It’s not uncommon for a person to grow up live and die within 20 miles of their birthplace, as we’ve seen throughout much of history. On the other hand, there have been intrepid explorers who circled the globe or studied remote islands far from home. But regardless how far we travel from our birthplace, 99% of humans who have ever lived never leave the Earth. Even great explorers like Magellan lived his whole life on an astronomical scale, in the same place. In more recent years, humanity has started to take its first baby steps into space.
But just how far has our civilizations reach extended from Earth? How far have we gone?
On April 12th, 1961, humanity finally became a spacefaring species. Soviet cosmonaut Yuri Gagarin blasted off from a cosmodrome in southern Kazakhstan. He started his 105-minute journey beyond the reach of Earth. Gagarin Vostok One spacecraft orbited the earth once. He reached a maximum height of 327 kilometers. That’s just over the distance from Dallas Texas to Shreveport Louisiana. Yuri Gagarin assured in the space age with his historic first flight. In the fifty or so years since we’ve continued to push the boundaries of space travel farther and farther.
On July 20th, 1969, the United States successfully landed the first two humans on the moon. About 20 minutes after his famous declaration, Neil Armstrong and pilot Buzz Aldrin spent about two and a half hours gathering lunar material to bring back to earth for study. This voyage far exceeded the distance traveled by Gagarin eight years earlier. This because the moon sits roughly 384,000 kilometers from Earth. To put that in perspective, the circumference of the earth is roughly 40,000 kilometers. So, if you took an enormous ball of twine and circled the earth nine and a half times then stretched it out, you’d have roughly the distance the Apollo 11 crew traveled to reach the moon. That’s pretty impressive and far beyond the distance, most people will ever travel in their lifetime.
But, we’ve still gone farther. The record for the farthest distance humans have traveled from Earth has stood for over 40 years.
In April of 1970, NASA‘s Apollo 13 crew swung around the dark side of the moon at an altitude of 254 kilometers. That put them at a total distance of 400,171 kilometers from the rest of the human race on earth. In the nearly half-century since 1970, no human has ever ventured further into the cold depths of space than the crew of the Apollo 13 mission. However, there has recently been a lot of planning regarding sending a manned mission to Mars. This will happen sometime around the year 2030. When we inevitably land the first human on the Red Planet, it will smash our previous record.
At its very nearest, Mars sits about 54.6 million kilometers away from Earth, with an average distance of around 225 million kilometers. That’s about 200 times the distance the Apollo crew traveled to get to the far side of the Moon. A voyage to Mars when it’s at its closest to earth would be the equivalent of circling the globe 1,365 times. It would take somewhere between 150 and 300 days. This depending on the craft, cargo, and amount of fuel you are willing to burn. 54.6 million kilometers is a massive distance from our tiny human perspective.
But what if we counted unmanned probes in our thought experiment? How far has a man-made object traveled into the void?
On September 5th, 1977, the American made Voyager 1 probe blasted into space from Cape Canaveral, Florida. Aboard this intrepid explorer is what’s called the Voyager Golden Record and the materials needed to play it. The record is a message to possible future explorers who find the probe somewhere out in the universe. the content of the record itself is a fascinating array of earth sounds, images, and human greetings. The sounds of waves crashing on the shore, wind, thunder, birds, whales, and other animals. 90 minutes of music from around the world, and spoken greetings from Earth and 55 languages.
As of May 10th, 2017 Voyager is 20.6 billion kilometers from Earth. This means it has entered interstellar space, the vast expanse between stars. This nearly 40-year old probe has traveled farther than any human or man-made object in history. It’s unlikely that we will ever launch anything that will overtake it in the decades to come. Perhaps the most amazing thing about Voyager 1, is that despite its age and distance from earth, we can still communicate with it. The probe is equipped with a tool that can measure the ions surrounding it.
In April of 2013, it detected the presence of a wave from our Sun and by measuring the density of the plasma the team behind Voyager was able to determine that the craft was indeed in the space between stars. To extend our thought experiment even further, we can include Space Telescopes as part of humanity’s presence among the stars.
The famous Hubble telescope has given us the ability to look out into the darkness. Observe things that humans won’t see in person for a thousand lifetimes, if at all. It’s given us stunning images of the cosmos. Since light takes time to travel to earth, Hubble can essentially see back in time and observe what is often referred to as adult, teenage, and child galaxies of the universe. Meaning galaxies that form between the present and up to ten billion years ago. A vast expanse of space and time to be sure, but, beyond that… darkness.
To see even farther, back to the infant galaxies, the so-called first light to the universe, we’re developing the James Webb Space Telescope.
Scheduled to launch in October of 2018, Webb’s incredibly advanced sensors combined with its planned position 1.5 million kilometers from Earth will allow the massive telescope to gather information far beyond Hubble’s capabilities. Webb will be able to determine the composition of atmospheres around distant planets, such as those in the Trappist one system.
Also, determine whether they can support life. Most importantly, it will allow us to see back almost to the very beginning of the universe. Just a few hundred million years after the Big Bang. With advanced telescopes like Webb, humanity’s reach will go far beyond what we can ever hope to accomplish with manned missions. Seeing far into the breathtaking depths of space and while we may not be able to visit all the hundreds of billions of galaxies. At least we can know our place among them.