Planetary moons #8 : Iapetus

in #steemstem6 years ago

It is the third largest moon of Saturn and at the same time the most remote of all the larger satellites of this planet. The moon has two hemispheres that differ significantly in appearance and color. It also has an amazing mountain ridge running on its surface.

Iapetus as seen by the Cassini probe
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By NASA/JPL/Space Science Institute link [Public domain]

Discovered by Cassini in 1671, the moon was distinguished by two sides: light and dark. Iapetus orbits Saturn in an orbit with a diameter of about 7 million kilometers. It is inclined at an angle of about 17 degrees from the plane. The entire lap around the planet takes the satellite for a little over 79 days. Like our Earth Moon - one hemisphere of Iapetus is always facing Saturn. Thanks to the large distance from the planet, you can probably see Saturn's rings. The rest of the satellites are too close to be able to see these huge rings.

These two Iapetus images show differences in the brightness of his hemispheres

By NASA/JPL/Space Science Institute link [Public domain]

The Iapetus surface is divided into two hemispheres. Scientists say that the Saturn ring is responsible for this, whose matter has dropped on one of the satellite's hemispheres for millions of years. Already the discoverer of the moon, Giovanni Cassini, discovered the difference in the brightness of the hemispheres. The dark hemisphere on Iapetus was called Cassini Regio in honor of its discoverer. The characteristic features of the surface of the satellite are numerous craters. About 20 of them have a diameter of over 100 km. The largest crater on Iapetus is Turgis with a diameter of 580 kilometers. It is also one of the largest craters in the entire Solar System. It is located on the dark side of the moon.

Mountainous terrain at the unique equatorial ridge of Iapetus

By NASA/JPL/Space Science Institute link [Public domain]

The equatorial diameter of the satellite is 1492 kilometers, and its density is 1.08 kg / dm3, which means that almost all ice is built. The most characteristic feature of the Iapetus surface is the mountain ridge running across the equator. It is about 1,300 km long, 20 km wide and 13 km high, which is why it is one of the highest mountain ranges in our entire Solar System. These mountains are dotted with impact craters, which is why they are very old. Their origin is unknown. The Cassini spacecraft discovered them in 2004.

The equatorial ridge on Iapetus

By By NASA/JPL/Space Science Institute link [Public domain]

Greetings to lovers of Astronomy!

Sources:

Iapetus (moon)
Moons of Saturn
List of natural satellites
and my knowledge...

All rights reserved by @astromaniac 2018

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