## The asteroid 2013 TX68 is reported to be passing by the Earth on March 5, 2016.

While NASA researchers are still trying to find out its exact trajectory, it is estimated that the asteroid may get as close to Earth as 11000 miles, i.e., closer than some communication satellites orbiting Earth.

The asteroid 2013 TX68 was first discovered on Oct. 6, 2013, by the Catalina Sky Survey while flying at a distance of 1.3 million miles (2 million km) from Earth, and has been under monitoring since then. Although NASA has acknowledged that the 100 foot (30 meters) asteroid will not hit Earth, yet it is uncertain about the exact trajectory of this space rock.

Due to the lack of proper data regarding the asteroid TX68 trajectory, the calculations yield different results. Some calculations indicate that the asteroid may pass no further than 9 million miles (14.5 million kilometers) from Earth and no closer than 11000 miles (17,000 km). Another calculation predicts the distance of 311,000 miles (500,000 kilometers) as TX68’s closest distance from Earth. In order to have an estimate of the asteroid’s trajectory, it’s worth mentioning that the diameter of Earth is about 7,926 miles (12,756 km) and the average distance between Moon and Earth is about 238,606 miles (384,000 km).

### The Discovery of Asteroids

One of the open challenges to the astronomers has been finding a law governing the distances of the planets from the sun. After the successes of the Newton’s classical mechanics in predicting the position of the planets, an extensive research was made to find a pattern based on which the distance of the planets from the sun could be formulated.

In 1766, the astronomer Johann Titius (1729-1796) succeeded to present a very precise rule that was later publicized by another astronomer Johann Elert Bode (1747-1826). According to the rule that is now called Bode’s Law, the distance of the solar system planets can be approximated by the following formula:

d = 0.4 + 0.32n in the Astronomical Unit (AU is the average distance between Earth and Sun, which is approximately about 93,000,000 miles or 150,000,000 km)

By assigning the values for n, the formula gave a surprising result that coincided with the location of planets from Sun, except for n=3 which predicted the existence of a planet in an area of space where no planet had been discovered before. Later discoveries indicated that although there was no such a planet at this distance, i.e. in an orbit between the planets Jupiter and Mars, there were many rocks with different diameters forming an asteroid ring. The first asteroid was discovered in 1801 and since then, the detection of asteroids, as well as the study of their origins, has been a topic of attention for both professional and amateur astronomers. Currently, the number of asteroids in our solar system with the diameter larger than 100m is estimated to be over 150 million.

### The Future of the Asteroid 2013 TX68

Like other orbiting objects, as long as TX68 does not hit any planet during travel on its trajectory, it is going to have other appearances in the future. Although its full trajectory has not been fully calculated, NASA has predicted its next appearance will be in Sep. 2017, with a very low hit probability. Other appearances of this small rock are predicted to be in 2046 and 2097, with the risk of any hit being much smaller. The next few weeks will provide much more data to refine their calculations and obtain more detailed information about the future path of TX68.

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