If you look farther and farther away, you also look farther and farther into the past. If the number of galaxies, the densities and properties of those galaxies, and other cosmic properties like the temperature and expansion rate of the Universe didn’t appear to change, you’d have evidence of a Universe that was constant in time. (Credit: NASA/ESA/A. Feild (STScI))
When the Hubble Space Telescope first launched in 1990, there was so much we didn’t know. Here’s how far we’ve come.
On April 24, 1990, the Hubble Space Telescope launched into low Earth orbit.
Zoom image will be displayed
This photo shows the Hubble Space telescope being deployed, on April 25, 1990, one day after its launch. It was taken by the IMAX Cargo Bay Camera (ICBC) mounted aboard the space shuttle Discovery. Originally launched to an altitude of ~620 km, Hubble is now about ~100 kilometers lower as of May 2024, and will continue its orbital decay due to atmospheric drag. (Credit: NASA/Smithsonian Institution/Lockheed Corporation)
Originally, a flaw in the optics led to disappointingly blurry images.
Zoom image will be displayed
The before-and-after difference between Hubble’s original view (left) with the mirror flaws, and the corrected images (right) after the proper optics were applied. The first servicing mission, in 1993, brought the true power of Hubble to the forefront of astronomy, where it’s remained ever since. (Credit: NASA/STScI)
But subsequently, servicing missions transformed Hubble into the legendary observatory we all know.
Zoom image will be displayed
Pluto, shown as imaged with Hubble in a composite mosaic, along with its five moons. Charon, its largest, must be imaged with Pluto in an entirely different filter due to their brightnesses. The four smaller moons orbit this binary system with a factor of 1,000 greater exposure time in order to bring them out. Nix and Hydra were discovered in 2005, with Kerberos discovered in 2011 and Styx in 2012. These five moons were likely formed via an early collision, rather than either in situ or as a result of gravitational capture. (Credit: NASA, ESA, and M. Showalter (SETI Institute))
It’s shown us the Universe, answering many of our deepest questions.
Zoom image will be displayed
This deep-field region of the GOODS-South field contains 18 galaxies forming stars so quickly that the number of stars inside will double in just 10 million years: just 0.1% the lifetime of the Universe. The deepest views of the Universe, as revealed by space telescopes, take us back into the early history of the Universe, where star-formation rates were much greater than today, but where fewer than 1% of the Universe’s cumulative stars had already formed. Many of the most distant galaxies are found in close proximity to other foreground galaxies, whose mass distorts and magnifies the light from background objects. (Credit: NASA, ESA, A. van der Wel (Max Planck Institute for Astronomy), H. Ferguson and A. Koekemoer (Space Telescope Science Institute), and the CANDELS team)
We finally know what’s out there in the deepest depths of space.
