Shooting Stars

A Traveler From Outer Space
Pays Earth a Short Visit Today

Perhaps the retirement of the Shuttle Fleet has something to do with it. The fact is, out of the blue, it seems that meteor-related news have been popping up like, well, shooting stars, lately.
It all sort of culminates today, of course, when asteroid 2005 YU55 passes by earth at a shorter distance than our Moon. Pretty close, in astronomical terms, but far from harm us.
That may not be the kind of news apocalyptic cults all over, and religions zealots of many cloths, would wish for. Thank goodness. Once again, they get tripped over by their own predicament.
As for reality-bounded folks like us, though, there’s still a lot to contemplate from what’s going on above us. For when meteors are not busy ending civilizations, they do teach us a lot about our origins and, quite possible, our near future.
2005 YU55, the 400-meter diameter carbon-rich rock that’s about to zip by was discovered in Dec. 2008, and despite some concerns, was never considered big enough to wipe the planet clean. But, make no mistake about it, damage from its impact would still cause worldwide catastrophe. So yes, close but no cigar.
Not the case in 1976, when an unnoticed larger piece of rock came much closer and could, arguably, have turned our clocks back a few centuries, with its impact. But we obviously escaped that one too.
NASA’s Deep Space Network has been tracking YU55 for a while, but your chances of actually seeing it at its closest approach, 3:28pm Pacific Time, will be hindered by daytime in the West Coast and a gibbous moon in the East.
Which is just as well. These fast visitors from outer space, credited by some for having brought life to earth as comets, are themselves tiny little lifeless worlds, hiding secrets of our origins too deep inside their cores.
So, while many a lover has sworn eternal devotion at their sight, and considering the (justified) fears with which ancient peoples greeted their arrival, you do need years of training to be able to decipher their messages.

But astronomers the world over keep trying, even though they tend to get more questions than answers. Last year, for instance, the European Space Agency sent a satellite to fly by the 121km-long potato-shaped asteroid 21 Lucrecia.
Many now consider the huge body a planetesimal, or a ‘stillborn’ planet, in the florid language of astronomers, that may yield valuable insights about our own origins. The answer to that and many other questions, however, will have to wait into several years into the future.
NASA currently has its own Dawn satellite orbiting Vesta, the brightest object in the asteroid belt. Scientists believe that Vesta is also the source of a large number of meteorites that fall to Earth.
In 2005, NASA even smashed a space probe into a comet, just to have an idea of how such an even may happen. And the good ole Hubble, of course, keeps his big eye on them too, just in case.
It even captured last year an amazing view of what some rushed to call a X-shaped ‘spaceship,‘ traveling at 11,000 mph. The object hasn’t been completely identified yet, but it’s likely to be the product of a collision between two comets.

We probably lost our innocence about these unpredictable space zappers once it became evident that one did the dinosaurs in and, worst, destruction on global scale caused by a meteor had already happened even before that.
But blissful ignorance was never capable to divert reality, as far as we know. And what we now know, changes the way we look back. Add technology and other developments in applied research, and you have a very detailed but increasingly nervous picture about what may be waiting for us around the corner.
We now know, for example, that the hundreds of fuzzy objects passing in front of the sun that astronomer Jose Bonilla observed in 1883, were part of a billion to a trillion tons comet coasting as close as a few hundred miles from Earth.
Despite being unsure about what he was witnessing, Bonilla diligently documented the two-day sky parade. A century later, astronomers studying his data say that some of the 450 objects he cataloged may have been as big as a mile across.
To have an idea, the 1908 explosion over Tunguska, Siberia, believed to have been caused by an object a few tens of meters wide, was equivalent to about 1,000 times the atomic bomb detonated in Hiroshima, Japan, and flatten some 80 million trees.
If today we have a better understanding about these doomsday messengers, and more ways to detect them, there’s still no consensus on what to do, once we’d learn that they’re carry our number. By the look of things, though, it’s very likely that we’ll only act if we absolutely have to.
Gung-ho advocates of nuclear blasts tend to minimize both the risk of handling highly-weaponized radioactive material, and of breaking apart one of these flying continents, ending up showering the planet with incandescent debris.
But at the end of the day, many tools of knowledge may be useful if not to prevent such a cataclysmic event, at least to learn from those that happened in the past. For that, science has been enlisting help from unexpected places, such as Google Earth.

The previously unknown Kamil crater, found in the Egyptian desert, is 16 metres deep and 45 metres wide. Scientists say it was probably caused by a ten ton mass of iron traveling through space at more than 12,000 kph.
It all happened a few thousand years ago, and the fireball was likely witnessed by humans more than a thousand kilometres away. Mineralogist Vincenzo De Michele, though, spotted it on his own home computer, while using the search engine.
As if in anticipation of the November 17 Leonids Meteor Showers, a single shooting star did zip through the skies of Michigan this past week. What’s amazing in this day and age, though, is that it wasn’t caught on video.
So comets, asteroids, meteor showers and shooting stars are all sort of related, but vary wildly in their composition, orbit and degree of danger. As in many natural events, they are as beautiful as unpredictable, spectacular as lethal to our species.
They can harbor both the secret of life on earth and the sentence marking its end. In between such extremes, we wish upon them, get mesmerized by their alien credentials, and ride with them in our imagination to the confines of the universe and back.
As one of them brushes up the orbit of our home planet later on today, let’s just wish that, against our best rationale and just like we do when they shoot up on the horizon, that no other one will ever come any closer.

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