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Astronomy/Cruithne "Earth's second Moon"

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Expert: Jesse Martinez - 7/28/2010


Question
I would like to know more about "Cruithne" I'm doing a year 11 course called Research Project, I would like to find out more about it.

Answer
Greetings Raju

Cruithne,is a 3 mile wide asteroid that has been described as a quasi-satellite, or as some say "Earth's second moon". I do not agree with the latter description as it is not a moon of Earth. It is merely an object with a 1:1 orbital resonance with the Earth but does not orbit the Earth. At this time, Earth and Cruithne are orbiting the sun at about the same rate, creating the impression that the two objects are related. They are not. There are additional asteroids that are quasi-satellites around the Earth and other planets, but they are just coincidences in my opinion, since these relationships are not stable. They may last for 10 years or hundreds years but they eventually get out of synchronization.
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See the attached image for a 2D representation of the relationship. In 3D, the orbits are inclined by 19 degrees.

http://upload.wikimedia.org/wikipedia/commons/2/23/Orbits_of_Cruithne_and_Earth....

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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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