APOD: Venus Once Molten Surface (2010 Aug 01)

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Expand view Topic review: APOD: Venus Once Molten Surface (2010 Aug 01)

Re: APOD: Venus Once Molten Surface (2010 Aug 01)

by sliderul@bellsouth.net » Mon Aug 02, 2010 3:48 pm

The radar image of Venus shows a feature that is immediately recognizable and is ominous. it is a giant boxing glove, turned palm side up. the next time we are in the vicinity, we need to punch it and see if the wearer is perhaps knocked out, lying on its back and therefore inert/harmless.

Don Klne

Re: Just a Venusian minute there.

by Beyond » Mon Aug 02, 2010 4:12 am

orin stepanek wrote:
neufer wrote: A Venusian day is 116.75 Earth days long so maybe
a Venusian minute is 116.75 Earth minutes long.
Art; is that a 'new math'? :lol:
You're close Orin. It's "Neufer Math"-- strangest stuff in the Universe :!:

Re: APOD: Venus Once Molten Surface (2010 Aug 01)

by john.rhoads@clearwire.net » Mon Aug 02, 2010 2:18 am

Didn't the Soviet Minerva series finally take pictures for about an hour on the surface of Venus? I recall the first on didn't last but for a few minutes but unless my text books were wwrong, the latter lasted a long time given the surface conditions.

Re: Just a Venusian minute there.

by orin stepanek » Mon Aug 02, 2010 12:55 am

neufer wrote: A Venusian day is 116.75 Earth days long so maybe
a Venusian minute is 116.75 Earth minutes long.
Art; is that a 'new math'? :lol:

Just a Venusian minute there.

by neufer » Sun Aug 01, 2010 9:15 pm

agr wrote:"Venus' surface is so hot and hostile that no surface probe has lasted more than a few minutes."

If you visit http://en.wikipedia.org/wiki/Venera, you'll see that several of the Soviet union's Venera probes lasted an 50 minutes or more on the surface of Venus, with the longest lasting 127 minutes. That more than a few minutes in my book.
A Venusian day is 116.75 Earth days long so maybe
a Venusian minute is 116.75 Earth minutes long.

Re: APOD: Venus Once Molten Surface (2010 Aug 01)

by agr » Sun Aug 01, 2010 8:49 pm

"Venus' surface is so hot and hostile that no surface probe has lasted more than a few minutes."
If you visit http://en.wikipedia.org/wiki/Venera, you'll see that several of the Soviet union's Venera probes lasted an 50 minutes or more on the surface of Venus, with the longest lasting 127 minutes. That more than a few minutes in my book.

Re: APOD: Venus Once Molten Surface (2010 Aug 01)

by Beyond » Sun Aug 01, 2010 7:25 pm

Looks like some-one dropped a thick woolen mitten to me.

Re: APOD: Venus Once Molten Surface (2010 Aug 01)

by neufer » Sun Aug 01, 2010 5:10 pm

moonstruck wrote:
Sure looks like a giant catchers mitt to me :roll:
http://asterisk.apod.com/vie ... 53#p127853

Re: APOD: Venus Once Molten Surface (2010 Aug 01)

by moonstruck » Sun Aug 01, 2010 4:54 pm

Sure looks like a giant catchers mitt to me :roll:

Re: APOD: Venus Once Molten Surface (2010 Aug 01)

by Chris Peterson » Sun Aug 01, 2010 3:09 pm

If I can step into Ann's territory a bit, I'd like to point out how color can, well, color our perceptions. This is a radar image- the source data contains nothing but intensity information (and that outside the visible range). It has had the standard HEAT (or similar) pseudocolor palette applied. Here's another standard palette:
ds9b.jpg
It certainly gives a very different sense of the place. Almost seems habitable! Neither choice of palette is better or worse from a scientific standpoint, despite the different impression our brains place on the result.

Re: APOD: Venus Once Molten Surface (2010 Aug 01)

by Chris Peterson » Sun Aug 01, 2010 2:29 pm

Thanks, nice reference. What this makes me think is that virtually every planetary system that is even a little bit similar to our own is likely to have habitable planets or moons- places where life similar to what we know here could at least survive, and probably develop (something we don't know very much about). I suspect many of these are not sufficiently stable over long periods to allow complex animal life, however. All of which supports my belief that "pond scum" life is abundant in the Universe, while more complex life- especially highly intelligent life- is not.

Re: APOD: Venus Once Molten Surface (2010 Aug 01)

by neufer » Sun Aug 01, 2010 2:15 pm

Ann wrote:
And to think that Venus used to be classified as a habitable planet. Is it still classified as such? Chris just said that there are five habitable planets in our solar system. Apart from the Earth and Mars, which has not been proved to be a completely dead world, which would the other three be? Europa and Enceladus, probably, because of their probably liquid interiors. Which is the fifth one? Possibly Ganymede, which just might be liquid inside, too, or even Callisto? No, I don't believe in Callisto. Titan? At those temperatures? I don't believe it, but maybe Chris thinks that Titan could become prime Solar System real estate when the Sun starts stoking its furnace for real and turns into a red giant.

But like I said, Venus used to be considered habitable. It makes you wonder if it Venus that is the spectacular and unexpected failure, or if it is the Earth that is the wonderful exception.
http://en.wikipedia.org/wiki/Extraterrestrial_life wrote:
Extraterrestrial life in the Solar System
Many bodies in the Solar System have been suggested as being capable of containing conventional organic life. The most commonly suggested ones are listed below; of these, five of the ten are moons, and are thought to have large bodies of underground liquid (streams), where life may have evolved in a similar fashion to deep sea vents.

* Mars — Life on Mars has been long speculated. Liquid water is widely thought to have existed on Mars in the past, and there may still be liquid water beneath the surface. Methane was found in the atmosphere of Mars. By July 2008, laboratory tests aboard NASA's Phoenix Mars Lander had identified water in a soil sample. The lander's robotic arm delivered the sample to an instrument which identifies vapors produced by the heating of samples. Recent photographs from the Mars Global Surveyor show evidence of recent (i.e. within 10 years) flows of a liquid on the Red Planet's frigid surface.

* Mercury — The MESSENGER expedition to Mercury has discovered that a large amount of water exists in its exosphere.

* Europa — Europa may contain liquid water beneath its thick ice layer. It is possible that vents on the bottom of the ocean warm the ice, so liquid could exist beneath the ice layer, perhaps capable of supporting microbes and simple plants, just like in Earth's hydrothermal vents.[4]

* Jupiter — Carl Sagan and others[who?] in the 1960s and 70s computed conditions for hypothetical amino acid-based macroscopic life in the atmosphere of Jupiter, based on observed conditions of this atmosphere. These investigations inspired some science fiction stories.

* Ganymede — Possible underground ocean (see Europa).

* Callisto — Possible underground ocean (see Europa).

* Enceladus — Geothermal activity, water vapor. Possible under-ice oceans heated by tidal effects.

* Titan (Saturn's largest moon) — The only known moon with a significant atmosphere. Data from the Cassini-Huygens mission refuted the hypothesis of a global hydrocarbon ocean, but later demonstrated the existence of liquid hydrocarbon lakes in the polar regions - the first liquid lakes discovered outside of Earth. Analysis of data from the mission has uncovered aspects of atmospheric chemistry near the surface which are consistent with – but do not prove – the hypothesis that organisms there are consuming hydrogen, acetylene and ethane, and producing methane.

* Venus — Recently, scientists have speculated on the existence of microbes in the stable cloud layers 50 km above the surface, evidenced by hospitable climates and chemical disequilibrium.

Numerous other bodies have been suggested as potential hosts for microbial life. Fred Hoyle has proposed that life might exist on comets, as some Earth microbes managed to survive on a lunar probe for many years. However, it is considered highly unlikely that complex multicellular organisms of the conventional chemistry of terrestrial life (i.e. animals and plants) could exist under these living conditions.

Even if microbial extraterrestrial life were found on another body in the Solar System, it would still need to be proven that such life did not originate from Earth in the recent or distant past. For example, an alternate explanation for the hypothetical existence of microbial life on Titan has already been formally proposed — theorizing that microorganisms could have left Earth when it suffered a massive asteroid or comet impact (such as the impact that created Chicxulub crater only 65 mya), and survived a journey through space to land on Titan 1 million years later. The Living Interplanetary Flight Experiment, developed by the Planetary Society and due to be launched in 2011, has been designed to test similar theories.>>

Re: APOD: Venus Once Molten Surface (2010 Aug 01)

by Chris Peterson » Sun Aug 01, 2010 2:07 pm

Ann wrote:And to think that Venus used to be classified as a habitable planet. Is it still classified as such? Chris just said that there are five habitable planets in our solar system. Apart from the Earth and Mars, which has not been proved to be a completely dead world, which would the other three be?
I figured the Earth and Mars for certain (we know Mars is habitable, even if life never developed on it), and a handful (or more) of the moons of gas giants, a number of which appear to have internal temperatures capable of sustaining liquid water, as well as chemical energy sources. There could be a dozen such moons. I wasn't including Venus, although it probably should be included. It was probably habitable a few billion years ago, and there's no reason to think it couldn't become habitable again. For a planet to produce and sustain life may only require a few hundred million years of habitable conditions.

Re: APOD: Venus Once Molten Surface (2010 Aug 01)

by León » Sun Aug 01, 2010 1:56 pm

Now we have Venus in the East, coincidentally aligned as we saw the last day, looks like a star, but of course does not blink so it is a planet that sunlight returns, but the question is imposed, when stop being star whose heat core is still firing, slowing the consolidation of the surface.

Of course the theory says nothing about the formation of planets, but here we have evidence as Popper said does not advance scientific knowledge confirming new laws, unlike laws that contradict the ruling experience.

Ahora tenemos a Venus en el Este, casualmente alineado como vimos el día pasado, luce como estrella, pero claro no titila por tanto es un planeta que devuelve la luz del sol, pero la pregunta se impone, cuando dejo de ser estrella cuyo calor del nucleo esta despidiendo todavía, retrasando la consolidación de la superficie.

Claro la teoría dice otra cosa en cuanto a la formación de los planetas, pero ahí tenemos la evidencia y como dijera Popper el conocimiento científico no avanza confirmando nuevas leyes, al contrario descartando leyes que contradicen la experiencia.

Re: APOD: Venus Once Molten Surface (2010 Aug 01)

by neufer » Sun Aug 01, 2010 1:46 pm

Image Venus Once Molten Surface
http://en.wikipedia.org/wiki/Moulting wrote:
<<In biology, molting (or moulting, also known as sloughing, shedding, or for some species, ecdysis) signifies the manner in which an animal routinely casts off a part of its body (often but not always an outer layer or covering), either at specific times of year, or at specific points in its life-cycle. Molting can involve the epidermis (skin), pelage (hair, fur, wool), or other external layer. In some species, other body parts may be shed, for example, wings in some insects. Examples include old feathers in birds, old hairs in mammals (especially dogs and other canidae), old skin in reptiles, and the entire exoskeleton in arthropods.>>
  • _______ Hamlet, Prince of Denmark Act 2, Scene 2

    HAMLET: I will tell you why; so shall my anticipation
    • prevent your discovery, and your secrecy to the king
      and queen moult no feather. I have of late--but
      wherefore I know not--lost all my mirth, forgone all
      custom of exercises; and indeed it goes so heavily
      with my disposition that this goodly frame, the
      earth, seems to me a sterile promontory, this most
      excellent canopy, the air, look you, this brave
      o'erhanging firmament, this majestical roof fretted
      with golden fire, why, it appears no other thing to
      me than a foul and pestilent congregation of vapours.

Re: APOD: Venus Once Molten Surface (2010 Aug 01)

by neufer » Sun Aug 01, 2010 1:40 pm

Henning Makholm wrote:
Ann wrote:Chris just said that there are five habitable planets in our solar system. Apart from the Earth and Mars, which has not been proved to be a completely dead world, which would the other three be?
I took them to be Venus, Earth, Mars, Europa and Titan, based on Chris' earlier choice of liquid solvents as the threshold property.
Enceladus, Earth, Mars, Europa and Titan?

Re: APOD: Venus Once Molten Surface (2010 Aug 01)

by owlice » Sun Aug 01, 2010 12:14 pm

For those confused by Ann's post re: habitable planets and what Chris said, her comments refer to another thread which can be found here.

If you're interested in learning more about Venus, Dr. Nemiroff's lecture on Mercury, Venus, and Mars, which is part of his free introductory astronomy course, is available for download here.

Re: APOD: Venus Once Molten Surface (2010 Aug 01)

by orin stepanek » Sun Aug 01, 2010 12:09 pm

in a few million years; if Venus cools down it may become habitable! Who knows? Stranger things have happened.

Re: APOD: Venus Once Molten Surface (2010 Aug 01)

by Henning Makholm » Sun Aug 01, 2010 12:06 pm

Ann wrote:And to think that Venus used to be classified as a habitable planet. Is it still classified as such?
I don't think there is any authoritative technical definition of "habitable". You get to use the word however you like for the purposes you need it.
Chris just said that there are five habitable planets in our solar system. Apart from the Earth and Mars, which has not been proved to be a completely dead world, which would the other three be?
I took them to be Venus, Earth, Mars, Europa and Titan, based on Chris' earlier choice of liquid solvents as the threshold property.
It makes you wonder if it Venus that is the spectacular and unexpected failure, or if it is the Earth that is the wonderful exception.
Why would either of them have to be unexpected? If the true possibility of settling into an Earth-rather-than-Venus pattern is about 50%, then neither outcome in any particular situation ought to be a surprise.

Re: APOD: Venus Once Molten Surface (2010 Aug 01)

by Ann » Sun Aug 01, 2010 11:57 am

And to think that Venus used to be classified as a habitable planet. Is it still classified as such? Chris just said that there are five habitable planets in our solar system. Apart from the Earth and Mars, which has not been proved to be a completely dead world, which would the other three be? Europa and Enceladus, probably, because of their probably liquid interiors. Which is the fifth one? Possibly Ganymede, which just might be liquid inside, too, or even Callisto? No, I don't believe in Callisto. Titan? At those temperatures? I don't believe it, but maybe Chris thinks that Titan could become prime Solar System real estate when the Sun starts stoking its furnace for real and turns into a red giant.

But like I said, Venus used to be considered habitable. It makes you wonder if it Venus that is the spectacular and unexpected failure, or if it is the Earth that is the wonderful exception.

Ann

Re: APOD: Venus Once Molten Surface (2010 Aug 01)

by orin stepanek » Sun Aug 01, 2010 11:44 am

I wouldn't want to live there; not a nice place to visit either. :mrgreen:

Re: APOD: Venus Once Molten Surface (2010 Aug 01)

by Beyond » Sun Aug 01, 2010 4:40 am

OW!! OOOH-OOOH YIKES!! Toooo hot a topic for ME to handle :!:

APOD: Venus Once Molten Surface (2010 Aug 01)

by APOD Robot » Sun Aug 01, 2010 4:07 am

Image Venus Once Molten Surface

Explanation: If you could look across Venus with radar eyes, what might you see? This computer reconstruction of the surface of Venus was created from data from the Magellan spacecraft. Magellan orbited Venus and used radar to map our neighboring planet's surface between 1990 and 1994. Magellan found many interesting surface features, including the large circular domes, typically 25-kilometers across, that are depicted above. Volcanism is thought to have created the domes, although the precise mechanism remains unknown. Venus' surface is so hot and hostile that no surface probe has lasted more than a few minutes.

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