Why does Earth have a moon, and how does it affect our planet?
Published 5 Jul 2019, 16:03 BST, Updated 29 Oct 2020, 09:49 GMT
A full moon, captured in 2005 by a crew member of the International Space Station, appears to be rolling along atop Earth's deep-blue stratosphere.
Photograph by NASA
A sliver of moon sits above a perfect cross-section of Earth's atmosphere, including rarely seen noctilucent clouds (top), wispy formations that appear about 50 to 60 miles (75 to 90 kilometers) above Earth's surface. This shot was captured by an astronaut aboard the International Space Station as the craft sailed over Mongolia in 2003.
Photograph by NASA
A total solar eclipse is a rare occurrence, happening on average about once per year. They are caused when a new moon passes directly between the sun and the Earth, blocking out all but the sun's wispy corona.
Photograph by National Optical Astronomy Observatories
A ghostly full moon rises over the Anasazi ruins known as Wukoki in Wupatki National Monument, Arizona.
Photograph by David Edwards
A pale full moon appears through dense clouds and silhouettes a bird roosting on a dead tree in Alaska.
Photograph by Michael S Quinton
A tree on Minnesota's Leech Lake is backlit by a full moon on the rise.
Photograph by William Albert Allard
A cheetah uses the light of a full moon to scan the Namibian savannah for prey.
Photograph by Chris Johns
Thin clouds give a gauzy glow to a full moon over the iceberg-choked ocean around Antarctica.
Photograph by María Stenzel
A brilliant yellow moon peeks above dense clouds in Wyoming's Yellowstone National Park.
Photograph by Joël Sartore
A green-tinted aurora borealis cascades above a glowing moon in Churchill, Manitoba, Canada.
Photograph by Norbert Rosing