Who Invented the Telescope?

galileo and telescope
Galileo offering his telescope to three young women seated on a throne. He may not have invented the telescope, but he was the most famous user of his time. Painting by unknown artist. Library of Congress.

Of all the inventions used in astronomy, the telescope is the most important instrument for astronomers. Whether they use it atop a mountain in a huge observatory, or in orbit, or from a backyard observing spot, skygazers are benefitting from a great idea. So, who invented this incredible cosmic time machine? It seems like a simple idea: put lenses together to gather up light or magnify dim and distant objects. It turns out telescopes date back to the late 16th or early 17th century, and the idea floated around for a while before telescopes came into widespread use.

Did Galileo Invent the Telescope?

A lot of people think Galileo came up with the telescope. It's well known that he built his own, and paintings often show him looking through the sky at his own instrument. But, it turns out he was not the inventor. He was more of an "early adopter".

Yet, that very usage of it prompted people to assume he invented it. It's far more likely he heard of it and that's what started him building his own. For one thing, there's a lot of evidence that spyglasses were in use by sailors, which were had to come from somewhere else. By 1609, he was ready for the next step: pointing one at the sky. That's the year he began using telescopes to observe the heavens, becoming the first astronomer to do so.

His first construction magnified the view by a power of three. He quickly improved the design and ultimately achieved a 20-power magnification. With this new tool, he found mountains and craters on the moon, discovered that the Milky Way was composed of stars, and discovered the four largest moons of Jupiter.

What Galileo found made him a household name. But, it also got him in a lot of hot water with the church. For one thing, he found the moons of Jupiter. From that discovery, he deduced the planets might move around the Sun the same way those moons did around the giant planet. He also looked at Saturn and discovered its rings. His observations were welcome, but his conclusions were not. They seemed to completely contradict the rigid position held by the Church that Earth (and humans) were the center of the universe. If these other worlds were worlds in their own right, with their own moons, then their existence and motions called the Church's teachings into question. That couldn't be allowed, so the Church punished him for his thoughts and writings. That didn't stop Galileo. He continued to observe most of his life, constructing ever-better telescopes with which to see the stars and planets. 

So, it's easy to see why the myth lingers that he invented the telescope, some political and some historical. However, the real credit belongs to someone else.

Who? Believe it or not, astronomy historians aren't sure. Whoever did it was the first person to put lenses together in a tube to gaze at distant objects. That started a revolution in astronomy. 

Just because there's not a good and clear chain of evidence pointing to the actual inventor doesn't keep people from speculating about who it was. There are some people who are credited with it, but there's no proof that any one of them was "the first." However, there are some clues about the person's identity, so it's worth taking a look at the candidates in this optical mystery.

Was It the English Inventor?

Many people think that the 16th-century inventor Leonard Digges created both the reflecting and refracting telescopes. He was a well-known mathematician and surveyor as well as a great popularizer of science. His son, the famous English astronomer, Thomas Digges, posthumously published one of his father's manuscripts, Pantometria and wrote of the telescopes used by his father. However, those aren't proof that he actually did the inventing. If he did, then some political problems may have prevented Leonard from capitalizing on his invention and getting the credit for having thought of it in the first place. If he wasn't the father of the telescope, then the mystery deepens.

Or, Was It the Dutch Optician?

In 1608, Dutch eyeglass maker, Hans Lippershey offered a new device to the government for military use. It used two glass lenses in a tube to magnify distant objects. he certainly seems to be a leading candidate for inventor of the telescope. However, Lippershey might not have been the first to think of the idea. At least two other Dutch opticians were also working on the same concept at the time. Still, Lippershey has been credited with the telescope's invention because he, at least, applied for the patent for it first.  And, there the mystery remains, and will likely stay that way unless and until some new proof shows up that someone else put the first lenses into a tube and created the telescope.


Revised and updated by Carolyn Collins Petersen.