Starship Asterisk*

Anon wrote: ↑Sun Feb 10, 2019 7:21 am I wonder what Earth would look like under a similar radar scan. Perhaps adjusting the “color” to something more Terran like blue/green.

Chris Peterson wrote: ↑Sun Feb 10, 2019 3:39 pm

BDanielMayfield wrote: ↑Sun Feb 10, 2019 3:32 pm

distefanom wrote: ↑Sun Feb 10, 2019 11:08 am Hi,
do Venus has surface activity? I think to Vulcan, lava flows and maybe even tectonic movements?
I think, because it's similar in size to earth, that it should have some activity of this kind...

If no...WHY do Earth has such activity? What's the difference from our planet and Venus & Mars?

Earth's superiority over Venus and Mars as far as habitability is concerned is due to many factors. The most important is our planet's orbit right in the sweet spot of the Sun's habitable zone, so that Earth has been able to retain its water, and mostly in liquid form. The Earth's size has also given us a very long lived liquid outer core, which produces our protective magnetosphere and keeps tectonics and volcanic activity going. Our massive Moon has also kept Earth's tilt stable among several other benefits. Those are the three main things Earth has that Venus and Mars lack; right location, right size, and right satellite

And the formation of the Moon from a massive collision might be what caused us to have that active liquid core, unlike Venus's similarly massive, but largely solid core.

distefanom wrote: ↑Sun Feb 10, 2019 3:44 pm Hi Ann,
you quoted from Wiki:
"the lack of evidence for plate tectonics on Venus, possibly because its crust is too strong to subduct without water to make it less viscous."
can we *really* suppose that the oceans can "softer" the Earth's crust so it can subduct ?
Oceans on Earth are an average (let's say) of 8 km deep, how this can be comparable to the earth's radius which is more than 6000 km?
For me, just for a simple analogy, it's not really more than a "whetted" surface of an apple.
so how can this, be thought responsible for such planet-wide effect?
for me, instead, other effects are responsible for this *so different" appearance and behavior...
Maybe volcanoes on Venus behave differently than the one on earth. And the lack of seismology data, contributes to blur the interpretation of current data.

BDanielMayfield wrote: ↑Sun Feb 10, 2019 3:32 pm

distefanom wrote: ↑Sun Feb 10, 2019 11:08 am Hi,
do Venus has surface activity? I think to Vulcan, lava flows and maybe even tectonic movements?
I think, because it's similar in size to earth, that it should have some activity of this kind...

If no...WHY do Earth has such activity? What's the difference from our planet and Venus & Mars?

Earth's superiority over Venus and Mars as far as habitability is concerned is due to many factors. The most important is our planet's orbit right in the sweet spot of the Sun's habitable zone, so that Earth has been able to retain its water, and mostly in liquid form. The Earth's size has also given us a very long lived liquid outer core, which produces our protective magnetosphere and keeps tectonics and volcanic activity going. Our massive Moon has also kept Earth's tilt stable among several other benefits. Those are the three main things Earth has that Venus and Mars lack; right location, right size, and right satellite

distefanom wrote: ↑Sun Feb 10, 2019 11:08 am Hi,
do Venus has surface activity? I think to Vulcan, lava flows and maybe even tectonic movements?
I think, because it's similar in size to earth, that it should have some activity of this kind...

If no...WHY do Earth has such activity? What's the difference from our planet and Venus & Mars?

Ann wrote: ↑Sun Feb 10, 2019 7:42 am

Anon wrote: ↑Sun Feb 10, 2019 7:21 am I wonder what Earth would look like under a similar radar scan. Perhaps adjusting the “color” to something more Terran like blue/green.

Well, Earth has a very diverse surface. There are large oceans, icecaps (for now), large deserts, rain forests (for now), grasslands and urban areas. Surely Earth would look very different than Venus even in a radar image.

Ann

Anon wrote: ↑Sun Feb 10, 2019 7:21 am I wonder what Earth would look like under a similar radar scan. Perhaps adjusting the “color” to something more Terran like blue/green.

distefanom wrote: ↑Sun Feb 10, 2019 11:08 am Hi,
do Venus has surface activity? I think to Vulcan, lava flows and maybe even tectonic movements?
I think, because it's similar in size to earth, that it should have some activity of this kind...

If no...WHY do Earth has such activity? What's the difference from our planet and Venus & Mars?

Wikipedia wrote:

Without seismic data or knowledge of its moment of inertia, little direct information is available about the internal structure and geochemistry of Venus. The similarity in size and density between Venus and Earth suggests they share a similar internal structure: a core, mantle, and crust. Like that of Earth, the Venusian core is at least partially liquid because the two planets have been cooling at about the same rate. The slightly smaller size of Venus means pressures are 24% lower in its deep interior than Earth's. The principal difference between the two planets is the lack of evidence for plate tectonics on Venus, possibly because its crust is too strong to subduct without water to make it less viscous. This results in reduced heat loss from the planet, preventing it from cooling and providing a likely explanation for its lack of an internally generated magnetic field. Instead, Venus may lose its internal heat in periodic major resurfacing events.

Anon wrote: ↑Sun Feb 10, 2019 7:21 am I wonder what Earth would look like under a similar radar scan. Perhaps adjusting the “color” to something more Terran like blue/green.