Kelly McSweeney

Aug 22nd 2019

Chandra X-Ray Observatory Celebrates 20th Anniversary


The Chandra X-Ray Observatory is a crucial tool that astronomers use to understand the nature and history of the high energy universe. It covers an important area of the electromagnetic spectrum, X-rays, that are not detectable from the ground. Without Chandra and its vantage point in space, we would be blind to many of the most fascinating aspects of the universe. This year, we celebrate Chandra’s 20th anniversary.

Chandra’s Origins

Originally named AXAF, it was renamed Chandra to honor Subramanyan “Chandra” Chandrasekhar, the Indian American physicist and 1983 Nobel laureate. Chandra is the first space telescope named for a person of color, according to National Geographic.

The Chandra telescope is comprised of high resolution grazing incidence X-ray optics, transmission gratings and focal plane detectors that can collect spectra and images. Chandra launched aboard the space shuttle Columbia in July of 1999. Weighing nearly 13,000 pounds at launch, the telescope is powered by a pair of solar arrays, and it only requires 2 kilowatts of power to operate — that’s about the same as operating a hair dryer, notes Chandra’s website.

It was built by Northrop Grumman and is operated by the Harvard-Smithsonian Center for Astrophysics from a facility in Cambridge, Massachusetts.

Pieces of a Space Technology Puzzle

Chandra observes space in the X-ray bandwidth with a hundred times greater sensitivity than humans have ever known, according to National Geographic. Over the last 20 years, it has revealed some of the universe’s highest-energy phenomena in unprecedented detail.

Chandra’s orbit is highly eccentric, with an apogee over a 1/3 of the way to the moon. It complements the data from other telescopes that observe in different parts of the electromagnetic spectrum. They all come together like pieces of a space technology puzzle to reveal the universe. CNN explains that the Chandra X-ray Observatory is in NASA’s Great Observatories family. They each capture different wavelengths of light:

  • Chandra covers X-rays.
  • Spitzer captures infrared light.
  • Hubble detects visible and UV light.
  • Compton observes gamma rays.

What Do X-Rays Tell Us About Space?

“Since virtually every astronomical source emits X-rays, we need a telescope like Chandra to fully view and understand our universe,” said Chandra X-ray Center director Belinda Wilkes.

Chandra is a part of many of the biggest space discoveries. It recently made news for its part in capturing the first image of a black hole, according to NASA. We don’t just “see” black holes — Chandra has also detected sounds produced by a black hole. In its 20-year career, this X-ray telescope has provided evidence to back essential principals of astrophysics as we know it.

  1. Dark Matter: Chandra has traced the separation of dark matter from normal matter in the collision of galaxies in a cluster. The data contributes to both dark matter and dark energy studies.
  2. Supermassive Black Holes: Chandra has found black holes across the universe. It captured the eruptions of supermassive black holes, including the X-rays from hot particles right until the last second before they swirl into the black hole.
  3. Supernovas: The telescope has mapped how supernovas leave behind glowing bits of stardust that contain the elements necessary for life.

Trailblazing for the Next Generation of Powerful Telescopes

When Chandra launched 20 years ago, there wasn’t evidence for many of the phenomena that it observes today, such as the effects of gravitational waves, radiation and dark matter. The success of Chandra has scientists dreaming of tomorrow’s discoveries. That’s the beauty of astronomy: We’re always exploring the exciting unknown.