New Climate Model Accurately Predicts Millions of Years of Ice Ages

Artist's impression of ice age Earth at glacial maximum. Credit: Wikipedia Commons/Ittiz

Earth experiences seasonal changes because of how its axis is tilted (23.43° relative to the Sun’s equator), causing one hemisphere to always be tilted towards the Sun (and the other away) for different parts of the year. However, because of gravitational interactions between the Earth, Sun, Moon, and other planets of the Solar System, Earth has experienced changes in its orientation (obliquity) over the course of eons. This has led to significant changes in Earth’s climate, particularly the recession and expansion of ice sheets due to significant variations in the distribution of sunlight and seasonal changes.

These warming and cooling periods are known as interglacial and glacial periods (“ice ages”). Another interesting change is how the glacial-interglacial cycle has become slower with time. While scientists have long suspected that astronomical forces are responsible, they have only recently been able to test this theory. In a recent study, a team of Japanese researchers reproduced the cycle of glacial periods during the early Pleistocene Epoch (1.6 to 1.2 million years ago) using an improved computer model that confirmed astronomical forces were responsible.

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Mars has Been Through Many Ice Ages in the Last Billion Years

Deuteronilus Mensae (DM)has many rough surface features. The Mars Reconnaissance Orbiter has shown that many areas in DM are sub-surface glaciers covered by a thin layer of debris. Image: NASA/JPL/University of Arizona

Like Earth, Mars has experienced periods of extreme glaciation or ice sheet coverage, which are known as ice ages. As these ice ages come and go, glaciers expand and contract along the planet’s surface, grinding huge boulders down to smaller rocks. By examining the size of boulders and rocks at specific locations on Mars, we should be able to understand the history of the Martian ice ages.

A new study did just that.

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800 Million Years Ago, it Was Raining Asteroids on the Earth and Moon

An artist's illustration of an asteroid shower on the Earth-Moon system. Image Credit: Murayama/Osaka Univ.

Natural processes here on Earth continually re-shape the planet’s surface. Craters from ancient asteroid strikes are erased in a short period of time, in geological terms. So how can researchers understand Earth’s history, and how thoroughly it may have been pummeled by asteroid strikes?

Scientists can turn their attention to our ancient companion, the Moon.

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