On April 25, 1990, the Hubble Space Telescope was deployed into orbit from the payload bay of the Space Shuttle Discovery. On the anniversary of this milestone in space exploration, here are five things we’ve learned from the Hubble Space Telescope...
The Hubble Provided Baby Pictures of the Universe
The universe is huge, and it takes a long time for light to reach where we humans live, so scientists were astonished when the Hubble Telescope captured images of 3,000 distant galaxies. But none of the 3000 galaxies pictured in the "Hubble Deep Field" were recent. Hubble had photographed galaxies from billions of years in the past—that's how long it took the light to reach us. These baby pictures of distant galaxies from billions of years ago were from the beginning of time.
Scientists Discovered the Universe Isn’t Slowing Down
After the Big Bang, it made sense that the expansion of the universe would eventually slow down. However, the Hubble Space Telescope showed just the opposite and that its speed was increasing. It is believed that this expansion is because of the dark energy, which is a force that repels and counteracts gravity. Scientists have said that entirely new types of physics may be required to explain these exciting developments.
It Proved the Existence of Enormous Black Holes
The theory of relativity proved by Albert Einstein predicted the existence of black holes, but it was a problem for scientists to prove this theory. Although a black hole dubbed Cygnus X-1 was discovered in 1971, it hadn’t been proven that the centers of galaxies contained black holes that were supermassive. Enter the Hubble Space Telescope, which proved it was true by photographing a supermassive black hole centered in the M87 galaxy in 2019. It is one of the most astonishing discoveries in the telescope's three decades.
Ganymede Has an Ocean NASA’s Hubble Space Telescope provided evidence of an underground saltwater ocean on Ganymede, Jupiter’s largest moon. The subterranean ocean is believed to have more water than all the water on Earth's surface. “This discovery marks a significant milestone, highlighting what only Hubble can accomplish,” said John Grunsfeld, associate administrator of NASA’s Science Mission Directorate at NASA Headquarters. “In its 25 years in orbit, Hubble has made many scientific discoveries in our own solar system. A deep ocean under the icy crust of Ganymede opens up further exciting possibilities for life beyond Earth."
Shoemaker-Levy 9 The comet Shoemaker-Levy 9 collided spectacularly with Jupiter in 1994, an impact Hubble captured in all its startling glory. The giant planet's gravitational pull ripped the comet apart into fragments, resulting in 21 visible impacts. The largest collision created a fireball that rose about 1,800 miles above the Jovian cloud tops as well as a giant dark spot more than 7,460 miles across — about the size of the Earth — and was estimated to have exploded with the force of 6,000 gigatons of TNT. Not only did Hubble's observations heighten public interest in the effects of cosmic impacts, they also shed light on Jupiter's atmosphere.