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Thursday, September 27, 2012

Head of the Seagull Nebula


This image from ESO’s La Silla Observatory shows part of a stellar nursery nicknamed the Seagull Nebula. This cloud of gas, known as Sh 2-292, RCW 2 and Gum 1, seems to form the head of the seagull and glows brightly due to the energetic radiation from a very hot young star lurking at its heart. The detailed view was produced by the Wide Field Imager on the MPG/ESO 2.2-meter telescope.

Photo credit: ESO

Note: For more information, see The Rich Colors of a Cosmic Seagull

Tuesday, September 25, 2012

Halo of Hot Gas Around the Milky Way


Galactic Halo: An enormous halo of hot gas (in blue) around the Milky Way galaxy with a radius of at least 300,000 light years.

Astronomers have used Chandra to find evidence that our Milky Way Galaxy is embedded in an enormous halo of hot gas that extends for hundreds of thousands of light years. This artist's illustration shows the halo of hot gas, in blue, around the Milky Way and two small neighboring galaxies. The mass of the halo is estimated to be comparable to the mass of all the stars in the Milky Way galaxy. If the size and mass of this gas halo is confirmed, it could be the solution to the "missing-baryon" problem for the Galaxy.

Illustration credit: NASA/CXC/M.Weiss; NASA/CXC/Ohio State/A Gupta et al.

Note: For more information, see Galactic Halo: Milky Way is Surrounded by Huge Halo of Hot Gas.

Wednesday, September 19, 2012

Juno's Two Deep Space Maneuvers are 'Back-To-Back Home Runs'




NASA's Juno spacecraft successfully executed a second Deep Space Maneuver, called DSM-2 last Friday, September 14. The 30 minute firing of its main engine refined the Jupiter-bound spacecraft's trajectory, setting the stage for a gravity assist from a flyby of Earth on October 9, 2013. Juno will arrive at Jupiter on July 4, 2016.

The maneuver began at 3:30 p.m. PDT (6:30 p.m. EDT), when the Leros-1b main engine began to fire. The burn ended at 4 p.m. PDT (7 p.m. EDT). Based on telemetry, the Juno project team believes the burn was accurate, changing the spacecraft's velocity by about 867 mph (388 meters a second) while consuming about 829 pounds (376 kilograms) of fuel.

The burn occurred when Juno was more than 298 million miles (480 million kilometers) from Earth.

Juno executed its first deep space maneuver (DSM-1), one of comparable duration and velocity change, on August 30. Together, both maneuvers placed Juno on course for its Earth flyby, which will occur as the spacecraft is completing one elliptical orbit around the sun. The Earth flyby will boost Juno's velocity by 16,330 mph (about 7.3 kilometers per second), placing the spacecraft on its final flight path for Jupiter. The closest approach to Earth, on October 9, 2013, will occur when Juno is at an altitude of about 348 miles (560 kilometers).

"It feels like we hit back-to-back home runs here with the near-flawless propulsion system performance seen during both DSM-1 and DSM-2." said Juno Project Manager Rick Nybakken of NASA's Jet Propulsion Laboratory in Pasadena, California. "These successes move us closer to being ready for our most critical mission event, the Jupiter Orbit Insertion main engine burn in July 2016. We're not in the playoffs yet, as that will come in 2016 when we arrive at Jupiter, but it does feel fantastic to have hit both of these DSMs out of the park."

Juno was launched on August 5, 2011. Once in orbit, the spacecraft will circle Jupiter 33 times, from pole to pole, and use its collection of eight science instruments to probe beneath the gas giant's obscuring cloud cover. Juno's science team will learn about Jupiter's origins, structure, atmosphere and magnetosphere, and look for a potential solid planetary core.

Juno's name comes from Greek and Roman mythology. The god Jupiter drew a veil of clouds around himself to hide his mischief, and his wife, the goddess Juno, was able to peer through the clouds and reveal Jupiter's true nature.

Illustration credit: NASA/JPL-Caltech

Tuesday, September 18, 2012

New Impact Crater South of Echus Chasma


How exactly can we tell if an impact crater is new?

In this observation, we see a dark spot with a larger, rayed "blast zone" that was also apparent in a Context Camera image taken in 2011 (an instrument with a larger footprint than HiRISE and also on the Mars Reconnaissance Orbiter). However, a THEMIS image of the same area acquired in 2009 does not show the dark spot at all.

This is a great example of using three different instruments to view the same area not only to look for changes in the Martian landscape, but also to use the resolution of HiRISE to determine if this is indeed a new impact site.

Photo credit: NASA/JPL/University of Arizona

Note: This impact crater is located just south of Echus Chasma.

Monday, September 17, 2012

Bs in the Beehive


Astronomers have discovered two gas giant planets orbiting stars in the Beehive cluster, a collection of about 1,000 tightly packed stars. The planets are the first ever found around sun-like stars in a cluster of stars. Such planets, even though they are not habitable, would have skies filled with many bright stars as illustrated in this artist's concept. A gas giant planet is shown to the right of its sun-like star, and all around, the stars of the Beehive cluster shine brightly in the dark.


This image of the Beehive star cluster points out the location of its first known planets, Pr0201b and Pr0211b, or, as astronomers call them, the first 'b's' in the Beehive. The "open cluster," also called Praesepe, is a collection of about 1,000 stars all loosely bound together by gravity, located about 550 light-years away. The stars were born out of the same cloud and have remained together for the past 600 million years. Eventually, they will disperse and head out on their own.

Astronomers found the planets Pr0201b and Pr0211b orbiting different sun-like stars in the cluster. The planets are both "hot Jupiters," which are gas giants like Jupiter but whip closely around their stars in just days. They are the first planets ever found around sun-like stars in a cluster, offering further proof that planets can sprout up in dense stellar environments.

The Beehive cluster can be seen in dark northern skies in late winter or early spring with the naked eye. The stars themselves can be seen individually with the help of a telescope.

Illustration credit: NASA/JPL-Caltech; image credit: Stuart Heggie

Note: For more information, see First Planets Found Around Sun-Like Stars in a Cluster.

Sunday, September 16, 2012

SN 1604 - Kepler's Supernova Remnant


Kepler's Supernova Remnant: The debris from a supernova observed in 1604.

This composite image of Kepler's supernova remnant shows different colors ranging from lower to higher energies: red, yellow, green, blue and purple. An optical image from the Digitized Sky Survey (pale yellow and blue) shows stars in the field. The Kepler supernova was a Type Ia event, the thermonuclear explosion of a white dwarf. New analysis suggests that the supernova explosion was not only more powerful, but might have also occurred at a greater distance, than previously thought.

Scale: Image is about 5 arcmin across (19-33 light years).

Image credit: X-ray: NASA/CXC/SAO/D.Patnaude, Optical: DSS


Note: For more information, see Kepler's Supernova Remnant: Was Kepler's Supernova Unusually Powerful?

Saturday, September 15, 2012

Colorful Surface Near Nili Fossae


This enhanced-color image shows a surface with diverse colors just southwest of Nili Fossae. The color diversity of this mesa suggests that the surface has a varied composition, perhaps recording chemical processes of ancient Mars.

Much of the surface shows a chaotic mix of colors, but the northern impact crater exposes distinct layers. Different layers have different colors. There are several possible reasons for this: the events that formed the layers could have drawn material from different sources, or the layers could have been altered differently after they formed, for reasons such as varying porosity.

This is a stereo pair with ESP_019898_2000.

Photo credit: NASA/JPL/University of Arizona

Friday, September 14, 2012

NGC 2736 - The Pencil Nebula


The oddly shaped Pencil Nebula (NGC 2736) is pictured in this image from ESO’s La Silla Observatory in Chile. This nebula is a small part of a huge remnant left over after a supernova explosion that took place about 11,000 years ago. The image was produced by the Wide Field Imager on the MPG/ESO 2.2-meter telescope at ESO’s La Silla Observatory in Chile.

Photo credit: ESO

Note: For more information, see A Celestial Witch’s Broom?


Thursday, September 13, 2012

Full Topographical Maps of Vesta


This image from NASA's Dawn mission shows the topography of the northern and southern hemispheres of the giant asteroid Vesta, updated with pictures obtained during Dawn's last look back. Around the time of Dawn's departure from Vesta in the late summer of 2012, dawn was beginning to creep over the high northern latitudes, which were dark when Dawn arrived in the summer of 2011.

These color-shaded relief maps show the northern and southern hemispheres of Vesta, derived from images analysis. Colors represent distance relative to Vesta's center, with lows in violet and highs in red. In the northern hemisphere map on the left (Figure 1), the surface ranges from lows of minus 13.82 miles (22.24 kilometers) to highs of 27.48 miles (44.22 kilometers). Light reflected off the walls of some shadowed craters at the north pole (in the center of the image) was used to determine the height. In the southern hemisphere map on the right (Figure 2), the surface ranges from lows of minus 23.65 miles (38.06 kilometers) to 26.61 miles (42.82 kilometers).

The shape model was constructed using images from Dawn's framing camera that were obtained from July 17, 2011, to August 26, 2012. The data have been stereographically projected on a 300-mile-diameter (500-kilometer-diameter) sphere with the poles at the center.

The three craters that make up Dawn's "snowman" feature can be seen at the top of the northern hemisphere map on the left. A mountain more than twice the height of Mount Everest, inside the largest impact basin on Vesta, can be seen near the center of the southern hemisphere map on the right.

These images are the last in Dawn's Image of the Day series during the cruise to Dawn's second destination, Ceres. A full set of Dawn data is being archived at http://pds.nasa.gov/.

Image credit: NASA/JPL-Caltech/UCAL/MPS/DLR/IDA/PSI

Note: For more information, see Vesta in Dawn's Rear View Mirror.

Wednesday, September 12, 2012

Let it snow, let is snow, let it...


Observations by NASA's Mars Reconnaissance Orbiter have detected carbon-dioxide snow clouds on Mars and evidence of carbon-dioxide snow falling to the surface.

Deposits of small particles of carbon-dioxide ice are formed by snowfall from carbon-dioxide clouds. This map shows the distribution of small-grain carbon-dioxide ice deposits formed by snowfall over the south polar cap of Mars. It is based on infrared measurements by the Mars Climate Sounder instrument on the Mars Reconnaissance Orbiter.

Image credit: NASA/JPL-Caltech

Note: For more information, see NASA Observations Point to 'Dry Ice' Snowfall on Mars.

Tuesday, September 11, 2012

B-Ring Clumps and Strands


Zooming in on clumps in Saturn’s B-ring (lower left), the image also spans the ringlets of the Cassini Division towards the A-ring in the top right. The view looks toward the sunlit side of the rings from about 31 degrees below the ring plane. The image scale is approximately 2 km per pixel.

Photo credit: NASA/JPL/Space Science Institute

Monday, September 10, 2012

3-D View from Bradbury Landing


This 3-D image from NASA's Curiosity was taken from the rover's Bradbury Landing site inside Gale Crater, Mars, using the left and right eyes of its Navigation camera. Between the rover on the right, and its shadow on the left, looms the rover's eventual target: Mount Sharp. The mountain's highest peak is not visible to the rover from the landing site.

This full-resolution, 360-degree stereo panorama was taken on sols 2 and 12 of the mission, or the 2nd and 12th Martian days since landing (Aug. 8 and 18, 2012). It requires viewing with the traditional red-blue 3-D glasses, with red going over the left eye.

Image credit: NASA/JPL-Caltech

Sunday, September 9, 2012

Hadley Crater


High-Resolution Stereo Camera (HRSC) nadir and color channel data taken during revolution 10572 on 9 April 2012 by ESA’s Mars Express have been combined to form a natural-color view of Hadley Crater. Centered at around 19°S and 157°E, the image has a ground resolution of about 19 m per pixel. The image shows the main 120 km wide crater, with subsequent impacts at later epochs within it. Evidence of these subsequent impacts occurring over large timescales is shown by some of the craters being buried.

Photo credit: ESA/DLR/FU Berlin (G. Neukum)

Saturday, September 8, 2012

Chernozem Cropland


This ALOS satellite image shows an area with extensive agricultural use in western Russia, with roads and rivers cutting through the cropland. This area, part of Russia’s Black Earth Region, is about 400 km directly south of Moscow. Many grains are grown here, such as winter wheat and rye.

This image is a compilation of three passes by the Japanese Advanced Land Observation Satellite’s radar on 14 June 2009, 14 September 2009 and 2 August 2010. Each image at the different recording date is assigned a color (red, green or blue) and combined to produce this representation. The colors reveal changes in the surface between the satellite’s passes.

Photo credit: JAXA, ESA

Friday, September 7, 2012

ARP 116


Two very different galaxies feature in this image taken by the NASA/ESA Hubble Space Telescope, forming a peculiar galaxy pair called Arp 116.

Arp 116 is composed of a giant elliptical galaxy known as Messier 60, and a much smaller spiral galaxy, NGC 4647.

Astronomers have long tried to determine whether these two galaxies are actually interacting. Although they overlap as seen from Earth, there is no evidence of new star formation, which would be one of the clearest signs that the two galaxies are indeed interacting. However, recent studies of very detailed Hubble images suggest the onset of some tidal interaction between the two.

Photo credit: NASA, ESA

Note: For more information, see A Family Portrait of Galaxies.

Thursday, September 6, 2012

Messier 4


This image from the Wide Field Imager attached to the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory shows the spectacular globular star cluster Messier 4. This great ball of ancient stars is one of the closest of such stellar systems to the Earth and appears in the constellation of Scorpius (The Scorpion) close to the bright red star Antares.

Photo credit: ESO

Note: For more information, see A Cluster With a Secret.

Wednesday, September 5, 2012

August Blue Moon


The second full Moon of the month – known as a ‘blue’ Moon – just before it disappeared from the MSG-3 satellite’s sight behind the southern hemisphere. The image was captured by the Spinning Enhanced Visible and Infrared Imager (SEVIRI) instrument at 11:20 GMT on 31 August 2012.

Photo credit: Eumetsat

Tuesday, September 4, 2012

Arctic Ice Cover Decrease


This animation shows Arctic ice cover from 1978 to 2010. The past five years have seen the lowest Arctic sea-ice extent since satellite measurements began in the 1970s.

Video credit: ESA/DLR