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February 18, 2013 [LINK / comment]

Asteroid barely misses Earth

Was it just a coincidence that a large meteor caused major damage in Russia on the very same day that a dreaded asteroid came within a mere 17,000 miles of colliding with Mother Earth? Well, that's what the scientists tell us. To a layman, the odds that such a disaster would happen on the very same day that an asteroid passed so close to the Earth would seem astronomical. (Irony.) But the asteroid, which was named 2012 DA14, was travelling south to north, in contrast to the meteor trail. The asteroid was estimated to be 150 feet wide, and would have caused a global cataclysm of biblical proportions. (More irony.) The meteor which struck near Chelyabinsk, Russia was about the size of a bus, they say. Most of the damage was caused by the shock waves emitted as the meteor burned up in the atmosphere, not by any direct collision with any fragments of it. (A meteorite is an object from space that has already landed, and a meteroid is an object in space before it reaches our atmosphere.) For more, see

UPDATE: You can see some of the videos of the meteor at; link via Facebook.

I was somewhat dubious of the initial reports, with multiple video clips of the rare celestial phenomenon. How could so many people just happen to have video cameras running at that exact moment? Well, as we have since learned, millions of people in Russia use police-style dashboard video cameras to protect themselves from liability lawsuits or extortion from thugs who deliberately cause auto collisions or pedestrian injuries in hopes of cashing in. That's a sad commentary on the deeply cynical values which prevail in post-communist Russia.

The moons of Jupiter

It was just last month that Jupiter had a close encounter (apparent, not real) with the moon, which I photographed. That prompted me to wonder whether I could get a picture of Jupiter's own moons, of which four can be seen with binoculars. Sure enough, this past Thursday night I managed to capture a photographic image of at least two of those moons. Last night I went out again, and finally succeeded, more or less. (It was bitterly cold, which made it hard to operate the camera efficiently.) The autofocus struggles to deal with interplanetary objects, and I'm having a heck of a time getting used to the manual controls on my new Canon camera. Maybe I'll get a better picture some time in the future.

Jupiter, moons 17 Feb 2013

Jupiter and three of its four largest moons (I have no idea which is which) just above, on February 17. Do a mouse rollover to see a similar image, February 14, when just two of the big four moons were visible. You can see two nearby stars that serve as a convenient frame of reference to track Jupiter's gradual transit across the sky. The one on the right is distinctly bluish. I'm pretty sure the star at the top left on Feb. 14 is the same one seen at the bottom on Feb. 17.

It was 403 years ago, on January 7, 1610, that Galileo discovered the four moons of Jupiter that later became known as Io, Europa, Ganymede, and Callisto. Those moons range in size from about as big as our moon to the planet Mercury. The closest one, Io, circles Jupiter in less than two days (!), while the two outer moons take seven days to complete an orbit. Compared to our moon, which takes 28 days to orbit the Earth, that is extremely fast. (See

Galileo's discovery was a big part of the revolution in the field of astronomy, confirming the heliocentric theory of Nicholas Copernicus (1473-1543). It had previously been assumed that the Earth was the center of the universe. Unfortunately, this scientific "paradigm shift" raised troubling theological issues for the Roman Catholic Church, and Galileo was later coerced into recanting his "heresies." This retraction took place during the Thirty Years War (1618-1648), when the Hapsburg Empire was trying to gain hegemony on the continent of Europe, purportedly a crusade on behalf of the Catholic faith. No wonder there was a Protestant Reformation!

Posted (or last updated or commented upon): 18 Feb 2013, 12: 49 PM

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