We often think of Earth’s gravity as constant and uniform, but in reality, it isn’t. NASA scientists have mapped something strange beneath the South Atlantic: a massive gravity anomaly stretching over 7,000 kilometers—a place where Earth's gravitational pull is significantly weaker than expected.
They’re calling it one of the most baffling geophysical mysteries on the planet.
- What Is a Gravity Anomaly?
A gravity anomaly refers to a region where the force of gravity is stronger or weaker than the global average. This specific area, beneath the South Atlantic Ocean, is a low-gravity zone so vast and pronounced that scientists have dubbed it a "gravity hole."
You wouldn’t notice it while swimming or flying overhead—but satellites and sensitive instruments certainly do.
- Who Found It? (And How?)
The discovery comes from NASA’s GRACE mission (Gravity Recovery and Climate Experiment), which launched a pair of satellites to monitor gravitational changes on Earth. By measuring subtle shifts in gravity, GRACE created one of the most detailed gravity maps ever made.
Working with institutions like the German Research Centre for Geosciences (GFZ), scientists found a large dip in gravity that couldn’t be explained by surface features or ocean depth alone.
- Why Is Gravity So Weak Here?
Several theories have been proposed, including:
Remnants of ancient tectonic plates submerged deep beneath the Earth’s mantle
Unusual mantle convection patterns—slow-moving flows of hot rock within the Earth
Evidence of past planetary-scale collisions that reshaped Earth’s interior
So far, no single explanation fits all the data, and the cause remains a mystery.
- Does It Affect Humans?
Not directly. Humans can’t feel minor variations in gravity—especially over such vast distances. However, these anomalies can influence:
Satellite trajectories
GPS systems and communications
Climate models and Earth’s rotation calculations
Understanding them helps scientists better model the Earth’s interior and predict long-term planetary behavior.
- Could It Be Related to Other Anomalies?
Coincidentally—or perhaps not—the same region is home to another puzzle: the South Atlantic Anomaly, an area where Earth’s magnetic field is weaker than usual. This region has already damaged several satellites and affects high-altitude flights.
Some scientists are now asking: Could the gravity hole and the magnetic anomaly be linked? If so, the implications could change how we view Earth's inner dynamics.
Did you know?
The gravity difference in this anomaly is enough to subtly alter satellite orbits and skew data if not accounted for. That’s why every major space agency factors it into mission planning.
Curious minds never stop exploring—and if this article sparked your interest, there's so much more waiting for you at factfun.co
From ancient archaeology and mind-bending science to bizarre creatures and forgotten history, we dive deep into the world’s strangest facts. Best of all? Our articles are available in 5 different languages, so knowledge is truly for everyone.