Posts tagged ‘earth’
Science educator James Drake built this amazing timelapse video from the perspective of the International Space Station as it flew over North and South America. He created this video by downloading a series of 600 photographs that were available online at the Gateway to Astronomy Photograph of Earth, and then stitching them together into a complete video. You can see more of James work at his blog: infinity imagined. [from Universe Today]
This movie begins over the Pacific Ocean and continues over North and South America before entering daylight near Antarctica. Visible cities, countries and landmarks include (in order) Vancouver Island, Victoria, Vancouver, Seattle, Portland, San Francisco, Los Angeles. Phoenix. Multiple cities in Texas, New Mexico and Mexico. Mexico City, the Gulf of Mexico, the Yucatan Peninsula, El Salvador, Lightning in the Pacific Ocean, Guatemala, Panama, Columbia, Ecuador, Peru, Chile, Lake Titicaca, and the Amazon. Also visible is the earths ionosphere (thin yellow line), a satellite (55sec) and the stars of our galaxy.
Exquisite views of our earth plus enchanting song by Loreena McKennitt. What a blissful combination!
The Earth is very old—4.5 billion years or more according to scientific estimates. Most of the evidence for an ancient Earth is contained in the rocks that form the Earth’s crust. The rock layers themselves—like pages in a long and complicated history—record the events of the past, and buried within them are the remains of life—the plants and animals that evolved from organic structures that existed 3 billion years ago.
Also contained in rocks once molten are radioactive elements whose isotopes provide Earth with an atomic clock. Within these rocks, “parent” isotopes decay at a predictable rate to form “daughter” isotopes. By determining the relative amounts of parent and daughter isotopes, the age of these rocks can be calculated.
Thus, the scientific evidence from rock layers, from fossils, and from the ages of rocks as measured by atomic clocks attests to a very old Earth.
See USGS Fact Sheet 2007-3015 at http://pubs.usgs.gov/fs/2007/3015/ for ages of geologic time periods. Ages in the spiral have been rounded from the age estimates in the Fact Sheet. B.Y., billion years; M.Y., million years. For more information, see the booklet on Geologic Time at http://pubs.usgs.gov/gip/geotime/.