NASA celebrates Hubble’s 32nd birthday with a stunning photo of five galaxies
NASA launched the Hubble Space Telescope into orbit 32 years ago. The anniversary is marked, as it is every year, by a photograph taken by Hubble while on duty.
NASA has released yet another amazing image to celebrate Hubble’s 32nd birthday. It depicts The Hickson Compact Group 40, an unusually close-knit cluster of five galaxies.
In the photo, you can see three spiral-shaped galaxies, an elliptical galaxy, and a lenticular (lens-like) galaxy. “Somehow, these different galaxies crossed paths in their evolution to create an exceptionally crowded and eclectic galaxy sampler,” NASA writes.
As far as the size goes, NASA explains that this galaxy group is “so crowded that it could fit within a region of space that is less than twice the diameter of our Milky Way’s stellar disk.” And this snapshot isn’t only noteworthy because it was taken on Hubble’s birthday:
“Though such cozy galaxy groupings can be found in the heart of huge galaxy clusters, these galaxies are notably isolated in their own small patch of the universe, in the direction of the constellation Hydra.
One possible explanation is that there’s a lot of dark matter (an unknown and invisible form of matter) associated with these galaxies. If they come close together, then the dark matter can form a big cloud within which the galaxies are orbiting. As the galaxies plow through the dark matter they feel a resistive force due to its gravitational effects. This slows their motion and makes the galaxies lose energy, so they fall together.
Therefore, this snapshot catches the galaxies at a very special moment in their lifetimes. In about 1 billion years they will eventually collide and merge to form a giant elliptical galaxy.”
The journey of Hubble began on April 24, 1990. I’m surprised, too, that 1990 was 32 years ago. Putting the joke aside, the space shuttle Discovery and its five-person crew picked up the telescope on the 24th from NASA’s Kennedy Space Center in Florida. It was launched into Earth’s orbit on April 25 and has already collected 1.5 million observations of about 50,000 celestial targets. Happy birthday, Hubble, and many more amazing discoveries! And if you’re curious about what it captured on your birthday, click here.