Terms: Ozone Layer
Matches: 5    Displayed: 3

Categories

• Science > Astronomy > Mars > Terraforming
• Social Studies > Current Events > Future > Doomsday
• Science > Astronomy > Stars > Gamma-Ray Bursts
• Science > Astronomy > Solar System
• Social Studies > Current Events Archives > Science > 2009

Specific Results

1. Terraforming Mars - Short Description (NASA - Quest)
   "First, greenhouse gases, like chlorofluorocarbons that contribute to the growing ozone layer on Earth, will be released into the atmosphere. This traps the heat from the Sun and raises the surface temperature by an average of 4 degrees Celsius."
   
   "The increasing temperature would vaporize some of the carbon dioxide in the south polar cap. Introducing carbon dioxide into the atmosphere would produce additional warming, melting more of the polar cap until it has been vaporized completely. This would produce an average temperature rise of 70 degrees Celsius."
   
   "With the temperature this high, ice will start melting, providing the water needed to sustain life. This water would raise the atmospheric pressure to the equivalent of some mountaintops. While this would be a survivable level, it may still require the use of an oxygen mask. The next step, which may take up to several centuries, would be to plant trees that thrive on carbon dioxide and produce oxygen." 02-06

2. Gamma-Ray Bursts (Wikipedia.org)
   "Gamma-ray bursts (GRBs) are the most luminous events known in the universe since the Big Bang. They are flashes of gamma rays coming from seemingly random places in deep space at random times. GRBs last from milliseconds to many minutes, and are often followed by 'afterglow' emission at longer wavelengths (X-ray, UV, optical, IR, and radio). Gamma-ray bursts are detected by orbiting satellites about two to three times a week, as of 2007, though their actual rate of occurrence is much higher."
   "One line of research has investigated the consequences of Earth being hit by a beam of gamma rays from a nearby (about 500 light years) gamma ray burst. This is motivated by the efforts to explain mass extinctions on Earth and estimate the probability of extraterrestrial life. The consensus seems to be that the damage that a gamma ray burst could do would be limited by its very short duration, and the fact that it would only cover half the Earth (the other half would be in its shadow). A sufficiently close gamma ray burst could do serious damage to atmospheric chemistry, perhaps instantly wiping out half the ozone layer, and causing nitrogen-oxygen recombination, generating acidic nitrogen oxides. These effects would diffuse across to the other side of the Earth and result in long-term climate and atmospheric changes, resulting in a mass extinction. The damage from a gamma ray burst would probably be significantly greater than a supernova at the same distance." 10-07

3. -06-28-09 The Suns's Protection is Not Constant (NewScientist.com)
   "The sun protects us from cosmic rays and dust from beyond the solar system by enveloping us in the heliosphere - a bubble of solar wind that extends past Pluto. These cosmic rays would damage the ozone layer, and interstellar dust could dim sunlight and trigger an ice age. However, when the solar system passes through very dense gas and dust clouds, the heliosphere can shrink until its edge is inside Earth's orbit." 06-09