Moon of the Austral Sky


Sunset and Waxing Moon over AAT Dome

When visiting southern latitudes nothing disorients a northern hemisphere astronomer more than seeing our familiar Moon turned “the wrong way!”

With the Moon now dominating the night sky, my photo attention in Australia turns to it as my celestial subject.

It’s wonderful to see the Moon as a crescent phase in the evening sky, but now flipped around so it looks like the Moon we see from home up north when it is a waning crescent in the morning.

However, the lead image above actually shows the waxing crescent in the evening. It shines above the volcanic hills near Warrumbungles National Park, with the added silhouette of the dome of the Australian Astronomical Telescope, the largest optical telescope in Australia.

After a lifetime of seeing the Moon in its northerly orientation, seeing the austral Moon throws off your sense of time and direction. Are we looking west in the evening? Or east in the morning? The Moon just doesn’t make sense!

Full Moon with Glitter Path
This is a two-exposure composite: a long exposure for the sky and ocean, and a short exposure for the disk of the Moon itself, to preserve some detail in the disk, specifically the mare areas to show the face of the Moon and not an overexposed white disk. Both with the 135mm telephoto and Canon 6D, from Woolgoolga, NSW.

Then there’s the Full Moon. It rises in the east, as does the Sun. But like the Sun, the “down under Moon” moves from right to left across the northern, not southern sky. And the familiar “Man in the Moon” figure is upside down, as seen above.

The photo above is from Friday night, and shows the Full Moon rising in the northeast over the Pacific Ocean.

Golden Glitter Path of the Moon
The apogee Full Moon of April 22, 2016 rising over the Pacific Ocean and lighting the waters with a golden glitter path of reflected moonlight. I shot this from the Woolgoolga Headlands viewpoint, with the 135mm telephoto and Canon 6D. This is a high dynamic range stack of 5 exposures to compress the range in brightness. Even so, the Moon itself is still overexposed.

This “HDR” image above from earlier in the evening captures the golden glitter path of moonlight on the ocean waves. I photographed these Full Moon scenes from the Headlands viewpoint at Woolgoolga, a great spot for panoramic seascapes.

The Full Moon this night was the apogee Full Moon of 2016 – the smallest and most distant Full Moon of the year, the opposite of a “supermoon.”

Gibbous Moon Over Upper Ebor Falls
This is a high dynamic range stack of 7 exposures to preserve the range in brightness between the bright sky and Moon, and the dark ground in the dim twilight.

Earlier in the week I was inland, high on the New England Tablelands in New South Wales. This image shows the waxing gibbous Moon in the evening twilight over Ebor Falls on the Guy Fawkes River, one of the few waterfalls on the famed Waterfall Way in New Soith Wales that has water flowing year round.

— Alan, April 24, 2016 / © 2016 Alan Dyer / www.amazingsky.com

 

The March “Mini-Moon”


Apogee-Perigee Moon Comparison

The Full Moon of March 5 will be the smallest and most distant Full Moon of 2015.

In recent years there’s been a huge ado about “supermoons,” the largest and closest Full Moons of the year. This year the biggest Full Moon occurs on September 27.

Photographers wishing to capture a comparison of the biggest Full Moon with the smallest will need to shoot the Moon this week, on March 5. That’s the date for 2015’s most distant and smallest Full Moon – the “mini-moon” of March.

On March 5 the Moon reaches its “apogee” – the most distant point in its monthly elliptical orbit around Earth about 10 hours before it reaches the moment of full phase at mid-day on March 5 for North America. On March 5 the Moon’s maximum distance will be 406,384 kilometres from Earth (measured from the centre of Earth to the centre of the Moon).

By nightfall on March 5 the Moon will be a little closer than that but not by much. Seven Full Moons later, on September 27, the Moon will reach its monthly “perigee” point closest to Earth less than an hour before full phase, at a distance of 356,877 kilometres.

That will be the much-publicized “supermoon” of 2015. Shoot both Full Moons with the same optical system (preferably a telescope with a focal length of at least 600mm to make the Moon large enough on the camera frame) and you’ll have a pair of real images comparing the minimum and maximum apparent sizes of the Moon, much like the simulations above.

You’ll certainly be out shooting the September 27 Full Moon, as that night it also undergoes a total eclipse. The Full Moon will turn deep red in the early evening for North America. But wait until the umbral phase is over, and you’ll have a normal looking Full Moon to create the comparison pair.

There’s also a total lunar eclipse next month, on the morning of April 4, six Full Moons before the September “supermoon” eclipse.

However, that’s not the smallest Full Moon of 2015. On April 4 the Full Moon comes three days after the Moon’s monthly apogee point, putting it a little closer than this week’s Full “mini-Moon” of March. The difference between the two extreme Moons is only about 12 percent, between a lunar disk 30 arc minutes across (1/2 degree) at apogee and one 34 arc minutes across at perigee.

The difference is impossible to detect to the eye, not without two Moons side-by-side in the sky, something we’ll never see. But by taking photos of the March and September moons with the same optics you can create a matched two-moon comparison.

Clear skies!

– Alan, March 1, 2015 / © 2015 Alan Dyer / www.amazingsky.com