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Astronomy/moon's angular diameter

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Expert: Jesse Martinez - 5/3/2010


Question
If the moon's angular diameter were .35 degrees instead of .5, what would that do to it's phases, eclipses, months, tides, perigee and apogee?

Answer
Hello Denise. There would be no change in the phases, months, tides or perigee and apogee if the mass remains the same. The one thing that would change is the eclipses.

Our moon at its current angular diameter has the property of occasionally being the exact same angular size as the sun, providing us with spectacular views of a somewhat rare event, the total solar eclipse.

At best we could experience some annular eclipses that would still probably WOW us, with 80% coverage of the sun in your scenario.

The particular properties of angular diameter and apparent angular size and distances from each other of the three different bodies, Earth, Moon and Sun are quite unique in the universe, especially the part that has the moon and the sun with the same angular diameters. That is indeed rare and improbable.

That was a very smart question to ask. I believe my explanation is complete unless you need to know how. Should you require further information I would be more than happy to help you. Follow up with me.

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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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