Our Beginnings...On A Comet?

Our Beginnings...On A Comet?

   Today marked something historic, something never accomplished, and something that may reveal how we all, including our planet earth, came to be.  Today, a probe landed on a comet.  Ten years in the making, eight years actively transmitting and two years staying in hibernation, this mission by the European Space Agency was summed up in one quick two-minute video (there are several videos but scroll down and watch the first two minutes of this particular webcast: First Go/NoGo 20:30 CET). 

   Now one might think that this wasn't that spectacular an accomplishment, after all, we've regularly sent missions to the moon, docked with the International Space Station and even landed a probe on Mars.  But here's what the engineers that calculated this mission faced...get to a small ice ball (the comet is small, only about the size of Manhattan at a little over two miles in length), one irregularly shaped (looks almost like an old dumbbell with a supporting rod in the center of two spheres), one located tens of millions of miles away (it passed Earth twice and Mars once), one hurtling through space (at a speed of about 30,000 miles per hours), catch up to the comet (and then accelerate and slow enough to match the speed of the comet), orbit the comet for several months (while moving and matching the comet's wobbly movement), then get close enough to launch a probe onto the comet's rough and pitted surface, a surface made entirely of ice.

   One there, will your probe remain on the surface (imagine driving your car at full speed and trying to park it on a moving lake of ice)...the anchor harpoons didn't deploy on the probe (but the ice screws in the legs did).  The twenty-six instruments all turned on and were transmitting.  And now comes the giddy expectations, the possible answers to how on earth (pardon the pun) did our planet get its water?  One theory is that all (yes, all) of our water came from crashing comets.  But if the hydrogen in the ice proves too heavy, that theory just might collapse. 

   At the dawn of this century, NASA launched its own probe (on February 7, 1999) to try and collect some interstellar dust, something that might possibly help us understand how our planet came to be, and part of this "dust" was to be from following a comet called Wild 2 (the probe that landed today is on Comet 67P...don't ask).  This dust is microscopic.  The probe waited until the comet neared, poked out its collector, then repositioned itself for its two-year journey back to Earth.  Here's how author Mark Miodownik described it in his book, Stuff Matters, which just won the top award at the Royal Society:  Having collected the comet dust, the Stardust spacecraft returned to Earth, arriving back two years later.  As it approached the Earth it veered away, jettisoning a small capsule, which fell under Earth's gravity, entering the atmosphere at a speed of 12.9 kilometers per second, the fastest re-entry speed ever recorded, and so becoming for a while, a shooting star itself.  After fifteen seconds of free-fall, and having reached red-hot temperatures, the capsule deployed a drogue parachute to slow down the rate of decent.  A few minutes later, at a height of ten-thousand feet above the Utah desert, the capsule jettisoned the drogue chute and deployed the main parachute.  At this point the recovery crews on the ground had a good idea of where the capsule was going to land and headed out into the desert to welcome it back from its seven-year, four-billion kilometer round trip.  The capsule hit the sands of the Utah desert at 10:12 GMT on Sunday, January 15, 2006.  "We feel like parents awaiting the return of a child who left us young and innocent, who now returns holding answers to the most profound questions of our solar system," said the project manager, Tom Duxbury, of NASA's Jet Propulsion Laboratory in Pasadena, California.

   While the results are still being studied, even to this day, one interesting finding was the presence of "aluminum-rich melt droplets.   It's very hard to understand how these compounds could have formed in a comet that had only ever experience the icy conditions of space, since they (the compounds) require temperatures of more than 1200 degrees C to do so.  Since comets are thought to be frozen rocks that date back to the birth of the solar system, this has come as a bit of a surprise, to say the least.  The results seem to indicate that the standard model of comet formation is wrong, or there is a lot more we don't understand about how our solar system formed.

   And now we arrive at a new comet, this time a ten-year waiting period finally over.  But what else will we find?  Supposed the ice on the comets doesn't match our planet's water composition (as some suspect)?  Then we are back to square one...how did our planet receive so much water?  And why our planet and not Venus or Mars?  Or did all the planets have water but ours was the only one capable to keeping it?  And even so, where did the water come from in the first place? 

   But another question comes from what seems to be a dwindling bar of patience.  In today's super-computing world that demands fast results, will governments and agencies have the foresight to develop, plan, and launch something that may or may not succeed, something that may take a decade or more to even arrive at its destination, something that may shatter much of what we thought we knew. 

   Landing on a comet might seem pointless to some, especially considering the billions of dollars and Euros that it took to accomplish such a feat.  But what would we have lost if we never tried?  Perhaps we all have our own probes to launch --that book we wanted to write, that job we wanted to try, that person we wanted to thank or embrace-- but that would take time, and effort, and possibly money.  And would we have the patience?  And would we like the results?