Asteroid 2012 DA14 will be closer than even Earth's network of GPS satellites.
A near-Earth asteroid that NASA calls "small" at 150 feet (45 meters) across will approach and pass earth on February 15, and it will pass so closely that it will actually be closer than earth's outer ring of satellites. It will be so close, in fact, that it will be the closest approach by an object of this size on record. The asteroid will be about 17,200 miles (27,200 kilometers) above Earth's surface, travelling at 17,400 miles per hour (7.8km per second). NASA will be using the Goldstone radar in the Mojave desert to image the asteroid, and they hope to build a 3D model of it in order to get an unprecedented look at such a large near-Earth object. 2012 DA14 was discovered in February 2012 by astronomers at the La Sagra Sky Survey in Spain, just after it had passed much further away from earth. NASA has confirmed that there is absolutely no chance for 2012 DA14 to impact earth, and that this is the closest it will come in the next 30 years.
It won't be bright enough to see with the naked eye, if you're lucky enough to be where it's passing overhead, but a telescope or a good pair of binoculars should suffice. Viewers in Indonesia will have the best chance of a sighting, but people located in Eastern Europe, Asia, and Australia will also be able to catch a glimpse. Once the asteroid passes this close, Earth's gravity will have altered its course and it won't take the same trajectory ever again - its orbital period will have been shortened to 317 days from 368. An asteroid of about this size is believed to pass earth once every 40 years, but only impact about once every 1,200 years. It's believed that the asteroid which caused the "Tunguska Event" in 1908, smashing hundreds of square miles of forest in Siberia, was about the size of 2012 DA14.