How One Photograph Forever Changed Astronomy
On April 24, 1990, the Space Shuttle Discovery launched the Hubble Space Telescope into orbit. It was the first and only telescope of its kind, capable of capturing truly incredible images. The telescope had the ability to “turn back time,” revealing the earliest glimpses of the universe.
However, as soon as Hubble went online, scientists noticed a serious issue with its mirror. It was one of the most precise mirrors ever made, but a small defect of just 2 microns made it nearly impossible to obtain clear images. Three years later, scientists were able to correct the flaw, and the telescope finally began to fully explore the universe and uncover its secrets.
Hubble has been operational for over 30 years, capturing some of the greatest photographs in human history. Among its achievements, it has captured:
- The largest star formation region, the Carina Nebula
- The galaxy NGC 2275, located 67 million light-years from Earth
But like everything in this world, Hubble is not eternal and may soon reach the end of its journey.
What Lies Hidden in the Depths of the Universe?
During its existence, Hubble has taken millions of astonishing photographs. Traveling above the Earth’s atmosphere, it has an unobstructed view of the universe, capturing even the faintest and most distant lights that have reached Earth. Additionally, it can observe parts of the electromagnetic spectrum that are inaccessible to other telescopes.
Arguably, the most important photograph taken by Hubble is the snapshot of the history of the universe. It may not be the most visually impressive, but it is unique in its own right. Typically, astronomers use telescopes to focus on a specific object. However, this photograph, known as the “deep field image,” was taken without aiming the telescope at anything in particular.
So why is this photograph 13 billion years old? It’s more accurate to say that this is the “age” of the light in the image. The most distant galaxies in the photograph are billions of light-years away from Earth, meaning their light took billions of years to reach us. Essentially, by looking at this image, we are peering into the past, returning to a time when the universe was just forming—about a billion years after the Big Bang.
The Hubble Space Telescope is one of the most significant pieces of technology ever created by humankind, and we owe much of our knowledge of the cosmos to it. While the star explorer may not have much time left, it is set to be succeeded by the James Webb Space Telescope, which will be launched in March 2021. The new space explorer promises even more technologically advanced images and measurements in the search for extraterrestrial life.