Hubble Space Telescope
The Hubble Space Telescope (HST) is a joint NASA and ESA observatory launched on April 24, 1990, aboard the Space Shuttle Discovery (STS‑31). Positioned in low Earth orbit at about 547 kilometers altitude, Hubble avoids atmospheric distortion and captures high-resolution observations in ultraviolet, visible, and near-infrared light.
Named after American astronomer Edwin Hubble, the telescope was inspired by Lyman Spitzer’s 1946 proposal to place telescopes in space. Hubble features a 2.4-meter primary mirror and a suite of scientific instruments designed to be upgraded during space servicing missions.
Soon after deployment, a flaw was discovered in the shape of its primary mirror, which was corrected by astronauts during the first servicing mission in 1993. Over its lifetime, Hubble received five servicing missions, which not only fixed technical issues but also significantly upgraded its capabilities.
Hubble has transformed our understanding of the universe. It helped determine the age of the universe (~13.8 billion years), provided evidence for the acceleration of cosmic expansion due to dark energy, revealed the presence of supermassive black holes in galaxies, and observed planets outside our solar system.
Iconic images captured by Hubble—such as the Pillars of Creation and the Hubble Deep Field—have expanded public engagement with space and allowed astronomers to peer billions of years into the past, studying galaxy formation and cosmic evolution.
Now operating alongside the James Webb Space Telescope, Hubble continues to provide critical observations despite aging hardware, including issues with gyroscopes. Its contributions to astronomy remain unparalleled, offering a legacy of scientific discovery and technological achievement.
Sources
APODs including "Hubble Space Telescope"
Trifid Pillars and Jets
3 May 2026
Dust pillars are like interstellar mountains. They survive because they are more dense than their surroundings, but they are slowly being eroded away by a hostile environment. Visible in the featured picture by the Hubble Space Telescope is the end of a huge gas and dust pillar in the Trifid Nebula (M20), punctuated by a smaller pillar pointing up and an unusual jet pointing to the upper left. Many of the bright dots are newly formed stars. A star near the small pillar's end is slowly being stripped of its accreting gas by radiation from a tremendously brighter star situated off the top of the image. The jet extends nearly a light-year and would not be visible without external illumination. As gas and dust evaporate from the pillars, the hidden stellar source of this jet will likely be uncovered, possibly over the next 20,000 years. Explore the Universe: Random APOD Generator