<p>Double star Circinus X-1 (center) has produced the brightest x-ray light echoes (black rings) ever observed. Located 30,700 light-years from Earth, the system is nicknamed 'Lord of the Rings.'</p>

Echoes

Double star Circinus X-1 (center) has produced the brightest x-ray light echoes (black rings) ever observed. Located 30,700 light-years from Earth, the system is nicknamed 'Lord of the Rings.'

X-ray by NASA/CXC/Univ. of Wisconsin-Madison/S.Heinz et al; Optical: DSS

Week's Best Space Pictures: Auroras Bloom and an Exoplanet 'Bleeds'

The northern lights bloom over Earth, while radiation blasts an exoplanet's atmosphere.

Feed your need for heavenly views of the universe with our pick of the most awe-inspiring space pictures. This week, researchers capture echoes from a double star, engineers protect a billion-dollar telescope, and thawing patches of carbon dioxide etch gullies on the surface of Mars.

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