Two years ago, a small asteroid, named 2013 TX68, flew pass Earth at a safe distance of about 2 million km (1.3 million miles) and now it will pass even closer to our planet next month, on March 5, 2016, but this time nobody is certain just how close.

According to NASA’ experts, the trajectory of the asteroid is not precisely known but we could estimate it. During its second flyby on March 5, the space rock could come close somewhere between 11,000 miles (17,000 kilometers) — less than 5% of the distance Earth-Moon — and 9 million miles (14 million km).

The variation in possible closest-approach distances is due to the wide range of possible trajectories for this object, since it was tracked for only a short time after discovery,

NASA officials said in a statement.

Asteroid 2013 TX68 is estimated to be about 100-ft-wide (30 meters) in diameter — by comparison, the asteroid that exploded over the Russian city of Chelyabinsk in February, three years ago, was 20 meters — and it was discovered by the NASA-funded Catalina Sky Survey on Oct. 6, 2013 as it approached Earth. After 3 days of observations, it passed into the daytime sky, thus, scientists were unable to collect enough data to accurately determine the rock’s trajectory. However, scientists are certain that this asteroid will not collide with Earth on this pass.

This asteroid’s orbit is quite uncertain, and it will be hard to predict where to look for it,

said Paul Chodas, manager of CNEOS (NASA’s Center for NEO Studies).

There is a chance that the asteroid will be picked up by our asteroid search telescopes when it safely flies past us next month, providing us with data to more precisely define its orbit around the sun.

However, they have identified an extremely remote chance that this asteroid could impact on Sep. 28, 2017. Flybys in 2046 and 2097 have an even lower probability of impact — NASA has a list of its next five close approaches to Earth.

The possibilities of collision on any of the three future flyby dates are far too small to be of any real concern,

said Chodas.

I fully expect any future observations to reduce the probability even more.

So what are the risks? The odds of a major asteroid impact are very small, but if asteroid 2013 TX68 or another rock of its size were to hit Earth — traveling at more than 32, 0000 miles per hour — it would produce a shock wave at least twice as intense as that of the Chelyabinsk meteor.