Banner by Alisa Zhang

Outer Space: Gone Without A Trace

By Jamie Sheppard

Can you remember the last time you saw a star-studded sky? Not merely a dark blue veil scarcely scattered with tiny globes of light, but instead the entire Milky Way broadcasted overhead? For many people, especially city-dwellers, this is not a common phenomenon. Light pollution, which emanates from streetlights, buildings, or other sources of light,3 is becoming more pervasive, so much so that according to National Geographic, 83 percent of people in the world live in regions that are light-polluted.1 The term is analogous to light-trespass, which the article from the journal of Frontiers in Ecology and the Environment defines as “unwanted artificial light” that shines into neighboring property.4 And while it may not appear as threatening as other forms of pollution that afflict the air, water, or soil, it still generates many silent yet adverse effects, which became especially widespread after a period of exponential growth in technology and urban civilization in recent history.  

During the mid-18th and 19th centuries, rapid technological advancement spurred the Industrial Revolution into motion, which was quite the catalyst for light pollution. With more innovation and progress came a greater push to work through the night in an effort to maintain productivity and efficiency. In the process, our ancestors placed our breathtaking view of the Milky Way on the back burner. Now, most of us are forced to face the consequences of a starless sky. The International Dark-Sky Association, a non-profit organization that aims to combat light pollution, asserts that “the history of scientific discovery and even human curiosity itself is indebted to the natural night sky.”2 Without the dark sky, the cosmic connection that our ancestors once had with the Earth and beyond is vanishing just like the stars in every city sky. From the days of the caveman up until the era of Isaac Newton, a brilliant dark palette interwoven with bands of light from the Universe was a spectacle that graced the skies every night. Once we become untethered to the galactic wonder that floats above our heads, we become estranged with what it means to be human; we become estranged with the Universe. An article from NASA Science remarked about the commonality of every human culture throughout time “to tell stories about the stars and about the nature and origin of the Universe.”6 Yet these stories are no longer being told. An ancient and timeless piece of human culture thousands of years old has disappeared - all within the span of the last 250 years.  

 In terms of practicality, astronomers are forced to find isolated areas to observe the sky. Those located closer to cities have found it more difficult to observe the Milky Way.3  In a Forbes magazine article, Mario Humay, the head of the Association of Universities for Research in Astronomy (AURA), revealed that light trespass from neighboring cities threaten the astronomical observatories in Chile.7 In many areas, the dry desert-like conditions and lack of clouds grant many observatories the dark, clear sky required to peer into the depths of the Universe.7 Yet Chile Route 5, a major highway that runs through the country, threatens the La Silla Observatory.7 Other sources of light pollution, such as the cities of La Serena and Coquimbo, prove to be great challenges for AURA.7 However, this problem is not an isolated one; astronomers all over the world are forced to adapt as light pollution infringes on their ability to see the skies. Most astronomical observatories are located away from human towns and cities, especially atop mountains, due to the preferable atmosphere and considerable distance from urban life.8 

Unfortunately, there is even more to the story than our polluted relationship with the cosmos. A surplus of light that spills into wildlife habitats at night disrupts the natural balance and processes of ecosystems. An article from Frontiers in Ecology and the Environment, a peer-reviewed journal of science that discusses issues of ecology and the environment, exemplified the many species that light pollution immensely harms. Birds alone face danger in countless ways. Light from cities and towns disturb migratory patterns, cause birds led astray to collide with buildings or each other, and lead them into the paths of predators.4 Moreover, hatching turtles, who would otherwise move instinctively toward the ocean with help from the contrast of moonlit silhouettes on the sand, are disorientated by man-made light and therefore drift from their routes.4 Light pollution even throws off the natural balance of predator-prey interactions. Species who rely on the darkness to forage are jeopardized as the excess light at night puts them at greater risk of getting spotted.4 An overabundance of light that invades natural habitats during the night is actively and increasingly devastating ecological processes across the globe.  

Light pollution can even have adverse effects on human health. The phenomenon is associated with sleep disorders, and in more extreme cases, cancer.5 An article from Environmental Health Perspectives notes that melatonin, a hormone that helps control the body’s sleep cycle, is produced during the night and “triggers a host of biological activities.”5 The disruption of the so-called “circadian clock,” which refers to the twenty-four-hour cycle of day and night, “is linked to several medical disorders in humans, including depression, insomnia, cardiovascular diseases, and cancer,” according to Paolo Sassone-Corsi, a molecular biologist from Italy.5 In a Harvard study that appeared in the Journal of the National Cancer Institute, they discovered an association between breast cancer and female nurses “who had worked 30 or more years on rotating night shifts.”5 The data was collected from a survey of over 120,000 registered female nurses in the 1988 Nurses’ Health Study (NHS).5 In another study from the same journal, it was found that nurses who were given 3 night shifts every month over a period of 15 years “had a 35% increased risk of colorectal cancer.”5 Although scientists must conduct more research to determine the extent of the link between artificial light disturbances at night and health problems, specifically cancer, there is a basic understanding that light pollution has the power to negatively impact all facets of life, human or nonhuman.  

This issue is certainly not going away any time soon. National Geographic compiled a list of possible solutions to the crisis, but they will require a widespread effort. On an individual level you can “maintain as much overnight dark as possible” to protect your nighttime schedule by leaving all lights off in your house during the night, even when using the bathroom, and turning “off devices an hour before bedtime.”1 If you are interested in reducing your light-trespass, “use lower temperature LEDs and compact fluorescents.”1 A common solution to bird-building collisions is the placement of “drapes or blackout curtain” in tall structures.1 The issue is undoubtedly a complicated one, as light benefits human societies tremendously, but if one thing is clear, it is that at the end of the day (pun intended), unnecessary light sources are worth less than the health and safety of not only ourselves but our ecosystems. Of course, a bonus to reducing light pollution would be seeing the sky in its natural beauty. The Milky Way should make you think of more than just the chocolate bar. It should make you pause every night to look up at the painted tapestry of sky and remember your place in this incredible universe.