The same atmosphere that makes images taken from Earth blurrier than those taken from space also serves as a screen for Earth-bound astronomers trying to examine higher forms of radiation.

The more energetic forms of electromagnetic radiation, such as X-rays, cannot penetrate the atmosphere. While this is beneficial for life, it puts quite a damper on high-energy astrophysics from Earth.

But solely being in orbit is not what qualifies the Chandra X-ray Observatory for this list of technological marvels. Its mirror does. For where Hubble went wrong, Chandra was perfectly right.

"To reflect something, the smoothness of the mirror has to be comparable to the wavelength of the radiation," explains Tucker, who may be a little biased (we at SPACE.com, however, are responsible for putting Chandra on the list). "And the wavelength of X-rays is comparable to the size of atoms, so they had to make the mirror smooth to within a few atoms."

The mirrors are also significantly more curved than optical mirrors and resemble a barrel. This way, the incoming X-rays, which are nearly parallel to the mirrors, graze and reflect into the detector instead of passing right through.

Past X-ray observatories had mirrors, but with Chandra, astronomers are seeing some of the most energetic events in the universe with resolution that approaches Hubble's.

"The X-ray technology was a technological feat that some people didn't think was possible," Tucker says. "And you begin to see for the first time, due to this technology, the extreme X-ray universe with the same resolution you're seeing at other wavelengths."

Astronomers have used Chandra to understand how heavy elements are made in and expelled from stars during supernovae. Chandra has also provided the best views ever of the energetic environments immediately surrounding black holes. It’s also provided fresh insight into pulsars and other high-energy stars, as it peers through the dusty exteriors of celestial objects into their energetic cores, often rivaling Hubble's work.

Before you type your hate mail, note these three telescopes that were within a hair-width of making the list. And yes, we know, there are others that could, arguably, qualify.

• Mt. Wilson Observatory, California
• Keck Observatory, Mauna Kea, Hawaii
• Arecibo Observatory, Puerto Rico