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Fear of Sun, Moon, and Comets

Responding to Public Questions and Misconceptions

David Morrison

April 15, 2011

Question: The Moon was at its closest distance of 221,567 miles on March 19, 2011. The Moon on that day is called the Supermoon. Was the Moon much brighter and bigger than on a normal evening? I have also heard that previous Supermoons caused the Tsunami in the Indian Ocean in 2004 and the tornado in Darwin, Australia, in 1974. Will March’s Supermoon cause some disaster now, such as an earthquake or tsunami?

Every month, as the Moon circles our planet in its elongated orbit, its distance from the Earth varies. At perigee (the Moon’s closest position to Earth), it is 14 percent closer than at apogee (the Moon’s farthest position from Earth) and therefore appears 14 percent larger. This change is too small to be noticed, unless you have some way to make a precise measurement of the Moon’s apparent size. In March 2011, the perigee happened within one hour of full phase.

The moment of full moon is also not easily apparent, and most people will call the Moon’s phase “full” over two or three days. So yes, the full moon was a little bit closer and brighter in March than usual, but if you missed it, it will be very nearly as close at the next full moon. The Moon’s perigee is nearly the same in every orbit, varying by less than 2 percent. Further, there is no evidence that the Moon is associated with anything on Earth except the tides. Neither earthquakes nor weather are correlated with the position or phases of the Moon. I received this question while attending the annual Lunar and Planetary Science Conference in Houston. About 1,500 scientists spent a week discussing fascinating new science, including spectacular high-resolution images from the NASA Lunar Orbiter, two space missions that have recently had close encounters with comets, and a flood of exciting new information about the planet Mars. Not one person mentioned 2012 doomsday or Nibiru, pole shifts, supermoons, or any of the other pseudoscience that circulates widely on the Internet. It is a jolt for me to shift attention from discussing exciting new scientific discoveries with my colleagues to answering questions I receive every day from people who fear imaginary threats like Nibiru or pole shifts or supermoons.

Question: There are reports and videos of two suns seen close together in the sky over China. What is in these videos; is it a second sun or planet? There was also a second sun seen in New Zealand at the time of the earthquake in Christchurch.

Answer: Let’s use common sense to analyze this question. (1) It is fascinating that people sit at their computer consoles and write to me about a second sun without stepping outside to see for themselves. If there really were a second sun in the sky close to the real sun, it would be equally visible everywhere to anyone who looked in the daytime. Since the image in the most popular video from China shows this “second sun” as being nearly as bright as the real sun, we would also be receiving nearly twice as much light and therefore be burning up. In other words, the idea of two suns in our sky is obviously untrue. (2) You mention that the second image could be a planet. Planets shine by reflected sunlight and are millions of times fainter than the sun. That is why it is so difficult for astronomers to photograph planets around distant stars. So we can easily reject that option. (3) Aren’t you concerned that the second sun images are being presented in videos, which are inherently low resolution? They are amateur videos at that with no accompanying documentation. These facts strongly suggest fakery. (4) A photo with two images of the same size side by side can be faked by shooting through double glass. The separation and relative brightness of the images depend on the spacing between the glass and the angle of the shot. (5) A few astronomers have suggested that this phenomenon could be produced under rare atmospheric conditions by a mirage. They may be right, and I would look seriously at these suggestions if I thought the double-sun photos were real. But scientists have been fooled in the past because they do not expect fake data. Professional magicians, who understand fakery, are often better skeptics than scientists.

Question: Everyone is freaking out about Comet Elenin, but no one has much real information. Has anyone determined its size and mass? If you don’t know its size and mass, how can you calculate its orbit? What are the chances that Elenin will either impact us or get close enough to cause a major catastrophe?

Answer: Comet C2012 X1 Elenin (to give its full name) is a small, long-period comet that takes about 10,000 years to complete one orbit around the Sun. Russian amateur astronomer Leonid Elenin discovered it with a robotic telescope in New Mexico on December 10, 2010. Astronomers have not measured its size because it is only a few kilometers across, and its solid nucleus is shrouded by the surrounding gas. The mass is too small to cause any change in the orbits of other objects, and so its mass is unlikely ever to be measured. However, we do not need to know either the size or the mass of a comet to calculate its orbit, as some readers may remember from their college physics or astronomy courses. It is precisely because Elenin is small and distant that journalists, and the public, have not shown much interest. Although there are still some uncertainties in its orbit, Elenin’s perihelion (when it will be closest to the Sun) is in early September 2011 at a distance from the Sun of forty to forty-five million miles. It will be closest to Earth on about October 16, 2011, at a distance of about twenty-one million miles, which is nearly a hundred times farther than the distance between the Earth and the Moon. It will probably be visible using binoculars during October.

Unfortunately, there is a rapidly growing list of conspiracy theory websites (apparently written by people who don’t know, or don’t care, what a comet is) making wild claims that Elenin will hit the Earth, disturb our orbit, cause changes to the tides, or interact with our magnetic field. Such claims are pure fiction. One of the worst examples is a video posted on March 1, 2011, claiming that the magnetic field of the comet would cause a large shift in the rotation axis of the Earth and produce mega-earthquakes on March 15, 2011. In reality, comets don’t have magnetic fields, and magnetic fields can’t change the rotation axis or cause earthquakes no matter how large they are. Unfortunately, the comet hysteria has grown since the tragic March 10 earthquake in Japan, which many pseudoscientific websites blame on this comet.

Question: Are you claiming that the March 10 earthquake in Japan and Comet Elenin are coincidences? Someone predicts an earthquake—basing it on Elenin orbit—and it happens. Isn’t it worth re-evaluating the prediction?

There is no connection between Comet Elenin and the March 10 earthquake. Scientific explanations depend on cause and effect. This comet can have no gravitational or electromagnetic effect on Earth. It is only a billionth of the mass of the Earth, and comets don’t have magnetic fields. Also remember that there was no large change (greater than 10 degrees was predicted) in the rotation axis of Earth, so there was no pole shift to trigger any earthquake. Equally important, earthquakes are not caused by external forces—not by gravity, electromagnetism, or pole shifts. Earthquakes are a product of the active geology associated with plate tectonics. The Japan earthquake was ordinary (although exceptionally large) and occurred on one of the most active subduction fault systems in the world. This is the same fault system that killed even more people in the great Yokohama quake and fire in 1923. Earth’s active geology caused this earthquake, not some poor little comet that is too faint to see without a telescope.

Question: NASA scientist Richard Hoover recently claimed to have found life in meteorites. Were these findings debunked or are they still inconclusive?

I have not yet met any astrobiologist who is convinced by Richard Hoover’s claims, which probably explains why you have not heard any updates on this story. One of the biggest problems is likely contamination by terrestrial microbes after the meteorite fell to Earth. It is also troubling that this result was not published in a real scientific journal but instead on an unreviewed online website. Over the past fifty years many scientists have investigated thousands of meteorites, and they have not seen anything that looks like life. Remember also that the meteorite parent objects are asteroids, not planets (except for the few meteorites we have from the Moon and Mars, which are in a special class). It would be unexpected to find life on a small, airless asteroid. This claim of fossil life is an example of an exceptional claim, and as Carl Sagan taught us, exceptional claims require exceptional evidence to be accepted. Hoover’s unreviewed paper is not exceptional evidence.

I am struck by the differences between this claim and the treatment given to the evidence for fossil life in a Mars meteorite reported in 1996. In that case, many scientists carefully reviewed the evidence, which was published in a prestigious scientific journal, yet it was presented at a NASA press conference as a tentative result with opportunity for critics to indicate their skepticism. Although the Mars claim is not generally accepted today, it stimulated a lot of excellent follow-up research. If Hoover wants to be taken seriously by the community of astrobiologists, he needs to publish his work in a real journal and respond to the criticisms from other scientists. That is the way science advances.

David Morrison

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David Morrison is a long-time NASA senior scientist and Committee for Skeptical Inquiry fellow. He now divides his time between the SETI Institute and the NASA Lunar Science Institute. He hosts the "Ask an Astrobiologist" column at NASA's website.