From the first stone tools to sea-faring ships to the internet, technology has been at the heart of human exploration and discovery.
But to starting exploring space, the final frontier, humans first had to master a deceptively simple piece of technology: the telescope.
“Telescopes have opened a window into a world of science that before we couldn’t have imagined,” said Brian Odom, acting NASA Historian.
Our knowledge of the universe has grown exponentially because of telescopes — and how they challenged the prevailing science and status quo every step of the way.
The first known telescope was made in the Netherlands in the early 17th century. A patent was filed in October 1608 for a tube containing a concave and convex lens. Spectacle maker Hans Lippershey is often credited for the invention, which allowed for “seeing faraway things as though nearby”.
Then in 1609, the telescope was used to study the night sky for the very first time, according to NASA. Italian Galileo Galilei built his own telescope that, while small and only capable of providing a fuzzy resolution, gave the astronomer a chance to see the moon’s craters and mountains, along with the Milky Way galaxy.
In the centuries since Galileo, telescopes have significantly grown in size and capabilities, with advanced telescopes now in observatories scattered across the globe.
“We can use these great telescopes to look beyond the Solar System, which I think brings a whole new spectrum of questions together,” Odom said.
Above it all
But unlike traditional tube telescopes that — as Lippershey’s patent described — allow users to see faraway objects up close, advanced telescopes allow users to “see” faraway objects by detecting information that’s too far away and invisible to the human eye.
The naked eye can only see a small sliver of the electromagnetic spectrum, which is the full range of energy in the universe. While the electromagnetic spectrum includes a number of frequencies, such as those of X-rays and gamma rays, the frequency humans are able to see includes visible light and colors.
“We think about our large ground-based observatories that look into space. It’s kind of like being at the bottom of a pool and looking up,” Odom said.
“The water is occluding what you’d see, and the atmosphere performs a similar function to occlude the electromagnetic spectrum, as things like X-rays, gamma rays will bounce off,” he added.
“By getting above the atmosphere, we can look at these with a clear lens.”
The first space telescopes
In 1968, NASA launched its first successful space telescope. Called the Orbiting Astronomical Observatory (OAO) 2, or affectionately known as “Stargazer”, it was NASA’s first observatory in the stars, giving scientists a view of the electromagnetic spectrum never before seen in space.
OAO 2 ushered in a new era of space exploration. It helped start an initiative called America’s Great Observatories, which involved the construction and launch of other and more advanced space telescopes.
One of which was the Hubble Space Telescope. According to Odom, plans for Hubble were first proposed by astronomer Lyman Spitzer nearly 50 years before Hubble was launched in 1990.
As Hubble had a “father”, it too had a “mother“: NASA’s first Chief Astronomer Nancy Grace Roman.
“She was a network builder, she was somebody who was a collaborator,” Odom said. According to Odom, Roman was at the very heart of NASA’s astronomy program and due to her collaborative efforts, she was able to build support for the funding and construction of Hubble.
Because of Hubble’s location above the Earth’s atmosphere, it can see with a clarity unlike any telescope that came before it. According to NASA, Hubble can see objects in space with an angular size of 0.05 arcseconds, which is similar to seeing a pair of fireflies in Tokyo that are less than 10 feet apart from Washington, D.C.
How The Telescope Became Our Window Into The Universe
Telescopes have allowed us to peer into the universe and examine our place within it. But even more so, telescopes have also allowed us to examine ourselves and our beliefs.
“Before Galileo, there had been some understanding that the Earth was at the center of the universe,” Odom said.
Because of the telescope, Galileo was able to challenge the prevailing science with new evidence.
“The telescope was a social instrument — it was an instrument of social change,” Odom said. “The telescope has a monumental influence on how we see ourselves, how we see the universe and how we see ourselves within that universe — it altered everything.”
“The work that the human mind has done to answer the questions that it couldn’t have imagined before the technology was developed, that process is what makes humans special,” Odom said.
“If we can dedicate ourselves to something, a challenge like that, overcome that challenge and get these things into operation and ask those big questions about the nature of time, the nature of the universe, there’s really nothing we can’t do.”