All the little chalk scratches are actually the paths of airplanes. If you look up at the sky, you often see the white tail of an airplane cruising through the sky. When you look down from far, far, above, you see a lot of those little airplane tails aggregated over and over and over and over again. The result is something like a cloud cage over most of our population centers.  This will have two effects. First, it will reflect sunlight back into space. Second, it will trap heat down below. The net effect is an increase in warming. It is possible that the increase in air travel has contributed to the warming seen over the past century.  The good news is that this is a much easier problem to solve than global warming. Just using less water in jet fuel will massively reduce these clouds. That said… I wonder whether it is a good idea. Those clouds are reflecting a lot of light. I’d want to see much more research about this before making any changes. What if the light reflected is actually mitigating the effects of global warming? 

mabelmoments:

CREDIT: NASA/Goddard Space Flight Center, SeaWiFS Project and ORBIMAGE

How the Japan Earthquake Shortened Days on Earth

The massive earthquake that struck northeast Japan Friday (March 11) has shortened the length Earth’s day by a fraction and shifted how the planet’s mass is distributed.

A new analysis of the 8.9-magnitude earthquake in Japan has found that the intense temblor has accelerated Earth’s spin, shortening the length of the 24-hour day by 1.8 microseconds, according to geophysicist Richard Gross at NASA’s Jet Propulsion Laboratory in Pasadena, Calif.

Gross refined his estimates of the Japan quake’s impact – which previously suggested a 1.6-microsecond shortening of the day – based on new data on how much the fault that triggered the earthquake slipped to redistribute the planet’s mass. A microsecond is a millionth of a second.

“By changing the distribution of the Earth’s mass, the Japanese earthquake should have caused the Earth to rotate a bit faster, shortening the length of the day by about 1.8 microseconds,” Gross told SPACE.com in an e-mail. More refinements are possible as new information on the earthquake comes to light, he added.

The scenario is similar to that of a figure skater drawing her arms inward during a spin to turn faster on the ice. The closer the mass shift during an earthquake is to the equator, the more it will speed up the spinning Earth. [continued]

exogenerian:

This image released by NASA shows an enhanced photo image of Mercury from its Messenger probe’s 2008 flyby of the planet. NASA says it was a taste of pictures likely to come after March 17, 2011, when the probe enters Mercury’s orbit. Read more.