Hubble Space Telescope: Best Discoveries & Fun Facts
On April 24, Hubble is celebrating an anniversary: 35 years in space! Since its launch, Hubble has been giving us jaw-dropping views of the Universe and answering some of the biggest questions about space. Whether it’s capturing the stunning beauty of faraway galaxies or showing us black holes in action, Hubble never fails to amaze. And the best part? You can even track its path across the sky using the Sky Tonight app! So, let’s dive into what makes Hubble not just awesome but out-of-this-world.
Contents
- What is Hubble?
- Hubble forever: why is Hubble cool
- Hubble today: work in progress
- Hubble tomorrow: HST’s future
Top questions about Hubble
- Who is Hubble named after?
- Was Hubble the first space telescope?
- Why is Hubble able to see much better than telescopes on Earth?
- What went wrong with Hubble when it was first launched into orbit?
- Does Hubble get close to observed objects?
- Can Hubble take pictures of Earth?
- Why are some Hubble images cut in a stair-shaped pattern?
- Hubble Space Telescope: to sum up
What is Hubble?
Hubble, also known as HST, is a space-based telescope launched on April 24, 1990. Free from the distortion of Earth’s atmosphere, it has revealed galaxies, nebulae, and distant stars in incredible detail. More than just a camera, Hubble has transformed our understanding of the cosmos — helping scientists measure the age of the universe, discover its accelerating expansion, and explore worlds beyond our Solar System.
Hubble forever: why is Hubble cool
During its 35 years of operation, Hubble made more than 1.6 million observations, which contributed to over 21,000 peer-reviewed scientific papers. If you were to stack them all on top of each other, they would reach about 53 meters (175 feet) – a bit higher than the Statue of Liberty without a pedestal! If we tried to list every discovery made with Hubble, you'd likely be scrolling through this article for a week straight. So, let’s focus on just a handful of exciting discoveries.
First to shed some light on dark matter and dark energy
Hubble helped scientists discover that the Universe is not just expanding but doing so at an accelerating rate! By looking at distant supernovae, Hubble showed that galaxies are moving away from each other faster than expected. This led to the discovery of dark energy – an “anti-gravity” force that pushes things apart instead of pulling them together. Dark energy is believed to make up about 68% of the Universe and is responsible for the accelerating expansion of the cosmos.
Hubble has also played a key role in helping scientists study dark matter, a mysterious substance that makes up a significant part of the Universe’s mass (up to 27%). It doesn’t emit light, so we can't see it directly, but Hubble’s observations have helped show that dark matter affects the way galaxies are held together and move through space.
First to confirm that supermassive black holes exist
Hubble is great at revealing the invisible, including black holes. Their gravity is so strong that not even light can escape them, but before Hubble, astronomers could only hypothesize their existence. Hubble provided solid proof by capturing the most detailed and clear images of gas and stars surrounding black holes, as well as measuring their speeds. Thanks to Hubble, we now know that supermassive black holes are likely at the centers of most, if not all, large galaxies. This discovery has given us valuable insights into how galaxies form and evolve.
First to take images of astronomical objects colliding
In 1994, Hubble witnessed the Shoemaker-Levy 9 comet crashing into Jupiter. The comet had broken into pieces, and when it hit the planet, it created huge explosions that left some “scars” on Jupiter’s surface. This gave scientists a chance to study Jupiter’s atmosphere and learn more about how planets handle big impacts from space objects.
Hubble has also captured a number of galaxy collisions. These images reveal what happens to stars, gas, and dust when galaxies interact. By the way, did you know that our home galaxy, the Milky Way, is set to collide with the Andromeda Galaxy? Hubble was the first to provide evidence of this future cosmic event.
Hubble today: work in progress
Since its launch, Hubble has continuously expanded our understanding of the Universe, and it’s still going strong today.
Is Hubble still active?
Yes! Each year, Hubble receives about 1,000 proposals for observations and data usage from scientists around the world.
Thanks to its ability to be serviced and upgraded in space, Hubble is more scientifically productive today than ever before. It has undergone five servicing missions carried out by NASA astronauts aboard the Space Shuttle, each one boosting its capabilities and extending its lifespan. These missions included installing new instruments, repairing and upgrading existing equipment, and replacing aging components. Even though the last servicing mission took place in 2009, Hubble is expected to remain operational until the mid-2030s.
What is Hubble observing now?
You can check what Hubble is observing now by visiting the Space Telescope Live website. Note that the images shown on the site may not always be from Hubble itself. They could come from other telescopes, providing a preview of the targets Hubble is currently focusing on in its ongoing observations. The reason for this is that Hubble doesn't provide real-time streaming. Instead, it captures images, stores them on its onboard memory, and then transmits the data back to Earth. Then, the data has to be processed and archived. From data capture to public release, the process can span from a few days to over a year.
Can you see Hubble from Earth?
Yes, under the right conditions, Hubble can be seen with the naked eye! If it passes closely enough overhead on a clear, dark night, Hubble will appear as a fast-moving dot of light across the sky. It can reach a magnitude of 0.5, which is almost as bright as Betelgeuse from Orion, Achernar from Eridanus, or the planet Saturn. To track Hubble’s movements, check out the Sky Tonight app, where you can find real-time tracking information for viewing.
Hubble tomorrow: HST’s future
What will happen to Hubble after its mission comes to an end?
Initially, the plan was to safely deorbit Hubble at the end of its operational life, preserving it as a museum exhibit. However, as the Space Shuttle program was shut down, this plan is unfeasible. Hubble has no engines, so its orbit is gradually decaying due to atmospheric drag. It is expected that Hubble will re-enter Earth's atmosphere and disintegrate.
What telescopes will succeed Hubble?
As Hubble nears the end of its service, several advanced telescopes are poised to continue and enhance its legacy:
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James Webb Space Telescope (JWST): Launched in December 2021, JWST observes the Universe in the infrared spectrum, allowing it to peer deeper into space and time. It complements Hubble's capabilities by focusing on different wavelengths.
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Euclid Space Telescope: Launched in July 2023, Euclid aims to map the large-scale structure of the Universe to better understand dark energy and dark matter. It observes the Universe in visible and near-infrared wavelengths.
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Nancy Grace Roman Space Telescope (RST): Scheduled for launch in May 2027, this telescope will conduct expansive surveys of the Universe in visible and near-infrared wavelengths, focusing on dark energy, dark matter, and exoplanet research.
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Large Ultraviolet Optical Infrared Surveyor (LUVOIR): Proposed for 2039, LUVOIR is designed to observe the Universe across ultraviolet to near-infrared wavelengths with high resolution. It aims to study Earthlike exoplanets, galaxy formation, and more.
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Habitable Worlds Observatory (HWO): Proposed for the first half of 2040s, HWO is envisioned as a flagship mission to search for signs of life on Earth-like exoplanets.
Top questions about Hubble
Who is Hubble named after?
The Hubble Space Telescope is named after the astronomer Edwin Powell Hubble (1889–1953). In the 1920s, Dr. Hubble showed that the Milky Way is just one of many galaxies, changing how we see our place in the Universe. His greatest discovery came in 1929 when he found that the farther a galaxy is from Earth, the faster it moves away. This idea helped form the Big Bang theory.
Was Hubble the first space telescope?
No, Hubble was not the first space telescope. In 1962, both the US and UK launched orbiting solar telescopes, the Orbiting Solar Observatory (OSO) and Ariel 1, respectively.
Why is Hubble able to see much better than telescopes on Earth?
First, a telescope in space has clearer images because it isn't affected by Earth's atmosphere, which causes stars to twinkle. Second, Hubble can see near-infrared and ultraviolet light, which the atmosphere blocks. These wavelengths allow scientists to study objects in space that are invisible to ground-based telescopes.
What went wrong with Hubble when it was first launched into orbit?
When the first images came down from Hubble, it was clear that the telescope wasn’t focusing properly. The primary mirror was just 2 microns (about 1/50th of the width of a human hair) too shallow, meaning it couldn’t gather light as intended. In December 1993, a servicing mission installed a new camera, dramatically improving the sharpness of Hubble’s images.
Does Hubble get close to observed objects?
No, Hubble stays in its orbit around Earth and doesn’t travel to other parts of space. It gets clear images because it's above Earth’s atmosphere, not because it moves closer to cosmic objects.
Can Hubble take pictures of Earth?
Its pointing system isn't built for that. Hubble’s main purpose is focused on distant stars, galaxies, and other cosmic objects. In fact, the shortest exposure time for any of Hubble's instruments is 0.1 seconds, and in that brief time, Hubble travels nearly 700 meters (about half a mile) due to its orbital motion. As a result, any picture Hubble took of Earth would be completely streaked due to its rapid movement.
Why are some Hubble images cut in a stair-shaped pattern?
The "stair-step" corner in some Hubble images is an artifact from the Wide Field and Planetary Camera 2 (WFPC2), a previous camera on Hubble that was removed in 2009. The camera had four detectors: three for wide-field images and one for high-resolution images. When the data from these detectors were combined, a mismatch in their field of view created gaps between them. This resulted in the "stair-step" effect, where some areas of the image appear dark or missing.
Did you like all those fun facts about the Hubble space telescope? If you want to dive even deeper, check out our infographic for more Hubble facts!
Hubble Space Telescope: to sum up
The Hubble Space Telescope isn’t just cool because it gives us stunning pictures of space; it’s also the key player in some of the most mind-blowing discoveries! From proving the expanding universe and uncovering dark energy and dark matter to confirming the existence of supermassive black holes, Hubble has completely changed our understanding of the cosmos. And while its journey isn’t over yet, future telescopes will continue to build on the foundation Hubble set. Try tracking Hubble’s next move with the Sky Tonight app – it’s your personal guide through the cosmos!
