February Stargazing: The Rise of Space Junk
Swarms of satellites may soon compromise our view of the night sky
A few nights ago, I was photographing the Tadpoles Nebula, near the constellation of Auriga, when an unfamiliar object appeared in one of my images. At first, I thought it might be a meteor. But meteors tend to leave bulgy, irregular streaks resembling the stroke of a leaky calligraphy pen. The trail of this object was thin and pencil straight, extending across the entire length of the five-minute exposure.
After some online searching, I found that one possible culprit was a telecommunications satellite, one of a “constellation” of more than 70 known as Iridium, orbiting nearly 500 miles above Earth’s surface. Because of the shape of their highly reflective antennas, the Iridium satellites can sometimes “flare” concentrated pulses of sunlight. In certain conditions, these flares can be 20 times brighter than Venus, making them, momentarily, the most visible objects in the night sky aside from the moon.
The telltale trail of a satellite passing through a five-minute exposure of the Tadpoles Nebula
The Iridium array, which went online in the late 1990s, is small compared with the massive satellite constellations that will soon be migrating across the sky. Last month, Elon Musk’s venture SpaceX launched dozens of satellites as part of an ambitious project called Starlink. At a conference in 2015, Musk described the effort as nothing less than “rebuilding the Internet in space.” To date, the Hawthorne, California–based company has put 120 Starlinks into orbit, each of which weighs around 500 pounds and is about the size of a dinner table. SpaceX’s goal is to fling more than 10,000 of these dinner tables into orbit—more than six times the entire number of satellites currently circling the planet. When fully functional, the Starlink array will beam broadband internet across the globe. Like Iridium, the Starlink satellites are also highly reflective and have been seen moving across the sky in train-like processions at dawn and dusk.
Few areas on Earth have been spared the flotsam and jetsam of commerce, with plastic debris showing up on some of the world’s most remote and isolated landmasses, and even in the deepest reaches of the ocean. Now, the sliver of space around our planet is also becoming a dumping ground. According to the European Space Agency, we have sent 8,950 satellites into space since 1957. Only 5,000 remain in orbit—and of these, only 40 percent are still functional, blipping data between one another or down to the planet’s surface. More concerning, perhaps, are the smaller bits of refuse—shed rocket stages, nuts and bolts, flecks of paint and shards of jagged metal from spacecraft that failed to burn up on re-entry. The ESA estimates that there 900,000 pieces of debris between one and 10 centimeters in size and more than a hundred million that are smaller than a centimeter inhabiting a cloud of refuse around the planet. In essence, we’ve created the equivalent of the Great Pacific Garbage Patch miles above our heads. The International Space Station must, on occasion, perform maneuvers to avoid colliding with bits of debris hurtling around the planet at 17,500 miles per hour (a scenario portrayed with horrifying realism in the 2013 film Gravity).
Space pollution also threatens scientific research. The journal Nature reported that these swarms of satellites may impact radio astronomy and the massive new Large Synoptic Survey Telescope. When the telescope goes online later this year, the LSST, which sits atop an 8,700-foot mountain in Chile, will utilize a mirror 27 feet in diameter along with what is reportedly the largest digital camera ever designed to capture minute changes in the visible universe. Dave Clements, an astrophysicist at Imperial College London, told the BBC how networks of thousands of star-mimicking satellites could hinder such an effort: "[I]t's like someone's walking around firing a flashbulb every now and again."
There are more philosophical concerns too. James Lowenthal, an astronomer from Smith College, recently told The New York Times that if Starlink and other massive satellite arrays are deployed, the night sky soon “will look like it is crawling with stars.” A statement from the International Dark-Sky Association reads, “The rapid increase in the number of satellite groups poses an emerging threat to the natural nighttime environment and our heritage of dark skies. We do not yet understand the impact of thousands of these visible satellites scattered across the night sky on nocturnal wildlife, human heritage, or our collective ability to study the cosmos.”
For its part, SpaceX has said it will voluntarily paint future satellites to be less reflective. The European Space Agency has proposed designing a spacecraft—a “self-destructing” robot, as it has been described—capable of hoovering up bits of space debris (much as the Ocean Cleanup project has begun siphoning up bits of plastic from the Pacific Gyre). Such plans are only in their beginning stages, though, and are sure to prove technically difficult.
For the amateur enthralled by the unsullied beauty of a dark sky or a professional astronomer attempting to unravel the secrets of the universe, the trashing of space gives rise to bigger questions: Should ecological ethics extend beyond the planet’s surface to the heavens above? Do we need a cosmic code of stewardship—a Clean Space Act—to protect the integrity of the night?
Back at home, I took a second photograph of the Tadpoles Nebula. This one did not have the bright streak that had marred my earlier image. For the moment, the small patch of sky I was observing was satellite-free. The nearer heavens, however, were abuzz with activity. Planes and helicopters cut across the sky, up above the millions of incandescent lights shimmering from within the urban galaxy of the San Francisco Bay Area.
What Else to Look for This Month
To see one of the brightest satellites in the sky, look for the International Space Station as it passes overhead, 250 miles above Earth’s surface. The ISS, which is currently the home of six astronauts from three countries, makes 15 orbits of the planet each day and can be spotted on almost any evening of the year—that is, if you know where and when to look. The hours around sunrise and sunset are the best times for viewing, as sunlight reflects off the body of the 240-foot-long spacecraft. From Earth, the ISS resembles a bright, golden-hued star moving rapidly across the night sky. Use NASA’s Spot the Station website to determine the best time to see the ISS from your location. Pro tip: Choose a night when the space station is at a maximum height of more than 20 degrees above the horizon, high enough to avoid obstructions such as trees and rooflines. As you wait, see how many other satellites you can count creeping amid the stars.
On February 9, grab a warm coat and head outside to see the Snow Moon. It will reach peak brightness around 11:30 P.M. PT and will be one of the brightest full moons of the year. According to the Farmer’s Almanac, the Cherokee tribe referred to the February full moon as the Bone Moon because at this time of year there was so little game that “people gnawed on bones and ate bone marrow soup.”
February is also a month of close encounters. On February 18, in the hours before dawn, look for the moon as it passes within less than a degree (about the width of your pinky at arm’s length) of Mars. On February 19, it will do the same with Jupiter. The moon will also make a close approach to Saturn on February 20, but that will be difficult to see from most of North America since both objects will be very low on the horizon.