Asteroid to by-pass earth

On February 15, 2013, an asteroid will come close enough to Earth to knock satellites out of orbit

The Guardian Express,

7 January, 2013

Near Earth Asteroid (NEA) 2012 DA14 has its annual flyby of the earth on February 15, 2013. Its projected orbit according to NASA will bring it well within the orbits of geosynchronous satellites currently orbiting our planet.

NASA has indicated that there is no danger of this asteroid impacting our planet, however they have not ruled out our gravity changing the asteroids orbital pattern.

NEA 2012 DA 14 was discovered on February 23, 2012 by the Observatorio Astronómico de Mallorca (OAM), near the Spanish city of La Sagra.

According to NASA’s Near Earth Object Program, NEO, the asteroid will pass the earth at a distance of 21,000 miles, putting the asteroid’s trajectory in between the earth and the satellites orbiting our planet.

Geosynchronous satellites orbiting our planet orbit at a distance of roughly 26,200 miles above the earth. Geostationary orbiting objects orbit at a distance of roughly 22,236 miles above the Earth’s equator.

These objects are considered to be in High Earth Orbit (HEO).

Any object in space considered to be in a Low Earth Orbit (LEO) is approximately 1250 miles above the equator.

The term Medium Earth Orbit (MEO) refers to an orbiting object approximately 12,500 miles above the Earth’s equator, in between objects in an LEO and a HEO, geosynchronous orbit.

With Near Earth Asteroid 2012 DA 14′s flyby falling somewhere in between geosynchronous satellite orbit, and objects orbiting in a Medium Earth Orbit pattern, the potential for this NEO impacting other objects orbiting our planet appears to be almost guaranteed.

Could one of these objects be impacted by the asteroid and then be propelled back into our atmosphere?

The chance of this happening is low, and NASA has not indicated if this potential happenstance will occur.

Asteroid 2012 DA 14 has an estimated diameter of about 45 meters, and a mass of roughly 130,000 metric tons, making it a medium-sized asteroid.

If Asteroid DA 14 were to impact the Earth, it would do so with the energy of 2.4 Megatons.

Additionally NASA estimates the closest it can get to the earth will be 17,000 miles above the equator.

NASA continually tracks these asteroids, through their Near Earth Object Program (NEO) in association with the Jet Propulsion Laboratory (JPL).

NASA’s Wide-field Infrared Survey Explorer program (WISE) searches the skies of our solar system making observations in an effort to assess Potentially Hazardous Asteroids (PHA) orbiting close to our planet.

Potentially hazardous asteroids are a smaller subset of the larger group called the Near Earth Asteroids (NEA) that have close orbits to the Earth’s and are big enough to survive passing through our atmosphere and causing damage of great proportions.

The asteroid hunting portion of the WISE program is called NEOWISE.

“The NEOWISE analysis shows us we’ve made a good start at finding those objects that truly represent an impact hazard to earth,” said Lindley Johnson, program executive for the Near Earth Object Observation Program at NASA. “But we’ve many more to find, and it will take a concerted effort during the next couple of decades to find all of them that could do serious damage or being mission destination in the future.”

“NASA’s NEOWISE project, which wasn’t originally planned as part of WISE, has turned out to be a huge bonus,” said Amy Mainzer, NEOWISE principal investigator, at NASA’s Jet Propulsion Laboratory in Pasadena California. “Everything we can learn about these projects helps us understand their origins and fate. Our team was surprised to find the over abundance of low inclination PHA’s. Because they will tend to make more close approaches to earth, these targets can provide the best opportunities for the next generation of human and robotic exploration.”

Pres. Obama has called for NASA to access an asteroid in orbit for the purposes of exploring ways to divert its orbit away from the earth in the event of a potential impact.

A new project, initiated by scientists at California’s Institute for Space Studies, would put an asteroid into orbit around the Earth’s moon, giving us the ability to study it from a closer distance then the asteroids standard orbit.

The majority of asteroids orbiting in our solar system do so in the main asteroid belt, between the planets Mars and Jupiter.

'Doomsday' asteroid Apophis more massive than first thought

Astronomers following the so-called doomsday asteroid Apophis, which will be whizzing past Earth on Thursday morning, have found the rock is much larger than had previously been assumed. Since the asteroid could hit Earth in 2036, that's a problem.

the Register,

9 January, 2013

The asteroid, named after an Egyptian god of death, had been thought to be around 885 feet (270 meters) wide, plus or minus a couple of hundred feet (60 meters). But as Apophis approached last weekend, astronomers at the Herschel Space Observatory took new observations and have concluded that astronomers have seriously underestimated both its size and its mass.

"The 20 per cent increase in diameter, from 270 to 325m, translates into a 75 per cent increase in our estimates of the asteroid's volume or mass," saidThomas Müller of the Max Planck Institute for Extraterrestrial Physics in Garching, Germany.

"These numbers are first estimates based on the Herschel measurements alone, and other ongoing ground-based campaigns might produce additional pieces of information which will allow us to improve our results."

In addition, the asteroid has a much different reflectivity, or albedo, than previously thought; 0.23 rather than the previous estimates of 0.33. This changes astronomer's calculations of the Yarkovsky effect, or how the Sun's heating and cooling influence will alter the asteroid's progress in orbit.

Apophis caused alarm on Christmas Eve 2004 after a report that it had a 2.7 per cent chance of hitting Earth in 2029, and even if it missed, the encounter could set it up for another strike in 2036. The asteroid topped the Torino Scale of risk, briefly reaching level four out of 10 – where zero is no threat and 10 is WE'RE DOOMED!)

After checking the data and weeding out the false reports, Apophis was downgraded to a level one threat and is currently expected to whizz past on Friday, April 13, 2029 at a distance of about 36,000 kilometers, just inside the orbit of our geostationary satellites. But there's a kicker.

If the asteroid passes through a gravitational zone, it will perturb its progress just enough to make sure that it will most likely hit the Earth on April 13, 2036. According to Neil deGrasse Tyson, geek icon and director of the Hayden Planetarium, if it passes through the center of the gravitational "keyhole" it'll hit the Pacific off Santa Monica, California and "sandblast the Western seaboard" with the resulting wave of tsunamis.

The asteroid is making a relatively close appearance past Earth on Thursday, coming within nine million miles of us at 1am UTC (5pm Wednesday PST) and it's being shown live on the Virtual Telescope Project. NASA and other space agencies are watching it closely to check on the current state of play with the asteroid's orbit as it enters and leaves Earth's orbit.

The odds of a 2036 impact are still tiny – an estimated 1 in 250,000 – but human ingenuity being what it is, there are already fertile minds working on a plan to deflect the asteroid. A recent Australian scheme called for paintballs to be fired at Apophis to increase the Yarkovsky effect and swing it out of harm's way, and solar sails have been mooted.