Kepler's Orbit Around The Sun [720p]

Kepler's orbit was chosen to enable continuous observation of the target stars. This requires that the field of view of Kepler never be blocked. For a spacecraft in low-Earth orbit, nearly half of the sky is blocked by the Earth and the obscured region is constantly changing. The most energy efficient orbit beyond Earth orbit is a heliocentric (Sun centered) Earth-trailing orbit. An Earth-trailing heliocentric orbit with a period of 371 days provides the optimum approach to maintaining a stable trajectory that keeps the spacecraft within telecommunications capability. Another advantage of this orbit is that it has a very-low disturbing torque on the spacecraft, which leads to a very stable pointing attitude. Not being in Earth orbit means that there are no torques due to gravity gradients, magnetic moments or atmospheric drag. The largest external torque then is that caused by light from the sun. This orbit also avoids the high-radiation dosage associated with an Earth orbit, but is subject to energetic particles from cosmic rays and solar flares. For more information, read Launch Vehicle and Orbit at http://kepler.nasa.gov/sci/design/orbit.html

Credit: Dana Berry

Category:

Science & Technology

Tags:

• Kepler mission
• extrasolar planets

[madluc810]

Oh no, of course not off the screen. Ellipses have foci, and the sun should be oriented at one of the foci. When teaching my students about ellipses, I'd like to show them a natural occurrence of ellipses, but one that is physically accurate =) don't want to misinform them in any way

[djxatlanta]

@madluc810 - In nearly every scientific visualization, animators often take a small amount of artistic license in some areas to emphasize primary points. In the case of this animation, the animator most likely purposely chose to ignore the Earth's orbital eccentricity because the subject is Kepler's position with respect to Earth. Remember that many of these animations are designed for laypersons, and demonstrating orbital eccentricity might be visually distracting in this case. =)

[madluc810]

great except it's inaccurate. the sun should not be in the center of the orbital path

[djxatlanta]

@madluc810 - and where would you put it -- offscreen? ;-)

[sockslabs]

@madluc810 - Wow. And you had no problem with the relative sizes of Earth, sun and Kepler? The slow drift of the star-field in the background? That the Earth year is only 10 seconds long? :-)

[djxatlanta]

@sockslabs - LOL... in his case, it's the old classic -- missing the forest for the trees... for most visualizations, it's about getting across a concept -- it didn't even occur to him that perhaps the artist was trying to illustrate Earth's orbit from an angle and not from above. ;-)

[TheXRealXBrapp]

Is this to scale?

[jdtaramona]

It is a good graphical explanation about Kepler Mission, but I have a question, please, is there someone who can tell me what is the actual altitude of Kepler respect to the Earth surface, and what is its inclination respect to tthe Equatorial Earth Plane.

[guaild]

Yes, the orbit of Earth is elliptic, but probably not noticeably so if seen from space like the video shows. The eccentricity is small, relatively close to a circle: 0.01671022. I doubt that you could tell it apart from a circular shape.

[BallsInYourJawsBitch]

Wow, this is high tech, just what I was looking for...