This looks a bit like a tornado, but it's a low angle view of the volcanic ash cloud. Full story.
Fears about the cloud forced President Obama to cut his visit to Ireland short and fly to London.
Yesterday's PhotoBlog post.
Jon Magnusson / Getty Images Contributor
The eruption of the Grimsvotn volcano sends thousands of tonnes of volcanic ash into the sky on May 23 above Iceland. The cloud has forced the closure of Icelandic airspace and spread fears of a repeat of the global travel chaos that was caused by last year's Icelandic eruption, although authorities insist that this Grimsvotn poses a lesser threat.
Forestry School grad dresses up for Yale graduation
Tight security protects President Obama on Ireland visit