The Miocene Epoch of the Tertiary Period stretched from 22 million years ago (MYA) to 5 MYA. During that time, ancestral apes and early hominids appeared in Africa, Kure Island (now an atoll) and Midway Island developed above the Hawaiian hotspot, the Columbia Plateau formed from massive basalt flows, Iceland emerged from the sea, the Intermountain West was uplifted another 5000 feet, the Gulf of Aden began to open and the East African Rift started to form. In addition to ancestral apes and hominids, the first true elephants, giraffes, okapis, hippos and North American pronghorns made their appearance.
Two weeks ago, on August 24, astronomers from the University of California observed the sudden appearance of a supernova in the Pinwheel Galaxy, 21 million light years from Earth; in other words, they observed the explosion of a star that occured during the early Miocene. Brightening by the day, the display is expected to peak between September 9 and September 12, when it should be visible with powerful binoculars or a small telescope. Located in the Ursa Major (Big Dipper) constellation, the supernova will appear as a bluish-white star just above and slightly left of the last two stars in the Big Dipper's handle.
When we look at the night sky, we are looking back in time. The light from stars, traveling at 186,000 miles per second, takes years to reach Earth, even from our closest neighbors; Sirius, for example, the brightest star in the sky, is 8.7 light years away (if it exploded eight years ago, we will not know until next May). While the Miocene supernova in the Pinwheel Galaxy exploded 21 million light years from Earth, it was a nearby event relative to the vast expanse of the Universe.
