# Questions tagged [earths-orbit]

The tag has no usage guidance.

21 questions
Filter by
Sorted by
Tagged with
102 views

### Distance from Earth to Sun averaging method in AU definition

Historically, $1~\text{AU}$ is defined as $1/2(r_{min}+r_{max})$, but the problem is that this is not the average radius if Earth orbit would be transformed into circle, with Sun at the center and ...
68 views

### How to find the Moon's node longitude crossing

Yes, I asked this in the past but I got sidetracked and did other things. Now my question is, can one find the exact time when "north node" reaches a certain longitude? I am looking for 15....
• 167
275 views

### Voyager spacecraft distance from Earth

According with NASA JPL the earth catches up with the spacecraft because Earth is moving a lot faster than the spacecraft. Can one calculate the times when the spacecraft gets closest to Earth
• 167
96 views

### Why do these two sources list different values for the Solar axial tilt to the ecliptic and Earth's orbital inclination to the Solar equator?

On the Wikipedia article for axial tilt the Solar axial tilt is listed as 7.25° to the ecliptic, whereas on the Wikipedia article of orbital inclination Earth is listed as having an orbital ...
• 275
400 views

### Elevation difference of analemmas' taken at different hours and the reason for the tendency of analemmas' being slanted with deviation from the noon

According to Wikipedia, in astronomy, an analemma (/ˌænəˈlɛmə/; from Ancient Greek ἀνάλημμα (analēmma) 'support') is a diagram showing the position of the Sun in the sky as seen from a fixed location ...
• 133
747 views

### How did the year 1904 not have 367 days?

We know that the Earth completes a revolution around the Sun about every 365.25 days. But we consider each year 365 days and add one day to the year every four years in order to have the leap year and ...
• 1,137
164 views

### What is approximate numerical equation of the apsidal precession of the Earth-Moon barycenter?

What is approximate numerical equation of the apsidal precession of the Earth-Moon barycenter? Or is it only constant 11.45 arcsec/year with unchanged accuracy to 0.01 arcsec/year for a million years?...
• 339
98 views

### How would the synodic period of Venus appear to change if both planets were moved 10 million additional miles away from the Sun?

Let us say that Earth and Venus are both moved 10 million additional miles from the sun. How would the synodic period of Venus appear to change for an observer on Earth? If 584 days is Venus' current ...
• 171
204 views

### Why does the axis tilt (obliquity) of Earth change over time?

I have recently learned that the polar axis of Earth moves in a complex fashion. There are both precession and nutation. I have learned that Earth's obliquity varies between 22.1 and 24.5 degrees on a ...
• 151
331 views

### Earth-Moon Barycenter Perihelion

I am trying to implement an algorithm I created to get the sun rise, transit and set accurately, but in order to do that I need to get the Earth-Moon barycenter (EMB) perihelion, and not the Earth ...
• 173
181 views

### Neptune's eccentricity stability

Will Neptune's orbital eccentricity remain lower than earth's forever? It currently is at around 0.008, compared to Earth's 0.0167.
• 161
194 views

### Are all the steps below leading this approximation for a zero-shadow latitude correct?

Here we calculate an approximation of the latitude which experiences zero shadow on (at the start of) a given day of a year. Assumptions: The Earth is spherical Its orbit is circular and the ...
3k views

### Is Jupiter warming the Earth? (Earth, Sun Jupiter system)

If Sun-Jupiter baricentre is outside the Sun, does that mean the Sun is orbiting around that point too right? Then the Sun shouldn't be nearer to the Earth at some point during the Sun-Jupiter orbit (...
• 267
5k views

### What if Earth gained 1 km/s orbital velocity?

How would Earth's orbit be affected if we (hypothetically) added $1 {\rm km/s}$ to its orbital velocity? Would Earth reach close to Mars' orbit? Could Earth get gravitational assist from Mars and go ...
• 81
1 vote
105 views

### 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 ...
• 5,377
119 views

### What would happen when the speed of the Sun's spin changes?

Does the Sun's spin have effect on the orbit of the Earth?
• 143
1 vote
328 views

### The position of Polestar

Despite the revolution of the earth around the sun, why does the Polestar appear to be at the same place all through the year? My daughter, a class 8 student, asked me this question.
2k views

### Can we change Earth's orbit with modern technology? [closed]

It is well known that, according to Newton's 3rd law, spacecrafts entering or leaving Earth provoke tiny (insignificant) changes to Earth's orbit (see related question here). My question is about ...
• 363
301 views

### Keplerian Elements for the Moon and Earth around their Barycenter

So I'm looking to replicate the inner Solar System to a decent degree of accuracy. So far I've been utilizing the Keplerian Elements and Equations for the planets, as shown here. There is one issue ...
• 245
1 vote