Little Worlds Have Bigger Features (Synopsis) [Starts With A Bang]

“How well I have learned that there is no fence to sit on between heaven and hell. There is a deep, wide gulf, a chasm, and in that chasm is no place for any man.” -Johnny Cash

The largest mountains, the greatest chasms, steepest cliffs and the tallest peaks on Earth are certainly impressive, particularly when compared to the scale of a human. But compared to the mountains on Mars, Io, Vesta or Iapetus, or the canyons and cliffs on Mars, Mercury, or even Charon, Earth’s features look puny.

Valles Marineris on Mars, taken by the Viking orbiters. Image credit: NASA.

How could these small worlds, some of which — like Vesta — are barely 5% the diameter of Earth, have features that dwarf our own planet’s? The answer is in gravity itself: without the incredible gravitational pull that Earth experiences at its surface, these irregularities are unchecked by the same forces that pull Earth into such a nearly perfect sphere.

Rheasilvia Mons on the asteroid Vesta, the largest base-to-peak mountain known in the Solar System. Taken by NASA’s Dawn spacecraft. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.

Go get the full story on why the largest Earth features are so small compared to the rest of the Solar System!

from ScienceBlogs http://ift.tt/2953zhN

“How well I have learned that there is no fence to sit on between heaven and hell. There is a deep, wide gulf, a chasm, and in that chasm is no place for any man.” -Johnny Cash

The largest mountains, the greatest chasms, steepest cliffs and the tallest peaks on Earth are certainly impressive, particularly when compared to the scale of a human. But compared to the mountains on Mars, Io, Vesta or Iapetus, or the canyons and cliffs on Mars, Mercury, or even Charon, Earth’s features look puny.

Valles Marineris on Mars, taken by the Viking orbiters. Image credit: NASA.

How could these small worlds, some of which — like Vesta — are barely 5% the diameter of Earth, have features that dwarf our own planet’s? The answer is in gravity itself: without the incredible gravitational pull that Earth experiences at its surface, these irregularities are unchecked by the same forces that pull Earth into such a nearly perfect sphere.

Rheasilvia Mons on the asteroid Vesta, the largest base-to-peak mountain known in the Solar System. Taken by NASA’s Dawn spacecraft. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.

Go get the full story on why the largest Earth features are so small compared to the rest of the Solar System!

from ScienceBlogs http://ift.tt/2953zhN