Saturday, August 8, 2009

All our eggs in one basket

Among the six abyssal lunar south pole craters picked as finalists for the impact of LCROSS, October 9, is Shoemaker, only just recently named in honor of Eugene Shoemaker, the legendary lunar and planetary scientist who, among other things, led the United States' Surveyor robotic lander program on behalf of NASA JPL.

With the equally legendary planetary scientist and writer David Levy and wife Carolyn, Gene Shoemaker co-discovered Comet Shoemaker-Levy 9 on March 24, 1993.

They resolved the shattered comets fragments and quickly traced back them back to what must have been a close encounter with Jupiter in July 1992.

Originally a larger, single comet, Shoemaker-Levy 9 had passed within Jupiter's Roche Limit, where the tremendous gravity-well of Jupiter acted unequally on the primordal icy body, wrenching it apart. Within days it became clear at least nine "calves" of that original comet were destined to slam into Jupiter's southern hemisphere, in mid July 1994.

When the time arrived, Carolyn and Gene Shoemaker, with Dr. Levy and, by way of webcam, Arthur C. Clarke, live from Sri Lanka, on the opposite side of the globe, waited in a NASA-TV studio, live, as virtually all of humankind's telescopes, including Hubble, turned to watch, and no one was disappointed.

Between July 16 and July 22, 1994 the cometary fragments bombarded Jupiter at nearly the same southern latitude and the vaporizing impacts were visible though their points of impact were just beyond view, on the pre-dawn side of the Jovian disk.

One by one, expanding halos, each the size of Earth, rotated into view as the planet turned, winding around into the sunlight as newer impacts continued with a brilliance that lit eclipsed faces of Jupiter's shadowed moons beyond.

That all this "legend" coincided in serendipity, legendary men, women and their instruments, demonstrated a stark fact beyond much in the way of doubt.

Such a display probably did not just happen, like a tree falling in the forest, because, there were ears to hear, or because, for the first time in human history, a passive audience just happened to be looking that way. Such happenings, as Earth's Moon testifies loudly to any who might listen, have to be very common.

There may have been a peak in the shuffling of that single percent of this star system's mass that is not presently part of the Sun, even a Grand Bombardment, 3.9 billion years ago, that very slowly reduced in frequency and in the size of impactors, but the bombardment is still underway.

If there was lingering doubt, fifteen years later, in July 2009, the aftermath of a "Shoemaker-Levy" class cometary impact, a resulting scar-like halo like those seen in 1994, showed up once again, but this time without any advance notice.

As the Daily Galaxy picked up on the story, the Lunar Pioneers are reminded of two compelling reasons to learn the lessons of the Moon, the secrets of the history of the Solar System, writ both large and small on its surface.

We ought not put all Mankind's eggs in one basket.

And while we're reading that "fine print" of the Moon's story, which is also the story of Earth, we had better allow our relatively large natural satellite to teach us hard lessons of survival in the most hostile of environments, the same part of the Universe where the Earth is. After news of this latest impact on Jupiter hit, many were asking that silly question again, "can it happen here?"

No doubt of it. The answer remains the same as it was in 1994. It's not "if," but "when?"

(Another) Pacific Ocean-Sized impact on Jupiter highlight's Hawking's Asteroid Theory

"In further evidence that space itself is an action movie (or at least that God watches Michael Bay movies), an explosion the size of the Pacific ocean has scarred Jupiter. Yes, the entire ocean. The explosion occurred on July 19 when an asteroid slammed into the planet, and although Jupiter has no solid ground the gas can still get thick enough for things like "impacts" and "KABOOM" to happen. - Daily Galaxy, July 24"

Read the feature story HERE.

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