Monday, September 23, 2013

Hanging On By a Delicate Thread....

This is a random, short post about how fragile life on earth actually is.  Sounds pretty optimistic, huh?

Sometimes nature reminds us that we're not as tough as we think we are.  We think we're pretty invincible with technology and our guns, armies, and nuclear weapons.  We drill oil wells and mine coal and other minerals to grab up all we can of the earth's resources to make us more powerful.  We create biological and chemical weapons that have devastating potential.  Sometimes, as a result, we think the only thing that can destroy humanity is itself.  For the most part, our technology and what we can do with it is pretty amazing.  The human race, despite all of its flaws, has achieved some remarkable things.  We put people on the moon!  Even today that still sounds kind of crazy.

However, in the grand scale of the universe, we're still just a tiny speck.  Here's a story to remind you that, despite our best efforts, our very existence depends in part on luck.....

Read on after the jump.

I was intrigued a few years back when I read a 2010 BBC article about a paper published in Astrophysical Journal Letters documenting images of a "bruise" that occurred on the planet Jupiter in 2009 when it was apparently hit by an object thought to be an asteroid (read about the 2009 Jupiter impact here on National Geographic's webpage).  The asteroid was likely about 500 meters (about 1640 feet) wide. The impact released a force described in the article as a few thousand nuclear bombs and caused a scar the size of the Pacific Ocean.  It produced a pattern of debris about half the size of the Earth.

Remember that Jupiter has a radius about 11 times that of earth, giving it a volume of about 1300 earths.  It's a huge planet (the biggest in the solar system), with 2.5 times the mass of all the other planets in our solar system combined (read more about Jupiter on NASA's webpage here).

While this impact isn't all that catastrophic to something as big as Jupiter, just think about what it would do to us.  Astronomers naturally want to observe as many planetary impacts as they can to get an idea of what would happen to the Earth if a collision with an asteroid, comet, etc. occurred.  They are starting to think that impacts on Jupiter are much more common than they previously thought.  Now, I'll grant you that Jupiter is a big target to hit, but asteroid impacts have occurred on earth and most certainly will occur again....someday.

One thing that was pretty cool about this impact was that it was first spotted by amateur astronomers.  The actual impact created a flash that could be seen from earth.  The NASA images of the "bruise" shown above were captured later by the Hubble space telescope.  Another impact on Jupiter was also caught by amateur astronomers in September 2012 (read more about it here).  Unlike some scientific fields, astronomy is a field where amateurs can sometimes be involved in spotting new discoveries in real time.     

Basically, the Jupiter observation confirms what we already know:  We're in some deep trouble if something that big hits the earth.  Agustin Sanchez-Lavega of the University of the Basque Country in Bilbao, Spain said (quoted in the BBC article), "It would be a catastrophe...entire continents could be destroyed."  Thankfully, we do have some astronomers and astrophysicists that try to track asteroids and other objects that could come close to earth, including those at NASA's Near Earth Object Program.  I know I harp a lot on the topic of research funding, but I think we should keep these guys in mind when it comes time to determine our budgets.  There's not a very high chance at all that anything is going to hit the earth any time soon, but the sooner we know something is coming, the sooner we might be able to figure out what we can try to do about it.              

Remember the Dinosaurs?   If they had our brains, they probably would have thought that they were pretty invincible, too.  Now we know that an impact event is very likely what proved that wrong (you can read more about that here and here).        

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