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Astronomy/moons of venus and mercury

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Expert: Jesse Martinez - 9/29/2009


Question
All the planets except Venus and Mercury have moons. Any particular reason?

Answer
Good question Linda, you are making me think.

This was a fact I had always accepted without giving it much thought. First thing that comes to mind is that most of the other moons, except Earth's, are captured asteroids. Since the Earth, Venus and Mercury are too far away from the asteroid belt, they missed out on being able to grab a few during solar system formation. Earth's moon is a special case and has other theories behind its existence. The Earth's moon is believed to have been a result of collision with another object 4½ billion years ago when the Earth was being formed. It is widely regarded to be a fluke, a highly unlikely occurrence.

http://www.psi.edu/projects/moon/moon.html

When you take into account the proximity of Venus and Mercury to the sun, another factor comes into play. The sun's gravity would surely have affected the odds of these planets' ability to capture and retain a smaller body like an asteroid or any other mass coalescing during solar system formation.

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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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