What Effects Has Humanity Had on Outer Space?
We’ve left clues and evidence of our existence to intelligent life forms — what are they?
When renowned astrophysicist Neil deGrasse Tyson was born in 1958, no one had heard of the words “black hole”. Humanity had launched Sputnik, the first satellite, just a year prior, and the rocket used to deliver it into orbit was a modified missile that would have stood puny next to the 363-foot Saturn V rocket developed only ten years later. Civilization has been racing to push the limits of technology, science, and research in an attempt to reach beyond our own atmosphere; but for what? Amidst not-so-recent claims that space travel and technological developments are a fragile endeavor to preserve humans’ legacy and accomplishments, what effects has humanity had on our Solar System, galaxy, and universe during our 60 years in spaceflight?
Our Solar System as we currently know it contains eight planets, only one of which any human has set foot on. Everything that we have ever known about human history — all the people we’ve loved, all the memories we’ve made, all the loss we’ve experienced — has been on or near our home planet, the Earth. Because of this, our influence in our own Solar System (outside of Earth’s atmosphere) has been minimal in the grand scheme of time and space.
We’ve sent out around 6,000 satellites to orbit our home, but less than half are currently operational. If humans suddenly stopped maintaining satellite systems, a large portion of them will have fallen and burned in our atmosphere within 30 years, practically ruling them out as discoverable by other intelligent life forms. Currently, there are 15 operational space probes headed to various destinations in our Solar System, but most of these will too break down due to radiation, shattering into unrecognizable chunks of space junk within the next few centuries.
The indicator of human presence in our Solar System that will remain long after our extinction is twofold: our nuclear radiation and radio signals. The Chernobyl site alone will continue to spew radioactive waves for over 20,000 years, and traces of the nuclear pollution that humans have created will survive in our Solar System for long after we’re gone. Radio waves are perhaps the most discoverable thing that humans have managed to shoot into our Solar System and beyond — we’ve created a “bubble” of radio waves a little over 100 light years (or five hundred eighty-seven trillion nine hundred billion miles) long, making it undoubtedly one of the farthest-reaching marks of humanity.
Few human products have ever made it out of our Solar System, causing human influence in the Milky Way Galaxy as a whole to be unimaginably minimal. Radio waves continue to be one of the most likely footprints that humanity has projected into the “space between the stars” — the vast areas between our Sun’s sphere of influence and other Solar Systems. Only five manmade objects have ever made it out of our Solar System: the two Pioneer probes, the two Voyager probes, and the New Horizons spacecraft. Voyager 1, launched in 1977, is currently 152 astronomical units from the Earth, reaching well out of our Solar System and advancing towards the Ophiuchus constellation, which it is expected to pass during the year 40,272 AD. Both Pioneer spacecraft carried identifying plaques, meant to be decipherable by alien species who may find them. This was continued — and elevated — during the Voyager 1 and 2 missions. Both of these probes carried 12-inch copper disks known as the Golden Records, which were meant to harness humanity in a nutshell. Both sides of the records were decorated with information containing images, sounds, music, and greetings that are designed to be understood by intelligent life forms. The records also have a sample of uranium embedded to allow the interceptors to gauge how long it has been since the spacecraft left the Earth. Currently, Voyager 2 is the farthest physical indicator of humanity’s presence, located at about 112 astronomical units beyond the reaches of our Solar System.
Despite the approx. 650 billion USD spent on NASA alone since its inception, it is highly unlikely that any alien species that happens to stumble across what is left of our home planet — or any signs that we have pushed into the universe — will ever know about our rockets, satellites, or multi-planetary expeditions. After our blip in the timeline has passed, the only sustainable mark that we will have left outside of Earth’s atmosphere to define us are our radio, television, and communication waves — bouncing around the universe for the foreseeable eternity.