Earthlight – The Amazing Sky

March 16, 2015March 16, 2015

The Waning Moon of Morning

The waning crescent Moon shines with sunlight and Earthlight in the morning sky.

This was the Moon before dawn this morning, March 16, 2015. It’s the waning crescent Moon four days before the New Moon of March 20, when the Moon will eclipse the Sun.

This view shows the sunlit crescent and the dark side of the Moon also lit by sunlight, but sunlight reflecting off the Earth first. The night side of the Moon is lit by blue Earthshine.

To record details in both the bright and dark sides of the Moon I shot six exposures, from 1/160th second to 6 seconds, combining them in a high-dynamic range stack with Photoshop and Adobe Camera Raw for the tone-mapping.

I shot it through my 92mm refractor, shown here in a beauty shot from the evening before.

$TMB Refractor & Mach1 Mount$

The upcoming solar eclipse by the Moon is visible as a partial eclipse from much of northern Europe (but not from North America, except from a teenie bit of Newfoundland), and as a total eclipse from a path running up the North Atlantic.

The only landfall for the total eclipse path are the Faroe Islands and the Arctic island of Svalbard.

For more details about the eclipse see The Great American Eclipse.

I’ll be missing this eclipse, the first total solar eclipse I’ve chosen to sit out since 1995, 20 years ago. My next total solar eclipse will be August 21, 2017. At least, that’s the plan!

Clear skies to all my eclipse chasing friends, on land, on the sea, and in the air on Friday morning.

December 26, 2014December 26, 2014

Both Sides of the Boxing Day Moon

The dark and bright side of the Moon appear together in a portrait of the 5-day Moon.

This was the waxing crescent Moon on Friday, December 26 – Boxing Day.

In this image you can see both the bright crescent directly lit by the Sun, and details in the dark side of the Moon lit only by sunlight reflected off Earth – Earthshine.

I used a composite of 5 exposures from 8 seconds to 1/50 second to capture both sides of the Moon, with the images merged in Photoshop’s HDRPro module.

I shot the images through my TMB 92mm apo refractor using the Canon 60Da camera, on a very clear night in New Mexico.

Happy Boxing Day to all!

November 29, 2014November 29, 2014

A Stellar Occultation by the Moon

The double star Beta Capricorni disappears in a wink behind the Earthlit edge of the Moon.

The evening of Wednesday, November 26 provided a bonus celestial event, the eclipse of a double star by the Moon.

The star is Beta Capricorni, also known as Dabih. I had a ringside seat Wednesday night as the waxing Moon hid the star in what’s called an occultation.

Dabih is a wide double star, composed of a bright magnitude 3 main star, Beta1 Capricorni, and a fainter magnitude 6 companion, Beta 2 Capricorni. You can see both in the still image view at top. Their wide separation makes them easy to split in binoculars.

In reality, they are separated in space by an enormous gap of 21,000 times the distance from the Earth to the Sun. By comparison, distant Pluto lies an average of just 40 times the Earth-Sun distance.

With such a wide separation Beta1 and Beta2 take an estimated 700,000 years to orbit each other.

Beta1 is a giant orange star 600 times more luminous than our own Sun and 35 times bigger. Beta2 is a blue subgiant 40 times more luminous that the Sun.

Adding to the complexity of the system, Beta2 is also a close double, while Beta1 is a tight triple star, making for a quintuple star system.

The movie below records each occultation, first of the fainter blue Beta2 star, then of the brighter Beta1 star.

Each occultation happens in an instant to the eye. However, stepping through the video shows that the brighter star took 4 video frames to dim, about 1/10th of a second. Whether this is real, due to the star’s giant size, or just an effect of the twinkling of the atmosphere, is questionable.

Technical notes:

The still photo is a “high dynamic range” stack of 12 exposures from 4 seconds to 1/500th second, taken with the Canon 60Da camera at ISO 400, to capture the huge range in brightness, from the dark side of the Moon and stars, to the bright sunlit crescent. I used Photoshop’s HDR Pro module to stack the images and Adobe Camera Raw in 32-bit mode to do the tone-mapping, the process that compresses the brightness range into a final image.

I shot the video with the 60Da camera as well, setting it to ISO 6400, and using its video mode to record real-time video clips, both in HD 1920×1080 for the wide-field “establishing shots,” and in its unique 640×480 Movie Crop mode for the close-ups of the actual occultations. Those two clips appear as inset movies. I edited and processed the clips, plus added the titles, using Photoshop and its video capabilities.

All were shot from New Mexico with the TMB 92mm refractor at f/5.5.

November 25, 2014November 25, 2014

The Dark Side of the Moon in Twilight

The waxing crescent Moon shines amid the stars and deep blue twilight.

This was the scene last night, as the two-day-old Moon reappeared in the evening sky as a thin crescent.

The Moon looks full because most of the side facing us was brilliantly lit by Earthshine, sunlight reflected off the Earth and lighting the Moon. Here, only the thin crescent at right is directly lit by the Sun.

This was a particularly bright example of Earthshine, likely because so much of the northern part of the Earth is now covered with cloud and snow, making Earth even more reflective than it usually is.

To capture this scene through a telescope, I shot a set of high-dynamic-range exposures, from long to short, to capture the huge range in brightness from the dayside to the darkside of the Moon. The long exposure also captured the stars in the deep blue twilight of a clear New Mexico sky.