The invisible magnetic force called Gravity is spread across the planet Earth. It helps us and things stay on the ground but you will be surprised to know that gravitational pull in each part of the world is different. This might sound a little strange but that’s true.
According to NASA, gravity is determined by the mass and since Earth’s mass is not distributed equally across the planet, gravity also tends to change over time.
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NASA’s Gravity Recovery and Climate Experiment (GRACE) – helps scientists to look at levels of gravitational pull across the planet.
A few years ago, it shared a 3D representation of a gravity model, on a geoid map of Earth. The map showcased Earth’s real shape and not the sphere ball we assume it to be. The model based on the data collected from GRACE showed surprising variations in Earth’s gravity field.
The colors highlight the gravitational anomalies measured by GRACE. For those who don’t know, gravity is defined by the value of gravity for a perfectly smooth ‘idealized’ Earth, on the other hand, gravity anomaly is a measurement for the deviation of gravity from the standard.
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The red color represents gravity being stronger than the ideal, smooth value, and the blue represents areas with a weaker gravity than the ideal.
The 3D globe model shows that raised areas of the Northwest region of South America have a higher gravitational pull as compared to the southern region of India that gradually gets blue as it moves towards the edges, which shows these areas have a lower gravitational pull. The Himalayas, in north India, mark the dark red territory which shows higher gravitational pull.
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GRACE Twin Satellites
It is an initiative launched in March 2002 by the Centre for Space Research at the University of Texas, Austin, NASA’s Jet Propulsion Laboratory, Pasadena, California, the German Space Agency, and the German Research Centre for Geosciences Potsdam.
They made detailed measurements of Earth’s gravity field which eventually helped in discoveries about gravity and the earth’s natural systems. On October 27, 2017, the satellites ended their science mission. The GRACE-2 became non-functional after an age-related battery issue, leading to decommissioning.