According to NASA, an asteroid named 2015 TB145 is set to pass by Earth on October 31, 2015. It was discovered by astronomers in Hawaii with the Pan-STARRS (Panoramic Survey Telescope and Rapid Response System) telescope. Using PS1, as it's more commonly known to the astronomers, with its 1400 megapixel capabilities, they managed to track the moving object, calculate its orbit and detect if it will be a potential threat to our planet, Earth. There are in total four Pan-STARRS, each capable of capturing 1.4 billion pixels over a 40 centimeter square sensor. 

The asteroid was discovered less than two weeks ago using Pan-STARRS and is the largest object to closely approach Earth recently.

2015 TB145 is set to pass by Earth at 1.3 lunar distances which translates to about 310,000 miles or about 499,000 km on October 31, 2015. The asteroid has a diameter estimated between 280 and 620 m (918 to 2,034 feet) and traveling at a speed of 126000 km/h (78,293 mph).  

Since it's discovery, NASA expressed that the asteroid will safely pass by Earth and is following an eccentric, high inclination orbit. Which ultimately means, people of the world should not panic as this moving object is not a threat to mankind. 

This, however, will serve as an opportunity for space gazers and astronomers to take out their amateur telescopes. The asteroid will not be visible to the naked eye, so an amateur telescope with reasonable magnification and size will prove to be very useful. Observatories would be able to get the chance to track the object through their imaging and radar tracking. The next large rock encounter won't be until 2027, with 1999 AN10. 

The asteroid is set to travel through Orion at the evening of October 30 and the early morning hours of October 31, in the United States, California Time.