NASA-ina kontroverzna fotografija koja je navodila na vjerovanje da Zemlja nije okrugla: Ovo je znanstveno objašnjenje

The National Aeronautics and Space Administration (NASA) recently released a three-dimensional model of Earth’s gravitational field, sparking widespread discussion online. The image, which appears to depict a planet with an irregular shape resembling a potato, has led some to question whether Earth is truly spherical. However, scientists clarify that this representation does not show the physical surface of the planet but rather the geoid, a scientific model used to understand how gravity behaves across the globe. The geoid represents an equipotential surface of Earth's gravitational field. It serves as a reference point for defining mean sea level under conditions where water would remain still, unaffected by tides, winds, or ocean currents. This model helps scientists better understand variations in gravitational pull caused by uneven distribution of mass within the planet. According to data collected over 15 years by satellites, these subtle differences in gravity have been magnified up to 10,000 times in the visualization to make them visible to the naked eye. These variations stem from the fact that Earth’s internal mass is not uniformly distributed. Certain regions contain more or less dense materials, creating small gravitational anomalies. Michael Watkins, a scientist at NASA’s Jet Propulsion Laboratory (JPL), explained that these differences result in "mountains" and "valleys" in the gravitational field. For instance, large mountain ranges such as the Andes and the Himalayas exert slightly stronger gravitational forces than areas like the Indian Ocean or the Congo Basin. To create this model, researchers analyzed over one billion observations gathered by 19 satellites during the 15-year period. The resulting model, known as GOCO06s, combines data from the European Space Agency’s (ESA) GOCE mission and NASA’s GRACE program, which was developed in collaboration with the German Aerospace Center. These missions have provided unprecedented detail about Earth’s gravitational structure, allowing scientists to map even minor fluctuations in gravitational strength. The geoid visualization reveals variations ranging from approximately +85 meters above the reference level in Iceland to -106 meters below it in southern India. These differences do not indicate actual elevation changes but instead highlight shifts in gravitational intensity, a phenomenon typically imperceptible to humans. Scientists emphasize that while the geoid offers a more accurate depiction of gravity’s behavior, it does not alter the established understanding of Earth’s shape. The planet continues to be described as an oblate spheroid, slightly flattened at the poles and bulging at the equator. This new model enhances our comprehension of how gravity influences geological features and oceanic movements. It also aids in refining satellite navigation systems and improving climate change research by providing more precise measurements of Earth’s dynamic processes. As scientists continue to refine their models using advanced satellite technology, they aim to deepen our knowledge of the complex interactions shaping our planet.