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Recent Podcast
A Tour of a Collision Between Four Galaxy Clusters in Abell 1758
A Tour of a Collision Between Four Galaxy Clusters in Abell 1758
When two pairs of galaxy clusters collide, the result is not four separate objects, but one giant galaxy cluster. (2019-10-24)

Pillars of Erosion

Narrator (Megan Watzke, CXC): Erosion is a process. To put it simply, erosion is what happens when some sort of force - be it wind, water or radiation - wears down an object. Erosion is in many places and occurs on lots of different scales. Usually, erosion is a two-step process: first some force such as rain breaks an object up, and then this same force, or another one, often combined with gravity, carries material away.

We can see erosion around us in our day-to-day experiences. For example, erosion is responsible for the small pillars of dust left behind after a rainstorm.

On a larger scale, the effects of wind, rain and gravity combine to form the spectacular buttes and spires in the southwestern deserts of the United States and elsewhere around the world. Perhaps the most famous example of this is the Grand Canyon. This natural wonder was created by erosion over a period of six million years by the Colorado River.

Erosion also takes place on a cosmic scale in interstellar space, where intense radiation in the form of ultraviolet energy and X-rays from bright stars can sculpt shapes from dense clouds of gas and dust that are trillions of miles in size. It is this process that helped sculpt the so-called "Pillars of Creation," one of the most spectacular and renowned images ever taken by the Hubble Space Telescope.

While erosion does indeed subtract things, it is worth considering that this is not always bad. In fact, by removing material from an object or an environment, erosion may be responsible for the creation of new and perhaps even more spectacular structures around our planet and across the Universe.

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