Dawn Mission Status: Spacecraft Tests Ion Engine

http://www.nasa.gov/mission_pages/dawn/news/dawn-20071009.html

Ion engines, a new technology seems to be a viable new technology. High efficient use of fuel coupled with powerful propulsion.

How do these engines work?

What is the principle reaction behind the device?

What will this mean to space travel and life on earth?

How Do Artists Portray Exoplanets They've Never Seen?

http://www.sciam.com/article.cfm?chanID=sa004&articleID=FB77F014-E7F2-99DF-37E95D5497B875BE
After reading this article, what type of planet would you like to visit?

Create an image of your planet then write a description of it, including things like size, atmosphere, life, gravity, day length, etc.

Scientists see dramatic drop in Arctic sea ice

http://www.reuters.com/article/scienceNews/idUSN0134058320071002

WASHINGTON (Reuters) - Arctic sea ice declined this year to the lowest levels registered since satellite assessments started in the 1970s, extending a trend fueled by human-caused global warming, scientists said on Monday.

What will happen when all arctic sea ice on earth melts?

Should we worry and prepare or just deal with it when it happens? (If it ain't broke don't fix it argument)

Is global warming just a hoax? Is it a credible threat? Please link sources here!