- 3909 - VENUS - our sister planet? While Earth and Venus are approximately the same size, and both lose heat at about the same rate, the internal mechanisms that drive Earth’s geologic processes differ from its neighbor. It is these Venusian geologic processes that create this cooling mechanisms of Venus and the potential processes behind it.
------------ 3909 - VENUS - our sister planet?
- The
geologic processes that occur on Earth are primarily due to our planet having
tectonic plates that are in constant motion from the heat escaping the core of
the planet, which then rises through the mantle to the lithosphere, or the
rigid outer rocky layer, that surrounds it.
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- Once this
heat is lost to space, the uppermost region of the mantle cools, while the
ongoing mantle convection moves and shifts the currently known 15 to 20
tectonic plates that make up the lithosphere. These tectonic processes are a
big reason why the Earth’s surface is constantly being reshaped.
-
- Venus, on
the other hand, does not possess tectonic plates, so scientists have been
puzzled as to how the planet loses heat and reshapes its surface. Venus’ lithosphere is stagnant and thick.
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- The
researchers examined radar images from NASA’s Magellan mission taken in the
early 1990s depicting quasi-circular geological features on Venus’ surface
known as coronae. The reason why the images were taken using radar is that
Venus’ atmosphere is so thick that normal images taken in the visual spectrum
are unable to penetrate Venus’ thick, cloudy atmosphere.
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- Upon taking
measurements of 65 previously unstudied coronae within the Magellan images and
calculating the lithosphere’s thickness around them, the researchers found
these coronae form and exist where Venus’ lithosphere is the thinnest.
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- Using
computer models, they found the lithosphere around each corona is approximately
7 miles thick. This suggests the coronae could be geologically active since
these areas exhibit a greater average heat flow than Earth.
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- While Venus
doesn’t have Earth-style tectonics, these regions of thin lithosphere appear to
be allowing significant amounts of heat to escape, similar to areas where new
tectonic plates form on Earth’s seafloor.
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- Venus
provides a window into the past to help us better understand how Earth may have
looked over 2.5 billion years ago.
Spectroscopy (VERITAS) mission, which is currently scheduled to launch
no earlier than 2027.
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- Launched
from the Space Shuttle Atlantis in May 1989, Magellan arrived at Venus in
August 1990 and is considered to be one of the most successful deep space
missions ever. Despite this, “Magellan’s” data consists of low resolution and
large margins of error, so “VERTIAS” will essentially act as Magellan 2.0 by
producing three-dimensional global maps of Venus using a state-of-the-art
synthetic aperture radar, along with learning more about the surface
composition with a near-infrared spectrometer.
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- VERITAS
will study the planet’s interior by examining its gravitational field.
Altogether, VERITAS will paint scientists a greater picture of both ancient and
present geologic processes on our twin-sized and mysterious neighbor.
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- VERITAS
will be an orbiting geologist, able to pinpoint where these active areas are
and better resolve local variations in lithospher thickness. To determine if
volcanism really is making the lithosphere ‘squishy’ enough to lose as much
heat as Earth or if Venus has more mysteries in store.
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- Another Venus
mission of importance will be NASA’s” DAVINCI” mission, whose objective will be
to plunge through the Venusian atmosphere and examine its composition in
greater detail than ever before.
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- What new
insights will we learn from Venus and its geologic processes in the coming
years and decades? Only time will tell, and this is why we do the science! Could Earth be next in line?
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March 9, 2023 VENUS - our
sister planet? 3909
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--- Friday, March 10, 2023 ---------------------------
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