Last month, NASA scientists confirmed that the Voyager 1 space probe became the first man-made object to break through the atmospheric bubble created by the sun and enter interstellar space. To think that, 36 years and some 11 billion miles after its launch, a human creation has essentially left the solar system boggles the mind, especially when you consider that the car-sized spacecraft has only a fraction of the computing power of your smartphone. Now, technically, most scientists won’t consider the probe to have really left the solar system until it passes through a sheath of comets known as the Oort cloud and is no longer influenced the by sun’s gravity, but it will take Voyager another 300 years just to get there and another 30,000 to get through. But regardless of where you set the boundary, it’s still an impressive milestone.
One of the things that always intrigued me about the Voyager probe, aside from all the amazing photos it has sent back over the years, is the gold-plated record it carries. Designed to be played on some as-yet-unknown intergalactic turntable, the record contains images and sounds from Earth, including greetings in 55 different languages and music from Bach, Beethoven, Mozart, Louis Armstrong and Chuck Berry. Assuming Voyager continues its journey without incident, some extraterrestrial lifeform could one day be singing along to “Johnny B. Goode” long after life on our planet has ended. There are certainly worse ways to remember us by.
Of course, even something as innocuous as a planetary playlist was not met with universal approval when it was conceived. Many people, including Sir Martin Ryle, the British Astronomer Royal and Nobel Prize laureate, expressed concern that any attempts to contact extraterrestrial life would be the equivalent of sending up a flare to alert malevolent alien species to head our way for a quick meal of delicious human beings. But since we have been broadcasting radio and television signals around the planet for decades, it was likely already too late if we wanted to stay hidden.
Really, when it comes to space risks, aliens are the least of our worries. Space is immense. The nearest star to Earth is 4.2 light years away. If Voyager was headed in that direction, at its current speed, it would take more than 70,000 years to get there. So aliens would have needed quite a head start to pose a threat to our planet anytime soon.
No, our real space risks are actually much closer to home. Earlier in the year, for instance, we got a dramatic taste of the threat asteroids present when a space rock exploded over Russia, damaging buildings and injuring more than 1,000 people with a blast that was estimated to be the equivalent of about 500 tons of TNT. Bigger asteroids are out there and a direct hit could be a planet-killer.
On top of that, a recent emerging risk report from Guy Carpenter points out that we also need to be concerned with space debris and solar storm activity. While not as apocalyptic as ravenous aliens or rogue asteroids, these risks could be physically and financially catastrophic in their own right.
Currently, the U.S. Strategic Command’s Space Surveillance Network tracks about 20,000 objects larger than 10 centimeters in Earth’s orbit. Only about 1,000 of these are active satellites. Given the speed at which this space debris is travelling, a collision—even with a relatively small particle—could destroy billions of dollars’ of investment and compromise valuable communication, broadcasting and research technology.
Satellites are also threatened by solar weather. Perhaps more importantly, however, these large solar flares and coronal mass ejections (magnetic field and plasma bursts from the sun) can cause massive power outages as well. As recently as 1989, a geomagnetic solar storm caused a $2 billion blackout that affected nine million people in Canada. In a worst case scenario, a repeat of the largest solar flare on record, which mostly caused telegraph fires in 1859, would now leave an estimated 40 million people in the eastern United States without power for anywhere from 16 days to two years and cause up to $2 trillion in economic damages in the region.
It’s true that space may be fraught with its share of risks, but those risks, no matter how large, tend to take a backseat when we see an awe-inspiring, deep-space image captured by a NASA telescope or hear about Voyager’s steady progress through the cosmos. In the end, space will probably always be a source of wonder more than anything else. And as long as the aliens are friendly, the asteroids pass us by and the sun keeps to itself, we’ll always look to boldly go to that galaxy far, far away.