Saturday, February 25, 2017

Progress MS-05 Cargo Freighter Pulls into Port at ISS

The current visiting vehicle configuration at the International Space Station as of Feb. 24, 2017. Progress MS-05 is labeled as Progress 66. Image Credit: NASA

On Feb. 24, 2017, the uncrewed Russian Progress MS-05 resupply spacecraft docked with the International Space Station (ISS). The automated link-up with the Pirs docking compartment took place at 3:30 a.m. EST (08:30 GMT) while flying over the south Pacific Ocean.

Hardy Objects Seen in Saturn's F Ring

Image Credit: NASA/JPL-Caltech/Space Science Institute

As NASA's Cassini spacecraft continues its weekly ring-grazing orbits, diving just past the outside of Saturn's F ring, it is tracking several small, persistent objects there. These images show two such objects that Cassini originally detected in spring 2016, as the spacecraft transitioned from more equatorial orbits to orbits at increasingly high inclination about the planet's equator.

More Earth-Like Than Moon-Like

A solidified lava flow over the side of a crater rim of Elysium. Photo Credit: NASA HiRISE image, David Susko, LSU.

Mars’ mantle may be more complicated than previously thought. In a new study published today in the Nature-affiliated journal Scientific Reports, researchers at Louisiana State University (LSU) document geochemical changes over time in the lava flows of Elysium, a major martian volcanic province.

Cosmic Blast from the Past

Three decades ago, a massive stellar explosion sent shockwaves not only through space but also through the astronomical community. SN 1987A was the closest observed supernova to Earth since the invention of the telescope and has become by far the best studied of all time, revolutionising our understanding of the explosive death of massive stars.  Located in the Large Magellanic Cloud, a satellite galaxy of the Milky Way, Supernova 1987A is the nearest supernova explosion observed in hundreds of years. It marked the end of the life of a massive star and sent out a shockwave of ejected material and bright light into space. The light finally reached Earth on 23 February 1987 — like a cosmic blast from the past.  The NASA/ESA Hubble Space Telescope has been on the front line of observations of SN 1987A since 1990 and has taken a look at it many times over the past 27 years. To celebrate the 30th anniversary of the supernova and to check how its remnant has developed, Hubble took another image of the distant explosion in January 2017, adding to the existing collection.  Because of its early detection and relative proximity to Earth, SN 1987A has become the best studied supernova ever. Prior to SN 1987A, our knowledge of supernovae was simplistic and idealised. But by studying the evolution of SN 1987A from supernova to supernova remnant in superb detail, using telescopes in space and on the ground, astronomers have gained revolutionary insights into the deaths of massive stars.  Back in 1990, Hubble was the first to see the event in high resolution, clearly imaging the main ring that blazes around the exploded star. It also discovered the two fainter outer rings, which extend like mirror images in a hourglass-shaped structure. Even today, the origin of these structures is not yet fully understood.  However, by observing the expanding remnant material over the years, Hubble helped to show that the material within this structure was ejected 20 000 years before the actual explosion took place. Its shape at first surprised astronomers, who expected the dying star to eject material in a spherical shape — but faster stellar winds likely caused the slower material to pile up into ring-like structures.  The initial burst of light from the supernova illuminated the rings. They slowly faded over the first decade after the explosion, until the shock wave of the supernova slammed into the inner ring in 2001, heating the gas to searing temperatures and generating strong X-ray emission. Hubble’s observations of this process shed light on how supernovae can affect the dynamics and chemistry of their surrounding environment, and thus shape galactic evolution. Image credit: NASA, ESA, R. Kirshner, P. Challis, ESO/NAOJ/NRAO/A. Angelich, NASA/CXC/SAO.

Three decades ago, a massive stellar explosion sent shockwaves not only through space but also through the astronomical community. SN 1987A was the closest observed supernova to Earth since the invention of the telescope and has become by far the best studied of all time, revolutionizing our understanding of the explosive death of massive stars.

Saturn's Rings Viewed in the Mid-infrared Show Bright Cassini Division

A three-color composite of the mid-infrared images of Saturn on January 23, 2008 captured with COMICS on the Subaru Telescope. The Cassini Division and the C ring appear bright. Color differences reflect the temperatures; the warmer part is blue, the cooler part is red. (Credit: NAOJ)

A team of researchers has succeeded in measuring the brightnesses and temperatures of Saturn's rings using the mid-infrared images taken by the Subaru Telescope in 2008. The images are the highest resolution ground-based views ever made. They reveal that, at that time, the Cassini Division and the C ring were brighter than the other rings in the mid-infrared light and that the brightness contrast appeared to be the inverse of that seen in the visible light (Figure 1). The data give important insights into the nature of Saturn's rings.

Friday, February 24, 2017

10th Dragon Captured at International Space Station

The CRS-10 Dragon on final approach to the International Space Station on Feb. 23, 2017. Photo Credit: Thomas Pesquet / ESA

Twenty-four hours after an aborted rendezvous attempt, SpaceX’s CRS-10 Dragon capsule was captured by the International Space Station’s robotic arm. This second approach to the outpost went by the book. The capture took place at 5:44 a.m. EST (10:44 GMT) Feb. 23, 2017, while the orbiting laboratory was flying 250 miles (402 kilometers) over the west coast of Australia. At the controls of the robotic Canadarm2 were Expedition 50 Commander Shane Kimbrough and Flight Engineer Thomas Pesquet.

Vast Luminous Nebula Poses a Cosmic Mystery

MAMMOTH-1 is an extended blob of gas in the intergalactic medium called an enormous Lyman-alpha nebula (ELAN). The color map and contours denote the surface brightness of the nebula, and the red arrows show its estimated spatial extent. (Image credit: Figure 2 of Cai et al., Astrophysical Journal)

Astronomers have found an enormous, glowing blob of gas in the distant universe, with no obvious source of power for the light it is emitting. Called an "enormous Lyman-alpha nebula" (ELAN), it is the brightest and among the largest of these rare objects, only a handful of which have been observed.