What type of rock is best for radiometric dating
During the following years, the crater origin of the structure was demonstrated by geophysical and lithological studies and its age determined by radiometric dating (Swisher et al. The crater is about 19 miles (31 kilometers) wide, more than twice as big as the next largest Saharan crater known.It utterly dwarfs Meteor Crater in Arizona, which is about three-fourths of a mile (1.2 kilometers) in diameter.
In fact, the impact probability might go up to 50% before plunging to 0% [or vice versa]. Toutatis's orbit changes slightly with each 4-year trip around the sun.
Scientists say comets that suffer hiccups are those that emit bursts of gas, these bursts act like jets and alter the comet's orbit." "Collisions can launch large asteroid chunks into unstable orbits that move them into collision courses with our planet. It's possible some of these asteroids eventually will move onto an Earth-collision trajectory." "Computer models used to study numerous asteroid belt bodies lent support to the idea that the heated bodies experienced altered orbits.
Many of the fragments seem to have been swept into narrow chaotic zones known as resonances, where tiny gravitational kicks produced by nearby planets such as Mars, Jupiter, or Saturn can push asteroids out of the asteroid belt." "Let us say an [asteroid] would have been discovered...
The notion that a comet collided with Earth and caused these events was farfetched until recently, when the group of scientists began looking for evidence of a comet impact, which they call the Younger - Dryas Event.
"They turned to University of South Carolina archaeologist Dr.On June 1, 2006 scientists, using satellite data, discovered the 300-mile-wide crater buried more than a mile beneath the East Antarctic Ice Sheet in what's known as the Wilkes Land region of Antarctica.