NASA scientists will be tracking asteroid 2005 YU55 with antennas of the agency's Deep Space Network at Goldstone, Calif., as the space rock safely flies past Earth slightly closer than the moon's orbit on Nov. 8. Scientists are treating the flyby of the 1,300-foot-wide (400-meter) asteroid as a science target of opportunity – allowing instruments on "spacecraft Earth" to scan it during the close pass.
The 70-meter diameter Deep Space Network radio telescope located at Goldstone, Ca. will be live tracking asteroid 2005 YU55 on its historic near-Earth pass on November 8, 2011 (Click Image To Enlarge)
Tracking of the aircraft carrier-sized asteroid will begin at 9:30 a.m. local time (PDT) on Nov. 4, using the massive 70-meter (230-foot) Deep Space Network antenna, and last for about two hours. The asteroid will continue to be tracked by Goldstone for at least four hours each day from Nov. 6 through Nov. 10. Radar observations from the Arecibo Planetary Radar Facility in Puerto Rico will begin on Nov. 8, the same day the asteroid will make its closest approach to Earth at 3:28 p.m. PST.
Arecibo Planetary Radar Facility in Puerto Rico
The Arecibo radar telescope spotted the asteroid 2005 YU55 back in April 2010, and those observations provided the ghostly image of that asteroid below. Nasa hopes to get higher resolution snaps -- with details as fine as two metres per pixel -- during its flyby of Earth.
The Arecibo radar telescope spotted asteroid 2005 YU55 back in April 2010 and captured this ghostly image.
The trajectory of asteroid 2005 YU55 is well understood. At the point of closest approach, it will be no closer than 201,700 miles (324,600 kilometers) or 0.85 the distance from the moon to Earth. The gravitational influence of the asteroid will have no detectable effect on anything here on Earth, including our planet's tides or tectonic plates. Although 2005 YU55 is in an orbit that regularly brings it to the vicinity of Earth (and Venus and Mars), the 2011 encounter with Earth is the closest this space rock has come for at least the last 200 years.
During tracking, scientists will use the Goldstone and Arecibo antennas to bounce radio waves off the space rock. Radar echoes returned from 2005 YU55 will be collected and analyzed. NASA scientists hope to obtain images of the asteroid from Goldstone as fine as about 7 feet (2 meters) per pixel. This should reveal a wealth of detail about the asteroid's surface features, shape, dimensions and other physical properties (see "Radar Love" -http://www.jpl.nasa.gov/news/news.cfm?release=2006-00a).
Arecibo radar observations of asteroid 2005 YU55 made in 2010 show it to be approximately spherical in shape. It is slowly spinning, with a rotation period of about 18 hours. The asteroid's surface is darker than charcoal at optical wavelengths. Amateur astronomers who want to get a glimpse at YU55 will need a telescope with an aperture of 6 inches (15 centimeters) or larger.
The last time a space rock as big came as close to Earth was in 1976, although astronomers did not know about the flyby at the time. The next known approach of an asteroid this large will be in 2028.
NASA detects, tracks and characterizes asteroids and comets passing 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 plots their orbits to determine if any could be potentially hazardous to our planet.
NASA's Jet Propulsion Laboratory 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.
- More information about asteroids and near-Earth objects is at: http://www.jpl.nasa.gov/asteroidwatch.
- More information about asteroid radar research is at: http://echo.jpl.nasa.gov/ .
- More information about the Deep Space Network is at: http://deepspace.jpl.nasa.gov/dsn .
BEST PLACE TO VIEW IN NORTH AMERICA:
Best seen from North America, the little asteroid 2005 YU55 will race far across the constellations in just 11 hours. The box on the top chart below shows the area of the closeup above. There, the asteroid is plotted for just over an hour on the evening of November 8th for North America (from 1:51 to 3:12 November 9th Universal Time). North is up, east is left. On each of the little upside-down maps of the U.S., put a pencil dot on your location. These are the asteroid’s apparent positions at 2:00 and 3:00 UT for your site. Connect your dots with a straight line paralleling the line plotted, which is for Kansas.
Click Image To Enlarge
COMMENTARY: That famous communique from Apollo 11 during the historic first-ever moon walk,
"That's one small step for man. One giant leap for mankind."
was brought to you by the 64-meter antenna at NASA's Deep Space Network in Goldstone, Calif.
The antenna has accumulated a rich legacy during its 40 years of supporting space exploration. In addition to capturing the words of astronauts on all the Apollo moon missions, the dish has communicated with the computers and equipment on every one of NASA's major robotic solar system explorers.
The "Big Dish" enabled the world to see the first-ever close-up images of Jupiter, Saturn, Uranus and Neptune, their rings and their myriad moons, by the Pioneer, Voyager, Galileo and Cassini missions. The antenna has also communicated with NASA's Mars missions, including the currently-operating fleet of five: Mars Global Surveyor, Mars Odyssey, the Mars Exploration Rovers and Mars Reconnaissance Orbiter.
The antenna's history stretches back to 1963, when the United States and Russia were engaged in a high-stakes space race. Engineers were relying on smaller antennas to keep tabs on NASA's earliest missions, which ventured only as far as orbit around Earth. With the development of the Mariner Mars missions, more powerful communications tools were needed.
The plan was to build a 64-meter antenna at Goldstone, one of three sites of the Deep Space Network. In 1963, Rohr Corporation was awarded a $12 million contract to design and build the big dish.
After two years of construction, a testing phase began to determine how well the antenna would receive signals. In March 1966, engineers pointed the dish toward Mariner 4, which had been lost by smaller antennas after its historic Mars flyby in 1965. Eureka! Mariner 4 sent a signal, and the Goldstone antenna picked it up.
To commemorate this historic event, the 64-meter antenna was named "Mars," or more technically, Deep Space Station 14. After three months of calibrations and personnel training, the Mars antenna became the first operational 64-meter antenna of the Deep Space Network in June 1966.
NASA JPL's Deep Space Network includes three communications facilities placed about 120 degrees apart around the world at three strategic locations:
- Goldstone Deep Space Communications Complex (GDSCC) located at Goldstone, California.
- Madrid Deep Space Communications Complex (MDSCC) located at Madrid, Spain.
- Canberra Deep Space Communications Complex (CDSCC) located at Canberra, Australia.
The following map shows NASA JPL's Deep Space Network radio telescope locations in Goldstone, CA U.S. (Goldstone), Madrid, Spain (Robledo) and Canberra, Australia (Tidbinbilla):
Click Image To Enlarge
As Earth rotates, this strategic placement permits ground controllers to maintain constant observation of robotic spacecraft exploring the solar system and beyond.
Goldstone Deep Space Communications Complex (GDSCC):
Madrid Deep Space Communications Complex (MDSCC):
Canberra Deep Space Communications Complex (CDSCC):
The pioneering Mars antenna was later to expand its repertoire - and its size. In the late 1960s, the antenna was called on to support all the American lunar missions, including Apollo 11, and the nerve-wracking "Houston, we have a problem" Apollo 13 mission. During the critical re-entry of that space capsule, it was more essential then ever for engineers on the ground to maintain contact with the astronauts. The craft's minimal power was needed for re-entry, with little left over for transmitted communications. The antenna was able to capture the "whispers from space," and helped bring the astronauts home safely.
As the years passed, NASA pushed the boundaries of space travel farther and farther. The transmitting capability of the 64-meter antenna was expanded for the Viking Mars landers in the mid-1970s. In 1988, the antenna was enlarged to 70 meters (230 feet) to support the Voyager 2 flyby of the distant planet Neptune.
Today's 70-meter antenna can do much more than track spacecraft. It's also used for solar system radar, imaging nearby planets, asteroids and comets. It does this by transmitting a 500,000-watt signal to "bounce" off the object and return the resulting signal to Earth. Radar allows us to figure out the paths of asteroids and comets and determine whether any might be a possible future threat to earth. The antenna is also used for Very Long Baseline Interferometry, in conjunction with a radio telescope at one of the other Deep Space Network Stations, to precisely measure Earth's orientation. This information helps with spacecraft navigation.
With a fleet of NASA missions already flying and many more planned for the future, the 70-meter Goldstone antenna and the other dishes of the Deep Space Network have a busy lifetime ahead of them.
Courtesy of an article dated October 26, 2011 appearing in NASA's Asteroid and Comet Watch and an article dated March 28, 2006 appearing in NASA JPL's Deep Space Network and an article dated November 7, 2011 appearing in Wired.co.UK
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