The Planet Venus

GNC

King-Sized Canary
Joined
Aug 25, 2001
Messages
33,111
Reaction score
21,573
Points
334
Yes! I've noticed Venus as remarkably prominent in the night sky in recent weeks too. Maybe it's always that bright and I've only just noticed it recently, but the fact you've noticed it too, @Ermintruder might mean it's brighter than usual. Is it closer, maybe?
 

Ermintruder

Delineated by a professional cryptozoologist
Joined
Jul 13, 2013
Messages
5,969
Reaction score
9,226
Points
289
Maybe it's always that bright
No...it's somehow cyclic....I'm struggling to understand, it but I think it must be the Earth's relative position to Venus, perhaps with us (or, relatively, Venus) in mid-point conjunction with the Sun.
200px-Phases-of-Venus.svg.png


This is all totally new to me- fascinating!

Wiki said:
The phases of Venus are the different variations of lighting seen on the planet's surface, similar to lunar phases. The first recorded observations of them were telescopic observations by Galileo Galilei in 1610. Although the extreme crescent phase of Venus has been observed with the naked eye, there are no indisputable historical pre-telescopic records of it being observed
This is why I'm seeing it like a tear-shaped mini-moon....because that's nearly what it is!!
 

GNC

King-Sized Canary
Joined
Aug 25, 2001
Messages
33,111
Reaction score
21,573
Points
334
Lovely, thanks.
 

Ermintruder

Delineated by a professional cryptozoologist
Joined
Jul 13, 2013
Messages
5,969
Reaction score
9,226
Points
289
Please be in no doubt about this- I've personally-discovered/witnessed/deduced this for myself, just through observation. I had no idea this was the actual reality I was seeing. Wow!!!
https://en.wikipedia.org/wiki/Phases_of_Venus

The extreme crescent phase of Venus can be seen without a telescope by those with exceptionally acute eyesight, at the limit of human perception. The angular resolution of the naked eye is about 1 minute of arc. The apparent disk of Venus' extreme crescent measures between 60.2 and 66 seconds of arc, depending on the distance from Earth. Nevertheless it is possible for observers with extremely acute eyesight to see a crescent Venus under ideal atmospheric circumstances.

There have been numerous reports stating such observations. The phases of Venus are alleged to have been seen in Mesopotamian times by priest-astronomers. Ishtar (Venus) is described in cuneiform text as having horns. However, other Mesopotamian deities were depicted with horns, so the phrase could have been simply a symbol of divinity.

(@GNC )
 
Last edited:

Ermintruder

Delineated by a professional cryptozoologist
Joined
Jul 13, 2013
Messages
5,969
Reaction score
9,226
Points
289
Extra-weird....why is astrology explaining this to me better than astronomy?
https://en.m.wikipedia.org/wiki/Aspects_of_Venus
The table contains special positions of Venus until 2021. In general, Venus (or Mercury) is an "evening star" when it has an eastern elongation from the Sun, and is a "morning star" when it has a western elongation


2018-12-21 01.06.14.png




Aspects of Venus said:
Note: Greatest brilliancy is often confused with "maximum brightness". Although they are related, they are not quite the same thing. The "greatest brilliancy" is really a geometric maximum: it occurs when the apparent area of the sunlit part of Venus is greatest. Only if the luminance of Venus' apparent surface would be constant (i.e. the same at every point and at every phase) would the "greatest brilliancy" of Venus coincide with its maximum brightness. However, the reflection of sunlight on Venus more closely follows Lambert's law, which means that the maximum brightness occurs at a somewhat larger phase of Venus than its greatest brilliancy

(@GNC )
 
Last edited:

Ermintruder

Delineated by a professional cryptozoologist
Joined
Jul 13, 2013
Messages
5,969
Reaction score
9,226
Points
289
https://oneminuteastronomer.com/5326/phases-venus/

Venus and Mercury exhibit phases because they are closer to the Sun than Earth. Here’s how it works
Because....of course, we're third rock from the sun.

When Venus, for example, lies on the far side of the Sun from Earth, the planet is fully illuminated from our point of view. But its disk is small, just 10″ across, because the planet is nearly 300 million kilometres away.

Ok, but another key factor- I interpret this to be vital....it cannot be closest....it needs to be approaching or receding, to be brightly-visible.

When Venus is almost closest to Earth, on the near side of the Sun, it’s about 60 million kilometres away. Then it appears as a slender but much brighter crescent with a disk nearly 50″ across..

And bingo...a Venusian 'month' is a bit longer than 28 days
In between the planet can appear half-lit, like the first-quarter Moon, and in various gibbous phases. For Venus, the cycle from full to full takes 584 days
 

Ermintruder

Delineated by a professional cryptozoologist
Joined
Jul 13, 2013
Messages
5,969
Reaction score
9,226
Points
289
This looks very promising....a superior conjunction on 9 Jan 2019, coupled with a large western excursion. Was going to get up & see Venus this morning, but in the true spirit of scientific discovery, I may just go back to sleep instead. Courtesy of Heavens Above
2018-12-23 06.49.17.png
 
Last edited:

eburacum

Papo-furado
Joined
Aug 26, 2005
Messages
4,184
Reaction score
2,639
Points
189
Venus' brightness is largely decoupled from its distance from us, because when it is closest to us, it presents a thinner crescent, and when it is further away it is showing more of the lighted side.

Sometimes Venus is a little brighter, because of the comparative eccentricities of our two orbits- but usually this occurs when Venus is very close to the Sun in the Sky, so, ironically you can't see it.
But when Venus is at maximum elongation it can appear very bright, because it is in the darkest part of the sky. The best time to see it in the near future is 6 Jan 2019
https://in-the-sky.org/news.php?id=20190106_11_100

Hmm. At the moment Venus is at mag -4.5, and in January it is -4.4, so it is a little brighter now than it will be at maximum elongation, but the sky will be darker then.
 
Last edited:

XEPER_

Death to all but metal
Joined
Mar 3, 2013
Messages
798
Reaction score
961
Points
104
I don't remember Venus ever being so bright. My wife came in the other morning and told me to go and look at the big light in the sky. I've a basic knowledge of astronomy but even I thought it looked HUGE. Thought a comet might be about to hit us lol
 

eburacum

Papo-furado
Joined
Aug 26, 2005
Messages
4,184
Reaction score
2,639
Points
189
I'm surprised no-one mentioned Mars when it was at opposition earlier this year; it was brighter than any time since 2003 (when it sparked a few UFO reports). Venus is (of course) much brighter than Mars ever gets.
 

Ermintruder

Delineated by a professional cryptozoologist
Joined
Jul 13, 2013
Messages
5,969
Reaction score
9,226
Points
289
I don't remember Venus ever being so bright. My wife came in the other morning and told me to go and look at the big light in the sky
That's is precisely why I've re-ignited this thread. It is an amazing sight in the morning, easily-beating its evening self, and eg Sirius

I think it's as bright as Hale-Bopp was....but smaller.

This morning, Melvyn's irreplaceable "In Our Time" on R4UK was focussed entirely upon Venus. Have a listen to the podcast- really good. Venus: Lucifer, and the roots of cosmology
 
Last edited:

GNC

King-Sized Canary
Joined
Aug 25, 2001
Messages
33,111
Reaction score
21,573
Points
334
Unfortunately it's been cloudy all week here, in fact the cloud's so thick it's barely been daylight.
 

Ermintruder

Delineated by a professional cryptozoologist
Joined
Jul 13, 2013
Messages
5,969
Reaction score
9,226
Points
289
it's been cloudy all week here
Yes, this morning Venus was struggling to be seen through the clouds as well. But it still has that nearly-bright-as-moonlight magnitude, to almost beat the unclear skies.
 

EnolaGaia

I knew the job was dangerous when I took it ...
Staff member
Joined
Jul 19, 2004
Messages
24,794
Reaction score
37,913
Points
314
Location
Out of Bounds
A series of simulation studies suggest Venus was much more amenable to life / habitation during most of its history, and it dramatically shifted to the hell-hole we know today circa 700 million years ago.
Venus May Have Been Habitable Until a Mysterious Catastrophe Millions of Years Ago

Venus is not a nice place, by human standards. For a world named after a Roman goddess of love and beauty, it really is quite the toxic, super-heated hellscape. But it wasn't always this way.

In a new study, scientists make the case for how ancient Venus could have once supported life alongside oceans of liquid water, until a mysterious resurfacing event took all that away about 700 million years ago.

"Our hypothesis is that Venus may have had a stable climate for billions of years," says planetary scientist Michael Way from NASA's Goddard Institute for Space Studies.

"It is possible that the near-global resurfacing event is responsible for its transformation from an Earth-like climate to the hellish hot-house we see today."

The research – presented last week at the EPSC-DPS Joint Meeting 2019 in Geneva, Switzerland – builds upon two previously published studies by Way and his team, and related papers modelling virtualised Venus-like worlds and topographies.

The upshot, the team says, is that 3D GCM (general circulation model) mathematical modelling supports the 'optimistic' view that Venus "spent most of its history with surface liquid water, plate tectonics, and subsequently a stable temperate climate akin to that of Earth through much of its own [history]".

This period of Earth-like climatic stability with liquid water in Venusian oceans may have lasted for up to 3 billion years, the researchers think, based on a number of simulations of what the ancient planet's climate conditions may have been like. ...
FULL STORY:
https://www.sciencealert.com/venus-...-mysterious-catastrophe-millions-of-years-ago

CITED PAPER:
https://meetingorganizer.copernicus.org/EPSC-DPS2019/EPSC-DPS2019-1846-1.pdf
 

EnolaGaia

I knew the job was dangerous when I took it ...
Staff member
Joined
Jul 19, 2004
Messages
24,794
Reaction score
37,913
Points
314
Location
Out of Bounds
Isn't Venus often used as an example of what will happen to Earth if global warming goes unchecked?

Yes ... Venus' atmospheric conditions provide an extreme illustrative example of runaway "greenhouse" style warming.
 

EnolaGaia

I knew the job was dangerous when I took it ...
Staff member
Joined
Jul 19, 2004
Messages
24,794
Reaction score
37,913
Points
314
Location
Out of Bounds
A series of simulation studies suggest Venus was much more amenable to life / habitation during most of its history, and it dramatically shifted to the hell-hole we know today circa 700 million years ago. ...

See Also:
Did Venus, Earth's 'Twisted Sister' Hellscape Planet, Once Harbor Water — and Life?

Venus, our solar system's broiling, radiation-bombarded, sulfuric-acid-raining, toxic hellscape of a planet, may once have hosted vast oceans ... and could have been rather nice, actually.

In fact, a water-covered and life-friendly Venus possibly persisted for as long as 3 billion years, scientists recently reported.

But that idyllic time in Venus' past ended abruptly between 700 million and 750 million years ago, when a near-planet-wide release of carbon dioxide (CO2) stored in surface rocks disrupted the planet's atmosphere and triggered its transformation to the "hellish hothouse" that we know today, researchers said in a statement. ...

FULL STORY: https://www.livescience.com/venus-oceans-habitable.html
 

maximus otter

Recovering policeman
Joined
Aug 9, 2001
Messages
9,201
Reaction score
20,949
Points
334
Isn't Venus often used as an example of what will happen to Earth if global warming goes unchecked?

Yep: All those naughty Venusians driving big cars and eating space cows.

maximus otter
 

GNC

King-Sized Canary
Joined
Aug 25, 2001
Messages
33,111
Reaction score
21,573
Points
334
There's more than one way to warm a globe.
 

Mythopoeika

I am a meat popsicle
Joined
Sep 18, 2001
Messages
46,673
Reaction score
41,594
Points
334
Location
Inside a starship, watching puny humans from afar

Ermintruder

Delineated by a professional cryptozoologist
Joined
Jul 13, 2013
Messages
5,969
Reaction score
9,226
Points
289
Still two weeks until Venus begins to reassume the style & title of The Evening star. October the 10th, 2019.

Despite the fact it's an inhospitable hell-hole, I really look forward to seeing the way its high-magnitude mark is made upon the evening & morning skies.

(And feel slightly-cheated when it is away on its regular sun-sweeping orbit of cloaked concealment)
 

kamalktk

Antediluvian
Joined
Feb 5, 2011
Messages
6,149
Reaction score
10,989
Points
299
High enough in the Venusian atmosphere It's apparently nice enough humans could live there in balloons. Just don't fall overboard.
 

eburacum

Papo-furado
Joined
Aug 26, 2005
Messages
4,184
Reaction score
2,639
Points
189
High enough in the Venusian atmosphere It's apparently nice enough humans could live there in balloons. Just don't fall overboard.
That's right. Apart from the fact that the atmosphere there is poisonous, the 50km level is probably the most Earthlike environment in the solar system. Same temperature, same pressure, same gravity.
Here are a few images I've made of balloon habitats in various non-Earthlike planetary atmospheres; the universe is so inhospitable, that these locations might be the best we can get.
med_Cloud_Cities_on_a_Jovian_world.jpg

med_landis_balloon.jpg

med_Skulk4.png

med_cloudscape.jpg
 

PeteByrdie

Privateer in the service of Princess Frideswide
Joined
Jan 19, 2014
Messages
2,562
Reaction score
2,689
Points
164
That's right. Apart from the fact that the atmosphere there is poisonous, the 50km level is probably the most Earthlike environment in the solar system. Same temperature, same pressure, same gravity.
Here are a few images I've made of balloon habitats in various non-Earthlike planetary atmospheres; the universe is so inhospitable, that these locations might be the best we can get.
med_Cloud_Cities_on_a_Jovian_world.jpg

med_landis_balloon.jpg

med_Skulk4.png

med_cloudscape.jpg
These are awesome! I want to be a steampunk airship pirate above Venus.

 

Ermintruder

Delineated by a professional cryptozoologist
Joined
Jul 13, 2013
Messages
5,969
Reaction score
9,226
Points
289
Venus begins to reassume the style & title of The Evening star. October the 10th, 2019.
That being today. Though, the heavens seem only to open for rain, not starlight. Let's be hopeful we can get some sightings, even through the rain, and soon
 

EnolaGaia

I knew the job was dangerous when I took it ...
Staff member
Joined
Jul 19, 2004
Messages
24,794
Reaction score
37,913
Points
314
Location
Out of Bounds
A proposal under evaluation would generate the first new Venus probe project in more than a quarter century ...
VERITAS: Exploring the Deep Truths of Venus to Reveal the Inner Workings of Earth’s Mysterious “Twin”

Under consideration to become the next Discovery Program mission, VERITAS would reveal the inner workings of Earth’s mysterious “twin.”

Imagine Earth. Now fill the skies with thick, Sun-obscuring clouds of sulfuric acid; boil off the oceans by cranking up the temperature to 900 degrees Fahrenheit (nearly 500 degrees Celsius), and boost the air pressure high enough to flatten you like a pancake. What you now have is Venus, a rocky planet similar in size to Earth but different in almost every other way.

How these “sister planets” evolved so differently has been a burning scientific question for decades, and a proposed mission called VERITAS seeks to provide answers by transforming our understanding of the internal geodynamics that shaped the planet. The mission could lend insights into our own planet’s evolution and even help us better understand rocky planets orbiting other stars. ...

Proposed for a 2026 launch, VERITAS would orbit the planet and peer through the obscuring clouds with a powerful state-of-the art radar system to create 3D global maps and a near-infrared spectrometer to figure out what the surface is made of. It would also measure the planet’s gravitational field to determine the structure of Venus’ interior. Together, the instruments would offer clues about the planet’s past and present geologic processes, from its core to its surface. ...

FULL STORY: https://scitechdaily.com/veritas-ex...the-inner-workings-of-earths-mysterious-twin/
 

EnolaGaia

I knew the job was dangerous when I took it ...
Staff member
Joined
Jul 19, 2004
Messages
24,794
Reaction score
37,913
Points
314
Location
Out of Bounds
Retrospective analysis of Venus imagery and other data from the most recent four decades has revealed the existence of a previously unknown persistent planet-scale wave phenomenon in the Venusian atmosphere.
An Epic, Planet-Scale Wave Has Been Hiding in The Toxic Clouds of Venus For Decades

Deep in the thick, poisonous clouds wrapped around Venus, the atmosphere is behaving very oddly. A giant, previously unknown planet-scale wall of cloud travels westward around the planet every 4.9 days - and apparently has been doing so since at least 1983.

It can extend up to 7,500 kilometres (4,660 miles) long, stretching across the equator to both the north and south mid latitudes, at relatively low altitudes between 47.5 and 56.5 kilometres. It's a phenomenon that's never been seen anywhere else in the Solar System.

"If this happened on Earth, this would be a frontal surface at the scale of the planet," said astrophysicist Pedro Machado of the Institute of Astrophysics and Space Sciences in Portugal.

"That's incredible." ...

The new feature is different. It's much deeper than any atmospheric wave ever seen before on Venus, occurring in the cloud layer responsible for the greenhouse effect that makes the surface so scorchingly hot.

Careful analysis, as well as a study of past observations, showed that the feature has been recurrent, but heretofore unnoticed, since at least 1983, since it could only emerge through a collection of observations from a large number of instruments over a period of time. ...

The newly identified feature, the researchers found, can span up to 7,500 kilometres, and circles the planet once every 4.9 days at a velocity of around 328 kilometres per hour (204 miles per hour). That's a little faster than the clouds at this level, which have a rotation period of about 5.7 days.

But it's still unknown what causes it. ...

FULL STORY (With Imagery): https://www.sciencealert.com/an-epi...ding-in-the-toxic-clouds-of-venus-for-decades
 

GNC

King-Sized Canary
Joined
Aug 25, 2001
Messages
33,111
Reaction score
21,573
Points
334
Speaking of Venus, I noticed it in the sky tonight and it was massive (or very bright, anyway). Is it closer to Earth currently?
 

eburacum

Papo-furado
Joined
Aug 26, 2005
Messages
4,184
Reaction score
2,639
Points
189
No, but it is at maximum elongation - that means it is as far from the Sun in the sky as it ever gets, so it is in a darker part of the sky and looks brighter by contrast.

In this diagram the letter B shows where Venus is at the moment - about half phase. It looks bright, but that is due to contrast effects.

Venus is brightest at location A, but it is also considerably closer to the Sun in the sky, so it doesn't look quite so bright because the sky itself is brighter and you are probably seeing it at twilight.

Venus is closest to Earth when it is at position C, and when it is there you can't see it at all, because it is right next to the Sun.
venus-bright-phases-1.jpg
 
Top