What Is the Hubble Space Telescope and What Has It Discovered?

Since its launch in 1990, the Hubble Space Telescope has revolutionized our understanding of the universe. Positioned above Earth’s atmosphere, Hubble provides a clear and unobstructed view of space, capturing stunning images and revealing secrets that ground-based telescopes simply cannot.

But what exactly is the Hubble Space Telescope? How does it work? And what are some of its most groundbreaking discoveries? Let’s dive in.

What Is the Hubble Space Telescope?

The Hubble Space Telescope (HST) is a large, space-based observatory launched into low Earth orbit by NASA and the European Space Agency (ESA). It orbits approximately 340 miles (550 km) above the Earth and takes high-resolution images of planets, stars, galaxies, and other cosmic phenomena.

Key Features:

• Launch Date: April 24, 1990
• Telescope Type: Reflecting telescope with a 2.4-meter (7.9 ft) primary mirror
• Instruments Onboard: Cameras, spectrographs, and sensors for visible, ultraviolet, and near-infrared light

Hubble is unique because it avoids the distortion of Earth’s atmosphere, which allows it to capture images with unmatched clarity.

How Does Hubble Work?

Hubble collects light from astronomical objects using its large mirror. The light is then directed into scientific instruments that:

• Capture images
• Break light into its components (spectra) to analyze chemical composition, temperature, motion, and more

Because it operates across multiple wavelengths, Hubble can see everything from visible light to ultraviolet and near-infrared—revealing objects that would be invisible to the naked eye.

Major Discoveries by the Hubble Space Telescope

Over its decades in operation, Hubble has made thousands of discoveries. Here are some of the most important:

1. Age of the Universe

By observing distant stars and galaxies, Hubble helped scientists determine the age of the universe to be about 13.8 billion years.

2. Dark Energy

One of Hubble’s most unexpected findings was evidence for dark energy, a mysterious force causing the universe’s expansion to accelerate.

3. Deep Field Images

Hubble’s Ultra Deep Field and Deep Field images are some of the most famous ever taken. They show thousands of galaxies in a tiny patch of sky, giving us a glimpse into the early universe.

4. Exoplanet Atmospheres

Hubble was among the first to detect atmospheres on planets outside our solar system, helping identify elements like water vapor, hydrogen, and sodium.

5. Galactic Evolution

By observing galaxies at different stages of development, Hubble helped build a timeline of how galaxies form and evolve over billions of years.

6. Star Birth and Death

From the glowing clouds of the Pillars of Creation in the Eagle Nebula to the remnants of supernovae, Hubble has captured star birth and death in incredible detail.

7. Moons and Planets in Our Solar System

Hubble has provided detailed images of planets, moons, and other celestial bodies in our solar system, including Jupiter’s storms, Saturn’s rings, and the icy surface of Pluto.

Why Is Hubble Important?

Hubble is more than just a telescope; it’s a time machine. Because light takes time to travel, Hubble lets us look into the distant past of the universe. Its data has been used in over 18,000 scientific papers, making it one of the most productive scientific instruments ever built.

What Comes After Hubble?

Although Hubble is still in operation, it’s aging. Its successor, the James Webb Space Telescope (JWST), launched in 2021, is now working alongside Hubble to explore even deeper and farther into the cosmos using infrared technology.

The Hubble Space Telescope has reshaped astronomy and deepened our understanding of the universe. From capturing the birth of stars to observing galaxies billions of light-years away, Hubble has turned our gaze outward and changed our view of the cosmos forever.

As we continue to explore space, Hubble’s legacy will remain one of humanity’s greatest achievements in science and discovery.