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Astronomy/How is it that planets are travelling at perfect speed for orbit

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Expert: Jesse Martinez - 11/22/2009


Question
How is it that planets are travelling at the perfect speed for orbit. Slightly slower and would fall into the sun, slightly faster and they would fly off. How did they form these perfect orbits/speed? It cant be coincidental

Answer
Hi Stephen,

Think of it this way. The planets have settled into the orbits that their velocities allow. Remember that a velocity is a direction and a speed. A slight variation in velocity would not be the end. The planet could settle into another orbit.

As the planets were being formed in the early solar system history, they condensed from the particulate matter around the sun and began settling into orbits that suited their velocity. Try playing around on the web site below and you will gain a better understanding of how this works. It is loads of fun. I play around with it every now and then. By trying different things here, you will see how initial speed and direction can affect an orbit and that many different orbits are possible from the same starting point.

http://galileoandeinstein.physics.virginia.edu/more_stuff/flashlets/kepler6.htm

Let me know if you still have questions. I will be glad to elaborate. Call on me anytime.

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Jesse Martinez

Expertise

General and specific questions about the solar system and stellar and galactic astronomy, are what I can easily answer off the top of my head. For example, what is the largest planet in the solar system? How far away is the moon? Have there been any confirmed planets in orbit around stars other than the sun? How many stars are there? The tougher ones like explaining the big bang theory and black holes I will leave to the PhD’s. Even though I could muster an answer, I would have to research it more than I would like. I would also like to answer questions that involve Astronomy with other sciences, chemistry, biology, physics, geology and mathematics as long as they are not PhD level.

Experience

I have been into astronomy since I was 8 years old. I have kept detailed journals of my observations through small telescopes. Over the years I have participated in amateur observation projects for organizations like ALPO. My personal research has involved "discovering" the moons of Jupiter with a 4½-inch Newtonian reflector without any outside information like charts and tables. In a summer long project, I determined the existence of and plotted the orbits of the four major moons of Jupiter. From these observations, my data on orbital elements was surprisingly accurate (orbital radius and orbital period).

Education/Credentials
80 hours of college credits while studying physics and geophysics. Completed correspondence photography course while in high school. Took two semesters of electronics training at a community college. Studied computers and graduated from a technical school at the turn of the millennium, gaining A+ and Microsoft Certified Professional credentials. Hablo Español. Si quieres preguntar en Español, estoy a su servicio.

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