Learn how we know the Earth is round, and the science behind the shape of our gravitational field.

Earth, in most renderings, is a smooth sphere with a glossy complexion—a blue marble, as pictures snapped from space have shown us. Earth scientists know that’s not exactly true. Earth, in fact, is an ...

[UPDATE (April 5, 2011): It turns out some of the descriptions I used below to describe a geoid were not accurate. I refer you to this page at the University of Oklahoma for a good description. I’ve ...

The Earth’s geoid is the shape the planet would assume if its surface were made of water. Naturally, there’s little dispute over the shape of the geoid over the oceans, where it varies by only 100 ...

Have you ever thought to use a clock to identify mineral deposits or concealed water resources within the Earth? Some scientists are convinced that ultraprecise portable atomic clocks will make this a ...

When we’re told about newly released satellite images of our Earth, we imagine beautiful swathes of green and blue with the occasional white of swirling storm clouds or snow-topped mountain ranges.

Bottom line: There's a well-known "hole" in Earth's gravity field just off India's coastline, known as the Indian Ocean Geoid Low (IOGL). A new study is providing a potential explanation for this ...

Editor’s Note: Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. There is a “gravity hole” in the Indian ...

The region of lower gravity, discovered in 1948, manifests as a vast depression in the ocean's surface that reaches some 348 feet deep at its greatest extent. A mysterious “gravity hole” in the Indian ...