Timeline for How brightly does Venus's hot surface glow at night? Could you see it? Could you see well enough to walk around?
Current License: CC BY-SA 4.0
18 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Mar 8, 2023 at 14:06 | answer | added | Kasper Sorbom | timeline score: 4 | |
| May 3, 2022 at 0:52 | answer | added | Woody | timeline score: 4 | |
| Apr 25, 2022 at 17:24 | comment | added | Roger Wood | @uhoh yes, agreed, the temperature of the rocks and the atmosphere are probably very close. The temperature of the atmosphere decreases with height which is presumably why the temperature map matches the topographic map. So I think it all depends on how transparent is the atmosphere at ~700 nm. Wikipedia says the sulphuric acid haze at ~30 km is at 100 C, so that's a big contrast looking straight up! | |
| Apr 25, 2022 at 11:54 | comment | added | uhoh | @RogerWood Yes I think that's true, but only true inside a closed cavity; I don't think Venus' atmosphere will necessarily work like that, after all my question shows a photograph of Venus' surface radiating through the atmosphere in near-infrared. I don't know the optical depth at longer wavelengths but at that height the atmosphere could be somewhat cooler (or hotter) that the surface itself. | |
| Apr 25, 2022 at 6:24 | comment | added | Roger Wood | @uhoh Doesn't emissivity + reflectivity = 1 by definition? So if everything is at the same temperature there will be no contrast at all. I assume the rock and 'air' temperatures will be very similar. I think the only hope is that the 'air' may be quite transparent in which case you might see a faint sillouette of the horizon against a cooler sky. CO2 doesn't appear to have an absorption band at at ~700 nm. | |
| Apr 24, 2022 at 22:01 | comment | added | uhoh | @RogerWood there will be a little bit of contrast due to differing emissivity, and I think the atmosphere's temperature will be a little bit cooler, but mostly yes, even if there is some visible light it will offer very little useful contrast. I think that's important enough that it should be included as an answer. | |
| Apr 24, 2022 at 18:45 | comment | added | Roger Wood | If everything is the same temperature, then the everything has the same total emission+reflection, so that doesn't help either. The only hope is that the sky is somewhat transparent at deep red wavelengths so at least you could tell sky from ground. | |
| Apr 24, 2022 at 16:24 | comment | added | Roger Wood | you also have the issue that everything will be at a very similar temperature. So you would only have differences in emissivity/reflectivity to distinguish different objects. | |
| Apr 24, 2022 at 12:45 | answer | added | Oscar Lanzi | timeline score: 8 | |
| Feb 10, 2022 at 19:14 | comment | added | uhoh | @BrendanLuke15 "... the idea being that the lowlands are hotter and so glow more brightly due to thermal radiation." | |
| Feb 10, 2022 at 18:00 | history | tweeted | twitter.com/StackSpaceExp/status/1491834367995527177 | ||
| Feb 10, 2022 at 12:51 | comment | added | BrendanLuke15 | Neat that both flybys flew by the same surface features, I am surprised that the optical/NIR image looks so similar to the inverted topography | |
| Feb 10, 2022 at 9:08 | comment | added | Fred | @BrendanLuke15: I recall reading something similar during the past couple of weeks, wjile reading material for this question. I think it might have been a Wikipedia article. | |
| Feb 10, 2022 at 5:08 | comment | added | tckosvic | For example, the exhaust duct on a stationary power gas turbine engine glows dull red at 1000 F at night. Been there lots of times. | |
| Feb 10, 2022 at 3:20 | comment | added | uhoh | @tckosvic if you are looking at steel that hot with the lights off and dark-adapted eyes you might be violating some safety rules. But it sure sounds fun! | |
| Feb 10, 2022 at 3:15 | comment | added | tckosvic | Sorry, but I deal in deg F. Surface temp as stated to be 735 K would be about 860F. Just from experience steel at 900 - 1000 F appears to be very dull red. If that was the only light souce you couldn't see anything from it. I doubt if any material of venus surface would have any dramatically different emission properties than a piece of steel. So I would say you couldn't see any glow and you couldn't walk around in a safe manner based upon that light. | |
| Feb 10, 2022 at 0:19 | comment | added | BrendanLuke15 | Can't find the source but I recall an article quoting a Soviet Venera engineer saying that the daytime lighting level was akin to dusk on Earth. | |
| Feb 10, 2022 at 0:13 | history | asked | uhoh | CC BY-SA 4.0 |