After reading Newscientist’s article July eclipse is best chance to look for gravity anomaly by Phil McKenna, TBF has explored NASA’s archives to find out what our earth’s gravity looks like.
The total eclipse
The solar eclipse that will take place on Wednesday, July 22, 2009 will be a total eclipse of the Sun with a magnitude of 1.080 that will be visible from a narrow corridor through northern India, eastern Nepal, northern Bangladesh, Bhutan, the northern tip of Myanmar, central China and the Pacific Ocean, including the Ryukyu Islands, Marshall Islands and Kiribati. The longest total solar eclipse of the 21st century has sparked tourist fever in eastern China, which according to experts is the best place to view the event.
Gravity and the Earth’s Shape
Gravity is the force that is responsible for the weight of an object and is determined by how the material that makes up the Earth is distributed throughout the Earth. Because gravity changes over the surface of the Earth, the weight of an object changes along with it.
The colors in these images represent the gravity anomalies measured by Gravity Recovery and Climate Experiment (GRACE). One can define standard gravity as the value of gravity for a perfectly smooth ‘idealized’ Earth, and the gravity ‘anomaly’ is a measure of how actual gravity deviates from this standard. Red shows the areas where gravity is stronger than the smooth, standard value and blue reveals areas where gravity is weaker.
GRACE is a collaborative endeavor involving the Center for Space Research at the University of Texas, Austin; NASA’s Jet Propulsion Laboratory, Pasadena, Calif.; the German Space Agency and the German Research Center for Geosciences, Potsdam. GRACE, twin satellites were launched in March 2002 and they are making detailed measurements of Earth’s gravity field which will lead to discoveries about gravity and Earth’s natural systems.