The sliver of a crescent moon seems to dip into Earth's atmosphere in a picture taken by NASA astronaut Ron Garan from the International Space Station on July 31. The station completes an orbit of Earth every 90 minutes, so astronauts can see the moon set about 16 times a day.
Combining multiple wavelengths in high resolution, a newly released picture from NASA's Solar Dynamics Observatory shows jets of material called spicules shooting up from the sun. These jets are known to sway like seaweed in the sun's atmosphere due to magnetic field ripples called Alfvén waves.
By tracking the motions of the jets—which loom roughly 32,000 miles (51,500 kilometers) high—scientists were able to measure the energy being carried by the Alfvén waves. In a study published July 28, the team shows that the waves have enough energy to power two mysterious solar phenomena: The waves could be heating the corona to about 20 times hotter than the sun's surface, and they may be powering the solar wind, which blasts particles off the sun at up to 1.5 million miles (2.4 million kilometers) an hour.
Image courtesy SDO/NASA
One Fine Ring
The Fine Ring nebula, seen in a picture released August 1 by the European Southern Observatory, is an unusual example of a planetary nebula. Such space objects form after a sunlike star dies, expanding into a red giant and then shedding its outer gas layers, leaving behind a stellar corpse known as a white dwarf that's surrounded by a shell of debris.
Most known planetary nebulae are spherical, elliptical, or bipolar (with two symmetrical lobes). Astronomers think that odder shapes arise when the dead star has a binary companion—as does the white dwarf at the center of the Fine Ring.
A closeup picture taken by NASA's Dawn spacecraft on July 24 shows a set of three craters nicknamed the Snowman on the northern hemisphere of the asteroid Vesta. Dawn is the first mission to orbit an object in the main asteroid belt, between the orbits of Mars and Jupiter.
Dawn settled into orbit around Vesta—the brightest asteroid in the main belt—on July 16. The craft will spend a year studying Vesta before moving on to the dwarf planet Ceres. (Find out more about the Dawn mission.)
Image courtesy NASA/Caltech/UCLA/MPS/DLR/IDA
Drought conditions in Texas have led to the discovery of a piece of the space shuttle Columbia, seen above in a handout picture taken by local police August 1. The shuttle broke apart during reentry in February 2003, scattering debris over east Texas and Louisiana.
The recent dry spell caused low water levels in Lake Nacogdoches, exposing the 4-foot-wide (1.2-meter-wide) sphere. NASA has confirmed that the object is part of the shuttle, identifying it as a fuel-storage tank.