What is Earth's orbit: Definition and 57 Discussions

Earth orbits the Sun at an average distance of 149.60 million km (92.96 million mi), and one complete orbit takes 365.256 days (1 sidereal year), during which time Earth has traveled 940 million km (584 million mi). Ignoring the influence of other solar system bodies, Earth's orbit is an ellipse with the Earth-Sun barycenter as one focus and a current eccentricity of 0.0167; since this value is close to zero, the center of the orbit is close, relative to the size of the orbit, to the center of the Sun.
As seen from Earth, the planet's orbital prograde motion makes the Sun appear to move with respect to other stars at a rate of about 1° eastward per solar day (or a Sun or Moon diameter every 12 hours). Earth's orbital speed averages 29.78 km/s (107,208 km/h; 66,616 mph), which is fast enough to cover the planet's diameter in 7 minutes and the distance to the Moon in 4 hours.From a vantage point above the north pole of either the Sun or Earth, Earth would appear to revolve in a counterclockwise direction around the Sun. From the same vantage point, both the Earth and the Sun would appear to rotate also in a counterclockwise direction about their respective axes.

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  1. Delta2

    I Earth's orbit not perfect ellipse

    Listen to the following arguments: Earth's orbit isn't perfect ellipse because classically there is the gravitational field of moon and possibly of Mars and Venus which affect it According to general relativity isn't perfect ellipse because there is the curvature of space time which doesn't...
  2. R

    B Earth's orbit and the expansion of the Universe

    Does the Earth's orbit get very slightly larger over long periods of time due to the expansion of the universe? If so does it stay at the slightly larger distance or somehow does the energy to go back to the earlier orbit go somewhere else and if so where? If the orbit does not get slightly...
  3. D

    B Observing Orbital Mechanics from the 2nd Focus of Earth's Orbit

    If a hypothetical spacecraft could keep station at the 2nd focus of Earth's orbit, what useful observations could be made? Each minute sees a new solar triangle Earth Sun Craft (ESC). Swept area remains constant, as should length SC, and length CE + ES. With the Sun as our point source...
  4. matteo446

    Time that a comet spends inside Earth's orbit

    I tried in the first place to use the effective potential of a parabolic orbit which is 0 to get the angular momentum L. Evaluating the function U(r) at r = rP i get U(rP) = L^2/(2m(rP)^2) - GmM/rP = 0. Here I get L = m√(2GMrP). Now the relationship between angular momentum L and areal...
  5. N

    Analytic solution of the Earth's orbit around the Sun

    The exercise is to compare numerical and analytical solution. I have worked out the code from earlier exercise (see code under this text), but I don't understand how the analytical solution works. I have tried to use the equation r(theta) = a(1-e^2)/(1+e*cos(theta)), which is OK but I don't...
  6. Evenlander

    B What is the shape of an asteroid impact on Earth?

    The Earth's orbit around the Sun is an elliptical orbit. Why is that so? Does that mean Sun, much like Earth bulged at some points which makes the gravitational force between Earth and Sun stronger at some points and weaker at some comparatively?
  7. Bob R

    B How GR Predicts Earth's Orbit Around Sun: Geodesic Path & Curvature

    How does GR predict the Earth's orbit around the sun? Newtonian mechanics predict a gravitational force that is a function of the two masses. Is the geodesic path of the Earth a function of both the sun's and Earth's curvature of space?
  8. P

    Perigee & Apogee: How Earth's Orbit Impacts Summer Temperatures

    does the Perigee and Apogee of the Earth's orbit relative to the seasons affect the temperature of our summers?
  9. F

    Writing: Input Wanted Duration: flights to L-4 point, and 90 degrees Earth orbit

    Assumptions: 200+ years from now Asteroids have been moved to all Lagrange points, and at least 90, 180, and 270 degrees on Earth's' orbit for mining, and shielding humans and equipment Tech to acceleration/decelerate at 1 gravity without need to carry fuel. (My main fiction.) Direct line of...
  10. D

    I Time dilation for the Earth's orbit around the Sun

    If we have 2 atomic clocks on Earth's orbit around the Sun, one on Earth's surface, at one pole, and the other on a spaceship, far from Earth, but traveling with the same speed around the Sun, the clocks would suffer the same kinematic time dilation or not? I'm asking this because the clock on...
  11. R

    B Earth's orbit around the sun -- looking for an equation

    Hi, I'm looking for some help please. I'm struggling to find an equation of the Earth orbiting around the sun. I don't need to include the mass of the sun and the gravity laws, etc. Just the equation to calculate a position in x and y. Can anybody help me please? My idea is to put the orbit...
  12. Buzz Bloom

    I Do Solar Tides affect Earth's Orbit?

    Solar tides on the Earth are currently approximately 1/2 as strong as lunar tides. The lunar tides affect the Earths rotation as well as the moon's orbit. Therefore it seems plausible that the solar tides would affect the sun's rotation and the Earth's orbit. Can someone confirm for me that...
  13. V

    Calulate the distance of objects in Earth's orbit

    Homework Statement I am working on a report dealing with the velocity and acceleration of objects in Earth's surface based on distance from the Earth and thus far I have used the orbital speed equation and the acceleration equation. To get dive deeper into the math I would like to attempt to...
  14. Rwindsor1

    Change in the Earth's orbit radius from changing mass of the Sun

    Homework Statement Consider the Earth's orbit around the sun orbit as circular. Suppose the sun slowly loses mass from mass M1 to mass M2. Suppose that the initial orbit is R1 and the final orbit is R2. Express R2 in terms of the other parameters. 2. The attempt at a solution The problem I'm...
  15. A

    I Gravitational Waves Impact Earth's Orbit: Effects & Possibilities

    What happens to the path of Earth if a strong gravitational waves hit earth. Would there be a possibility of Earth moving out/changing the path of its current orbit? Can a high frequency gravitational waves knocks the Earth out from sun's gravitational field? (I know it is very unlikely that a...
  16. J

    Contributions to Earth's orbit

    If one writes down the Newton's equations of motion for the Earth, the forces that act on the Earth are the gravitational forces exerted by all other massive bodies, such as the Sun, the Moon, the planets etc. The largest of these forces is that of the Sun: keeping into account only the Sun's...
  17. I

    Earth's orbit & precession affected by Venus & Jupiter?

    I watched a program that said that some of Earth's past climate change was due to variations in Earth's orbit and precession due to the the gravitational perturbations caused by Venus and Jupiter. Why would that be so? I know that the orbits of the planets are eliiptical generally and they...
  18. xpell

    Heliocentric polar orbit crossing the Earth's orbit twice

    Sorry, the title's length didn't allow me to explain this better and I need it for a story that I'm writing, if you're so kind to help me. I've been trying it hard to solve it myself but I've been unable to. The problem looks simple but it isn't (for me): Please assume we have a space probe of...
  19. E

    Earth's Orbit & Fleming's Left Hand Rule

    Please forgive me as I am inquisitive enough to be dangerous. Question First, Thoughts Behind It: * How much validity is there in the application of Fleming's Left [edit: RIGHT!] Hand Rule towards the orbit of the Earth around the Sun? * I saw that NASA recognizes this but they seem to sort...
  20. P

    Why do the constellations appear to move differently in different seasons?

    If the Big Dipper goes around once every 24 hours, why is it in a different position at midnight in December contrasted with midnight in June?
  21. W

    Measuring Earth's Orbit: Methods and Distortions Explained

    How do scientists measure the distance between the Earth and sun as it orbits? Do they use visual distance or do they account for distortions?
  22. T

    Calculating Earth's Orbital Velocity from Varying Distance to the Sun

    Homework Statement Given that the Earth's distance from the sun varies from 1.47 to 1.52x10^11m, determine the minimum and maximum velocities of the Earth in it's orbit around the sun. Homework Equations F=G\frac{m1m2}{r^2} E=K+U ? The Attempt at a Solution I think the...
  23. A

    Exploring Earth's Orbit with a Changing Sun

    Homework Statement If the mass of the sun were 1/2 it's current mass suddenly show the orbit of the Earth would be a parabola... The Attempt at a Solution I'm not sure what kind of approach to apply here, if the total energy equals zero then the orbit is a parabolic trajectory, if it is less...
  24. A

    Parallax during the earth's orbit?

    Hi, Would the difference in the distance between the Earth and the sun when the Earth is in perihelion and when it is in aphelion be considered a parallax? Thanks,
  25. E

    How delicate is the Earth's Orbit?

    The Earth has at times been struck by very large asteroids but this has not knocked our planet out of it's orbit. Why not? Does the Earth have some method of 'self correction'? Or is it not a very 'fine tuned' system so that a few impacts really won't make any difference? Alternatively have...
  26. M

    Calculating the Mass of the Sun Using Earth's Orbit Data

    The Earth orbits the sun in an approximately circular orbit of radius 1.496 * 10^11 m (about 93 million miles) in a period of 365 days. Use these data to determine the mass of the sun. Solution: F = (Ms)(Me)(G)/r^2 I have two unknowns... F and Ms... please give suggestions because I...
  27. J

    Earth's orbit and relative speed/time

    Hi, I am curious whether that when the Earth is in its closest position to the Sun, the Suns gravitational pull has a direct effect on the Earths orbital speed. Since the speed of an object has an effect on time. Would the increase in speed affect time in general. Of course the time is...
  28. G

    Solar panels and radar in Earth's orbit

    Hello, I am planning to design, and maybe build, a CubeSat, or a satellite that is 10cm x 10cm x 10cm, and weighs less than about 1.5 kg. I am looking to have 6 solar panels on the cube, one on each face, and also have a full 360º in all directions radar, along with a GPS and some radio...
  29. S

    Do We Experience a Centrifugal Force from Earth's Orbit Around the Sun?

    Gday all, I was just wondering if we would experience a (very small) centrifugal force due to the Earth's rotation around the sun or not. I don't think there would be because the Earth and everything on it is in a state of free fall around the sun, but I have been told there would be a...
  30. M

    Energy Needed to Move a Satellite to Earth's Orbit

    Homework Statement Determine how much energy is needed to move a satellite of mass 500kg to an orbit of height equal to Earth's radius.Homework Equations Gravitational Potential: V = \frac{-GMm}{R} Where M is the mass of Earth (6*10^24kg), m is the mass of the satellite (500kg) and R is the...
  31. I

    Escaping the solar system from Earth's orbit

    Homework Statement (a) What is the minimum speed, relative to the Sun, necessary for a spacecraft to escape the solar system if it starts at the Earth's orbit? Homework Equations Kinetic Energy=Potential Energy 0.5mv^2=rGM/(r^2) 0.5v^2=GM/r Where M is the mass of the sun, and r is the...
  32. R

    Why Earth's Orbit is Elliptical

    Why Earth's orbit is elliptical rather than being perfectly circular
  33. S

    Circular Motion of earth's orbit Problem

    Hello everyone! Please, help me understand the following problem: Homework Statement Earth's orbit around the Sun is nearly circular. The period is 1 yr = 365.25 d. (a) In an elapsed time of 5 d, what is Earth's angular displacement? Solved! (b) What is the change in Earth's velocity, Δv...
  34. U

    Escape velocity when in earth's orbit

    I have a problem where it ask to find the period/time(using Kepler's 3rd law) of an unpowered spacecraft to move from Earth's orbit to Mars orbit using the transfer orbit approach. I found P/T using kepler's 3rd law but the second part ask to find how fast the spacecraft need to be moving at...
  35. B

    Calculating Min Δv for a Comet to Intersect Earth's Orbit

    Homework Statement A comet in a circular orbit around the Sun has speed v0 and radius r0 = aRE , where RE is the radius of the Earth’s orbit and α is a constant > 1. The comet has its velocity reduced by Δv in a collision that does not change its initial direction. Show that the...
  36. G

    Could the Chicxulub asteroid have changed Earth's orbit or axis at all

    I heard that the recent Chile earthquake moved Earth's axis by 8cm or so. Could the Chicxulub asteroid (or the even bigger, Antarctic one I just http://www.dailygalaxy.com/my_weblog/2010/03/did-the-planets-most-massive-asteroid-impact-ever-occur-in-antarctica-nasa-gravity-maps-point-to-yes.html"...
  37. J

    What Caused the Change in Earth's Orbit 125,000 Years Ago?

    last night i was watching a public broadcasting special about climate change, and they mentioned that 125,000 years ago there was a large peak in CO2 in the atmosphere which caused a rise in global temp. they stated that the effect was caused by a "change in the Earth's orbit around the sun."...
  38. G

    Did Mars belonged in Earth's Orbit at one time?

    I am curious how easily my theory can be disproven... I have never heard anyone mention it, and as well I have no knowledge to support it. I was daydreaming of what would cause a planet simular to ours, to lose all of its elemental resources. It could be the fact that I am reading a book on...
  39. R

    Will the Moon escape Earth's orbit in billions of years?

    I've heard that the moon is very slowly moving away from Earth. Will it eventually escape Earth's orbit?
  40. S

    The Atmosphere and Earth's Orbit (Probably Easy Q)

    Hi, just wondering about a (probably) easy queation. Was learning about the coriolis effect today and how since the atmosphere is not rigidly connected to the Earth it appears to veer off a northerly/southerly course in a direction depending what hemisphere it occurs in... etc. Basically its...
  41. Y

    How does the Satellite manage to stay in earth's orbit?

    I have read that an object needs to have a velocity of around 8km/s to not fall back on Earth and to stay on orbit. Based on the above, are all our human made sattelites constantly traveling at around 8km/s to not fall back on earth? Is so doen't it need a lot of fuel? Does it store all this...
  42. G

    What would happen to Earth's orbit if it increased in mass or lost velocity?

    Would it begin to spiral into the sun or would it slip into a new orbit? Don't most meteorite impacts occur due to the Earth sweeping into the meteor like a car hitting bugs? Wouldn't each and every impact slow the Earth down a tiny bit while also adding to the mass of the planet? I...
  43. qntty

    How can I track Earth's distance to the sun on a specific date?

    A few weeks ago I saw a web page (I believe it was at NASA) that allowed you to enter a date and see Earth's distance to the sun on that date. I searched but can't find the site again, does anyone know where I can find this page?
  44. M

    How Long Does It Take Earth to Orbit the Sun?

    Please help... Given that the distance to the sun from the Earth is 1.5*10^11 m and the the mass of the sun is 1.9*10^30 kg. Using Keplers law find the period of the Earth's orbit recorded in seconds; show how to express your anwser in years; and if your anwser does not agree with the accepted...
  45. Philosophaie

    Earth's Orbit & Tilt in N. America: Winter Closest, Summer Farthest

    In the Northern Hemisphere of North America is the sun closest in the elliptical motion in the winter but the tilt is away from its intensity at the Tropic Of Capricorn? In the summer is the sun farthest in the elliptical motion but the tilt is toward the Tropic of Cancer and North America?
  46. B

    Disproving Kepler's Law: Evidence from Earth's Orbit

    Hello all! I read this post on another physics forum. I thought Keplers laws were accurate for our earth/sun system? "Keplers law is so easily disproven Keplers Law states that the planets move in elliptical orbits with the sun at one focus of the ellipse so that a line connecting...
  47. baywax

    Any Changes in Earth's Orbit or Rotation?

    Has the rotation or the orbit of the Earth gone through any significant or other changes in the past 100 years? This astrobiology article talks about some of the possible effects of orbital changes in the distant past. http://astrobiology.arc.nasa.gov/news/expandnews.cfm?id=771 Here's...
  48. W

    Gravity of Sun at the Earth's Orbit

    Homework Statement What is the acceleration due to gravity of the sun at the distance of the Earth's orbit? Homework Equations Confused on which one to use The Attempt at a Solution
  49. R

    Uniform motion earth's orbit question.

    the question: What is the acceleration due to gravity of the sun at the distance of Earth's orbit? before i attempt this problem, can someone help me identify the given information that i may need that is not given in the question, maybe gravity (9.8) or where to use it. i believe i may...
  50. T

    Finding Cruithne's Orbit & Return to Earth's Orbit

    Please could someone give me information on Cruithne? I am looking for it's orbit path and when it is meant to be in Earth's orbit again. Thank you very much.