The moon nibbles at the sun's disk during a solar eclipse over China's Changchun Province near dawn on Thursday.
Visible from much of Earth's remote northern reaches, the partial solar eclipse began over the eastern edge of Asia before moving "backward" across time zones to areas of Siberia, Scandinavia, Iceland, Canada and Alaska.
In some regions where the sun doesn't set in June, sky-watchers had the rare opportunity to see a midnight solar eclipse.
Seen from Finnish Lapland, last night's partial solar eclipse occurred during the first appearance of 2011's midnight sun in the area, according to photographer B. Art Braafhart. "Almost perfect circumstances with some clouds," Braafhart said in an email.
Solar eclipses occur when Earth, the moon, and the sun are aligned so that—as seen from Earth—the moon appears to cover all or part of the sun's disk.
The sun "smiles" over northern Finland last night during a midnight solar eclipse.
Partial solar eclipses, such as last night's, which is the second of 2011—happen when Earth crosses only through the faint outer part of the moon's shadow, known as the penumbra. (See pictures of January's partial solar eclipse.)
By contrast, during a total eclipse the sun is completely blotted out by the moon as its dark, central shadow, called the umbra, falls in a very narrow strip along Earth's surface.
The partially eclipsed sun swings low over misty mountains in Changchun, China, early this morning.
The first hint of the moon's silhouette taking a bite out of the sun's disk was seen from northern China and northern Japan between 4 and 5 a.m., local time, on Thursday. Shortly thereafter, about 60 percent of the sun went dark over Siberia, Russia.
Moving east to west, the solar eclipse's pathway crossed the date line, so far-northern European observers saw the eclipse around 11:30 p.m., local time, on Wednesday.
The moon comes between Earth and the sun—already partly obscured by the horizon—over Changchun, China, Thursday morning.
The next solar eclipse, on July 1, will be even more obscure than tonight's—visible from only a small patch of ocean off Antarctica, said Williams College eclipse expert Jay Pasachoff, whose work has been funded by the National Geographic Society's Committee for Research and Exploration. (The Society owns National Geographic News.)
"No airplane flights seem to be passing through that region at the proper time," he said. "So it is probable that no human will see it."
In Bodø, Norway some transparent clouds made the partial solar eclipse of June 1-2, 2011, look more dramatic. Observed with a H-alpha filter, more details on the sun are visible. The rare "midnight eclipse" began on Thursday, June 2, 2011, but crossed the International Date Line to end on Wednesday, June 1.
The partial solar eclipse of June 1-2, 2011, at maximum is shown as observed from Tromsø in Norway. The rare "midnight eclipse" began on Thursday, June 2, 2011, but crossed the International Date Line to end on Wednesday, June 1.
"Midnight" Partial Solar Eclipse Over Bratsk, RussiaCredit: Svetlana KulkovaPhotographer and skywatcher Svetlana Kulkova snapped this view of the partial solar eclipse of June 1-2, 2011 just after sunrise on June 2 from Bratsk, Russia. The partial solar eclipse was dubbed a "midnight" eclipse as its viewing path crossed the International Date Line.
