10 Discoveries That Shed Light On Mysteries Of Our Solar System

Mars’s Climate History

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Black Beauty, an ancient Mars meteorite found in 2011 in the Sahara Desert, may tell an intriguing tale of Mars’s climate history. The shiny, dark meteorite has embedded zircons, durable minerals that are created when lava cools and can survive almost all chemical attacks. That means they can help us to determine the age of rocks and give clues to a planet’s climate. “When you find a zircon, it’s like finding a watch,” Florida State Professor Munir Humayun said. “A zircon begins keeping track of time from the moment it’s born.”

Humayun and his team were surprised to find that some zircons in Black Beauty were created 4.4 billion years ago, when Mars was a new planet with an environment that may have had the ability to support life. space space science earth science space station science space travel space science earth science space station science

By studying variations in oxygen atoms in these zircons, Humayun was able to extract some of Mars’s climate history like an archaeologist would extract bits of human history from artifacts and human skeletons. That’s because the zircons act like an archive of Mars’s climate change by keeping records of what happened to water vapor during the history of the planet.

Humayun discovered that water was much more plentiful on Mars about 4.5 billion years ago, but then a dramatic change took place. The dry desert that characterizes Mars today has existed for a long time—at least 1.7 billion years. But if Mars was once a warm planet with abundant water, that again sparks the question: Is it possible that Mars sustained life at one time?

For current climate studies, other scientists are analyzing dust devils on Mars. As we’ve talked about, dust devils are like dusty tornadoes. But that’s where the comparison to Earth weather ends. “The Martian air is so thin, dust has a greater effect on energy transfers in the [Mars] atmosphere and on the surface than it does in Earth’s thick atmosphere,” said Udaysankar Nair of the University of Alabama.

In the daytime, dust in the air may block sunlight from heating the surface of Mars. At night, that same type of dust emits long-wave radiation that warms the surface. So a greater knowledge of atmospheric dust—and dust devils—should help us to develop a better understanding of Mars’s current climate.

Zebra Stripes In Van Allen Radiation Belt

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Earth is surrounded by two Van Allen radiation belts, an inner and an outer one, each shaped like a doughnut and containing high-energy electrons and protons. But in early 2014, scientists announced that NASA’s twin Van Allen Probes had discovered a strange but persistent zebra stripe pattern in the high-energy electrons in the inner radiation belt. space space science earth science space station science space travel space science earth science space station science

Earth’s magnetic field holds these radiation belts in place. But Earth seemed like an unlikely culprit in the zebra stripe mystery. Most scientists assumed that increased solar wind would cause this kind of structure. But that theory was discarded when the stripes continued to be visible even though solar wind activity was low.

Scientists eventually found the answer they’d previously considered so unlikely. It turns out that Earth’s rotation causes the zebra stripes. Due to the tilt in our planet’s magnetic field axis, Earth’s rotation produces a weak, oscillating electric field that affects the entire inner radiation belt. If you think of groups of electrons in the radiation belt as taffy, then the oscillations work like a candy machine to stretch and fold the taffy, which produces the striped pattern in the inner radiation belt.

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