Memento Mori

2012 DA14 will pass close to Earth around midday today (Seattle local time), right as I’ll sit down to lunch.  The 190,000-ton asteroid, identified only last year, will wander within 17,000 miles of us, closer than some of our satellites.  It will not enter the atmosphere and it will not impact our planet.

Not the sun.  The view hours ago near Chelyabinsk.

Not the sun.
The view hours ago near Chelyabinsk.

At 9:15AM local time today, a meteorite entered the atmosphere, burned, partially disintegrated, and exploded over Russia’s Ural Mountains, approximately 125 miles south of the city of Yekaterinburg.  Fragments of the meteorite may have impacted Chebarkul Lake and rural areas across the border in Kazakhstan.  But most of the damage and injuries (up to 1,000 so far) are from the immense shock wave of the atmospheric explosion, which blew out windows and doors in and around the city of Chelyabinsk.  The roof and one wall of a zinc factory collapsed, and the Russian government is using military aircraft to survey additional damage.  Over 20,000 troops have been dispatched to the area to assist in recovery efforts.

The Russian Academy of Sciences believes this meteorite weighed approximately 10 tons, a mere dwarf compared to 2012 DA14.  However, today’s impact in the Ural Mountains is completely unrelated to 2012 DA14‘s flyby.  It’s arrival was complete happenstance; the two objects arrived at Earth from opposite trajectories.  But, this celestial coincidence serves as a sobering reminder of our blue marble’s sometimes perilous position in the cosmos.  As American taxpayers and voters have continuously eroded NASA’s budget, the space agency has struggled to launch missions to survey the heavens for near-Earth asteroids and craft strategies to deflect or destroy potentially dangerous impactors.  Private groups, such as the B612 Foundation, are attempting to fill in the gaps.  But, as today’s celestial duet shows, our current gaze is far too narrow for such a big sky.

Thou art mortal.

Thou art mortal.

In another coincidence, just two days ago Western rite Christians participated in Ash Wednesday, a somber celebration of human mortality inaugurating the 40-day season of Lent.  With today’s worrisome coupling of 2012 DA14‘s passover and the Chelyabinsk bolide impact, it is worth contemplating our mortality in this carefully-balanced biosphere against the backdrop of our occasionally hostile celestial neighborhood.  The skies have warned us before, most notably in an event that occurred just over a century ago a mere 1,100 miles northeast of Chelyabinsk.  In 1908, a meteorite disintegrated in the skies above the remote Siberian wilderness of Tunguska.  The subsequent explosion and shock wave was 1,000 times more powerful than the atomic bombs detonated over Hiroshima and Nagasaki 37 years later, and instantly obliterated over 770 square miles of Siberian forest.  Had Tunguska been a city of millions, the devastation would have been beyond measure.

The meteorite responsible for the Tunguska event is thought to have been approximately the same size as 2012 DA14.

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About James Urton

I went to school to become a molecular biologist.  At some point in this long education, I discovered that I love communicating science to the general public: talks, writing, at a pub, on the street corner...  Whatever venue will let me hold your attention for a few moments.  Unfortunately, I can't do this for a living, since no one will pay me.  So, I have a job as a molecular biologist at the University of Washington, where I get to work with great scientists on some really awesome projects, and I'll blog about science here at Muller's Ratchet in my spare time. Why should the general public want to know anything about science? Here's my explanation (which also explains why I chose the name Muller's Ratchet for this site). Briefly as a graduate student (before I had to devote all of my time to graduating), I blogged at Adaptive Radiation.
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