Asteroids are usually referred to as being a solid rock from outer space whereas comets are usually a mixture of ice and rock and typically burn up before hitting the earth.In 1907 a large something from outer space destroyed thousands of acres of forest in Tunguska.Until this century, relative dating was the only technique for identifying the age of a truly ancient object.By examining the object's relation to layers of deposits in the area, and by comparing the object to others found at the site, archaeologists can estimate when the object arrived at the site.Cyanobacteria is the most common type of microalgae used for biofuel (“Massachusetts company making,” 2011) The biofuel from algae can be cost effective, only costing ten to twenty dollars a barrel to produce....[tags: environment, clean biofuel, oxygen] - Climate change or colloquially known as global warming, now pose a new threat to civilization as the levels of greenhouse gases (GHG) are soaring to new levels.
Green plants absorb the carbon dioxide, so the population of carbon-14 molecules is continually replenished until the plant dies.
ASTEROIDS: Scientists have discovered a very large asteroid impact site in Antarctica.
As little as 200 years ago mainstream English speaking scientist did not believe that stones fell from the sky contrary to all the anecdotal evidence over the past centuries.
Though still heavily used, relative dating is now augmented by several modern dating techniques.
Radiocarbon dating involves determining the age of an ancient fossil or specimen by measuring its carbon-14 content.