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‘Potentially Devastating’ Asteroid Approaching Earth for 2036
by
findingDulcinea Staff
Astronomers differ as to the chances of Asteroid Apophis hitting our planet; a Russian scientist argues that civilization can be confident of survival if it does.
30-Second Summary
When astronomers first identified Asteroid Apophis in 2004, they estimated that there would be a slim chance of collision as it passed within 20,000 km of Earth on April 13, 2029. Later calculations revised the date of the potential impact to 2036.
The risk posed to Earth is still thought small. However, if the asteroid passes through something called a “gravitational keyhole,” which may shift its orbit some hundred meters, that will increase the likelihood of a collision.
Such an impact would have enough force to raze an area the size of the Hawaiian island of Oahu.
Boris Shustov, of the Institute of Astronomy of the Russian Academy of Sciences, and Edward Lu, of the University of Hawaii, have studied the options open to mankind if a large asteroid should threaten the planet.
They agree that deflecting the object with an explosive, possibly a nuclear weapon, would be the best way to respond.
Other theorists have suggested a direct hit from a nuclear missile could dissolve the offending space rock.
Shustov and Lu hold that this would be an ill-advised course of action as the resultant debris could pepper the Earth with smaller meteorites. Cumulatively, these could cause as much damage as a single large asteroid.
The risk posed to Earth is still thought small. However, if the asteroid passes through something called a “gravitational keyhole,” which may shift its orbit some hundred meters, that will increase the likelihood of a collision.
Such an impact would have enough force to raze an area the size of the Hawaiian island of Oahu.
Boris Shustov, of the Institute of Astronomy of the Russian Academy of Sciences, and Edward Lu, of the University of Hawaii, have studied the options open to mankind if a large asteroid should threaten the planet.
They agree that deflecting the object with an explosive, possibly a nuclear weapon, would be the best way to respond.
Other theorists have suggested a direct hit from a nuclear missile could dissolve the offending space rock.
Shustov and Lu hold that this would be an ill-advised course of action as the resultant debris could pepper the Earth with smaller meteorites. Cumulatively, these could cause as much damage as a single large asteroid.
Headline Links: Theories abound
According to Russian government news service RIA Novosti, Boris Shustov, a Russian astronomer, identified an asteroid in 2004 that could potentially collide with Earth in 2029, although the risk is low. The energy released from the blast could surpass that of the Tunguska Valley collision in Siberia on June 30, 1908, which caused shock waves registering 5.0 on the Richter scale. Yet, Shustov believes the asteroid could be deflected with a microsatellite.
Source: RIA-Novosti
“Apophis is the only asteroid that ranks on the Torino scale, a Richter-style rating system adopted by NASA in 1999 to rank asteroids in terms of their size, chance of colliding with Earth, and level of damage they could do if an impact occurs. Apophis is classified as a level-one threat, for which the chance of collision is extremely unlikely with no cause for public attention or public concern. NASA continues to refine its understanding of Apophis’ course. Though the risk of a collision is small, NASA is considering plans for thwarting Apophis should future observations show it to be a threat.”
Source: NASA's official Web site
Background: Expected asteroids
NASA research shows that over the next 500 years, more than 1,000 asteroids and comets less than a football field in size are expected to impact Earth. While these objects have the potential to release more energy than both of the atomic bombs dropped on Japan during World War II, they would cause relatively little damage. The 1908 Tunguska collision, during which some 2,000 sq km of forest in eastern Siberia was knocked down and partially burned, is considered an extreme example of the damaging potential of space objects of this size category, termed “small impactors.” Most small impactors break up in the upper levels of the atmosphere, thus astronomers rarely keep track of them.
Source: NASA's official Web site
Asteroids, according to NASA’s Web site, are “rocky fragments left over from the formation of the solar system about 4.6 billion years ago ... sometimes referred to by scientists as minor planets, [they] can be found orbiting the Sun in a belt between Mars and Jupiter.”
Source: NASA's official Web site
The Exploratorium, a science museum in San Francisco, says that a meteoroid is “any small or rocky object” that orbits the sun. An asteroid is specifically an object falling under this description orbiting the sun between Mars and Jupiter, although gravitational interactions with other asteroids and with planets may deflect them, possibly sending them towards Earth. A meteor is any meteoroid, asteroid or comet that enters the atmosphere and burns up, creating a streak across the sky.
Source: Exploratorium's Web site
Key Players: Boris Shustov and the Planetary Society
Boris Shustov, the astronomer making the prediction that the asteroid could hit Earth, is the director of the Institute of Astronomy of the Russian Academy of Sciences. He holds doctorate degrees from the Tartu Observatory and from Moscow State University, and is a member of the International Astronomical Union, the European Space Agency, and the World Space Observatory Implementation Committee.
Source: Institute of Astronomy of the Russian Academy of Sciences
The Planetary Society, a non-profit, non-governmental international organization founded by high-profile astronomers Carl Sagan, Bruce Murray and Louis Friedman, does not rule out the possibility of a collision with Adophis in 2036. The group is running a contest for the individual or team that designs the best method to deflect the asteroid, offering $50,000 in prize money.
Source: Planetary Society
History: Impact of comets on life and Earth development
After a meteorite hit near the Andean town of Carancas near Lake Titicaca, rumors began to circulate concerning the emergence of foul-smelling gas near the impact site. Those living and visiting the region were complaining of headaches and nausea. Samples taken by Peru’s Mining, Metallurgy and Geology Institute revealed that underground deposits of arsenic were impacted during the collision, sending arsenic-laced vapors into the air.
Source: National Geographic
Some scientists have asserted that comets have had an impact on the development of life forms and the environment. W.M. Napier claims in an August 2007 paper entitled “The Origin of Life in Comets” that organic material constituting the building blocks of life came from comets bombarding Earth, rather than from the planet itself. The paper asserts that, during a comet’s aqueous phase, these comets' environments and composition are no less suitable to organic life forms than is Earth. Those arguing against this idea point out that this suggests only “clay, liquid water, and organics” are necessary for life, and that life can remain intact after being frozen for millions of years. The second paper, published by James Kennett, a paleoceanographer at the University of California at Santa Barbara, posits that a comet exploding over North America some 12,900 years ago was responsible for a relatively short, 1,000-year-Ice Age and immediately preceded an inter-glacial warm period. The main counterargument is that a comet of that size would not have burned up in the atmosphere and would have left a massive crater.
Source: NASA's Web site
Reference Material: Asteroid deflection strategies
The Institute of Astronomy of the Russian Academy of Sciences is the country’s authority on astronomy and astrophysics. Based in Moscow, the academy was founded in 1936 under presidential decree under the name The Astronomical Council of the USSR Academy of Sciences.
Source: The Institute of Astronomy of the Russian Academy of Sciences
“A [head-on] nuclear blast might not destroy a large asteroid completely, but merely split it into chunks. Instead of one large impact, you might end up with several smaller ones, which would end up doing nearly as much damage.”
Source: The BBC
NASA astronaut and former solar physicist at the University of Hawaii Edward Lu is calling for a ”space tractor” that would have the capability of nudging asteroids on a collision course with Earth. Estimated to cost between $200 million and $300 million, the spacecraft would hover close enough to an asteroid so that its gravitational pull would alter the object’s velocity, preventing an impact. A collision of the magnitude of the 1908 Tunguska event would be enough to raze the Hawaiian island of Oahu, said Robert Jedicke, another astronomer at the University of Hawaii. Due to the large-scale devastation, the risk of death in catastrophes resulting from an asteroid impact is about 1 to 10,000–20,000 over a lifespan of 100 years, or the same as dying in a plane crash.
Source: The Discovery Channel's Web site
The European Space Agency is working on an asteroid deflection mission called “Don Quijote,” which is to consist of two spacecraft operating on separate trajectories. The first, called “Sancho,” will land on the approaching asteroid. The vehicle will then fly around it using tracking equipment to measure its mass, diameter, position, shape and gravity field for several months before and after a second spacecraft, “Hidalgo”, will nudge the asteroid out of its orbit.
Source: European Space Agency
University of Arizona professor Jay Melosh suggests that sunlight could be focused on an approaching asteroid to burn it, much like an ant under a magnifying glass. A giant parabolic mirror would concentrate the sun’s rays on the asteroid, causing chunks to fly off and vaporize. Another possibility is the use of a “solar sail,” a giant kite that would harness the constant pressure of sunlight to move the asteroid steadily away.
Source: Space.com
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Source: findingDulcinea
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