Search for Near-Earth Asteroids Needs a Speed Boost
By Tia Ghose | SPACE.com – Tue, Feb 5, 2013RELATED CONTENT
- Only a few near-Earth objects would …
At the current rate that near-Earth asteroids are being detected, it will take astronomers 15 years to identify every one of significant size and even more than 10 times longer to characterize their materials, a new study suggests.
Astronomers should dramatically ramp up the sky surveys, not only to better prepare for threats to Earth but also to exploit asteroids' contents, scientists say.
These asteroids could be mined one day for valuable metals such as platinum and cobalt, yet at the current rate it will take 190 years to characterize their materials, Charlie Beeson, a doctoral candidate in astronomy at Harvard University, told an audience last month at the 221st annual meeting of theAmerican Astronomical Society in Long Beach, Calif.
Increasing the breadth of existing sky surveys and using an orbiting mission to search for asteroidscould speed up the cosmic hunt, Beeson said.
Danger and opportunity
Like the moon, Earth is pockmarked with craters caused by asteroid impacts, suggesting that such strikes happen frighteningly often, Beeson told SPACE.com.
For instance, during the Tunguska event in 1908 in Siberia, up to 80 million trees were wiped out in a mostly uninhabited 830-square-mile area (2,150 square kilometers) by an exploding space rock. The meteorite blast packed up to 1,000 times the power of the Hiroshima bomb, Beeson said.
But asteroids aren't just potential threats to Earth's safety, they are also potential sources of rich veins of platinum, cobalt, zinc, antimony and other valuable metals that might one day be harvested by manned missions. They could even be mined for hydrogen and oxygen for space travelers refueling their rockets, Beeson said. [Deep Space Industries' Asteroid-Mining Vision (Gallery)]
Scientists have estimated that 20,000 asteroids lurk in the solar system, of which only 6,000 have been identified, Beeson said.
Slow process
Beeson and her colleagues looked at the historical rate of asteroid discovery and found that, at the current pace, it will take about 15 years to identify all the asteroids in the solar system that are wider than 100 meters (328 feet).
Most of the missing asteroids are traveling by during the daytime or traveling through a patch of the sky not watched by existing surveys, she found.
To speed discovery, the team should expand the patch of sky observed by two programs, the Mount Lemmon and Catalina sky surveys, she said. To find asteroids that are crossing by Earth only during the day, scientists should prioritize the B612 Sentinel mission, which aims to send a telescope into a Venus-like orbit around the sun, Beeson added.
"Venus travels quite a bit faster, so it would scan the sky a lot quicker."
- Asteroid Basics: A Space Rock Quiz
- Close Approach of Asteroid 2012 DA14 - Fear vs. Fact | Video
- How Asteroid Mining Could Work (Infographic)
Powerful blizzard takes aim at northeastern U.S.
By Scott Malone and Shannon Stapleton | Reuters – 56 mins ago- Reuters/Reuters - Winter storms are seen over Canada and the northeastern United States in this February 7, 2013 GOES satellite image courtesy of NOAA. REUTERS/NOAA/Handout
BOSTON/NEW YORK (Reuters) - The northeastern United States braced for a possibly historic blizzard that could drop up to three feet (nearly one meter) of snow from Friday to Saturday and bring travel to a halt.
Blizzard warnings were in effect from New Jersey through southern Maine, with Boston expected to bear the brunt of the storm. The day began with light snow and winds that were due to pick up with much heavier snowfall by afternoon.
Officials urged residents to stay home, rather than risk getting stuck in deep drifts or whiteout conditions.
In New York City, still not fully recovered from the effects of October's devastating Hurricane Sandy, officials said they had 1,800 Sanitation Department trucks equipped with snow plows ready to be deployed.
Motorists, mindful of the severe fuel disruptions after Sandy, rushed to buy gasoline, leading to shortages in New York City. A Reuters photographer reported at least three service stations had run out of gas in the borough of Queens on Friday morning, with long lines formed at others.
Sandy knocked out power to hundreds of thousands of homes, taking gasoline stations out of service, and damaged port facilities, exacerbating the shortages by preventing operable stations from refueling.
"You always get long lines ahead of a storm, but as the wounds from Hurricane Sandy are still so fresh, it's not surprising that people are rushing to fill up," said Michael Watt, executive director of the Long Island Gasoline Retailers Association. "It's understandable. Even people like me who would normally think it was foolish to panic buy will be thinking about it."
Boston and surrounding communities said schools would be closed on Friday, and city and state officials told nonessential city workers to stay home.
Officials across the region ordered nonessential government workers to stay home, urged private employers to do the same, and told people to prepare for power outages and encouraged them to check on elderly or disabled neighbors.
In New Jersey, also hit hard by Sandy, state officials expected major coastal flooding, high winds, and possible blizzard conditions in the northeastern section of the state.
"This is a dangerous storm, and we ask motorists to be careful while driving," said Colonel Rick Fuentes, director of the New Jersey Office of Emergency Management. "(The) evening commute will be treacherous throughout much of New Jersey."
The National Weather Service, warning of a "major, maybe even historic, snowstorm," said Boston and much of New England could get up to three feet of snow on Friday and Saturday, its first heavy snowfall in two years. Winds could gust as high as 60 miles to 70 miles per hour (95 to 112 km per hour).
If more than 18.2 inches of snow falls in Boston, it will rank among the city's 10 largest snowfalls. Boston's record snowfall, 27.6 inches, came in 2003.
Cities from Hartford, Connecticut, to Portland, Maine, were expected to see at least one foot of snow.
Airlines have canceled more than 3,000 flights for Friday, according to website FlightAware.com, with the largest number of cancellations at airports in Newark, New Jersey; New York City; Chicago and Boston.
Another 881 flights were canceled for Saturday, according to the flight-tracking site.
Boston's Logan International Airport warned that once the storm roars in, all flights would likely be grounded for 24 hours.
United Continental Holdings Inc, JetBlue Airways Corp and Delta Air Lines Inc all reported extensive cancellations.
ECHOES OF '78
For some in the Boston area, the forecast brought to mind memories of the blizzard of 1978, which dropped 27.1 inches, the second largest snowfall recorded in the city's history. That storm started out gently and intensified during the day, leaving many motorists stranded during the evening commute.
Dozens of deaths were reported in the region after that storm, many from people touching downed electric lines.
Officials warned of a high risk of extensive power outages across the region due to the combination of heavy snow and high winds. Residents were also at risk of losing heat at a time when temperatures would dip to 20 Fahrenheit (minus 7 Celsius).
Across the region, store shelves were picked clean of food and storm-related supplies such as shovels and salt as residents scrambled to prepare.
Some big employers said they were considering pleas by officials to let workers stay home, including State Street Corp, one of Boston's largest employers in the financial sector.
(Additional reporting by David Sheppard in New York, Daniel Lovering and Tim McLaughlin in Boston, Dave Warner in Philadelphia, Karen Jacobs in Atlanta and Colleen Jenkins in North Carolina; Editing by Daniel Trotta; and Jeffrey Benkoe)
Also Read
No comments:
Post a Comment
Note: Only a member of this blog may post a comment.