Another asteroid on Earth Collision Course: 1999 RQ36

**American Patriot** · February 23rd, 2011, 15:56

http://www.csmonitor.com/Science/Coo...years-from-now

Huge asteroid on possible collision course with Earth (172 years from now)

The asteroid has a one-in-a-thousand chance of striking our planet in the year 2182, say NASA experts.

Asteroid 1999 RQ36 is on a possible collision course with Earth. And we've got only 172 years to do something about it.
AFP/Newscom/File

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By Paul Sutherland, Skymania News / July 28, 2010
A rather large asteroid is on a possible collision course with the Earth, space scientists have revealed. But there is no need to panic – even if an impact date is confirmed, it is not likely to be for 172 years.
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An international team, including NASA experts, say in new research that the space rock has a one-in-a-thousand chance of an impact.

They may sound like high odds, but they are enough to mean the threat from the 560-meter (612-yard) wide asteroid will have to be taken seriously.

IN PICTURES: Asteroids

If such a cosmic missile hit land, it would blast a crater several miles wide – enough to devastate a city and wreak destruction for hundreds of miles around.

The good news is the evidence suggests that if there is an impact then it is most likely to happen in 2182. That is clearly a long way of and provides time to work out strategies to deal with the threat.

The asteroid was discovered in 1999 and is dubbed 1999 RQ36. The scientists had labelled it a “potentially hazardous asteroid” of the Apollo group because its orbit brings it close to Earth. But it was then considered a much lower risk.

Now scientists from Spain, Italy and NASA’s Jet Propulsion Laboratory in California have used computer models to produce a more accurate forecast of its path. Their results are published in the science journal Icarus.

The asteroid’s orbit has been fairly well known thanks to 290 visual observations and 13 measurements using radar, say the scientists. It takes around 14 months to go round the Sun. However, a disturbance called the Yarkovsky effect, caused by the force of sunlight on smaller bodies, introduces a significant “orbital uncertainty”.

Maria Eugenia Sansaturio, of Valladolid University, Spain, said: “The total impact probability of asteroid 1999 RQ36 can be estimated at 0.00092 – approximately one-in-a-thousand chance – but what is most surprising is that over half of this chance (0.00054) corresponds to 2182.”

Scientists had previously suggested sending a space mission called OSIRIS-REx (corr) to collect samples of the cosmic missile. Bill Cutlip of NASA’s Goddard Space Flight Centre in Greenbelt, Maryland, said: “This asteroid is a time capsule from before the birth of our solar system. You can’t underestimate the value of a pristine sample.”

Scientists have reduced the threat from another 300-meter wide space rock called Apophis which is due to make two close approaches to Earth within the next 30 years.

The first, on Friday the 13th of April, 2029, is virtually certain to miss us though it will come closer than TV and other geostationary satellites, at a distance of only 18,300 miles. But uncertainty over the effect of that close encounter meant that astronomers could not rule out the chance of an impact seven years later in 2036.

Now, however, the chance of a catastrophic collision on 13 April of that year have dropped from one-in-45,000 to an even more reassuring one-in-250,000.

• Discover space for yourself and do fun science with a telescope. Here is Skymania’s advice on how to choose a telescope. We also have a guide to the different types of telescope available. Check out our monthly sky guide too!

**Ryan Ruck** · February 23rd, 2011, 16:58

Were you planning on leaving this stickied for the next 172 years?

**American Patriot** · February 23rd, 2011, 17:02

Yeah. why?

**American Patriot** · February 23rd, 2011, 17:03

It'll be forgotten if I don't. In three or four years from now it'll still be stickied there and we can all find it.

What's the problem?

LOL

**Ryan Ruck** · February 23rd, 2011, 17:09

Just giving you a hard time is all!

**American Patriot** · February 23rd, 2011, 17:11

I know.

I figured that who ever is running this place in 172 years can look back and say, "See Rick WAS right all along!"

LOL

**American Patriot** · February 24th, 2011, 19:45

Near Earth Asteroids

Potentially Hazardous Asteroids (PHAs) are space rocks larger than approximately 100m that can come closer to Earth than 0.05 AU. None of the known PHAs is on a collision course with our planet, although astronomers are finding new ones all the time.

On February 24, 2011 there were 1198 potentially hazardous asteroids.

Recent & Upcoming Earth-asteroid encounters:

Asteroid	Date(UT)	Miss Distance	Mag.	Size
2011 CL50	Feb 19	6.2 LD	--	13 m
2003 YG118	Feb 20	67.7 LD	--	1.8 km
2000 PN9	Mar 10	45.5 LD	--	2.6 km
2002 DB4	Apr 15	62.5 LD	--	2.2 km
2008 UC202	Apr 27	8.9 LD	--	10 m
2009 UK20	May 2	8.6 LD	--	23 m
2008 FU6	May 5	75.5 LD	--	1.2 km
2003 YT1	May 5	65.3 LD	--	2.5 km
2002 JC	Jun 1	57.5 LD	--	1.6 km
2009 BD	Jun 2	0.9 LD	--	9 m
2002 JB9	Jun 11	71.5 LD	--	3.2 km
2001 VH75	Jun 12	42.2 LD	--	1.1 km
2004 LO2	Jun 15	9.9 LD	--	48 m

Notes: LD means "Lunar Distance." 1 LD = 384,401 km, the distance between Earth and the Moon. 1 LD also equals 0.00256 AU. MAG is the visual magnitude of the asteroid on the date of closest approach.

**American Patriot** · May 25th, 2012, 18:34

Massive asteroid could hit Earth in 2182, warn scientists

By Niall Firth
UPDATED: 08:21 EST, 28 July 2010

A massive asteroid might crash into Earth in the year 2182, scientists have warned.

The asteroid, called 1999 RQ36, has a 1-in-1,000 chance of actually hitting the Earth at some point before the year 2200, but is most likely to hit us on 24th September 2182.

It was first discovered in 1999 and is more than 1,800 feet across. If an asteroid of this size hit the Earth it would cause widespread devastation and possible mass extinction.

And scientists say that any attempt to try and divert the asteroid will have to take place more than 100 years before it is due to hit to have any chance of success.

Artist's impression of the Chicxulub crater on the Yukatan peninsula in Mexico. The massive impact of the asteroid may have been responsible for the extinction of the dinosaurs

If the asteroid had not been spotted until after 2080 it would be impossible to divert it from its target, they warned in a new research paper.
While the odds may seem long, they are far shorter than that of the asteroid Apophis, which currently has a 1 in 250,000 chance of striking Earth in 2036.
A competition was launched in 2008 by the Planetary Society for designs for a space probe to land on Apophis and monitor its progress.

How to deflect an asteroid

Scientists have come up with a number of different ways of deflecting an incoming asteroid from its path, some more realistic than others. Here are a few of the best ideas:

Nuclear blast: A large nuclear explosion on an asteroid might be enough to deflect an asteroid but has significant political and ethical problems. And what if we just blew it into smaller pieces?
Using mirrors: A fleet of spacecraft carrying light-reflecting mirrors might be able to vaporise the asteroid's surface using the Sun's rays. The gases from its surface would create a tiny amount of thrust - enough to divert it
Gravity tractor: Crashing a spacecraft int the asteroid's surface would certainly be the cheapest option. The ship's own tiny gravity would then help move the asteroid's path. But this option would take a long time to make a difference

Maria Eugenia Sansaturio and scientists from the Universidad de Valladolid in Spain have used mathematical models to calculate the risk of the asteroid hitting the Earth anytime between now and the year 2200.
And they were shocked to discover that there are two potential opportunities for the asteroid to hit Earth in the year 2182.
‘The total impact probability of asteroid '(101955) 1999 RQ36' can be estimated in 0.00092 –approximately one-in-a-thousand chance-, but what is most surprising is that over half of this chance (0.00054) corresponds to 2182,’ Sansaturio said.
The asteroid is now behind the Sun and will next be observable only in the spring of 2011.
Scientists have estimated and monitored the potential impacts for this asteroid between now and 2200 using two different mathematical models.
Between now and 2060, the chances of Earth impacts from 1999 RQ36 are remote.
But the researchers discovered that the odds increase fourfold by 2080 as the asteroid's orbit brings it swinging back towards Earth.
The odds then drop before rising again in 2162 and 2182.

Asteroid 1999 RQ36 is part of the Potentially Hazardous Asteroids (PHA) group, which all have the possibility of hitting the Earth due to their orbits and are all considered likely to cause damage.
Even though the asteroid’s orbit is well-known thanks to 290 different observations by telescopes and 13 radar measurements there is uncertainty about its path because of the so-called Yarkovsky effect.
This effect, first discovered in 2003 and named after a Russian engineer, is produced by the way an asteroid absorbs energy from the sun and re-radiates it into space as heat. This can subtly alter the asteroid’s flight path.
The research, which has been published in Icarus journal, predicts what could happen in the upcoming years considering this effect.

An image of 1999 RQ36, the asteroid which has a 1/1000 chance of hitting Earth

Sansaturio said: ‘The consequence of this complex dynamic is not just the likelihood of a comparatively large impact, but also that a realistic deflection procedure (path deviation) could only be made before the impact in 2080, and more easily, before 2060.'
She added: ‘If this object had been discovered after 2080, the deflection would require a technology that is not currently available.
‘Therefore, this example suggests that impact monitoring, which up to date does not cover more than 80 or 100 years, may need to encompass more than one century.
‘Thus, the efforts to deviate this type of objects could be conducted with moderate resources, from a technological and financial point of view.’
The impact from the asteroid that created the famous Chicxulub crater in Mexico would have caused 'mega-tsunamis' many thousands of feet high.

It is believed that this asteroid led to the extinction of the dinosaurs.
Scientists around the world have long been discussing ways of deflecting potentially hazardous asteroids to prevent them hitting Earth.

One of the more popular methods is to detonate a nuclear warhead on an approaching asteroid to deflect it from its orbital path.
Last month physicist David Dearborn of the Lawrence Livermore National Laboratory in the US argued that nuclear weapons could be the best strategy for avoiding an asteroid impact - especially for large asteroids and with little warning time.

Read more: http://www.dailymail.co.uk/sciencete...#ixzz1vuLYj6kq

**American Patriot** · May 25th, 2012, 18:35

NASA Scientist Figures Way to Weigh Space Rock
05.24.12

This computer generated image of asteroid 1999 RQ36 was derived from data acquired by the NASA-supported Arecibo Observatory in Puerto Rico. Image credit: NASA/NSF/Cornell/Nolan › Larger view

A scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif., has accurately determined the mass of a nearby asteroid from millions of miles away. The celestial equivalent of "guess your weight" was achieved by Steve Chesley of JPL's Near-Earth Object Program Office by utilizing data from three NASA assets – the Goldstone Solar System Radar in the California desert, the orbiting Spitzer Space telescope, and the NASA-sponsored Arecibo Observatory in Puerto Rico.

Chesley presented his findings this past Saturday, May 19, at the Asteroids, Comets and Meteors 2012 meeting in Niigata, Japan.

For Chesley to define the asteroid's mass, he first needed to understand its orbit and everything that could affect that orbit -- including neighboring celestial bodies and any propulsive force (however minute) the asteroid could generate.

Incorporating extraordinarily precise observations collected by astronomer Michael Nolan at Arecibo Observatory in September 2011, Arecibo and Goldstone radar observations made in 1999 and 2005, and the gravitational effects of the sun, moon, planets and other asteroids, Chesley was able to calculate how far the asteroid deviated from its anticipated orbit. He found that 1999 RQ36 had deviated from the mathematical model by about 100 miles (160 kilometers) in the past 12 years. The only logical explanation for this orbital change was that the space rock itself was generating a minute propulsive force known in space rock circles as the Yarkovsky effect.

The Yarkovsky effect is named for the 19th-century Russian engineer who first proposed the idea that a small, rocky space object would, over long periods of time, be noticeably nudged in its orbit by the slight push created when it absorbs sunlight and then re-emits that energy as heat. The effect is hard to measure because it's so infinitesimally small.

"At its peak, when the asteroid is nearest the sun, the Yarkovsky force on 1999 RQ36 is only about a half ounce -- around the weight of three grapes," said Chesley.

"When you're talking about the force of three grapes pushing something with a mass of millions of tons, it takes a lot of high-precision measurements over a long time to see any orbital changes. Fortunately, the Arecibo Observatory provided a dozen years of great radar data, and we were able to see it."

This radar image of asteroid 1999 RQ36 was obtained NASA's Deep Space Network antenna in Goldstone, Calif. on Sept 23, 1999. Image credit: NASA/JPL-Caltech › Full image and caption

The final piece to the puzzle was provided by Josh Emery of the University of Tennessee, Knoxville, who used NASA's Spitzer Space Telescope in 2007 to study the space rock's thermal characteristics. Emery's measurements of the infrared emissions from 1999 RQ36 allowed him to derive the object's temperatures. From there he was able to determine the degree to which the asteroid is covered by an insulating blanket of fine material, which is a key factor for the Yarkovsky effect.

With the asteroid's orbit, size, thermal properties and propulsive force (Yarkovsky effect) understood, Chesley was able to perform the space rock scientist equivalent of solving for "X" and calculate its bulk density.

"While 1999 RQ36 weighs in at about 60 million metric tons, it is about a half kilometer across," said Chesley. "That means it has about the same density as water, so it's more than likely a very porous jumble of rocks and dust."

Asteroid 1999 RQ36 is of particular interest to NASA as it is the target of the agency's OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer) mission. Scheduled for launch in 2016, ORIRIS-Rex will visit 1999 RQ36, collect samples from the asteroid and return them to Earth.

NASA detects, tracks and characterizes asteroids and comets passing relatively close to Earth using both ground- and space-based telescopes. The Near-Earth Object Observations Program, commonly called "Spaceguard," discovers these objects, characterizes a subset of them, and establishes their orbits to determine if any could be potentially hazardous to our planet. JPL manages the Near-Earth Object Program Office for NASA's Science Mission Directorate in Washington. JPL is a division of the California Institute of Technology in Pasadena. JPL also manages the Spitzer Space Telescope and Goldstone Solar System Radar.

More information about asteroids and near-Earth objects is at: http://www.jpl.nasa.gov/asteroidwatch .

D.C. Agle
818-393-9011
agle@jpl.nasa.gov

Dwayne Brown 202-358-1726
NASA Headquarters, Washington
Dwayne.c.brown@nasa.gov

**American Patriot** · May 25th, 2012, 18:38

Looks like this asteroid is VERY interesting to science... only a 1-in-100 chance of hitting us though....

Asteroid specialist will present talk Thursday

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May 22, 2012 11:05 am • Arizona Daily Star
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Ed Beshore, the former director of the Catalina Sky Survey, will talk about the search for dangerous asteroids and comets and a mission to explore one of them at 3:30 p.m. Thursday at Academy Village, 13715 E. Langtry Lane.

Earlier this year, Beshore left the Catalina Sky Survey and assumed the role of deputy principal investigator for OSIRIS-REx, an $800 million mission to the near-Earth asteroid 1999 RQ36. The spacecraft will be launched in 2016 and arrive at the asteroid in 2019. It will spend nearly a year studying the asteroid before grabbing a sample and returning it to the Earth in 2023.

Beshore’s talk, free and open to the public, is sponsored by the Arizona Senior Academy. It will be held in the Academy’s great room, adjacent to the community center at Academy Village, 13715 E. Langtry Lane.

Academy Village is an active-adult community located off Old Spanish Trail six miles southeast of Saguaro National Park East.