The Gregorian calendar is the most widely used calendar in the world with a new year beginning on each 1 January. It is a solar calendar determining the length of the year by the Earth’s orbit around the Sun and its months not corresponding to the phases of the Moon.
Some countries however also use other types of calendars. The Chinese calendar, for example, is a lunisolar calendar. Months are based on the orbit of the Moon around the Earth and years on the orbit of the Earth around the Sun. Months begin on the day of a New Moon and years on the New Moon between 21 January and 20 February.
While China in general uses the Gregorian calendar, the traditional Chinese calendar is used to determine holidays, the most famous probably being the Chinese New Year. The Chinese New Year also marks the beginning of the Spring Festival, a two weeks event ending with the Lantern Festival on the 15th day of the year. In 2019, the Chinese New Year is today, February 5, and marks the beginning of the Year of the Pig, commonly associated with prosperity.
Happy New Year!
“A book cover is a distillation, a haiku, if you will, of the story.”
Chip Kidd at TED2012
I had a hard time with this cover, more specifically with the cover image. As the title of my book was going to be Sun and Moon, I naturally wanted both the Sun and the Moon on the book cover. While we usually observe the Sun during daytime and the Moon during nighttime, it is actually possible to see them both during the day. However, at and around new moon we most of the time cannot see the Moon as the Sun is not able to illuminate it. And at full moon, the Moon only rises at sunset and sets at sunrise. So I was hoping to catch a Crescent Moon and the Sun together. But I had to find out that either when both orbs were visible they were too far apart for a cover image or it was too cloudy to even see them.
Then I thought an aurora picture with the Moon in it would work too as the solar wind causes the polar lights. If you have followed my aurora adventure though, you know that this did not happen either. I missed the only chance I got for this picture on my first night in Yellowknife as I had traveled since the early morning hours and was simply too cold and tired to stay up any longer for the shot. The next night was too cloudy for any picture and afterwards the Moon was too far away from the lights for a cover shot.
I started to get desperate. Unexpected help arrived, however, in the form of my foreword author Daniel Reisenfeld. Dan is a professor of physics and astronomy at the University of Montana and an absolute expert when it comes to the sky. I am deeply grateful that he not only wrote the foreword for Sun and Moon but also provided a lot of insights and thereby helped making the book more accurate. In his foreword he shared what profound impact the first solar eclipse he observed had on him, back when he was still in high school. When I read his foreword, it just hit me: a solar eclipse image! That was to be my cover image.
So what you see on the cover of Sun and Moon is an image from the August 21, 2017 solar eclipse over North America. The bite taken out of the Sun in the lower left corner is the New Moon partly covering the disc of the Sun at the end of the eclipse. I am really happy with this cover image. Experts on Sun and Moon will know right away what they are looking at and people not so familiar with these two orbs will hopefully get a little curious and take a closer look. Open the book. Read Dan’s foreword, look at the pictures, and maybe want to follow me on …another inspiring and informative journey through the world above.
When I started out photographing skies, I tried to capture the atmosphere of a certain sky-moment, the feeling I had when looking at the sky right there and then. I was fascinated by clouds and the structures they formed. Back then, I avoided having any luminaries in my pictures. I felt that any bright objects would dominate the photographs and distract from what I wanted to show.
But lately I experimented with incorporating the Sun and the Moon into my photographs. And I also became curious about these orbs. Why does the Sun rise and set farther north in the northern hemisphere in summer? What are the darker and the brighter areas on the Moon’s surface? What happens during solar and lunar eclipses? And then these fascinating light displays, the aurora polaris or polar lights. What are they and what does the Sun have to do with them? So I did some research on Sun and Moon and some of the small and big solar and lunar events.
Slowly but steadily my new book Sun and Moon / Sonne und Mond emerged. It will be published in early December. I learned a lot along the way, about photography, astronomy, software, the publishing industry. While the road has been bumpy sometimes, I enjoyed working on this project a lot. I will share more in the next few weeks, so stay tuned!
Sunlight reflected from Earth illuminates the near side of the Moon the Sun cannot directly illuminate. Unlike the Sun, the Moon does not glow by itself but is only visible when illuminated by sunlight. During crescent moon, Earth blocks some sunlight that would at full moon completely illuminate the near side of the Moon and the Sun can only directly illuminate a part of this side of the Moon. Earth, however, also reflects some sunlight which then dimly illuminates the rest of the near side of the Moon, a phenomenon called earthshine.
“I with borrow’d silver shine,
What you see is none of mine.
First I show you but a quarter,
Like the bow that guards the Tartar:
Then the half, and then the whole,
Ever dancing round the pole.”
—Jonathan Swift, On the Moon, 1853
One rotation of the Moon around its own axis takes as long as it takes the Moon to orbit Earth once. From Earth therefore, an observer at any given location always sees the same side of the Moon. The side visible from Earth is called the near side and the unseen side far side.
The Moon does not glow by itself but is only visible when illuminated by the Sun. As Earth orbits the Sun and the Moon orbits Earth, visibility of the Moon observed from Earth varies. The shape of the visible part of the Moon is called the phase of the Moon or lunar phase. A full moon is when an observer from Earth can fully see the near side of the Moon and a new moon is when the Moon is completely invisible. In between these lunar phases, the visible part of the Moon either increases (waxing) from new moon to full moon or decreases (waning) from full moon to new moon.
Lunar phases occur at slightly different times depending where on Earth they are observed. The shapes of the waxing or waning Moon also differs depending on from what hemisphere it is observed: in the northern hemisphere the Moon waxes from right to left and in the southern hemisphere from left to right and wanes vice versa. Near the equator, the moon waxes from bottom to top and wanes from top to bottom.