Image Credit: NASA/R. Gendler; Acknowledgment: J. GaBany
When NASA launched the Hubble Space Telescope on April 24, 1990, aboard the space shuttle Discovery, it was a different world.
George Bush (the first one) was president, gas was only $1.16 per gallon, and cell phones looked more like purses with a corded phone attached.
It's hard to believe that the technology used to build Hubble back then has been so capable as to last all these years, capturing incredible images along the way (like Galaxy M106 shown above) and exploring areas of space never before seen.
Sure, it's been updated a lot over the years to keep it in tip-top shape, but still. It's pretty amazing that more than 27 years later, Hubble is still kicking.
About the Telescope
By Ruffnax (Crew of STS-125) [Public domain], via Wikimedia Commons
Since its launch, Hubble has made more than 1.3 million observations from its orbit 340 miles above Earth.
In that orbit, it travels at around 17,000 mph. Over the course of its life, it has traveled just about 4 billion miles.
The telescope has no thrusters. Instead, Newton's third law is used to change its angles. By spinning its wheels in the opposite direction of movement, it can turn at a speed roughly equivalent to the minute hand of a clock. In other words, it takes 15 minutes to turn itself 90-degrees.
Hubble has incredible accuracy as well. It's pointing accuracy of .007 arc seconds is equivalent to focus a laser beam on the head of a dime from a distance of 200 miles away. Not bad, right?!
Because the telescope orbits outside the haze of Earth's atmosphere, it can see distant astronomical objects that are just 0.05 arc seconds.
To illustrate how powerful that is, NASA uses this analogy: it's like seeing a pair of fireflies in Tokyo from your home in Maryland.
Editor's Tip: Hubble has created some extraordinary photos over the years. See your own photos as fine art, see how here.
That kind of power allows Hubble to see incredible distances - over 13.4 billion light-years from Earth. For context, one light year is about 5.88 trillion miles, so this thing can see really far.
That means that photos like the one above of the Cat's Eye Nebula, which is only 3,262 light-years away, are pretty easy pickings for Hubble.
By NASA or National Aeronautics and Space Administration [Public domain], via Wikimedia Commons
Being able to see that far means Hubble is not exactly a small piece of equipment.
At launch in 1990 (shown above), it weighed 24,000 pounds, and now weighs on the order of 27,000 pounds.
It's about 43.5 feet long - or roughly the length of a school bus - and its main mirror is nearly 8 feet across.
That mirror has captured plenty of incredible sights over the years, too. Its images are dispersed throughout this article.
In fact, the Hubble Archive has about 140 terabytes of data. It adds 10 terabytes of data each year.
All that information goes to good use, too. Over the years, astronomers using data from the Hubble Space Telescope have published over 15,000 scientific papers. That makes Hubble one of the most successful science instruments ever built.
Hubble's "Eyes" and Cameras
By HubbleExploded.svg: AndrewBuck derivative work: Julia\talk (HubbleExploded.svg) [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0) or GFDL (http://www.gnu.org/copyleft/fdl.html)], via Wikimedia Commons
What allows Hubble to see so far with such precision is its amazingly powerful "eyes."
What gives Hubble its vision is the Optical Telescope Assembly, a Ritchey-Chretien Cassegrain design that has two mirrors that form focused images.
As light travels down a tube, it's collected by the primary mirror, which is concave, or curved inward. The light is then reflected toward a smaller convex mirror that's curved outward.
That second mirror bounces the light back to the primary mirror, where the light passes through a hole in the center. At that point, the light is picked up by Hubble scientific instruments.
Among those instruments is Hubble's Wide Field Camera 3 (WFC3), which is capable of seeing visible light, near-infrared light, and near-ultraviolet light.
Its ultraviolet capabilities are used to explore galaxies and star formations. Its infrared capabilities are used to study light from distant galaxies, allowing scientists to study what early life was like when the universe formed.
The image above of the Horsehead Nebula was taken with the WFC3 camera's infrared channel.
Image Credit: NASA
Among Hubble's instruments, WFC3 has the highest resolution and field of view. That's because it's one of Hubble's newest instruments (it was installed in 2009) and thus makes use of the most modern technology.
The WFC3 camera not only expanded Hubble's vision into deep space, but it can also detect dark energy and dark matter, as well as the formation of stars.
Periodic repairs and updates over the years have kept Hubble on its game. Shown above is the final repair mission to the Hubble, during which astronaut Mike Good worked to repair Hubble's Space Telescope Imaging Spectrograph.
Image Credit: NASA
Another of Hubble's cameras, the Advanced Camera for Surveys (ACS) is able to see visible light.
It's used to study early activity in the universe, like the distribution of dark matter. It's also capable of detecting objects in the furthest reaches of the universe, including massive planets and clusters of galaxies.
The image above of the Tadpole Galaxy - which is about 420 million light-years away - was taken with the ACS camera in 2002.
The WFC3 and APS often work together as well.
Astronomers use the WFC3's multiple wavelength vision along with the ACS' ability to see visible light that results in images that are unparalleled in their field of view and clarity of detail.
But even before WFC3 was installed Hubble could pick up some detailed shots.
The image above, from 2003, is of the "Sombrero Galaxy," and was taken with the ACS.
By NASA, ESA, and M. Livio and the Hubble 20th Anniversary Team (STScI) [Public domain], via Wikimedia Commons
But as beautiful as the image of the Sombrero Galaxy is, it's hard to beat the image above taken with the WFC3.
It's what's known as the Mystic Mountain, which is located in the Carina Nebula, some 7,500 light-years away.
When comparing the two images, you can see the obvious benefits of the upgraded hardware in the newer WFC3 camera.
Either way, I think we can all agree that Hubble has been well worth the time and effort over the last 27 years.
Its cameras have captured never-before-seen areas of the universe and tantalized us with the beauty that surrounds our home planet both near and far.
I, for one, can't wait to see the photos captured by Hubble's upcoming replacement, the James Webb Space Telescope. They're sure to be even more tantalizing than those from Hubble!