Earthshine and binoculars (1 Viewer)

[Binastro]

Nowadays there is awful light pollution here, so I am at a disadvantage.

I have been following the waning crescent Moon and was using an old 10x25 Docter binocular.

I could just see the earthshine at 40% crescent getting quite easy at 30% in a transparent sky.

However, when the light pollution was less severe I could see earthshine at 50% illumination with a good binocular and even 60% with the best, say the Canon 10x42L IS.

It depends on the observing conditions, the observers eyesight, and the quality and specs of the binocular.

Seeing earthshine at over 50% illumination, i.e. gibbous is quite a severe test of binocular quality.

Earthshine is the visibility of the dark part of the Moon illuminated by reflection of sunlight onto the Earth and then onto the Moon to be viewed from the Earth.
This partly depends on the cloud cover on the Earth.

With unaided eyes earthshine is usually readily visible with a thin crescent Moon.

It depends also on location on the Earth, latitude and the elevation of the Moon above the horizon.

Regards,
B.

 

[William Lewis]

I'm up in North Norfolk at present and could observe earthshine quite well this morning with craters a mare regions being quite obvious through the 7x42's.

Sqm here is around 21.6, at home more like 20.3.

At home I can hardly see the milky way above me, up here the milky way, and further the dark lanes and lumps in it around cygnus were very apparent naked eye.

 

[Binastro]

NLM here about magnitude 2.5.

Apparently Cuba is dark with no electricity most of the time.

About ten years ago there was a total power cut over a vast area here.

I could actually see a dark sky.

I could not see a thing in my home until I found a torch.

I used to see M31 after astronomy meetings in Burlington House, Piccadilly without optical aid about 1980.
Also 13 Pleiads by the Baltic within city lights, late 1980s, just with eyes.

Regards,
B.

 

[Yarkho]

Seeing earthshine at over 50% illumination, i.e. gibbous is quite a severe test of binocular quality.

I'll say...

I have never actually seen earthshine on such an advanced phase of the Moon from anywhere (my darkest location is 48.5°N Bortle 3 with M8 being a naked-eye object). I will keep watching for it from now on, though.

Regarding binocular quality, I suppose one needs a) no veiling glare, b) almost no stray light, right? I find stray light from the Moon a bit of an issue with my Meostars. Not severe, but it appears to be there.

 

[Binastro]

Some of the Canon IS and some Leicas have very little veiling glare and almost no ghosts.

Although my eyes were average for resolution they were very good for faint objects.

I frequently saw 13 Pleiads with no optical aid within a city but by the sea.

I have fairly frequently seen earthshine at 50% Moon and sometimes more gibbous, but only with binoculars, not with unaided eyes.

It does depend on the cloud cover on the Earth, and the quality of the binocular.

I am not sure a very dark site helps as the illuminated Moon is then brighter.

Regards,
B.