About 10,000 years ago, Comet ISON left our solar system's distant shell, a region known as the Oort cloud, and began streaking toward the sun.
Sunset is a special time of day. Low-hanging clouds glow vivid red and orange as the background sky turns cobalt blue.
The U.S. government, led by the Pentagon and CIA, censored or withheld for reasons of national security
'Something unexpected' is happening on the Sun, Nasa has warned.
Earth could be getting a second sun, at least temporarily.
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