Posts Tagged ‘Antarctic’

Comments Off on Earth’s Ozone on Bumpy Road to Recovery

Weather effects surprisingly shape the Antarctic ozone hole. The Antarctic ozone hole reached its maximum single-day area for 2013 on Sept. 16. The ozone hole (purple and blue) is the region over Antarctica with total ozone at or below 220 Dobson units (a common unit for measuring ozone concentration). Last year the hole in the […]

Comments Off on Solar System Stories

About 3.8 to 4 billion years ago Earth suffered what scientists call the late Heavy Bombardment: a mysterious rain of asteroids and comets that pummeled most of its surface. The moon was heavily cratered then too. Art by Dana Berry; Sources: Stephen Mojzsis, University of Colorado/NASA Lunar Science Institute; William Bottke, Southwest Research Institute (SWRI).