Atmosphere of Earth development of animals. Today's atmosphere contains 21% oxygen, which is great enough for this rapid development of animals. "Air pollution" is the introduction into the atmosphere of chemicals, particulate matter or biological materials that cause harm or discomfort to organisms. Stratospheric ozone depletion is caused by air pollution, chiefly from chlorofluorocarbons and other ozone-depleting substances. The scientific consensus is that the anthropogenic greenhouse gases currently accumulating in the atmosphere are the main cause of global warming. On October 19, 2015 NASA started a website containing daily images of the full sunlit side of Earth on http://epic.gsfc.nasa.gov/. The images are taken
Atmosphere of Mercury pushes neutral atoms away from Mercury, creating a comet-like tail behind it. The main component in the tail is sodium, which has been detected beyond 24 million km (1000 R) from the planet. This sodium tail expands rapidly to a diameter of about 20,000 km at a distance of 17,500 km. In 2009, "MESSENGER" also detected calcium and magnesium in the tail, although these elements were only observed at distances less than 8 R. Atmosphere of Mercury Mercury has a very tenuous and highly variable atmosphere (surface-bound exosphere) containing hydrogen, helium, oxygen, sodium, calcium, potassium and water vapor, with a