Explorer 1 at 60: How has space travel changed us?
Rocket fire streaked across the dark evening sky over Cape Canaveral, Fla., on Jan. 31, 1958. The United States had just launched a satellite into orbit, piercing the barrier between our world and the rest of the universe.
The oblong聽聽satellite wasn鈥檛 the first human-made object in space. The Soviet Union鈥檚 Sputnik claimed that title on Oct. 4, 1957. But the first successful launch of an American satellite made space exploration an international endeavor, paving the way for scientific discoveries of cosmic proportions.
In the 60 years since, our mechanical envoys and human voyagers have gone to places previously imagined only in science fiction. But it hasn鈥檛 all been about studying other worlds. Scientists have also turned a mirror back on our own planet. And between the discoveries about Earth made from the heavens, and the eye-in-the-sky perspective we鈥檝e acquired, going to space has forever changed how we see our world and ourselves.
鈥淲e鈥檝e always been looking up at the stars before the space program, and now we鈥檙e able to look down on Earth from space, which was transformative in itself,鈥� says Jim Pass, executive editor of the Journal of Astrosociology and founder of the Astrosociology Research Institute.
, we鈥檝e tracked wildfires, watched photosynthesis in action, monitored the ozone layer and ice sheets, charted weather patterns, mapped pollution, and discovered that there鈥檚聽聽within the Earth鈥檚 molten core. We鈥檝e even mapped the prehistoric routes of the multi-ton statues on Easter Island. Furthermore, the space-based GPS has helped geologists hone the model of plate tectonics, painting a picture of a planetary crust that is constantly in motion, shifting and changing.
These scientific observations have given us a much more detailed view of the world we live in, but it鈥檚 not just tangible things that we鈥檝e learned about Earth. The perspective we鈥檝e gained by going to space has placed humanity in a cosmic context like never before.
鈥淏ecause we saw weird stuff on other worlds, it made us think, okay, it鈥檚 our right to have weird stuff here on Earth,鈥� says David Portree, space historian and community outreach specialist at Arizona State University鈥檚 School of Earth and Space Exploration. For example, he says, we used to think that most craters on Earth were from volcanic eruptions, not the impact of space rocks. 鈥淭hen when we started to look more carefully at impact craters on other worlds, we realized that they were all over the Earth, buried mostly, and highly eroded, but all over the place. And we started to understand that we get hit by these things, and they鈥檝e affected the history of life, and all sorts of stuff.鈥�
Seeing ourselves anew
Learning about other worlds has also helped us appreciate how unique Earth is. Before getting a closer look, we thought our neighbor planets would be quite similar to Earth. But Venus is hot, hot, hot, and Mars is turning out to be a pretty harsh place, too. And now, with probes exploring the Saturn and Jupiter systems, we鈥檙e finding that it may be the faraway outer solar system moons that bear the most similarities to Earth, despite being exotic in other ways. The icy crusts of Saturn鈥檚 moon Enceladus and Jupiter鈥檚 moon Europa are thought to enclose oceans of liquid water, and Saturn鈥檚 largest moon, Titan, seems to have dynamic processes聽similar to those on Earth, too.
鈥淏y having space to compare our planet to, we see that our planet is really special. It鈥檚 dynamic, it鈥檚 covered with chemicals doing crazy things like reproducing themselves, it has water in three states instead of just one 鈥� in most places it鈥檚 just solid. It鈥檚 a unique and special place,鈥� Mr. Portree says. 鈥淎nd so I think that over time that has gradually penetrated into people鈥檚 consciousness.鈥�
While satellites and planetary probes have taught us a lot about our world and placed Earth in the context of the rest of the solar system, the moment that humans took to space was momentous in shifting our perspective of our world, says Jennifer Levasseur, curator in the space history department at the Smithsonian National Air and Space Museum.
Most astronauts that have returned from space聽聽that they have experienced by looking back at the Earth. 鈥淭he astronauts see the Earth as a whole system, interconnected and complete. They realize that we live on a planet. It鈥檚 a natural spaceship that鈥檚 moving through the universe. And this leads to a new understanding of who we are, and where we are in the cosmos,鈥� says Frank White, who has detailed this phenomenon in his book 鈥淭he Overview Effect.鈥� 鈥淲hile we know this intellectually 鈥� we know we live on a planet 鈥� the experience we have everyday is not that. It鈥檚 that we live on a stable platform with the heavens rotating above us, the sun rises and sets.鈥�
But it isn鈥檛 just about orientation. Astronauts have also described a feeling of stewardship and protectiveness, as seeing the Earth as a small orb hanging in the dark void of space makes it seem more precious. Many have pointed to just how thin of a protective blanket our atmosphere appears from space. And others have noted how the effects of climate change and pollution can be spotted. Astronauts frequently use words like 鈥渇ragile鈥� and 鈥渙asis鈥� to emphasize how they鈥檝e seen the planet.
For some, war, borders and divisions fade away, and the astronauts say they see unity in humanity and the interconnectedness of nature. That鈥檚 not to say that the diversity and chaos you experience down on the surface of Earth isn鈥檛 there, Mr. White says. 鈥淭he overview effect gives us an understanding of diversity within a context of unity. You have to be able to hold both ideas at once.鈥�
Kinship with the cosmos
Returning to the surface of the Earth with this new awareness, some astronauts have gotten聽聽in environmental movements or peace-building activities. Others have made it their mission to share this perspective with those of us who don鈥檛 make it up into space.
This has largely been done through photography, starting with the famous 鈥淓arthrise鈥� photo taken from lunar orbit during the Apollo 8 mission. That and other images taken during the Apollo missions particularly captured people鈥檚 attention, and the dramatic visual of our spectacular home against the vast black of space was even used in the environmental movement that was picking up steam at the time.
As images flood in from the International Space Station today, people reflect on their habits, too. Just like you can see glaciers breaking apart and other effects of climate change, people have also been struck by the sparkling of artificial lights across the globe. This has prompted an awareness of light pollution, Portree says. 鈥淭hat鈥檚 interesting because light pollution keeps you from seeing space, and then from space we can look back and see why we鈥檙e not seeing space. And people are looking at those images and saying, I want to see that bright dot smaller.鈥�
Images of space have had a profound effect, too, Dr. Levasseur says. The Hubble Space Telescope images, for example, have shown us just how picturesque and diverse the rest of the universe can be, and these pictures have stimulated intrigue among the public in the scientific information that they hold.
Not everyone may be profoundly changed on a day-to-day basis by the perspective we鈥檝e gained by going to space, Portree says. But 鈥淚 think that the potential exists in a lot of people to feel a kinship with the cosmos because we know more about it.鈥�
