Tag Archives: Comets

NASA creates new office to lead asteroid defense efforts

A new office will lead NASA’s efforts to protect Earth from potential strikes from asteroids and comets, along with overseeing the agency’s efforts to discover and study the celestial objects.

NASA announced the formation of the Planetary Defense Coordination Office (PDCO) in a news release last Thursday, saying the new creation is an improvement on the agency’s existing endeavors to detect any potential hazards to Earth and defend the planet against impacts.

NASA said the new office will supervise the agency’s research into so-called near-Earth objects — asteroids and comets that will come close to the planet — and communicate with federal agencies and foreign governments to develop an action plan if there is any chance of a strike.

The agency said none of the 13,500 known near-Earth objects pose any threat of impacting Earth, but about 1,500 new objects are discovered every year. A space rock that came within 300,000 miles of Earth last Halloween went undiscovered until three weeks before its arrival.

NASA officials mentioned that event and a meteor that entered Earth’s atmosphere in 2013 and created a massive fireball above Chelyabinsk, Russia, when announcing the PDCO. Those events “remind us of why we need to remain vigilant and keep our eyes to the sky,” John Grunsfeld, the associate administrator for NASA’s Science Mission Directorate, said in a statement.

According to NASA, research and discovery of near-Earth objects has surged in recent years thanks to an influx of funding. The federal budget for fiscal year 2016 includes $50 million for planetary defense and asteroid and comet research, compared to just $4 million in 2010.

NASA said it believes it has discovered 90 percent of near-Earth objects that are bigger than 3,000 feet, and it’s currently focusing on discovering smaller rocks that are a little bit larger than a football field. The agency estimates it has only located about 25 percent of those mid-sized asteroids and comets, though it had been asked in 2005 to find 90 percent of them before 2021.

The agency is also developing some strategies to potentially stop problematic asteroids.

NASA is currently trying to robotically redirect an asteroid into an orbit around Earth’s moon. The agency’s success there could ultimately determine if scientists can steer an Earth-bound asteroid clear of the planet, though NASA says it will likely be the 2020s before it has its answer.

If it’s not possible to prevent an impact, the new office will work with the Federal Emergency Management Agency to help coordinate a response. The PDCO will also issue warnings about space rocks that will pass close to Earth and any potential impacts of their close presence.

“The formal establishment of the Planetary Defense Coordination Office makes it evident that the agency is committed to perform a leadership role in national and international efforts for detection of these natural impact hazards, and to be engaged in planning if there is a need for planetary defense,” Lindley Johnson, the PDCO’s Planetary Defense Officer, said in a statement.

Scientists: Giant Comets May Present Greater Risk to Earth than Asteroids

Giant comets and their debris may present a significantly higher risk to human life than asteroids and should be studied more closely, according to a team of British astronomers.

The astronomers say that hundreds of “centaurs,” huge orbs of ice and dust that usually are between 30 and 60 miles wide, have been discovered in far-flung parts of space in the past two decades. The researchers say the massive comets travel along unstable orbits near the four gas giants of Jupiter, Saturn, Uranus and Neptune.

Centaurs seldom enter the inner solar system, the astronomers say, but their research indicates that the gravitational pull of those four planets can redirect one toward Earth. One centaur will cross Earth’s orbit about every 40,000 to 100,000 years, according to their research.

As the centaurs approach the Sun, they disintegrate and spray debris throughout space. The astronomers say some of that debris will inevitably impact the Earth.

One centaur “contains more mass than the entire population of Earth-crossing asteroids found to date,” according to a news release from the Royal Astronomical Society, which published the study in the December issue of its journal, Astronomy & Geophysics.

Astronomers from Armagh Observatory and Buckingham University performed the research.

One of the study’s co-authors, Bill Napier, said in a statement that scientists have devoted a lot of time and energy to analyzing the risk of an asteroid colliding with the Earth, particularly in the past three decades.

“Our work suggests we need to look beyond our immediate neighborhood too, and look out beyond the orbit of Jupiter to find centaurs,” Napier said. “If we are right, then these distant comets could be a serious hazard, and it’s time to understand them better.”

NASA officials have publicly stated that there’s no known asteroid or comet that has any chance of impacting the Earth within the next 100 years.

However, scientists didn’t discover a space rock that came within 300,000 miles of the Earth – about 1.3 times the distance between the planet and the moon – until three weeks before it zoomed by this past Halloween.