Credit: NASA, ESA, and R. Sahai (Jet Propulsion Laboratory)
Tuesday, Mar. 11, 2014: A nebula known as AFGL 4104, or Roberts 22, appears like a cosmic butterfly. A star nearing the end of its life has flung off its…Read More »
outer layers, causing the nebula to emerge in this striking form. The lobes of Roberts 22 show a complex structure, with countless intersecting loops and filaments. The object currently exists as a preplanetary nebula, a short-lived phase that begins when a dying star has expelled much of the material in its outer layers into space, ending as the stellar remnant heats up enough to ionize surrounding gas clouds, causing them to glow. About 400 years ago, the star at the center of Roberts 22 lost its outer shells, which blasted outwards to form this butterfly. Soon, the central star will be hot enough to ionize the surrounding gas, thus evolving into a full planetary nebula.
Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
Monday, Mar. 10, 2014: Mercury’s uneven surface comes into sharp relief when the sun sits low on the planet’s eastern horizon. The relatively smooth floor…Read More »
of the Caloris basin lies on the right, with the rim and exterior of the basin to the left. The knobby texture outside of the basin may have arisen due to blocks of material ejected by the basin-forming impact. MESSENGER spacecraft acquired this image as part of the Mercury Dual Imaging System's high-incidence-angle base map. High incidence angles, obtained when the sun sits near the horizon, create long shadows that accentuate the small-scale topography of geologic features, as seen here.
Thursday, March 6, 2014: A NASA-funded sounding rocket flew into an aurora over Venetie, Alaska, on March 3, 2014, as seen in this dramatic image. The…Read More »
sounding rocket mission, known as Ground-to-Rocket Electrodynamics – Electron Correlative Experiment (GREECE), launched from Poker Flat Research Range in Poker Flat, Alaska. The mission intends to study classic “curls” in the nighttime aurora. GREECE mission seeks to understand what combination of events sets up these auroral curls in the plasma (charged heated gas) where auroras form. This information can help explain details of the sun-Earth connection and how energy and particles from the sun interact with Earth's magnetic system, the magnetosphere.
Wednesday, March 5, 2014: Saturn’s moon, Mimas, appearing as a tiny speck at lower right, orbits the planet, while a set of spokes appear in the B ring…Read More »
(just right of center). Scientists do not fully understand the mysterious spokes, but researchers believe the spokes will no longer appear when the sun moves higher in Saturn’s sky, as it approaches northern equinox. This occurrence may relate to the ability of micron-sized ring grains to maintain an electrical charge and levitate above the rings, forming the spokes. Therefore Cassini spacecraft may not see any more spokes in the future. The spacecraft took this image in visible light on Oct. 22, 2013, at a distance of approximately 1.6 million miles (2.6 million kilometers) from Saturn.
Tuesday, March 4, 2014: Astrophotographer Garry Owens sent in a photo of the recent brilliant auroral display seen in the United Kingdom. The auroral activity…Read More »
stemmed from sunspot AR1967 erupting, producing the strongest solar flare of 2014 whic produced auroras at lower latitudes than usual in the northern hemisphere. Owens took the shot on Feb. 27, 2014, in Prestatyn, Wales, UK. [See our video about the recent violent solar flare>.]
Credit: Koichi Wakata (via Twitter as @Astro_Wakata)
Monday, March 3, 2014: On Feb. 23, 2014, Dr. Koichi Wakata tweeted this image of the aurora australis taken aboard the International Space Station (ISS).…Read More »
In another tweet about watching the phenomenon, he wrote: “It looked like a storm of light.” Portions of the space station’s equipment appear at left, while a few stars peek out of the inky blackness of space at bottom. Wakata represents the Japan Aerospace Exploration Agency (JAXA) as a Flight Engineer on International Space Station (ISS) Expedition 38 and the Commander of Expedition 39. [See our gallery of Expedition 37/38 images.]