Photos of the Day: Photos of the day 05/23
In Pictures: Huge hurricanes
In Pictures: Oh to be young again, Mr. President!
In Pictures: Facing the devastation of the Oklahoma tornadoes
Photos of the Day: Photos of the day 05/22
Photos of the Day: Photos of the day 05/21
In Pictures: Sinkholes around the world
In Pictures: What happened to the green revolution in Iran?
In Pictures: Sandy: Chronicle of an unrelenting storm
AURORA BOREALIS: The aurora borealis, or the northern lights, are seen above Bear Lake in Alaska in January 2005. The lights are the result of solar particles colliding with gases in Earth's atmosphere. Newscom/FILE
AURORA AUSTRALIS: The aurora australis, or the southern lights, are viewed from the Space Shuttle Endeavour, part of which can be seen in top right foreground of this April 1994 NASA photograph. Newscom/FILE
AURORA AUSTRALIS: The aurora australis light up the night sky over the Australian research station Casey in the Australian Antarctic Territory in March 2007. Chris Wilson/AFP/Getty Images/Newscom/FILE
AURORA AUSTRALIS: The aurora australis light up the sky over the Australian research station of Davis in the Australian Antarctic Territory in March 2007. Hosung Chung/AFP/Getty Images/Newscom/FILE
AURORA AUSTRALIS: The southern lights are seen at Scott Station in Antarctica in July 2008. Newscom/FILE
AURORA AUSTRALIS: At Scott Station in Antarctica, the aurora australis can be seen in July 2008. Newscom/FILE
AURORA BOREALIS: The northern lights can be seen here in Lapland, Finland. Newscom
AURORA BOREALIS: The northern lights are seen over a tent with the Brooks Range in the background in Alaska. Newscom
AURORA AUSTRALIS: The aurora australis is viewed in June 2008 from Antarctica. Newscom/FILE
AURORA AUSTRALIS: The southern lights are seen from the International Space Station (ISS) on May 29 as the ISS was located over the Southern Indian Ocean. NASA/AFP/Getty Images/Newscom
AURORA BOREALIS: The northern lights are seen in this undated photograph. Newscom
AURORA BOREALIS: The aurora borealis are seen in Alaska. What looks like hanging colors of light closer to the North Pole can be seen from directly underneath in Alaska. The reddish color is rare as the northern lights are typically green. Newscom
AURORA BOREALIS: In the Brooks Range in Alaska, the aurora borealis can be seen around Mt. Snowden. Newscom
Photos of the Day: Photos of the day 05/23
In Pictures: Huge hurricanes
In Pictures: Oh to be young again, Mr. President!
In Pictures: Facing the devastation of the Oklahoma tornadoes
Photos of the Day: Photos of the day 05/22
Photos of the Day: Photos of the day 05/21
In Pictures: Sinkholes around the world
In Pictures: What happened to the green revolution in Iran?
In Pictures: Sandy: Chronicle of an unrelenting storm
Science is closer to explaining how electrons in the earth's upper atmosphere can generate spectacular auroras.
Scientists may have solved a longstanding mystery about the origin of the energetic particles that cause Earth's dramatic aurora displays.
/Photo-Galleries/Photos-of-the-Day/2013/Photos-of-the-day-05-23
/Photo-Galleries/In-Pictures/Huge-hurricanes
/Photo-Galleries/In-Pictures/Oh-to-be-young-again-Mr.-President
/Photo-Galleries/In-Pictures/Facing-the-devastation-of-the-Oklahoma-tornadoes
/Photo-Galleries/Photos-of-the-Day/2013/Photos-of-the-day-05-22
/Photo-Galleries/Photos-of-the-Day/2013/Photos-of-the-day-05-21
/Photo-Galleries/In-Pictures/Sinkholes-around-the-world
/Photo-Galleries/In-Pictures/What-happened-to-the-green-revolution-in-Iran
/Photo-Galleries/In-Pictures/Sandy-Chronicle-of-an-unrelenting-storm
/Photo-Galleries/Photos-of-the-Day/2013/Photos-of-the-day-05-20
/Photo-Galleries/In-Pictures/Weather-extremes-2013
/Photo-Galleries/In-Pictures/A-West-Bank-wall