Questions tagged [ecliptic]
Questions regarding the plane containing the orbit of the Earth around the Sun.
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What is the duration of a year on the Moon (Tropical/Sidereal period) for orbit about the Sun ? How/why does length of lunar days vary ? Soltices?
The inclination of the lunar equator to the ecliptic is 1.543°.
Synodic period or Length of a day on the moon = 708.7344 hours
Moon Fact Sheet
100 Lunar Days - Parts I and II
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Why does the moon move within the zodiacal circle if its orbit is at an angle to the plane of the ecliptic?
The moon moves along the zodiac circle along with other planets, this is a known fact. But at the same time, its orbit is inclined to the plane of the ecliptic.
According to the above diagram, the ...
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Demonstration- formula for angle between horizon and ecliptic
The most precise and quite intuitive formula I could find online is here: https://www.celestialprogramming.com/snippets/angleBetweenEclipticAndHorizon.html
$$\cos I = \cos ϵ \sin ϕ − \sin ϵ \cos ϕ \...
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Do all the planets travel along the same constellations?
If humans ever moved to another planet in this solar-system, what constellations would the sun meet from that perspective? What constellations would the sun look like it is meeting from the ...
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Calculate declination of Galactic N. Pole given obliquity of Ecliptic, rt. ascension of Galactic N. Pole, & angle between Galactic & Ecliptic Pole
I’m trying to back-calculate a value in astronomy using spherical trigonometry. (This is not a homework problem, I'm retired).
Using the following formula, where δ = the Declination of the Galactic ...
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Galaxy plane and Earth's orbit. Connection to seasons?
From my understanding, the Earth (Solar System) crosses a center line of the galactic plane (ecliptic *edit wrong definition, sorry!), while orbiting around the Sun. The Sun also wobbles up and down ...
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Why does Callisto only have eclipses every 3 years?
I don’t understand why Jupiter only eclipses Callisto in three year periods separated by three years. I get that the reason Callisto doesn’t always have eclipses is because of the combo of Jupiter’s ...
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Problem in converting equatoral coordinates to ecliptic coordinates
I would like to convert equatoral coordinates to ecliptique coordinates. I am following the source below:
Practical Astronomy with Your Calculator
The formula I am using is:
When I solve this example,...
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Would an accumulation of dust in a planet's L1 Lagrange point plausibly obscure it from Earth?
I'm designing a hypothetical newly discovered planet in our solar system that has an ecosystem comparable to Earth's that supports intelligent life. The explanation given for the planet remaining ...
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How the "precession of the ecliptic" can be distinguished from the "precession of the equator"?
The precession of the equinoxes (AKA general precession) is composed from two components:
A dominate component which is caused by the the tilt of the Earth's axis - which is called "precession ...
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Draco, Thuban and Northern Ecliptic Pole
I want to try confirm my thoughts on the position of Thuban (Alpha Draconis) in relation to the Northern Ecliptic Pole (NEP). I have been asked to specify how many degrees Thuban is from the NEP today ...
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On other planets, does the sun appear to pass through the same zodiac constellations?
Seen from Earth, the sun travels on a year-long orbit across the celestial sphere, passing through the twelve zodiac constellations.
As I understand it, this path depends on our orbital plane---if our ...
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Ecliptic and it's poles
Well, I have this picture and a couple of tasks to it:
It is the Sun's path, a.k.a. ecliptic in autumn, 22-23 of September or on the day when autumnal equinox happens. I am to answer these questions:
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Why aren't there eclipses every month when the moon's orbit is aligned with the ecliptic as a result of lunar precession?
I can understand why we don't have eclipses every month when the inclinations of the ecliptic plane and the moon's orbital plane are different. But the inclination of the moon's orbital plane changes ...
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How 3’ minute arc error in the Sun altitude might amount to 7’ minute arc displacement in Sun's longitude?
In reading "The Error in Kepler's Acronychal Data for Mars" by Curtis Wilson 1969 (unfortunately , this is not an open article), we read the following paragraph:
How did it come about that ...
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Would a telescope substantially away from the ecliptic plane improve TNO detection?
There have been lots of new TNOs found in the last decade.
Would a telescope far from the ecliptic plane be useful to image them, and spot new ones?
What about planet nine, assuming it exists: would ...
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J2000 conversion to Position of date
Having spent an inordinate amount of time comparing the LBR values of Meeus (Astronomical Algorithms 1998) vs. ELP82B (Chapront's ELP82b Fortran Program)
I have figured out the data set I'm using is ...
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Mars Ecliptic Latitude
It's stated Mars orbital plane is 1.8 degree to the ecliptic.
How then can Mars can ecliptic latitude went beyond 1.8 ?
Example; Jan 8th 2023, Mars latitude at +2.8. 24th Jan 2025, +4.3.
Isn't the ...
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Could there be an eclipse tomorrow if the Pleiades is covered by the Moon tonight?
I'm trying to solve this task:
Suppose today there is a covering of the Pleiades star cluster by the Moon. Could there be an eclipse of the sun tomorrow? The moon?
I think the answer to both is no, ...
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How did the ancients know the constellation in which the sun is located?
The zodiac constellations lie along the plane of the ecliptic. In Spring equinox, sun lies in Pisces constellations. So Pisces is not visible during the day (because the sun light) and not visible in ...
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Does the ecliptic plane change relative to the galactic plane?
The equatorial plane moves over time with respect to the plane of the ecliptic (that's precession!). The ecliptic is at an angle with the galactic plane, but does this angle change over time? Does the ...
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Questions on apparent motion of superior planets
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Why is it that superior planets seem to oscillate up and down of the ecliptic, from the view of an observer on Earth, with a period equal to the planet's orbital period?
Additionally, why do ...
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What is the period of the 'cycle' of Earth's ecliptic variation, relative to the 'invariable plane'? 70,000 or 100,000 years?
The plane of Earth's path around the Sun, the ecliptic, is different from the average of the solar system's as a whole (the invariable plane) by about 1.57°....
Our path around the Sun, though, goes ...
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Solar Azimuth angle Derivation
I tried posting this on math stack exchange to no avail so I thought maybe it's more relevant here :
I know a similar question has been posted here before but no links to any mathematical derivations ...
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How to find the local azimuth of the highest point of the ecliptic
I would like to use pyephem or skyfield1 to find the degree of the local horizon (starting from South = 0°) at which is located the highest point of the ecliptic.
Note that I am not trying to find the ...
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Launch windows for Venus transit; how to convert heliocentric longitudes to date?
Being a bit familiar with celestial mechanics, I know that the Hohmann transfer orbit is the quickest way to transfer between two circular orbits of different radii around a central body in the same ...
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Which way does the Earth tilt? [closed]
On which side does the earth tilt to? I have tried figuring it out myself but I can't seem to find the answer.
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Converting orbital elements from equatorial reference frame to ecliptic
I have a bunch of orbital elements (inclination, longitude of the ascending node, mean anomaly, argument of periapsis) that are all referenced from an equatorial reference frame. But the program I am ...
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Orientation of local star map
This image depicts our solar neighborhood
Source
The plane defined by the concentric circles, does it have a relationship to any galactic reference points or the ecliptic?
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Why does east and west appear to be mirrored in the celestial sphere?
I'm wondering why East is left and West on the right of the celestial sphere if you look at images of it?
Example below:
(source)
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How to tell which of the ecliptic cross horizon angles is to the east?
Jean Meeus' Astronomical Algorithms, 2nd ed. p. 99 gives a formula for finding the two longitudes where the ecliptic crosses the horizon:
$$\tan\lambda = \frac{-\cos\theta}{\sin\epsilon \tan\phi + \...
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What is the opposite of the vernal point?
The equator and the ecliptic cross at two nodes. One of those nodes is the vernal point. What is the other one called?
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Why does the Sun track out a seemingly sinusoidal path on the celestial sphere?
The question arose because I wanted to understand the path of the ecliptic after reading about it here: https://johnlucey.webspace.durham.ac.uk/users/solar-year/
Is the sinusoidal path due to Earth’s ...
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Where and when will someone on Earth be standing with the floor parallel to the Ecliptic plane?
I have been trying to figure this out and I think the answer might be - once per day for anyone living on the Tropic of Cancer or Capricorn. Is that right? To be clear - I want to know where on Earth ...
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Sun and moon's orbit in ecliptic coordinates using skyfield
I am new to using skyfield, is there any doc or help file that can show me on how to get the orbit of Sun and moon in ecliptic coordinate for a particular date and ...
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Orbits of planets in ecliptic coordinates
Is it possible to get the ecliptic coordinates of orbits of planets for a specific date and time? Does the ephemeris data of planets help in constructing that? Any help on this would be helpful. I ...
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Ecliptic line plot in a map
Is there any url that can give me data of ecliptic line that i can plot in a map. i.e i need earth's latitude and earth's longitude of ecliptic line for a specific time and date. Right now i only ...
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Ecliptic line data [duplicate]
I would like to get the data of ecliptic line with respect to celestial equator for a particular day.
Is there any specific URL that can give me this. I only have data for declination of Sun and the ...
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How do you draw the ecliptic on a celestial sphere sketch?
I don't really understand how it's drawn on sketches of the celestial sphere. At first I thought it goes through east and west, but it does not. How do you know where to draw it?
Example from Roy and ...
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Can Eight Retrograde (seen from Earth) planets occur?
First of all, for the purposes of this question Pluto is a planet. So the eight planets being considered are Mercury, Venus, Mars, Jupter, Saturn, Uranus, Neptune and Pluto.
My question is: can all ...
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Why is the equinoxes only 2 days and not more?
The earth is tilted at 23.5 degrees which means that in the solstices the north/south hemisphere is more radiated by the sun and the tilt to the sun is maximum.
In the equinoxes, the tilt is not ...
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Is the equinox Sun always at the same zodiac sign in the ecliptic belt?
During the year the Sun moves along the ecliptic passing all the signs of the zodiac belt, in my understanding. This means that it takes ~1 month to go from one zodiac sign to the next.
The ...
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Why does moon's highest altitude change during the year
I came across a question in which moon's highest altitude had to be calculated as seen from a certain latitude, also the month and the hour and the constellation in which moon would be in had to be ...
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Recreating Observer Ecliptic Lat/Lon from JPL Horizons using SPICE toolkit
I apologise if this is the wrong place to ask. I am trying to recreate part of the calculations by the JPL Horizons system using SPICE. Specifically the Observer Ecliptic Latitude and Longitudes.
I'd ...
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Did Eudoxus describe the eclipitic on his sun motion model?
In the description of Eudoxus’s model for the sun he says one the three circles which describe solar motion is “the circle which runs along the middle of the zodiac”. Does this refer to the ecliptic ...
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What is the great (platonic?) year?
How could a great year be explained in laymen's terms?
According to the definition in NASA's Aerospace Dictionary it is a complete cycle of the equinoxes around the ecliptic that completes in 26000 ...
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What is meant by sun's path through zodiac
I read somewhere that sun's daily course and complete cycle is visible in the ecliptic belt by zodiac constellations.
I didn't understand what that means closest I could find online is: https://www....
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Why is there free magnesium in the ecliptic (if there is) and why would some be orbiting within the ecliptic plane but retrograde?
This answer to the question What direct or indirect observations of dust can one make by eye or with binoculars? mentions Brian May's thesis and it's connection to Zodical Light:
Brian May (CBE):
In ...
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location of the sun on the celestial sphere
The Sun, in its apparent motion along the ecliptic through the year, passes over the background of distant stars. However, given that we can't observe those stars due to the brightness of the Sun, how ...
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Moon inclination
The Moon is inclined to the ecliptic 5.15 degrees, and the equator of the Earth tilts 23.44 degrees. Since the Moon's ascending node to the ecliptic rotates, the Moon's inclination to the Earth's ...
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