Author Topic: Incorrect information given about planet Venus (Read 14231 times)

jfri · « **on:** March 08, 2018, 03:26:35 AM »

I loaded Venus in US2 and when examining its data I found this
Planets temperature to be 340 deg Celsius
But the correct values are more than 450 degrees Celsius
another data I found was that the greenhouse effect would rise Venus temperature with 500 degrees
With the given temperature of 340 that would mean -160 C which I would consider not a possibility. And
even with the correct 450 C we would arrive at - 50 C and even that I found hard to believe.
What is going on here ?

Cesare · « **Reply #1 on:** March 11, 2018, 02:49:47 PM »

Yes. I am aware of the problem. Venus has incorrect temperature levels in Universe Sandbox 2. Read more here: https://en.wikipedia.org/wiki/Venus

Read how hot is Venus here: https://www.space.com/18526-venus-temperature.html

Developers will hopefully soon fix this temperature problem with Venus.

Jar · « **Reply #2 on:** March 13, 2018, 01:56:07 PM »

Thanks for reporting this. It looks like Venus is starting at the wrong temperature. If you load Home > Open > Solar System and start it paused, you'll see that the temperature is as you reported. But if you unpause it, you'll see that it quickly jumps to the correct temperature.

In other sims where the time step is lower, like in the Real Time Solar System, it takes a bit longer for the temperature to rise to the correct ~470 C. I'll report this to the team.

jfri · « **Reply #3 on:** March 14, 2018, 03:18:24 AM »

So even with incorrect start value of the temperature the simulation then arrive to the correct value ? Does this mean that the program can correctly calculate a planets surface temperature given data about its atmosphere and distance to a the central star with known data ?

Jar · « **Reply #4 on:** March 14, 2018, 11:14:02 AM »

Yes, there is a generic temperature simulation for all rocky planets (besides Earth and Mars, which use a separate climate model). You can see the factors in the Temperature tab of the planet's Properties.

Temperature simulation is changing a bit with our work on Planet Grids, which you can read more about here and in other posts on our blog: http://universesandbox.com/blog/2017/08/updated-2017-roadmap/

Cesare · « **Reply #5 on:** March 14, 2018, 12:30:52 PM »

I hope that planet grids will fix the problems with temperature for Venus and all other planets as well.

jfri · « **Reply #6 on:** March 16, 2018, 12:39:46 AM »

Quote from: Jar on March 14, 2018, 11:14:02 AM

Yes, there is a generic temperature simulation for all rocky planets (besides Earth and Mars, which use a separate climate model). You can see the factors in the Temperature tab of the planet's Properties.

Temperature simulation is changing a bit with our work on Planet Grids, which you can read more about here and in other posts on our blog: http://universesandbox.com/blog/2017/08/updated-2017-roadmap/

How does the generic simulation work and what is its limitations ? How does the simulation for Earth and Mars differ from the generic one ?

Jar · « **Reply #7 on:** March 16, 2018, 11:09:00 AM »

Here's an explanation of our climate model for Earth (and a brief explanation of factors for other planets at the top): http://universesandbox.com/blog/2014/10/climate/

You can also check out the climate tutorials in Home > Tutorials > Science.

Essentially, if you just compare the properties that are shown in the Climate tab for Earth and Mars to any other planet's Temperature tab, you will see what factors are simulated and which are not for each.

Cesare · « **Reply #8 on:** March 19, 2018, 04:16:21 PM »

Today, I have noticed that Venus has the wrong texture because it looks too green. Venus must be re-textured to make it look like the real Venus.

Please watch this video to find out more: https://www.youtube.com/watch?v=HYd4BFsGrEI&feature=em-uploademail

im4space · « **Reply #9 on:** March 20, 2018, 07:13:15 AM »

I agree that the color of Venus isn't correct. But how should Universe Sandbox Â² show Venus? If you are in a spaceship looking at Venus all you would see are clouds, and they are close to white. See
http://www.planetary.org/blogs/emily-lakdawalla/2009/2105.html

Or should Universe Sandbox Â² show Venus without the clouds? The pictures of Venus with lots of texture are made from radar images and any color could have been used. See
https://starchild.gsfc.nasa.gov/docs/StarChild/solar_system_level2/magellan_venus.html

My choice is to see objects in Universe Sandbox Â² as I would see them with my eyes from a spaceship. Maybe Universe Sandbox Â² could give us a option to see with human eyes or radar eyes.

Cesare · « **Reply #10 on:** March 20, 2018, 09:35:04 PM »

The clouds of Venus should be shown in Universe Sandbox 2 as exactly as they look like in real life when the atmosphere is shown on Venus in Universe Sandbox 2.

To see the real surface of Venus in Universe Sandbox 2, you need to hide the atmosphere. The color of Venus's atmosphere is too green, so its wrong. It's atmosphere should show whitish clouds with a more orangey atmosphere as it does in real life.

Please update the color and texture of Venus in Universe Sandbox 2 to reflect how the real Venus looks like.

Did you watch the video link I posted above?

im4space · « **Reply #11 on:** March 21, 2018, 06:23:33 AM »

Yes I saw the video link you posted. I believe the picture of Venus it shows came from radar scans. Radar pictures don't show colors, they show the altitude of the surface of the planet. Then any color can be applied to the resulting picture.

Have you looked at Venus through a telescope? It looks very white.

Cesare · « **Reply #12 on:** March 21, 2018, 07:54:50 PM »

I never seen Venus through a telescope.

Please make sure that the developers chance the color and texture of Venus in Universe Sandbox 2 to reflect the real Venus.

tkulogo · « **Reply #13 on:** March 22, 2018, 06:25:07 AM »

Wiki has a real color picture of Venus

https://en.wikipedia.org/wiki/File:Venus-real_color.jpg

Gurren Lagann TSS · « **Reply #14 on:** March 22, 2018, 06:52:08 AM »

Quote from: tkulogo on March 22, 2018, 06:25:07 AM

Wiki has a real color picture of Venus

https://en.wikipedia.org/wiki/File:Venus-real_color.jpg

tkulogo · « **Reply #15 on:** March 22, 2018, 11:03:48 AM »

Quote from: Gurren Lagann TSS on March 22, 2018, 06:52:08 AM

Quote from: tkulogo on March 22, 2018, 06:25:07 AM
Wiki has a real color picture of Venus

https://en.wikipedia.org/wiki/File:Venus-real_color.jpg

Nothing is ever good enough, lol

Cesare · « **Reply #16 on:** March 22, 2018, 07:52:51 PM »

I really like the real photo of Venus on Wikipedia because it displays Venus with its real color and clouds. That how Venus should look like in Universe Sandbox 2. The developer must update Venus with a new color and texture.

jfri · « **Reply #17 on:** March 25, 2018, 02:08:13 PM »

Quote from: Cesare on March 22, 2018, 07:52:51 PM

I really like the real photo of Venus on Wikipedia because it displays Venus with its real color and clouds. That how Venus should look like in Universe Sandbox 2. The developer must update Venus with a new color and texture.

One thing to consider here. Could these photos have been taken using some kind of filter ? Do they correctly show what a human eye would see ?

Cesare · « **Reply #18 on:** March 25, 2018, 10:11:52 PM »

It appears that these NASA photos does not have a filter. To be honest with you, those NASA photos of Venus don't have a filter. This is the real color and texture of Venus.

im4space · « **Reply #19 on:** March 26, 2018, 07:03:49 AM »

NASA does use filters to take photos. The cameras take black and white pictures with filters and then combine the pictures to make colored photos. To make photos that look like what we see they use red, green, and blue filters. They take the black and white picture taken through the red filter and color it red, the picture taken through the green filter gets colored green and the picture taken through the blue filter gets colored blue. These three colored pictures get combined together and show a picture that looks like what we would see with our eyes.

To show other detail they can use infrared or ultraviolet filters to show things that we cannot see. These are a black and white picture but are sometimes artificially colored to make them look better.

From the website
http://www.planetary.org/blogs/emily-lakdawalla/2009/2105.html

"This view of Venus was composed of images taken through red, green, and blue filters by MESSENGER on June 5, 2007 as it approached for its second flyby. Seen in natural color, Venus is nearly as featureless as a cue ball."

Cesare · « **Reply #20 on:** March 27, 2018, 05:20:22 AM »

I understand, but NASA does not always use filters. I know that, in general, NASA uses filters, especially for zooming on stars. For planets like Venus, NASA uses filters to see it in infrared or ultraviolet but sometimes NASA does not use filters at all to see planets like Venus.

im4space · « **Reply #21 on:** March 27, 2018, 06:59:51 AM »

Cesare can you find a NASA picture of Venus that was taken without a filter?

Cesare · « **Reply #22 on:** March 27, 2018, 07:14:45 AM »

Yes, I have managed to find a transit of Venus passing in front of the Sun.

Physics_Hacker · « **Reply #23 on:** March 28, 2018, 10:37:15 AM »

Quote from: Cesare on March 27, 2018, 07:14:45 AM

Yes, I have managed to find a transit of Venus passing in front of the Sun.

And can you see the real color of Venus in this photo?
I would say no. I'm pretty sure Venus isn't that dark...since it's the silhouette. Against the sun. Also, I'm pretty sure the currently simulated colors are mostly correct. Maybe a slight bit too green but if anything, it looks better than if it were the same color all the way into the shadowed side of the planet.

Cesare · « **Reply #24 on:** March 28, 2018, 11:45:30 AM »

No. It is not the real color of Venus. This photo only shows a transit of Venus passing in front of the Sun. Let's go back to the point. Venus must be re-textured and re-colored in Universe Sandbox 2 to make it look exactly like the real Venus.

Physics_Hacker · « **Reply #25 on:** March 28, 2018, 04:16:54 PM »

Quote from: Physics_Hacker on March 28, 2018, 10:37:15 AM

.... Also, I'm pretty sure the currently simulated colors are mostly correct. Maybe a slight bit too green but if anything, it looks better than if it were the same color all the way into the shadowed side of the planet.

Cesare · « **Reply #26 on:** March 29, 2018, 09:36:03 AM »

I know, but it still looks too green.