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Aurora, Milky Way Galaxy, Large Magellanic Cloud Galaxy and Small Magellanic Cloud Galaxy seen over Queenstown

Aurora, Milky Way Galaxy, Large Magellanic Cloud Galaxy and Small Magellanic Cloud Galaxy seen over Queenstown

Queenstown, New Zealand October 14, 2015 Image Credit & Copyright: Minoru Yoneto

September 20, 2016

The Egg Nebula

<div style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEghWWmLBfdCE-M9Ou5RL_UleD794CiZ5n3S43gZWSHBNR_BgZkykDPMRDRP07TjC0ztTJa9OmQ6fUtDb9fGn7aLDPHEDambgKlmdT_llOfOJFNz9RGXwUkr5VvIVY5UX5-WBLlwSmcZv7u9/s1600/Egg-Nebula-10.jpg" imageanchor="1"><img alt="Egg Nebula" border="0" height="602" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEghWWmLBfdCE-M9Ou5RL_UleD794CiZ5n3S43gZWSHBNR_BgZkykDPMRDRP07TjC0ztTJa9OmQ6fUtDb9fGn7aLDPHEDambgKlmdT_llOfOJFNz9RGXwUkr5VvIVY5UX5-WBLlwSmcZv7u9/s640/Egg-Nebula-10.jpg" title="" width="640" /></a></div><div style="text-align: center;"><br /></div><div style="text-align: center;">The NASA/ESA Hubble Space Telescope has been on the forefront of research into the lives of stars like our Sun. At the ends of their lives, these stars run out of nuclear fuel in a phase that is called the preplanetary or protoplanetary nebula stage. This Hubble image of the Egg Nebula shows one of the best views to date of this brief, but dramatic, phase in a star's life.</div><div style="text-align: center;"><br /></div><div style="text-align: center;">During the preplanetary nebula phase, the hot remains of an aging star in the center of the nebula heat it up, excite the gas and make it glow over several thousand years. The short lifespan of preplanetary nebulae means there are relatively few of them in existence at any one time. Moreover, they are very dim, requiring powerful telescopes to be seen. This combination of rarity and faintness means they were only discovered comparatively recently. The Egg Nebula, the first to be discovered, was first spotted less than 40 years ago, and many aspects of this class of object remain shrouded in mystery.</div><div style="text-align: center;"><br /></div><div style="text-align: center;">At the center of this image, and hidden in a thick cloud of dust, is the nebula's central star. While scientists can't see the star directly, four searchlight beams of light coming from it shine out through the nebula. Researchers hypothesize that ring-shaped holes in the thick cocoon of dust, carved by jets coming from the star, let the beams of light emerge through the otherwise opaque cloud. The precise mechanism by which stellar jets produce these holes is not known, but one explanation is that a binary star system, rather than a single star, exists at the center of the nebula.</div><div style="text-align: center;"><br /></div><div style="text-align: center;">The onion-like layered structure of the more diffuse cloud surrounding the central cocoon is caused by periodic bursts of material being ejected from the dying star. The bursts typically occur every few hundred years.</div><div style="text-align: center;"><br /></div><div style="text-align: center;">This image is produced from exposures in visible and infrared light from Hubble's Wide Field Camera 3.</div><br />Image Credit: ESA/Hubble, NASA<br />Explanation from: https://www.nasa.gov/multimedia/imagegallery/image_feature_2235.html

The Egg Nebula

The NASA/ESA Hubble Space Telescope has been on the forefront of research into the lives of stars like our Sun. At the ends of their lives, ...

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September 20, 2016

Proto-Earth May Have Been Significant Source of Lunar Material

<div style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgTgJ6gxJP12uKQ0BeYs2DcGFelJz9B0yj9jUnH1uhafRr7kNl9ev3Ym5CLwdvebMgsw0OtUmXo1LG4PPP1x-08mkNUdnZkjpmM6a0pyH8cJQa331jDZf8ZYu3o1qZYWya1b9HC9cIEfwmI/s1600/Proto-Earth.jpg" imageanchor="1"><img alt="Proto-Earth May Have Been Significant Source of Lunar Material" border="0" height="512" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgTgJ6gxJP12uKQ0BeYs2DcGFelJz9B0yj9jUnH1uhafRr7kNl9ev3Ym5CLwdvebMgsw0OtUmXo1LG4PPP1x-08mkNUdnZkjpmM6a0pyH8cJQa331jDZf8ZYu3o1qZYWya1b9HC9cIEfwmI/s640/Proto-Earth.jpg" title="" width="640" /></a></div><div style="text-align: center;"><br /></div><div style="text-align: center;">A giant impact between the proto-Earth and a Mars-sized impactor named Theia is the best current theory for the formation of the Moon. Scientists believe that Theia collided with the early Earth and that the Moon was created from the rubble left over from the collision. Researchers have estimated that more than 40% of the Moon-forming debris should have been derived from left over pieces of Theia, but new research by a team of geochemists led by Junjun Zhang at the University of Chicago suggests that the Moon is made mostly of material from early Earth instead. The team analyzed Oxygen isotopes and found that terrestrial and lunar samples were almost identical, which is inconsistent with earlier models.</div><div style="text-align: center;"><br /></div><div style="text-align: center;">The researchers measured ratios in lunar samples measured by mass spectrometry. After correcting for secondary effects associated with cosmic-ray exposure at the lunar surface, they found that the ratio of the Moon is identical to that of the Earth within about four parts per million, which is only 1/150 of the isotopic range documented in meteorites.</div><div style="text-align: center;"><br /></div><div style="text-align: center;">The isotopic homogeneity of this highly refractory element suggests that lunar material was derived from the proto-Earth mantle, an origin that could be explained by efficient impact ejection, by an exchange of material between the Earth’s magma ocean and the proto-lunar disk, or by fission from a rapidly rotating post-impact Earth.</div><div style="text-align: center;"><br /></div><div style="text-align: center;">However, it remains uncertain whether more refractory elements, such as titanium, show the same degree of isotope homogeneity as oxygen in the Earth–Moon system.</div><div style="text-align: center;"><br /></div><div style="text-align: center;">Scientists still believe the general idea of having an impact forming disk that coalesced into the Moon is probably right, but this paper shows that scientists still don’t fully understand exactly what the mechanisms were. There is a lot of exciting research still to be done in this field!</div><br />Image Credit: NASA<br />Explanation from: http://sservi.nasa.gov/articles/the-proto-earth-may-have-been-significant-source-of-lunar-material/

Proto-Earth May Have Been Significant Source of Lunar Material

A giant impact between the proto-Earth and a Mars-sized impactor named Theia is the best current theory for the formation of the Moon. Scien...

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September 19, 2016

Star-Forming Region NGC 6611

<div style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhoSFOFDXsq6KET49gAE9W2C7oy9kJdfAsjj3sdjEnB5OPstAPKZPGRMjIfb3SZaCMNUbmMYd0vuIMgi7qDzFT5okCe5EmHzhyphenhyphencgCL1ODE0cnuBJ0oTh67f2YJgC6lYDld3F4GqsudyHQi3/s1600/Star-Forming-Region-NGC-6611.jpg" imageanchor="1"><img alt="Star-Forming Region NGC 6611" border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhoSFOFDXsq6KET49gAE9W2C7oy9kJdfAsjj3sdjEnB5OPstAPKZPGRMjIfb3SZaCMNUbmMYd0vuIMgi7qDzFT5okCe5EmHzhyphenhyphencgCL1ODE0cnuBJ0oTh67f2YJgC6lYDld3F4GqsudyHQi3/s640/Star-Forming-Region-NGC-6611.jpg" title="" width="615" /></a></div><div style="text-align: center;"><br /></div><div style="text-align: center;">The NASA/ESA Hubble Space Telescope has once more turned its attention towards the magnificent Eagle Nebula (Messier 16). This picture shows the northwestern part of the region, well away from the centre, and features some very bright young stars that formed from the same cloud of material. These energetic toddlers are part of an open cluster and emit ultraviolet radiation that causes the surrounding nebula to glow.</div><div style="text-align: center;"><br /></div><div style="text-align: center;">The star cluster is very bright and was discovered in the mid-eighteenth century. The nebula, however, is much more elusive and it took almost a further two decades for it to be first noted by Charles Messier in 1764. Although it is commonly known as the Eagle Nebula, its official designation is Messier 16 and the cluster is also named NGC 6611. One spectacular area of the nebula (outside the field of view) has been nicknamed “The Pillars of Creation” ever since the Hubble Space Telescope captured an iconic image of dramatic pillars of star-forming gas and dust.</div><div style="text-align: center;"><br /></div><div style="text-align: center;">The cluster and nebula are fascinating targets for small and medium-sized telescopes, particularly from a dark site free from light pollution. Messier 16 can be found within the constellation of Serpens Cauda (the Tail of the Serpent), which is sandwiched between Aquila, Sagittarius, and Ophiuchus in the heart of one of the brightest parts of the Milky Way. Small telescopes with low power are useful for observing large, but faint, swathes of the nebula, whereas 30 cm telescopes and larger may reveal the dark pillars under good conditions. But a space telescope in orbit around the Earth, like Hubble — which boasts a 2.4-metre diameter mirror and state-of-the-art instruments — is required for an image as spectacular as this one.</div><div style="text-align: center;"><br /></div><div style="text-align: center;">This picture was created from images taken with the Wide Field Channel of Hubble’s Advanced Camera for Surveys. Images through a near-infrared filter (F775W) are coloured red and images through a blue filter (F475W) are blue. The exposures times were one hour and 54 minutes respectively and the field of view is about 3.3 arcminutes across.</div><br />Image Credit: ESA/Hubble & NASA<br />Explanation from: https://www.spacetelescope.org/images/potw1033a/

Star-Forming Region NGC 6611

The NASA/ESA Hubble Space Telescope has once more turned its attention towards the magnificent Eagle Nebula (Messier 16). This picture shows...

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September 19, 2016

Aurora and the Milky Way Galaxy

Aurora and the Milky Way Galaxy

Ifjord, Finnmark, Norway September 26, 2011 Image Credit & Copyright: Tommy Eliassen

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September 19, 2016

Ocean on Mars, 4 billion years ago

<div style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjvC46zNu5fP3LpdVa_3aCxJL_Ff0prmdxEthyiW_8MEa9yg4YicFQUooCNFjKYgyerQuyA1iqSlgTPr2i0PARJSNd-npBokab9xxhN0mOMDqbNgi88bC2PQuukTS14U7oxSgQHxwlg6KVc/s1600/mars-ocean.jpg" imageanchor="1"><img alt="Ocean on Mars, 4 billion years ago" border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjvC46zNu5fP3LpdVa_3aCxJL_Ff0prmdxEthyiW_8MEa9yg4YicFQUooCNFjKYgyerQuyA1iqSlgTPr2i0PARJSNd-npBokab9xxhN0mOMDqbNgi88bC2PQuukTS14U7oxSgQHxwlg6KVc/s640/mars-ocean.jpg" title="" width="640" /></a></div><div style="text-align: center;"><br /></div><div style="text-align: center;">A primitive ocean on Mars held more water than Earth’s Arctic Ocean, according to NASA scientists who, using ground-based observatories, measured water signatures in the Red Planet’s atmosphere.</div><div style="text-align: center;"><br /></div><div style="text-align: center;">Scientists have been searching for answers to why this vast water supply left the surface.</div><div style="text-align: center;"><br /></div><div style="text-align: center;"><i>“Our study provides a solid estimate of how much water Mars once had, by determining how much water was lost to space,”</i> said Geronimo Villanueva, a scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. <i>“With this work, we can better understand the history of water on Mars.”</i></div><div style="text-align: center;"><br /></div><div style="text-align: center;">Perhaps about 4.3 billion years ago, Mars would have had enough water to cover its entire surface in a liquid layer about 450 feet (137 meters) deep. More likely, the water would have formed an ocean occupying almost half of Mars’ northern hemisphere, in some regions reaching depths greater than a mile (1.6 kilometers).</div><div style="text-align: center;"><br /></div><div style="text-align: center;">The new estimate is based on detailed observations made at the European Southern Observatory’s Very Large Telescope in Chile, and the W.M. Keck Observatory and NASA Infrared Telescope Facility in Hawaii. With these powerful instruments, the researchers distinguished the chemical signatures of two slightly different forms of water in Mars’ atmosphere. One is the familiar H2O. The other is HDO, a naturally occurring variation in which one hydrogen is replaced by a heavier form, called deuterium.</div><div style="text-align: center;"><br /></div><div style="text-align: center;">By comparing the ratio of HDO to H2O in water on Mars today and comparing it with the ratio in water trapped in a Mars meteorite dating from about 4.5 billion years ago, scientists can measure the subsequent atmospheric changes and determine how much water has escaped into space.</div><div style="text-align: center;"><br /></div><div style="text-align: center;">The team mapped H2O and HDO levels several times over nearly six years, which is equal to approximately three Martian years. The resulting data produced global snapshots of each compound, as well as their ratio. These first-of-their-kind maps reveal regional variations called microclimates and seasonal changes, even though modern Mars is essentially a desert.</div><div style="text-align: center;"><br /></div><div style="text-align: center;">The research team was especially interested in regions near Mars’ north and south poles, because the polar ice caps hold the planet’s largest known water reservoir. The water stored there is thought to capture the evolution of Mars’ water during the wet Noachian period, which ended about 3.7 billion years ago, to the present.</div><div style="text-align: center;"><br /></div><div style="text-align: center;">From the measurements of atmospheric water in the near-polar region, the researchers determined the enrichment, or relative amounts of the two types of water, in the planet’s permanent ice caps. The enrichment of the ice caps told them how much water Mars must have lost – a volume 6.5 times larger than the volume in the polar caps now. That means the volume of Mars’ early ocean must have been at least 20 million cubic kilometers (5 million cubic miles).</div><div style="text-align: center;"><br /></div><div style="text-align: center;">Based on the surface of Mars today, a likely location for this water would be in the Northern Plains, considered a good candidate because of the low-lying ground. An ancient ocean there would have covered 19 percent of the planet’s surface. By comparison, the Atlantic Ocean occupies 17 percent of Earth’s surface.</div><div style="text-align: center;"><br /></div><div style="text-align: center;"><i>“With Mars losing that much water, the planet was very likely wet for a longer period of time than was previously thought, suggesting it might have been habitable for longer,”</i> said Michael Mumma, a senior scientist at Goddard.</div><div style="text-align: center;"><br /></div><div style="text-align: center;">NASA is studying Mars with a host of spacecraft and rovers under the agency’s Mars Exploration Program, including the Opportunity and Curiosity rovers, Odyssey and Mars Reconnaissance Orbiter spacecraft, and the MAVEN orbiter, which arrived at the Red Planet in September 2014 to study the planet’s upper atmosphere.</div><div style="text-align: center;"><br /></div><div style="text-align: center;">In 2016, a Mars lander mission called InSight will launch to take a first look into the deep interior of Mars. The agency also is participating in ESA’s (European Space Agency) 2016 and 2018 ExoMars missions, including providing telecommunication radios to ESA’s 2016 orbiter and a critical element of the astrobiology instrument on the 2018 ExoMars rover. NASA’s next rover, heading to Mars in 2020, will carry instruments to conduct unprecedented science and exploration technology investigations on the Red Planet.</div><div style="text-align: center;"><br /></div><div style="text-align: center;">NASA’s Mars Exploration Program seeks to characterize and understand Mars as a dynamic system, including its present and past environment, climate cycles, geology and biological potential. In parallel, NASA is developing the human spaceflight capabilities needed for future round-trip missions to Mars in the 2030s.</div><br />Image Credit: NASA/GSFC<br />Explanation from: http://www.nasa.gov/press/2015/march/nasa-research-suggests-mars-once-had-more-water-than-earth-s-arctic-ocean

Ocean on Mars, 4 billion years ago

A primitive ocean on Mars held more water than Earth’s Arctic Ocean, according to NASA scientists who, using ground-based observatories, mea...

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September 18, 2016

Spiral Galaxy NGC 6217

<div style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjmT44p0QvGR1Es6ii2N0WsQrAWm8mN-PJ5nA038-Rgl3V6D8_X2YcdLYUkQOL5adYH_u2tHAQuK8xlSZoH1hGQfu9bgeWg2hzuPDUfMfcs7alghuleyO9pbHD-DO_-yN7nZTACmdTSDO90/s1600/Spiral-Galaxy-NGC-6217.jpg" imageanchor="1"><img alt="Spiral Galaxy NGC 6217" border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjmT44p0QvGR1Es6ii2N0WsQrAWm8mN-PJ5nA038-Rgl3V6D8_X2YcdLYUkQOL5adYH_u2tHAQuK8xlSZoH1hGQfu9bgeWg2hzuPDUfMfcs7alghuleyO9pbHD-DO_-yN7nZTACmdTSDO90/s640/Spiral-Galaxy-NGC-6217.jpg" title="" width="512" /></a></div><div style="text-align: center;"><br /></div><div style="text-align: center;">The barred spiral galaxy NGC 6217 was photographed on 13 June and 8 July 2009, as part of the initial testing and calibration of Hubble’s ACS. The galaxy lies up to 90 million light-years away in the north circumpolar constellation Ursa Major.</div><br />Image Credit: NASA, ESA and the Hubble SM4 ERO Team

Spiral Galaxy NGC 6217

The barred spiral galaxy NGC 6217 was photographed on 13 June and 8 July 2009, as part of the initial testing and calibration of Hubble’s AC...

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September 18, 2016