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Dec
6
comment Does anyone know why three of Jupiter's largest moons orbit in 1:2:4 resonance?
en.wikipedia.org/wiki/Orbital_resonance
Dec
6
comment iteration to cover the whole sky with right ascension, declination, angle
@RobertCartaino Calculate the difference between the surface of a slice of sphere from pole to pole between two meridians and that of a rectangle which is D*sqrt(2) longer than needed. This is inside the squares only, you need to multiply for the relation among that of a circle of radius d and that of a square of side sqrt(2)*D/2.
Dec
5
comment iteration to cover the whole sky with right ascension, declination, angle
I actually gave you the formula: if the side of the square is sqrt(2)*D/2 that is exactly both RA_step and DEC_step
Dec
5
answered iteration to cover the whole sky with right ascension, declination, angle
Dec
5
answered How would we detect an Earth doppelganger planet?
Dec
5
answered Do parallel universes exist?
Dec
5
comment iteration to cover the whole sky with right ascension, declination, angle
Wouldn't it be easier if you use square sky patchs?
Dec
4
comment Changes to Earth's orbit
@dav1dsm1th It is a common misconception. Slowing an orbiting body actually makes it go farther, not nearer the central body. Note that this refers to orbital slowing. If you slow down the Earth until it is truly stopped it will be infinitely far away from the Sun. Orbital mechanics does not consider a full stop to happen on place (the energy required would be prohibitive anyway). About skaters arms, they fall to side due to gravity towards floor, not due to gravity towards the skater. If there were no floor, arms would continue extended with no effort.
Dec
4
comment Find distance from star to star?
@FrancescoMontesano It is still trigonometry, just not Euclid's one.
Dec
4
answered Find distance from star to star?
Dec
4
answered Has life been discovered outside of Earth?
Dec
4
comment How was Io not torn apart by tidal forces during its formation?
I have not them at hand, just memories from my degree and Google.
Dec
4
comment How was Io not torn apart by tidal forces during its formation?
Io's own gravity is self-explanatory. Reference for resonances can be found at en.wikipedia.org/wiki/Orbital_resonance
Dec
3
comment Why is the Moon receding from the Earth due to tides? Is this typical for other moons?
@ŁukaszL.There is no such thing like centrifugal force. There is only one force involved: gravity. It is the force that curves the otherwise rectilinear movement into an orbit. The lower the gravity, the more straight the orbit, that is, the bigger.
Dec
3
comment Moon orbits crossing each other
Please add this to your answer: upload.wikimedia.org/wikipedia/commons/9/99/JanusEpimetheus.gif
Dec
3
comment Moon orbits crossing each other
There is NO retrograde movement! The image is misleading if you do not take into account that it represents a rotating frame. Moons interchange orbits while rotating on the same direction!
Dec
3
answered Without using absolute magnitudes or isochrones, how might we tell a star's age and evolutionary status?
Dec
3
answered How was Io not torn apart by tidal forces during its formation?
Dec
3
awarded  Editor
Dec
3
revised How do you figure out the magnitude of stars?
Improvement over previous edit