KidSpirit

Astrophotography: Exploring the Universe from Below

Mysteries of the UniverseFeatures
Artwork by: Chris Baker. Copyright Chris Baker.

The universe is more beautiful than most humans can imagine.

Looking up at the sky, we often see distant moonlight faded by light pollution from cities. Even on the clearest days, our vision of the night sky is an incomplete version of what it really holds. Deep space objects, such as star clusters and nebulae beyond our solar system, are almost impossible to see without aid from specialized equipment.

In our fast-paced everyday lives, it is easy to overlook the fact that each of us is one human out of seven billion, in a solar system around one of trillions of stars. It’s hard to stay aware of that connection to our universe, but fields like astrophotography offer us insight into skies invisible to the human eye.

Astrophotography is a specialized type of photography for recording images of celestial objects in the night sky. It is popular among amateur astronomers who enjoy watching the sky as a hobby. Astrophotographers use a variety of equipment ranging from film cameras to video cameras hooked up to telescopes with varying magnification levels. Most astrophotographers set the cameras for long exposures, so they can capture the night sky as the Earth rotates.

The Witch's Broom Nebula. This photo was taken in 2014, using narrowband filters and a process known as the Hubble palette.

Photo courtesy of Chris Baker. Copyright Chris Baker.

In the past, astrophotography has been used for star classification and other specific fields of astronomical research. Many images taken by professionals reveal stars in the Milky Way that are too faint to observe through a telescope. This field has also contributed to our knowledge about objects beyond our galaxy. For example, in 1888 amateur astronomer Isaac Roberts took a long exposure picture that revealed the spiral structure of a nebula. It was the first photograph of an object from a different galaxy.

Today, however, astrophotography is more often used to enjoy our extraterrestrial surroundings. Delving into the field allows us to explore and appreciate the mysteries of our universe.

For this issue of KidSpirit, I interviewed Chris Baker, a professional astrophotographer based in the United Kingdom, to understand what incited his passion.

Fascinated by the night sky for as long as he can remember, Chris recalls borrowing his first small telescope around the age of 11 or 12. He explained that learning about and enjoying the night sky is possible using only the naked eye and binoculars. Chris mentioned, “Just identifying the constellations or watching a meteor shower can be so rewarding.”

Like Chris, I started discovering an interest in astronomy a few years ago while gazing at the night sky from my porch, though visibility was often poor because of clouds. One night when a foggy sky disappointed my hopes of watching the lunar eclipse, I found a link to a live broadcasting of the event. That night, as I discovered the field of astrophotography, I was able to enjoy the eclipse to an extent I never knew was possible. After I was amazed by the vivid high-definition images taken by professional photographers, I found a telescope to indulge in my developing passion.

Until now, the extent of my own astrophotography has been pictures taken from my telescope’s lens with my phone camera. I’ve been able to see and record Mars, Venus, and the Moon. Whenever I look into a telescope, I’m star-struck by the details I can see from more than 238,000 miles away. In order to enhance my experiences, I am currently in the process of convincing my parents to buy a professional camera I can attach to my telescope. I’ve also set up an Astronomy Club at my school, with plans to develop our knowledge of this field and further explore space through NASA-run projects.

Just as I am starting to expand my amateur interest with new equipment, Chris similarly started off slowly. As his enthusiasm developed, he started learning more about astrophotography, buying more advanced cameras and transitioning from black and white to color pictures. In 2012, he took a step forward and moved his equipment to a hosted site on top of a mountain in Spain. “Since then,” Chris says, “I have operated my equipment remotely, and given it is atop the mountain in a dark area with good weather, I can get a large amount of data with ‘narrowband’ imaging, which takes images through filters that only allow specific narrow wavelengths of light to be captured. It is this data I mainly use for my art.”

The Tulip Nebula. This photo was taken from Chris's hosted site in Spain in 2016, using narrowband filters and with an exposure time of 27 hours.

Photo courtesy of Chris Baker. Copyright Chris Baker.

Chris focuses on “deep-sky objects,” or “those outside our solar system, typically such things as nebulae and star clusters within our galaxy, the Milky Way.” The colors these objects appear to the naked eye are not as vivid as the colors I had seen in photographs like Chris’s. When I asked Chris about the colors of deep space objects, he told me that “most objects are very faint at the distances they are from earth or earth orbit and therefore the eye cannot detect any colors. Some objects have obvious color, like the bright star Sirius, which is blue, or Betelgeuse, which is clearly orange/red.”

Since the colors are so faint to the human eye, I wondered why the pictures are so vibrant. I asked Chris how he was able to portray such rich photographs. Chris explained, “I use specific filters to capture the emissions of certain ionized gases. These are Hydrogen Alpha (HII), Sulphur (SII), and Oxygen (OIII). I then process these and eventually assign each set of data to a color channel. I assign the sulphur to red, the hydrogen to green, and the oxygen to blue. Then I work on this to bring out the beautiful details and colors. This particular way of mixing the colors is known as the ‘Hubble palette,’ as many of the Hubble images use this convention. I like it because of the blue and gold colors it creates.”

The Hubble palette enables an astrophotographer to reveal details about objects in space that the human eye cannot see. The natural colors of nebulae and galaxies are reflections of the light emitted by various gases. Because many of these colors aren’t visible to the human eye and are relatively similar hues, we wouldn’t be able to distinguish the beautiful and detailed features of deep space objects in an unedited photograph. I think this justifies astrophotographers’ assigning different colors to various wavelengths of lights using the Hubble palette, as it makes the images more aesthetically pleasing and elaborate.

In addition to presenting his work online, Chris has recently started working in a new medium called Galaxy on Glass. “I have spent much of my career in the printing industry so am aware of many printing processes,” Chris said. “But my main driver for working with acrylic, glass, and aluminum was the desire to do something different and something that looked dramatic in an office or home as wall art. There are many good astrophotographers around the world who produce amazing images and some make available posters and such like. I did not want to do this, as I wanted to create something dramatic and something that would have a much higher value. Hence my experiments, and finally products, on glass and acrylic.”

For those interested in trying astrophotography, Chris suggested buying a simple camera for less than 150 dollars, which can be used to photograph the moon and planets — after all, he started with just our solar system! He also suggests attaching a DSLR camera to a telescope, or even trying to use a smartphone to capture images in the telescope’s lens. Perhaps most importantly, he suggests joining a local astronomy society where you can get advice from fellow enthusiasts.

The Moon. Vanita captured this image from her telescope's lens using an iPhone camera.

Photo by Vanita Sharma

Astrophotography is unknown to many young adults but can be a rewarding and unique passion. Even beyond the act of photographing the sky, it’s important to enjoy the beauty of the world around us. Perhaps, with a sky so boundless and beautiful, no life is truly lived until we spend time immersed in what’s above.

To learn more about Chris Baker’s work, please visit his website.

Vanita Sharma is a sophomore at Ridgewood High School in New Jersey. She enjoys playing tennis, reading, taking pictures, learning about astronomy, and Latin. She loves creative writing and writing short stories in her free time.