Anonymous
Anonymous asked in Science & MathematicsAstronomy & Space · 9 years ago

# What does Lorenzo Iorio's report on the Moon mean in layman's terms?

People are asking "What's wrong with the Moon" and getting answers like "There is nothing wrong." I can clearly see the moon is not the same as it was. Either Earth or the Moon has changed in some way. This was the only report by a reputable source I could find...however I do not understand it. So I will ask the right question..What does this report mean?!? Here is the link to the report http://arxiv.org/abs/1102.0212

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• 9 years ago

Thank you for providing a link. Not all people are that thoughtful.

By the way, you should check the actual report, not just the abstract; click on the PDF link to the right of the page if you haven't done so already.

Anyway, from the abstract:

<QUOTE>an anomalous increase of the eccentricity of the lunar orbit amounting to de/dt_meas = (9 +/- 3) 10^-12 yr^-1.</QUOTE>

Maybe in display math it'll look better: http://mathurl.com/6h6moh5.png

What this means is that the time variation in eccentricity (the "ovalness" of the Moon's orbit), de/dt, was measured to be 9 parts PER TRILLION (10^{-12}) per year, with a measurement error of about 30 % (ie 9 +/- 3). This is a VERY SMALL AMOUNT, 9 parts per trillion.

I'll illustrate with an example. Given that the distance between New York and Los Angeles is about 4 thousand kilometers (2500 miles), a proportion of 9 parts per trillion corresponds to a distance of 36 micrometers, or roughtly a one tenth of the width of a human hair...

For the Moon, its AVERAGE distance to Earth is 380 thousand kilometers, so we're talking about measuring variations in distance to the Earth of the order of 380E6 * 9E-12 = 3 milimeters per year. That's about 1/8 of an inch per year...

Given that the data used for the measurement was for about 38 years, this amounts to an average variation in the "ovalness" of the orbit of about 38 * 1/8 = about 5 inches over 38 years. That's 5 inches in about 220 thousand MILES, or about 14 BILLION inches, over the course of 38 years.

Anyway, the author goes on to ask "would this be a sign of Nibiru?!"

Just looking at the abstract, the author states:

<QUOTE>an Earth-sized planet would be at 30 au, while a jovian mass would be at 200 au. Thus, the issue of ﬁnding a satisfactorily explanation for the anomalous behavior of the Moon’s eccentricity remains open.</QUOTE>

In other words, the author illustrates that for an Earth-sized object to produce that anomaly, it would have to be at 30 astronomical units from us. That's about the distance of Pluto. And Pluto is less than half the size of the Earth, so at that distance such an hypothetical object would have already been found.

Then the author considers "maybe it's farther away!" For an object the size of Jupiter, the same perturbation would indeed place it farther away than 30 AUs. For a Jupiter-sized object, it would have to be about 200 astronomical units farther away. Just using Kepler's laws as an illustration, it would mean that it would have a return time of 200^3/2 = 2800 years, which means that it would have been easily EASILY spotted at the times of the Romans or the Greeks for example (and not just by those civilizations but by ALL civilizations at the time, in Europe, in Asia, in America, etc), and if it was coming around this time, an object the size of Jupiter passing near Earth in late 2012 would have to be EASILY spotted in the night sky by now.

Please don't get too impressed by the math there. It's something you can pick at undergraduate college classes.

• 9 years ago

The report means that high precision measurements by lunar laser ranging have uncovered a tiny change in the eccentricity of the Moon's orbit. When I say tiny, I really mean tiny. The change would amount to a displacement of the Moon's position by its own diameter after 500 million years.

This is just regular science. Form a theory of the motion of the Moon. Obtain more precise measurements. Update your theory to explain them.

This is a perfectly valid report. People who use it claim that the Moon's orbit is 'wrong' or the Moon is 'in the wrong place' either don't understand it or are deliberately trying to mislead. The author rules out the anomaly being caused by an unknown planet on the grounds that the effects of such a planet on other parts of the solar system would be relatively easily detected.