as the planet, this becomes 32.6" to 45.2". All well within the 60" (1 arcminute) angular resolution of the human eye. Now, when you use a ...


4

Direct viewing through an eyepiece When looking through an eyepiece, there is an apparent field of view. This answer says: Because I was lazy, I used the default telescopes and eyepieces. which means that the circles shown are what one would see if one had an eyepiece with a field of view equal to the default eyepiece used in the Stellarium simulation. If ...


4

You’ll find the answers you want in the Report of the IAU Working Group on Cartographic Coordinates and Rotational Elements 2015, published by Archinal et al in 2018. I found a copy at https://astropedia.astrogeology.usgs.gov/download/Docs/WGCCRE/WGCCRE2015reprint.pdf. A new version might be available this year, as the committee meets every three years… and ...


4

I've noted before that the IAU naming critera are guidelines rather than laws of nature. If applied to Jupiter's moons the four Galilean satellites would probably be "planets" (they don't share their orbits with anything else of comparable size and are large enought to be in hydrostatic equilibrium) There is a mean-motion resonance 4:2:1 between ...


3

It would be dark. Titan in eclipse can be dimly lit by refracted sunlight and light scattered by Saturn's rings. The refracted light would be reddened, but the scattered light would be white. But there isn't much light that far out, and so the brightness would be very low. It has been imaged in eclipse: See https://solarsystem.nasa.gov/resources/14528/...


3

I've noticed this before, too. My non-professional assessment is that it is a viscoelastic response to the impact, where the energy of the impact temporarily transforms the surrounding geology into a viscoelastic material. The central peak is essentially a rebound product of the impact. I'll venture that the peak of molten material solidified before it ...


2

Saturn has a diameter of about 116,000 km and is about 1.4 billion km from Earth. For Jupiter, the corresponding numbers are 140,000 and about 800 million km (the distances vary somewhat as the planets move around the Sun. The size of the images of the planets is determined by the ratios of these, so Saturn is about $$\frac{116000}{1400000000} = 0.00008$$ ...


2

The short answer is no, septuple eclipses can’t happen. Using a method described by Meeus in Mathematical Astronomy Morsels (p. 190), we find that while it is, in theory, possible, for the seven satellites to align, it happens only once per ~ 20 million years—and that’s among themselves only; I didn’t factor in the Sun’s position yet! The possibility that ...


2

This is basically a repeat of Aristarchus’ experiment of trying to figure out the distance between the Earth and the Moon from a lunar eclipse. See for example https://pwg.gsfc.nasa.gov/stargaze/Shipprc2.htm So, we know that Iapetus orbits Saturn in 79.3215 days, at an average distance of 3,560,820 km. Saturn’s diameter is 116,464 km, and it orbits the Sun ...


1

Because of the much greater distance from the sun, and the much greater size of Saturn compared to Earth, while there may be a brief period when Titan goes into eclipse where there will still be some refracted sunlight, as well as some reflected light from the rings, for the majority of the eclipse Titan will be effectively dark. And this assumes you have an ...


1

Leveraging Pierre Paquette's excellent answer and reference to Hilton and Mallama, the magnitude of Saturn can be estimated by: $$ V = 5 \log_{10} (rd) - 8.95 - 3.7\times10^{-4} \alpha + 6.16\times10^{-4} \alpha^2 $$ Here, $r\approx9.5$ AU is the distance from Saturn to the Sun, $d$ is the distance from Saturn to the observer, and $\alpha$ is the angle of ...


1

Most moons orbit in the equatorial planes of the planets they orbit. Earth's moon is a big exception. Because of the varying tilt angles of planets, some satellite systems are too far out out the planes between their planets and their stars, and so never pass into the shadows of their planets and never get eclipsed by their planets. Other planets have ...


1

Your Exit Pupil for your scope is too small with a 3mm eyepiece. Exit Pupil = Focal Length of Eyepiece / Focal Ratio of Telescope 3mm/7.89 (your scope focal ratio) = 0.38mm You need a minimum of 0.5mm to 0.7mm, therefore a minimum of 4mm focal length eyepiece. The maximum power is roughly 2 x 114 = 228X. You can use this site to get a glimpse of what you can ...


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