If you had X-ray vision — real X-ray vision, meaning you could actually see this type of high-energy radiation — your view of the universe would be vastly different than it is now. Especially if you could sail above the Earth’s atmosphere and stare at the sky. There, all kinds of objects that are normally hidden would suddenly appear.
Alas, humans have not evolved the ability to detect X-rays (or fly); luckily, we’ve built instruments that can. One of the greatest of these is the orbiting Chandra X-Ray Observatory, a space telescope launched 15 years ago today. Carried into Earth orbit by the space shuttle Columbia, Chandra has peered deep into some of the universe’s most mysterious realms — like exploding stars and the hearts of galaxies, where supermassive black holes churn away.
X-rays are produced in some of the most hot and energetic environments the cosmos can cook up. They can illuminate a pulsar’s jet (see this image of the Crab Pulsar), betray the gassy guts of supernova remnants, and reveal the turbulence of newborn star factories. X-rays even help astronomers find black holes, which by definition are invisible. Nothing, not even light, escapes a black hole’s massive gravity. But the area around a black hole is a roiling, chaotic environment that emits X-rays like crazy and points astronomers to the spot.
From its vantage point 86,500 miles above the Earth, Chandra has spied on many black holes (and helped take a black hole census!). X-ray data have directed scientists toward the remnants of a massive galactic pileup that enigmatically left behind a chunk of dark matter, and have told the story of a faraway planet being eroded by radiation from its star (at the rate of 5 trillion tons per second). The X-rays produced by multi-million degree gas are helping scientists determine how dark energy — the enigmatic, repulsive entity responsible for the universe’s accelerating expansion — has affected galaxy clusters over time. And, Chandra has been able to study one of the youngest X-ray binary star pairs yet discovered (this one comprises a neutron star orbiting a sun-like star).
I’ve compiled some of my favorite Chandra images in the gallery above, but there are many, many more on Chandra’s website. It’s great fun to click through the images and flip back and forth between the X-ray, optical, and infrared data that are often layered on various composites. You’ll be able to see how observations in each wavelength add up to the total — and even uncover some features you probably never would have known were there.