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The Asteroid Threat: The Search for City and Planet-killers

Part 1 of a series

On May 31 asteroid 1998 QE2 – not named after the cruise ship, but nine Queen Elizabeth 2 ship-lengths in size – had a not-so-close encounter with Earth. The asteroid benignly passed by our planet at 15 times the distance between Earth and the moon. And while astronomers at places such as NASA’s Goldstone Observatory in California and the National Science Foundation’s Observatory at Arecibo, Puerto Rico, have worked to get high-resolution radar images of 1998 QE2’s surface features, the search goes on for undiscovered but potentially dangerous smaller asteroids like the one that nearly caused a day-after Valentine’s Day massacre in the skies above Chelyabinsk, Russia on Feb. 15, 2013.

 For years, space experts have warned that we are perilously blind when it comes to detecting city-destroying asteroids, or in the case of the asteroid or comet that struck Mexico’s Yucatan Peninsula 65 million years ago during the Cretaceous period, otherworldly objects that can cause mass extinctions.

An Asteroid Explodes Over Chelyabinsk

In this image, the orbit of the Earth is the green circle. That of asteroid 2012 DA14, which passed by Earth, is the smaller nearly circular blue ellipse that is almost entirely within the orbit of the Earth. The larger, more elongated blue ellipse, stretching well beyond the orbit of Mars, is the first determination of the orbit of the Russian Chelyabinsk meteor. NASA / MSFC / Meteroid Environment Office image

In this image, the orbit of the Earth is the green circle. That of asteroid 2012 DA14, which passed by Earth, is the smaller nearly circular blue ellipse that is almost entirely within the orbit of the Earth. The larger, more elongated blue ellipse, stretching well beyond the orbit of Mars, is the first determination of the orbit of the Russian Chelyabinsk meteor. NASA / MSFC / Meteroid Environment Office image

In space policy circles, asteroids are one of the year’s major topics. The undetected 17-meter Chelyabinsk asteroid, weighing more than 7,000 tons and traveling more than 40,000 miles per hour, caused a stir not just because of the damage it did – a final count of 1,500 injuries and shattered windows across the city, all due to the shock wave from its explosion roughly 10 to 15 miles above the ground – but because of what it could have done in the event of a direct ground hit. With the power of 30 Hiroshima atomic bombs, it could have caused tens of thousands of casualties upon impact. 2012 DA14, the known asteroid that passed within 17,200 miles of Earth, also on Feb. 15, was large enough had it hit Earth to cause the kind of damage the 1908 Tunguska asteroid did, which devastated 830 square miles of Siberia.

For years, space experts have warned that we are perilously blind when it comes to detecting city-destroying asteroids, or in the case of the asteroid or comet that struck Mexico’s Yucatan Peninsula 65 million years ago during the Cretaceous period, otherworldly objects that can cause mass extinctions. Contrary to the famous Gary Larson “Far Side” cartoon, it was an unwelcome visitor from space, not cigarettes, that wiped out the dinosaurs.

 

A Mandate to Track Near Earth Objects

Asteroid 2012 DA14 on Feb 15, 2013

A graphic depicts the trajectory of asteroid 2012 DA14 on Feb 15, 2013. In this view, we are looking down from above Earth’s north pole. NASA/JPL-Caltech image

NASA, through its Near-Earth Object Program Office at the Jet Propulsion Laboratory in California, and with the support of ground based optical and radio telescopes, is currently tracking and characterizing about 95 percent of Near Earth Objects that are .62 miles (nearly 1,000 meters) or larger in diameter. And Congress has given NASA, as part of its 2005 Authorization Act, the mandate to initiate the George E. Brown, Jr. Near-Earth Object Survey Act (named for the late California Congressman who chaired the House Science and Technology Committee in the early 1990s) to detect, track, catalog, and characterize “by the end of 2020 90 percent of all potentially hazardous objects greater than 140 meters whose orbit passes within .05 astronomical units of Earth [five percent of the distance from the Earth to the Sun].” Using five ground-based telescopes, the space agency is making slow progress toward achieving this goal. NASA Administrator Charles Bolden told the House Science, Space, and Technology Committee in March that the task will not likely be completed until 2030, due to the modest $20 million annual funding of the agency’s asteroid detection program. The administration wants Congress to double the funding for asteroid detection.

 

NASA’s Grand Challenge

To help speed the process of finding rogue asteroids before they find us, NASA announced on June 18, 2013, a “Grand Challenge” focused on finding all asteroid threats to human populations and knowing what to do about them. The idea behind a “Grand Challenge” is that the government sets an ambitious goal, encourages the creation of public-private partnerships, and offers in some cases prize monies for efforts that help advance the goal. In this case, NASA is seeking the help of other government agencies (such as DARPA, the Air Force, Department of Energy, and the National Science Foundation), international partners, industry, academia, and citizen scientists in “detecting and characterizing asteroids and learning how to deal with potential threats,” says NASA Deputy Administrator Lori Garver.  The Grand Challenge, says Garver, serves as an extension of NASA’s Near-Earth Object Program, and through crowdsourcing will “harness public engagement, open innovation and citizen science to help solve this global problem.”

A CAD rendering of NEOSSat, the Canadian Space Agency's space telescope placed in orbit to look for dangerous Near Earth Objects (NEO). Image courtesy of MSCI

A CAD rendering of NEOSSat, the Canadian Space Agency’s space telescope placed in orbit to look for dangerous Near Earth Objects (NEO). Image courtesy of MSCI

Another tool NASA is funding through the University of Hawaii, as part of its Near-Earth Object Program, is ATLAS, the Asteroid Terrestrial-Impact Last Alert System. Using up to eight small telescopes spread throughout the Hawaiian islands and elsewhere, the ATLAS team predicts that, once fully operational in 2015, the system will offer a one-week warning for a 50-yard diameter asteroid or “city killer” and three weeks for a 150 yard-diameter small country killer. Project head John Tonry says “That’s enough time to evacuate the area of people, take measures to protect buildings and other infrastructure, and be alert to a tsunami danger generated by ocean impacts.”

All in all, not great options.

Other space agencies are also contributing to the asteroid detection effort. On May 22, 2013, the European Space Agency (ESA) started up a Near Earth Object Coordination Center in Frascati, Italy. There, ESA is developing a one-meter diameter telescope called FlyEye that will help search for asteroids.  The University of Pisa’s NEO Dynamic Site in Italy, supported by the ESA, performs high-precision orbit determination and trajectory prediction in parallel with NASA’s NEO Program Office, allowing analysis from these two organizations to be independently compared and cross-checked. The Russian Academy of Science is developing a monitoring system, and Roscosmos, the Russian Space Agency, has an active program to monitor space debris. Also, the Canadian Space Agency and Defence Research and Development Canada operate the Near-Earth Object Surveillance Satellite (NEOSSat). NEOSSat, which launched Feb. 25, 2013, is the world’s first space telescope dedicated to detecting and tracking asteroids and satellites. Expect action this fall at the United Nations General Assembly on a resolution to develop an international network of ground-based telescopes to track and analyze potentially dangerous asteroids.

By

Edward Goldstein has more than 20 years' experience in the U.S. space community. From...