The United States must do more to safeguard the Earth against destruction by an asteroid than merely prepping nuclear missiles, a new report has found.

The 134-page report, released Friday by the National Academy of Sciences, states that the $4 million spent by the United States to identify all potentially dangerous asteroids near Earth is not enough to do the job mandated by Congress in 2005. NASA is in dire need of more funding to meet the challenge, and less than $1 million is currently set aside to research ways to counter space rocks that do endanger the Earth ? measures like developing the spacecraft and technology to deflect incoming asteroids ? the report states.

An early draft of the report, entitled ?Defending the Earth: Near-Earth Object Surveys and Hazard-Mitigation Strategies,? was released in August 2009. The final report, written by a committee of expert scientists, says NASA is ill-equipped to catalogue 90 percent of the nearby asteroids that are 460 feet (140 meters) across or larger as directed by Congress.

The United States should also be planning more methods of defending Earth against an asteroid threat in the near-term. Nuclear weapons should be a last resort ? but they?re also only useful if the world has years of advance notice of a large, incoming space rock, the report states.

Likewise, decades of notice are required to build and launch spacecraft to push an asteroid clear of Earth or smash it with a forceful, but non-nuclear, projectile, the committee wrote in the report. Organized evacuations and other civil defense efforts would only be useful in the event of smaller objects with limited advance notice, it added.

NASA?s asteroid and near-Earth object experts have said that the agency has found about 85 percent of the largest nearby asteroids, ones that are a half-mile (1 km) wide or larger. But only 15 percent of the 460-foot wide asteroids near Earth have been discovered and tracked to date, and just 5 percent of nearby space rocks about 164 feet (50 meters) across have been found.

Lindley Johnson, NASA's manager of the Near-Earth Objects program, has said that NASA needs up to $1 billion in additional funding over the next 15 years in order to meet its goal of finding all nearby asteroids that could threaten Earth.

But neither President Barack Obama?s administration, nor that of former President George W. Bush, have set aside funding to support near-Earth object surveys, according to the report.

Recent meteor bursts over the United States have also highlighted the potential danger of even smaller asteroids, so NASA should also try to find as many of those objects ? which range between 30 and 50 meters in size ? as possible, the report?s committee found.

Even small space rocks pose a threat to people and property on Earth.

On Monday, a small, half-pound meteorite crashed through the roof of a doctor?s office in Virginia, punched through a wall and upper floor before slamming into pieces when it hit a concrete floor at a speed that may have hit 200 mph. No injuries were reported, but the doctor?s office was populated at the time.

According to the report, current long-term projections estimate that there could be up to 100 fatalities a year caused by space rock impacts, though admittedly the chances of such rare hits are remote.

Still, ?this presents the classic problem of the conflict between extremely important and extremely rare,? the report stated. ?The committee considers work on this problem as insurance, with the premiums devoted wholly towards preventing the tragedy.?