<http://schema.org/alternativeHeadline>
"Watching ISON doesn't pose a risk to your eyes, but staring too long at the sun can be dangerous. We'd recommend watching the comet online."^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.mnn.com/earth-matters/space/stories/how-to-watch-comet-isons-thanksgiving-sun-encounter>