Venus

As usual the ‘runaway greenhouse effect’ theory rears its ugly head, and the event that supposedly led to it ‘forced massive amounts of CO² into the atmosphere’. But the huge atmospheric pressure of Venus (> 90 times that of Earth’s surface), combined with its being nearer to the Sun than Earth, can adequately explain the observed temperatures.

A new study on the volcanic highlands of Venus casts doubt on whether the planet ever had oceans, reports Universe Today.
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Venus is often referred to as “Earth’s sister planet“, owing to the number of similarities between them.

Like Earth, Venus is a terrestrial (aka. rocky) planet and it resides with our Sun’s Circumstellar Habitable Zone (CHZ). And for some time, scientists have theorized that billions of years ago, Venus had oceans on its surface and was habitable – aka. not the hot and hellish place it is today.

However, after examining radar data on the Ovda Fluctus lava flow, a team scientists at the Lunar and Planetary Institute concluded that the highlands on Venus are likely to be composed of basaltic lava rock instead of granite.

This effectively punches a hole in the main argument for Venus having oceans in the past, which is that the Ovda Regio highlands plateau formed in the presence of water.

The study that describes their findings (and includes a new map of the highlands plateau) recently appeared in the Journal of Geophysical Research: Planets.

Ovda Regio, a crustal plateau near the equator in the western region of Aphrodite Terra, is the largest formation of its kind on Venus. Between 1989 and 1994, the region was mapped extensively by NASA’s Magellan spacecraft. This mission would be the first to use synthetic aperture radar (SAP) to map the surface of Venus and measure its planetary gravitational field.

At the time, scientists believed that the highlands were composed of granite rock – which requires the presence of oceans to form. Combined with the chemistry of the atmosphere, scientists theorized that the presence of these highlands were evidence of a past ocean.

However, after remapping the Ovda Fluctus lava flow and examining its morphology and geologic setting, the LPI team concluded it was likely to be basaltic in composition.

Unlike granite, basalt rock is linked to volcanic activity and can form with or without water. These result could significant implications for the evolutionary history of Venus, particularly when it comes to questions of its habitability.

Full article here.

via Tallbloke’s Talkshop

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October 11, 2019 at 09:31AM