I could decide that getting out of the way of a potentially lethal storm would offend God somehow. Or I could decide that God gave me a brain: and expects me to use it. The latter seems more prudent.
We've gotten pretty good at spotting tornadoes, and letting folks know that it's time to head for storm shelters. We've even got a tsunami warning system that usually works, and routinely track icebergs to protect shipping.
But we don't have an 'impact warning system' for telling folks that something's about to fall out of the sky. I think we've got the technology for something like that: and that now would be a good time to start building it.
From the Sky: Dust, Gravel, and the Occasional Mountain
In the last fifty years, astronomers have learned a great deal about Solar system: that collection of planets, dwarf planets, asteroids, comets, and miscellaneous debris orbiting the sun. Quite a few bits and pieces have orbits that come close to Earth's. Most of it's basically dust and gravel:"Every day about 100 tons of meteoroids -- fragments of dust and gravel and sometimes even big rocks - enter the Earth's atmosphere. Stand out under the stars for more than a half an hour on a clear night and you'll likely see a few of the meteors produced by the onslaught. But where does all this stuff come from? Surprisingly, the answer is not well known...."The dust and gravel isn't a problem here on Earth's surface. Once in a while, though, something bigger comes by. That's where holes in the ground like Barringer Crater in Arizona come from.
(NASA Science (March 1, 2011))
(From NASA Earth Observatory, via Wikipedia, used w/o permission)
Barringer Crater, also called Meteor Crater, in the American southwest. Taken by the NASA Earth Observatory, August 13, 2009.
Happily, big pieces like that don't come along very often. Barringer Crater is about 50,000 years old, and as far as I know there hasn't been an impact that big since.
Impacts from really big pieces, like what probably helped the dinosaurs die out, are even rarer. On the other hand, smallish lumps fall more frequently. For example, astronomers say that things the size of what exploded over Tunguska in the early 20th century hit Earth every hundred years or so.
Interestingly, a Tunguska-size lump of rock exploded over the Ural mountains last week: about a hundred years after the Tunguska event; and on the same day as Asteroid 2012 DA14's flyby. I put excerpts from news about those events at the end of this post.1
An Asteroid
Astronomers knew about Asteroid 2012 DA14, and had a very good idea of where it would go.It came very close to Earth, on a cosmic scale, passing inside the orbits of DirecTV-7S, MEASAT-3, Solidaridad-2, Yamal 201, and the hundreds of other satellites in geosynchronous orbit.
A satellite has to be 42,164 kilometers, or 26,199 miles, from Earth's center to complete one orbit in the 23 hours, 56 minutes, and a few seconds it takes Earth to turn once: so those satellites are still more than 20,000 miles up.
Asteroid 2012 DA14 came closer than that: 27,680 kilometers; or 17,200 miles. It was approaching Earth from 'below,' whizzing by us from the general direction of Earth's south pole:
(Karl Tate, via Space.com, used w/o permission)
Meanwhile, a smaller bit of rocky stuff coming from another direction exploded near the Ural Mountains.
A Meteor
(Reuters/Amateur video via Reuters TV, used w/o permission)
"Trail of a meteorite crossing the early morning sky above the city of Kamensk-Uralsky February 15, 2013, is seen in this still image taken from video footage from a dashboard journey recorder...." (Reuters)
Apart from hitting Earth within 24 hours of 2012 DA14's closest approach, and being an object in the Solar system, the Russian meteor had nothing to do with the asteroid. (Mike Wall, Space.com)
By the way, we call this sort of thing a meteor while it's still in the air, a meteorite when it hits the ground, and major trouble if it explodes over a city. Which this one did. I put links to a glossary and some background articles under under Background, below.
As far as I've heard, nobody was killed when the meteor exploded. That's remarkable, considering how much damage the blast caused.
(Reuters//Yevgeni Yemeldinov, used w/o permission)
"Workers repair damage caused after a meteorite passed above the Urals city of Chelyabinsk February 15, 2013." (Reuters)
The Russian Academy of Sciences estimated that the meteor's mass at around 10 tonnes. (as reported by BBC News) I take that to be the one tonne = 1,000 kilograms measure for deadweight tonnage, which is a lot of meteor.
Asteroid 2012 DA14 is a lot bigger, with a mass around about 190,000 metric tones. ("2012 DA14," Wikipedia) I'm very glad that DA14 didn't hit Earth.
Asteroid 99942Apophis, Greenwich Village, and Atlantic City
Another asteroid, 99942 Apophis, was in the news January. Science news, anyway. ("Asteroid 99942 Apophis pass of January, 2013," Sydney Observatory)That asteroid's claim to fame is that it'll come quite close to Earth in 2029: about 30,000 kilometers, or 18,600 miles. The last I heard, astronomers hope that data from the 2013 flyby will let them make a very precise prediction about the asteroid's position in 2036.
As of January, 2013, we're sure that 99942 Apophis will come very close to Earth in 2036: or hit this planet. If it does, it wouldn't be the end of the world. On the other hand, there could be a lot of damage.
I ran a rough simulation of what would happen if something the size of 99942 Apophis hit New York City's Greenwich Village. (Apathetic Lemming of the North (January 11, 2013))
Briefly, the value of real estate investments on Manhattan Island would drop to zero, millions of people would die, and we'd have a crater more than two miles across near the mouth of the Hudson.
The good news is that the damage would be fairly limited. In that scenario, folks in Atlantic City, about a hundred miles away, would feel the earth shake. Then, a few minutes later, quarter-inch-wide bits of New York City and environs would start falling out of the sky. Think of a hailstorm, with gravel instead of hail.
Globally, the major effect of the impact would probably be a flurry of headlines and television specials: and, of course, the impact of a major seaport and financial center disappearing.
Asteroids, Technology, and Ethics
Hollywood silliness like "Armageddon" and "Meteor" notwithstanding, big rocks and gigantic snowballs really do occasionally hit Earth: and the best way of dealing with them may not be setting off an improbably colorful nuclear explosion.My guess is that we'll eventually have potentially-dangerous objects cataloged: and routinely give them a nudge away from Earth. Most of the technology needed is available today; I think the hardest part of developing an 'Asteroid Patrol' will be convincing enough national leaders that asteroid impacts really happen, and that's another topic.
I'm quite sure that we can develop a system that will protect us from large impacts: just as we have developed systems to deal with storms, tsunamis, and ice bergs.
I'm also quite sure that we may develop technology for that purpose. We have dominion over creation, and are expected to be human. (Catechism of the Catholic Church, 2293, 2415) (January 27, 2013)
Technology, by itself, like science, isn't 'good' or 'bad.' What we decide to do with technology, and how we decide to learn about this astounding universe, is different. Ethics matter, always. (Catechism, 2294, 2415)
Finally, one of our tasks is handing this world on to future generations: and that's another topic. Topics. (February 10, 2013; January 14, 2013)
Related posts:
- Science and technology
- "Science, Technology, and Being Human"
(January 27, 2013)
Particularly - "Asteroid Miners"
Apathetic Lemming of the North (January 25, 2013) - "News, Good and Otherwise: and Billions of Worlds"
(January 11, 2013)
Particularly - "Earth Day, 2012: This Catholic's View"
(April 22, 2012)
Particularly - "Proposed Commission for Planetary Defense: H.R. 5587 Makes Sense"
Apathetic Lemming of the North (July 20, 2010)
- "Science, Technology, and Being Human"
- Getting a grip
- "Advanced Technologies and Responsible Stewardship"
(January 14, 2013) - "...The Man With the X-Ray Eyes," the Tuskegee Experiment, and Seeking God"
(February 10, 2013)
Particularly - "Guns, Gamma Ray Bursts, and Roller Coasters"
(January 4, 2013)
Particularly - "What Hurricane Irene Doesn't Mean, and Prayer"
(August 29, 2011) - "Courtney Nash, Organ Transplants, and Bingo"
(August 15, 2011)
- "Advanced Technologies and Responsible Stewardship"
- Asteroids
- "Asteroid Apophis: No 'Earth Shattering Kaboom' "
Apathetic Lemming of the North (January 11, 2013)
Particularly - "Asteroid Misses Earth, Good News; It's Not Unique, Not-So-Good News"
Apathetic Lemming of the North (June 29, 2011) - "Asteroid Apophis: Probably Won't Hit Earth in 2036 or 2068"
Apathetic Lemming of the North (March 10, 2011) - "Dinosaurs, Three Major Asteroid Impacts, and Massive Volcanic Eruptions"
Apathetic Lemming of the North (August 29, 2010) - "Asteroid 1999 RQ36 Won't Hit Earth in 2182: Probably"
Apathetic Lemming of the North (July 30, 2010)
- "Asteroid Apophis: No 'Earth Shattering Kaboom' "
- "The Search Is on for Meteorite"
Gautam Naik, Alan Cullison, The Wall Street Journal (February 19, 2013, updated from print article of February 19, 2013) - "NASA-backed meteor tracking system on horizon"
FoxNews.com (February 15, 2013) - "Meteorite explodes over Russia, more than 1,000 injured"
Andrey Kuzmin, Reuters (February 15, 2013) - "Asteroid Buzzes Earth in Record-Breaking Flyby"
Mike Wall, Space.com (February 15, 2013) - "Meteor strike injures hundreds in central Russia"
BBC News (February 15, 2013)
- "Top 10 Ways to Stop an Asteroid"
Robert Lamb, Discovery News (January 30, 2013) - "What's Hitting Earth?"
NASA Science (March 1, 2011) - "2012 DA14"
Wikipedia - "Chondrite"
Wikipedia - "Glossary of Meteorite Terms"
The Meteorites Australia - "Tunguska event"
Wikipedia
1 Excerpts from the news:
"The Search Is on for Meteorite"
Gautam Naik, Alan Cullison, The Wall Street Journal (February 19, 2013, updated from print article of February 19, 2013)
"The meteor that crashed to earth in Russia was about 55 feet in diameter, weighed around 10,000 tons and was made from a stony material, scientists said, making it the largest such object to hit the Earth in more than a century.
"Large pieces of it have yet to be found. However, a team from Ural Federal University, which is based in Yekaterinburg, collected 53 fragments, the largest of which was 7 millimeters, according to Viktor Grokhovsky, a scientist at the university.
"Data from a global network of sensors indicated that the meteor's fiery disintegration as it neared earth near Chelyabinsk, Russia, unleashed nearly 500 kilotons of energy, more than 30 times the energy of the Hiroshima atomic bomb.
"It is the largest reported meteor since the one that hit Tunguska, Siberia, in 1908, according to the National Aeronautics and Space Administration. The U.S. agency's new estimate of the meteor's size was a marked increase from its initial one.
" 'We would expect an event of this magnitude to occur once every 100 years,' said Paul Chodas of NASA's Near-Earth Object Program Office. "When you have a fireball of this size we would expect a large number of meteorites to reach the surface and in this case there were probably some large ones."...
"...The search was hampered, Dr. Grokhovsky said, by officials of Russia's Emergency Situations Ministry, which sealed off the area around an 25-foot-wide hole in the ice of Lake Chebarkul, near Chelyabinsk, where a chunk was believed to have fallen. Ministry divers didn't find anything in the lake.
"A top regional official told Russia's Interfax news agency that the hole appeared there for another reason and wasn't caused by the meteor. 'They just don't know what they are looking for,' said Dr. Grokhovsky....
"...As space visitors go, the meteor wasn't especially exotic. It was of a variety known as ordinary chondrites, which make up most meteorites found on Earth. But it is still of scientific interest...."
"NASA-backed meteor tracking system on horizon"
FoxNews.com (February 15, 2013)
"In the wake of the meteorite explosion over Russia's Ural Mountains on Friday, a meteor tracking system could be on its way.
"KHON in Honolulu reports that a professor at the University of Hawaii's Institute for Astronomy is developing what he calls an Asteroid Terrestrial-impact Last Alert System.
" 'It struck me that there was this kind of hole, that this imminent impacter risk is real and it comes from very small things,' said Dr. John Tonry said to the Fox affiliate. '“It's gonna involve small telescopes about the size of a good garbage can, but very wide fields of view and the intent is to basically scan the whole sky a couple times a night and that makes it possible for things to sneak through.'
"Tonry's ATLAS project has also recently received funding to the tune of $5 million from NASA and will be developed to precisely detect when and where a meteorite would hit...."
"...The meteorite that streaked across the Russian sky ... was estimated to be about 10 tons and 49 feet wide and entered the Earth's atmosphere at a hypersonic speed of at least 33,000 mph before shattering into pieces about 18-32 miles above the ground, the Russian Academy of Sciences said in a statement on Friday."
"Meteorite explodes over Russia, more than 1,000 injured"
Andrey Kuzmin, Reuters (February 15, 2013)
"A meteorite streaked across the sky and exploded over central Russia on Friday, raining fireballs over a vast area and causing a shock wave that smashed windows, damaged buildings and injured 1,200 people.
"People heading to work in Chelyabinsk heard what sounded like an explosion, saw a bright light and then felt the shock wave, according to a Reuters correspondent in the industrial city 1,500 km (950 miles) east of Moscow.
"The fireball, travelling at a speed of 30 km (19 miles) per second according to Russian space agency Roscosmos, had blazed across the horizon, leaving a long white trail that could be seen as far as 200 km (125 miles) away...."
"...The meteorite, which weighed about 10 metric tons and may have been made of iron, entered Earth's atmosphere and broke apart 30-50 km (19-31 miles) above ground, according to Russia's Academy of Sciences.
"The energy released when it entered the Earth's atmosphere was equivalent to a few kilotonnes, the academy said, the power of a small atomic weapon exploding.
"No deaths were reported but the Emergencies Ministry said 20,000 rescue and clean-up workers were sent to the region after President Vladimir Putin told Emergencies Minister Vladimir Puchkov to ease the disruption and help the victims.
"The Interior Ministry said about 1,200 people had been injured, at least 200 of them children, and most from shards of glass...."
"Asteroid Buzzes Earth in Record-Breaking Flyby"
Mike Wall, Space.com (February 15, 2013)
" An asteroid half the size of a football field buzzed Earth in a historic flyby today (Feb. 15), barely missing our planet just hours after a much smaller object exploded above Russia, injuring perhaps 1,000 people.
"The 150-foot-wide (45 meters) near-Earth asteroid 2012 DA14 cruised within 17,200 miles (27,000 kilometers) of Earth at 2:24 p.m. EST (1924 GMT) today, coming closer than many communications satellites circling our planet....
"...The flyby marked the closest approach by such a large asteroid that astronomers have ever known about in advance. But it wasn't even the most dramatic space-rock event of the day.
"That distinction goes to a brilliant fireball that exploded early this morning in the skies over Russia's Chelyabinsk region, which is about 930 miles (1,500 km) east of Moscow. The blast damaged hundreds of buildings and wounded perhaps 1,000 people, according to media reports. [Fireball Explodes Over Russia (Video)]..."
"Meteor strike injures hundreds in central Russia"
BBC News (February 15, 2013)
"A meteor crashing in Russia's Ural mountains has injured at least 950 people, as the shockwave blew out windows and rocked buildings.
"Most of those hurt, in the Chelyabinsk region where the meteor fell, suffered cuts and bruises but at least 46 remain in hospital.
"A fireball streaked through the clear morning sky, followed by loud bangs.
"President Vladimir Putin said he thanked God no big fragments had fallen in populated areas.
"A large meteor fragment landed in a lake near Chebarkul, a town in Chelyabinsk region.
"The meteor's dramatic passing was witnessed in Yekaterinburg, 200km (125 miles) to the north, and in Kazakhstan, to the south...."
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