Astronomy and Space
What is widely considered to be one of the earliest celestial observatories?
An asteroid came close to hitting Earth sometime in 2002. How much damage might it have done?
Asteroid 2002 EM7, a rock 230 feet (70 meters long), is estimated to have the capability of releasing the energy equivalent of a 4 megaton nuclear bomb.
Built in England between 2500 and 1700B.C.E., Stonehenge is one of the earliest observatories or observatory-temples. It is widely believed that its primary function was to observe the mid-summer and mid-winter solstices.