GRB 090423: The Farthest Explosion Yet Measured
Credit: Gemini Observatory / NSF / AURA, D. Fox & A. Cucchiara (Penn State U.), and E. Berger (Harvard Univ.)
Explanation: An explosion so powerful it was seen clear across the visible universe was recorded in gamma-radiation by NASA’s orbiting Swift Observatory. Farther than any known galaxy, quasar, or optical supernova, the gamma-ray burst recorded was clocked at redshift 8.2, making it the farthest explosion of any type yet detected.
The solar system representation of the star 18 Mon, created using imagery from the Space Engine simulator and assembled in photo editing software.
Procedurally generated worlds using Space Engine simulator.
The Beginning of the End of Star Formation
Time is running out for the galaxy NGC 3801, seen in this composite image combining light from across the spectrum, ranging from ultraviolet to radio. NASA’s Galaxy Evolution Explorer and other instruments have helped catch the galaxy NGC 3801 in the act of destroying its cold, gaseous fuel for new stars. Astronomers believe this marks the beginning of its transition from a vigorous spiral galaxy to a quiescent elliptical galaxy whose star-forming days are long past.
Visible light from the Sloan Digital Sky Survey is seen in yellow shining from all of the galaxy’s stars. Notice that NGC 3801 is starting to possess a broadly elliptical shape, the characteristic shape a galaxy assumes after forming from a merger of spiral galaxies. Some star formation is still taking place in NGC 3801, as shown in the ultraviolet by the Galaxy Evolution Explorer (colored blue), and in the dusty disk revealed in infrared light by NASA’s Spitzer Space Telescope (red).
According to theory, that lingering star formation will soon be quenched by shock waves from two powerful jets shooting out of NGC 3801’s central giant black hole. Radio emissions from those jets appear in this image in green. Like a cosmic leaf blower, the jets’ expanding shock waves will blast away the remaining cool star-making gas in NGC 3801. The galaxy will become “red and dead,” as astronomers say, full of old, red stars and lacking in any new stellar younglings.
Angular Sand on Martian Hills
Credit : Mars Exploration Rover Mission, JPL, NASA
Explanation: Why isn’t this sand round? The robotic Spirit rover currently rolling across Mars has found notably angular sand in the Columbia Hills on Mars. Previously, small bits of sand found in the plains of Gusev Crater were significantly more round. The finding indicates that angular hill sand has tumbled less and likely traveled a shorter distance than the corresponding round plain sand. Such tumbling has the general effect of making sand and rocks increasingly round and with fewer sharp edges. Pictured above, as taken last month, are angular sand grains magnified by Spirit’s Microscopic Imager. The above frame spans about three centimeters.
The Eskimo Nebula from Hubble
Credit: Andrew Fruchter (STScI) et al., WFPC2, HST, NASA
Explanation: In 1787, astronomer William Herschel discovered the Eskimo Nebula. From the ground, NGC 2392 resembles a person’s head surrounded by a parka hood. In 2000, the Hubble Space Telescope imaged the Eskimo Nebula. From space, the nebula displays gas clouds so complex they are not fully understood. The Eskimo Nebula is clearly a planetary nebula, and the gas seen above composed the outer layers of a Sun-like star only 10,000 years ago. The inner filaments visible above are being ejected by strong wind of particles from the central star. The outer disk contains unusual light-year long orange filaments.
Galaxy Group HCG 87
Credit: GMOS-S Commissioning Team, Gemini Observatory
Explanation: Posing for this cosmic family photo are the galaxies of HCG (Hickson Compact Group) 87, about four hundred million light-years distant toward the amphibious constellation Capricornus. The large edge-on spiral near picture center, the fuzzy elliptical galaxy immediately to its right, and the spiral near the top of the image are identified members of the group, while the small spiral galaxy in the middle is likely a more distant background galaxy. In any event, a careful examination of the deep image reveals other galaxies which certainly lie far beyond HCG 87. While not exactly locked in a group hug, the HCG 87 galaxies are interacting gravitationally, influencing their fellow group members’ structure and evolution. This image is from the commissioning phase of an instrument on the Gemini Observatory’s South Telescope at Cerro Pachon, Chile. It compares favorably with views of this photogenic galaxy group recorded by the Hubble Space Telescope.
Hubble helps astronomers map dark matter in Abell 1689
Abell 1689 is one of the most massive galaxy clusters known. The gravity of its trillion stars, plus dark matter, acts like a 2-million-light-year-wide “lens” in space. The gravitational lens bends and magnifies the light of galaxies far behind it.
Hubble Images Comet Tempel 1
NASA’s Hubble Space Telescope has snapped an image of Comet 9P/Tempel 1 just days before the Deep Impact spacecraft is scheduled to rendezvous with the comet. This image, taken on the morning of June 30, 2005, shows an undisturbed and quiet comet.
The Deep Impact Probe finally arrived at the comet this morning after a seven-month flight. Images just before and just after the impact were taken by a multitude of telescopes on the ground and in space. The space-based cameras viewing the probe-cometary impact are the Deep Impact spacecraft, as well as those aboard three of NASA’s Great Observatories — the Hubble Space Telescope, the Spitzer Space Telescope and Chandra X-ray Satellite.
Comets are thought to be “dirty snowballs,” porous agglomerations of ice and rock that dwell in the frigid outer boundaries of our solar system. Periodically, they make their journey into the inner solar system as they loop around the Sun. Comets are relics of our early solar system, chunks of leftover material from the formation of the planets. Locked beneath the comet’s surface is pristine material that astronomers want to study to learn how our solar system formed.
The comet’s name is derived from the amateur astronomer Ernst Wilhelm Leberecht Tempel of Marseilles, France, who discovered Comet Tempel 1 in 1867. Little is known about the history of the comet, except that it is a periodic comet that orbits the Sun every 5.5 years. It has probably made more than 100 passages through the inner solar system. Comet Tempel 1 is a potato-shaped object that is 8.7 miles (14 kilometers) wide and 2.5 miles (4 kilometers) long.
The Southern Milky Way Above ALMA
ESO Photo Ambassador Babak Tafreshi snapped this remarkable image of the antennas of the Atacama Large Millimeter/submillimeter Array (ALMA), set against the splendour of the Milky Way. The richness of the sky in this picture attests to the unsurpassed conditions for astronomy on the 5000-metre-high Chajnantor plateau in Chile’s Atacama region.
This view shows the constellations of Carina and Vela. The dark, wispy dust clouds of the Milky Way streak from middle top left to middle bottom right. The bright orange star in the upper left is Suhail in Vela, while the similarly orange star in the upper middle is Avior, in Carina. Of the three bright blue stars that form an “L” near these stars, the left two belong to Vela, and the right one to Carina. And exactly in the centre of the image below these stars gleams the pink glow of the Carina Nebula.
The Butterfly nebula
This image from the NASA/ESA Hubble Space Telescope shows NGC 7026, a planetary nebula. Located just beyond the tip of the tail of the constellation of Cygnus, this butterfly-shaped cloud of glowing gas and dust is the wreckage of a star similar to the Sun.
Planetary nebulae, despite their name, have nothing to do with planets. They are in fact a relatively short-lived phenomenon that occurs at the end of the life of mid-sized stars. As a star’s source of nuclear fuel runs out, its outer layers are puffed out, leaving only the hot core of the star behind. As the gaseous envelope heats up, the atoms in it are excited, and it lights up like a fluorescent sign.
This image of NGC 7026 shows starlight in green, light from glowing nitrogen gas in red, and light from oxygen in blue (in reality, this appears green, but the colour in this image has been shifted to increase the contrast).
Scientists Search for Flowing Water on Mars
Crater edge in Terra Sirenum has been imaged by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter. Gully watching thanks to repeat sweeps over the same landscape by orbiting spacecraft could catch gullies in action, if they are active today.
Credit: NASA/JPL/University of Arizona.
Saturn
1. This is an example of a beautiful picture of Saturn taken by NASA’s Voyager 1 spacecraft in 1980. As you can see, the quality has improved significantly over the image captured by Pioneer 11. Both Voyager 1 and Voyager 2 made quick flybys of Saturn and then sped off into space. When Voyager 1 completed its flyby of Saturn, it sped off into the depths of space, while Voyager 2 went on to visit Uranus and Neptune as part of its Grand Tour of the Solar System.
2. It’s not the best picture, but you’re looking at one of the first ever images of Saturn captured up close by NASA’s Pioneer 11. During its mission, Pioneer 11 passed just 20,000 km above the cloud tops of Saturn, and captured the first close-up images of Saturn.
Triton: The Outer Most Ocean in The Solar System
A new day dawns on Triton. It’s going to be a cold one, much like the last. And the one before that… and every day since the moon settled into its present orbit around Neptune. Even the volcanoes here spew out cold gases and liquid water rather than hot magma. But below the frigid surface, which registers a temperature of -235 °C, there’s something more clement: a liquid ocean.
At first glance, Triton seems to be just another icy moon – a featureless, barren world spinning around Neptune, the outermost planet of our solar system. But Triton is different.
For one thing, it orbits Neptune backwards, moving in the opposite direction to Neptune’s rotation. It’s the only large moon in the solar system to do so. Satellites can’t form in these “retrograde” orbits, so Triton must have begun life elsewhere before being captured by the gas giant. It looks a lot like Pluto, and probably came from the same place – the inner edge of the Kuiper Belt, close to Neptune.
The Voyager 2 spacecraft flew past Triton in 1989, sending back images of the moon’s frozen surface. They revealed signs of cryovolcanism – the eruption of subsurface liquids which quickly freeze when exposed to the cold of the outer solar system. As such, Triton joins a short list of worlds in the solar system known to be geologically active.
Its surface ice is unique, too: largely composed of nitrogen, with some cantaloupe-textured terrain, and a polar cap of frozen methane.
Sharpless 308
Credit & Copyright: Don Goldman
