This May 7 peek by not one but two NASA space telescopes lays bare secrets hidden in the heart of the Flame Nebula. There a stellar nursery, the star cluster NGC 2024, has older stars (some 1.5 million years old) around its outer edges and younger ones (only about 200,000 years old) at its center.
This discovery, revealed by combining an infrared view from the Spitzer Space Telescope and an x-ray image from the Chandra telescope, surprised astronomers. They'd expected the cluster's oldest stars to be at its center, cooking up new stars at its edges.
"Our findings are counterintuitive," said study leader Konstantin Getman of Penn State University, in a statement. "It means we need to think harder and come up with more ideas of how stars like our sun are formed."
Bursting from the surface of the sun, a solar flare is seen in all its menacing glory in this May 8 image from NASA's Solar Dynamics Observatory.
The medium-strength, M5.2-class flare erupting from the left side of the sun emitted a blast of radiation. If aimed at the Earth, such flares can disrupt GPS and other communication signals.
The trail of the April 27 tornado that killed 16 people in an Arkansas town is shown in this May 2 picture. Hundreds of homes were destroyed in the tragedy.
The image from NASA's Earth Observing-1 satellite shows a brown slash through Mayflower, Arkansas—the path the tornado took as it crossed Interstate 40 before flattening homes near Lake Conway.
Stellar dust clouds gleam amid distant star clusters in this May 2 Your Shot look from New South Wales, Australia.
Located some 17,000 light-years from Earth in the constellation Puppis, the star cluster NGC 2467 seen in this photo burns brightly with infant stars, illuminating the hollowed-out gas cloud that was their nursery.
Our own sun is suspected of originating in a similar star cluster, where wind from other infant stars and their solar eruptions would have helped shape the early solar system.
Shrouded in its signature haze, Saturn's moon Titan has a curious crescent within a crescent in this view from the international Cassini spacecraft released on May 5.
Curving across the moon's darkened southern sky, the smaller crescent is formed by a polar vortex circling Titan's south pole, raising a wave of haze just high enough to catch a fleeting bit of sunlight.
Flames that threatened the Chilean city of Valparaiso left behind the broad reddish-brown scar visible in the center of a May 4 image captured by NASA's Earth Observing-1 satellite.
The April wildfire, one of the deadliest fires in the region's history, claimed 15 lives, destroyed more than 3,300 homes, and burned 2,385 acres (965 hectares) of land.
While exploring Mars up close last week, NASA's Curiosity rover drilled into this sandstone outcrop.
A test hole and the full drill hole, some 2.6 inches (6.5 centimeters) deep, can be seen at the top center of the photo of the rock, dubbed "Windjana" by mission scientists reminded of an Australian gorge.
From the hole in the rock—the first sandstone drilled on Mars—the team captured a sample uncontaminated by the dust covering the surface of Mars. Curiosity's instruments will analyze its mineral and chemical content. The overriding mission of the $2.5-billion rover is to assess whether the red planet was once habitable.