Venus - Ashen Light

[John]

I've read quite a lot about the phenomena known as the Ashen Light on Venus which I understand is thought to be similar to Earthshine on the Moon's unlit hemisphere. Has anybody actually observed the Ashen Light on Venus and, if so, with what equipment and conditions ?

I was thinking with the current phase of Venus and it's good positioning in the sky that this might be the time to look out for it.

Thanks

[gooseholla]

I think you have to block the sunny side of Venus out, with some implement like a stick or such. Maybe you don't have to go so extreme, but that is what I have read in a book.

[John]

I've read that too. I've tried that to try and see Sirius B (without success, so far ) so maybe I'll try the same with Venus.

[DarkerSky]

I've not seen it, but I know people who have seen it and sketched it as recently as a few weeks ago. I think one guy was using a 102mm refractor and got the ashen light on the dark side of the south polar region.

The best time to look for it according to my Norton's is when Venus is a slim crescent near inferior conjuction. I guess having a bigger dark side vs. light helps with contrast effects. Blue or violet filters help to bring it out I think.

[John]

....I guess having a bigger dark side vs. light helps with contrast effects.....

That makes sense to me too. Thanks Seb

[nytecam]

I've not seen it, but I know people who have seen it and sketched it as recently as a few weeks ago. I think one guy was using a 102mm refractor and got the ashen light on the dark side of the south polar region.

The best time to look for it according to my Norton's is when Venus is a slim crescent near inferior conjuction. I guess having a bigger dark side vs. light helps with contrast effects. Blue or violet filters help to bring it out I think.

Venus is currently gibbous @ 62% phase - I've never heard of the AL being seen at gibbous phase but only during a slim crescent. I've never seen or recorded AL and would have more faith if a reasonably explanation was give as to where the illumination comes from - any takers?

[gooseholla]

Maybe a cloaked death star?

[DarkerSky]

Venus is currently gibbous @ 62% phase - I've never heard of the AL being seen at gibbous phase but only during a slim crescent. I've never seen or recorded AL and would have more faith if a reasonably explanation was give as to where the illumination comes from - any takers?

Going back longer than I care to remember, my planetary sciences lecturer suggested electrical activity in the cloud decks. I don't know if there is any scientific support for this explanation.

As an addendum I just found this: http://www.nasa.gov/vision/universe/solarsystem/venus-20071128.html

[John]

Sir Patrick Moore's mother put it down to Venusians having huge parties at night and hanging lanterns in the trees.

There may be a few flaws with that theory though

[gooseholla]

Patrick Moore, in his book "Venus" (2002, Cassell Illustrated) gives some plausible theories, but doesn't say what it is for sure, apart from something "electrical in nature" (p.80).

1. Aurorae in Venus' upper air (p.78)

2. Flashes of lightning in the atmosphere (p.80)

However, will we ever truly know?

[bish]

I've thought that I have seen it, but the eyes can play tricks.

[E621Keith]

I though it's a illusion. Until it is proven otherwise, I will stick with this explanation.

The electrical storms explanation sounds plausible, but I doubt it's Aurora because Venus doesn't have a magnetic field or Earth shine. The moon is a lot closer than Venus.

[DarkerSky]

I doubt very much that it is an illusion.

Here's an interesting snippet from the BAA Journal in 2007 about the Ashen Light written by Richard McKim and Sir Patrick Moore.

2007JBAA..117..265M Page 265

[Ganymede12]

One very old (and very unlikely) theory is that the dark part of venus that we don't usually see is lit up by fireworks launched by the Venusian aliens to mark the rise of a new emporor of Venus!

[nytecam]

No AL in my pics from May 1 but probably need an AL filter and long exp but pretty view anyway:hello2:

[Macavity]

Yep, couldn't see it either - Videowise. Nice images though! Not *quite* the same thing, but apparently worth looking in the near infra-red? Many "cams" still have SOME response around the one micron region? Filters are available? Just "heat" re-radiated from the atmosphere, the surface, but...

[nytecam]

Here's the 1st frame top left above but stretched to show the phase better:headbang:

Yes MC - my unfiltered Lodestar does NIR too and I may play [if skies ever clear] with NIR trans filter!

The problem with all AL observations is ghost of bright crescent from the scope optics which sometimes conveniently complete the 'globe effect'!

[nytecam]

Just checking my pic against CdC for phase on May 1 and it shows AL so it must be true:hello2: