Although, the passage of asteroid 2014-YB35 at a distance of 2.8 million miles is much farther away than the January 6 close approach of asteroid 2004 BL86 at a distance of only 745,000 miles, it is dangerously close on the astronomical scale, especially for an asteroid that size.
NASA astronomers estimate the size of 2014-YBS to be between 500-1,000 meters, but it is believed to be most likely about 990 meters across.
The close passage of asteroid 2014-YBS, first detected last year by the Catalina Sky Survey, brings to attention once again the menace posed to Earth by thousands of space rocks following orbital trajectories that bring them perilously close to Earth.
Although close approach by space rocks in the size class of 2014-YBS is comparatively rare — most asteroids passing close to Earth being much smaller — astronomers warn that it is only a matter of time before the Earth sustains collision with a space rock large enough to inflict significant damage.
Bill Napier, professor of Astronomy at the University of Buckinghamshhire in the UK, told the Express that impact by an asteroid as large as 2014-YBS could trigger disaster on a global scale. Although most asteroids making threatening approach to Earth are in the size range capable only of local devastation, there are a few asteroids like 2014-YB35 that could trigger unprecedented global disaster on impact and “pose a risk to the continuation of the planet.”
Napier emphasized, however, that “These events are very rare, it is the smaller yet still very damaging impacts which are a very real threat.”
“Smaller scale events like Tunguska are absolutely a real risk, largely they are undiscovered and so we are unprepared. With something like YB35, we are looking at a scale of global destruction, something that would pose a risk to the continuation of the planet. These events are however very rare, it is the smaller yet still very damaging impacts which are a very real threat.”
We may put the potential damaging impact of a 1 km asteroid into perspective with the information that the Tunguska impact event of 1908 that generated a blast estimated at about 15 megatons of TNT – about 1,000 times the energy unleashed by the Hiroshima bomb — and flattened a forest of 80 million trees in an area approximately 2,150 square kilometers, involved an asteroid only about 50 meters across.
An explosion equivalent to 15 megatons of TNT could destroy an entire city.
According to Napier, comets also pose a “real threat” to Earth. If the Earth passes through the tail of a comet it could generate “a massive plume of smoke with hugely significant consequences.”
“There is absolutely a real risk and if you look at history, certainly biblical records, there are reports of fires in the heavens. Red hot debris resulting from the impact of something a kilometer wide would be capable of incinerating the planet,” he added.
Experts estimate that collision with an asteroid as large as 2014-YB35 could unleash an explosive energy equivalent to 15,000 megatons of TNT. An explosion that powerful could cause devastating earthquakes, tsunamis and throw up debris that could have a profound life threatening impact on global climate.
But meanwhile, NASA scientists at the Goldstone Complex are monitoring the passage of 2014-YB35 using the Deep Space Network (DSN) facility. They are hoping to use the opportunity of the close approach by 2014-YB35 to obtain more information about the asteroid’s composition and size. They also hope to obtain data that will help to predict the asteroid’s future course more accurately.
Growing concern about the safety of our planet in the cosmic shooting gallery of Potentially Hazardous Asteroids (PHAs) has led astronomers to declare June 30 Asteroid Day. Astronomers hope to draw attention to the urgency of developing technological means of protecting our world from the inevitable event in which it sustains a collision with a large asteroid.
According to Grigorij Richters, one of the organizers of the Asteroid Day initiative, thousands of PHAs have not been identified and worrisome is the fact that “it just takes one asteroid to completely destroy life, not just humanity, but all species.”
The Minor Planet Center has listed asteroid 2014 YB35 among Potentially Hazardous Asteroids.
PHAs are identified on the basis of parameters that measure an asteroid’s potential to make threatening close approaches to the Earth