Picture of the day

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First Hint of Sunrise From Space
On July 30, 2013, Expedition 36 Flight Engineer Karen L. Nyberg of NASA took this photograph of a sunrise viewed from the International Space Station. As the space station orbits the Earth every 90 minutes, traveling at about 17,500 miles per hour, the crew sees about 16 sunrises and sunsets daily.

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THE FULL CIRCLE RAINBOW

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THE CROWN OF PALACES




The Taj Mahal (which literally translates to ‘crown of palaces’) is a white marble mausoleum located in Agra, Uttar Pradesh, India. It was built by Mughal emperor Shah Jahan in memory of his third wife, Mumtaz Mahal. The Taj Mahal is widely recognized as “the jewel of Muslim art in India and one of the universally admired masterpieces of the world’s heritage”. It is regarded by many as the finest example of Mughal architecture, a style that combines elements from Persian, Ottoman Turkish and Indian architectural styles.
In 1983, the Taj Mahal became a UNESCO World Heritage Site. While the white domed marble mausoleum is the most familiar component of the Taj Mahal, it is actually an integrated complex of structures. The construction began around 1632 and was completed around 1653, employing thousands of artisans and craftsmen. Ustad Ahmad Lahauri is generally considered to be the principal designer.
The tomb is the central focus of the entire complex of the Taj Mahal. This large, white marble structure stands on a square plinth and consists of a symmetrical building with an iwan (an arch-shaped doorway) topped by a large dome and finial. The marble dome that surmounts the tomb is the most spectacular feature. Its height of around 35 metres (115 ft) is about the same as the length of the base, and is accentuated as it sits on a cylindrical “drum” which is roughly 7 metres (23 ft) high.

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A Surprisingly Bright Superbubble

This composite image shows a superbubble in the Large Magellanic Cloud (LMC), a small satellite galaxy of the Milky Way located about 160,000 light years from Earth. Many new stars, some of them very massive, are forming in the star cluster NGC 1929, which is embedded in the nebula N44, so named because it is the 44th nebula in a catalog of such objects in the Magellanic Clouds. The massive stars produce intense radiation, expel matter at high speeds, and race through their evolution to explode as supernovas. The winds and supernova shock waves carve out huge cavities called superbubbles in the surrounding gas. X-rays from NASA's Chandra X-ray Observatory (blue) show hot regions created by these winds and shocks, while infrared data from NASA's Spitzer Space Telescope (red) outline where the dust and cooler gas are found. The optical light from the 2.2-m Max-Planck-ESO telescope (yellow) in Chile shows where ultraviolet radiation from hot, young stars is causing gas in the nebula to glow.

A long-running problem in high-energy astrophysics has been that some superbubbles in the LMC, including N44, give off a lot more X-rays than expected from models of their structure. These models assume that hot, X-ray emitting gas has been produced by winds from massive stars and the remains of several supernovas. A Chandra study published in 2011 showed that there are two extra sources of N44's X-ray emission not included in these models: supernova shock waves striking the walls of the cavities, and hot material evaporating from the cavity walls. The Chandra observations also show no evidence for an enhancement of elements heavier than hydrogen and helium in the cavities, thus ruling out this possibility as a third explanation for the bright X-ray emission. Only with long observations making full use of the capabilities of Chandra has it now become possible to distinguish between different sources of the X-rays produced by superbubbles.

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Black Hole Outburst

NASA's Chandra X-ray Observatory has discovered an extraordinary outburst by a black hole in the spiral galaxy M83, located about 15 million light years from Earth. Using Chandra, astronomers found a new ultraluminous X-ray source, or ULX. These objects give off more X-rays than most normal binary systems in which a companion star is in orbit around a neutron star or black hole.

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Astronaut Neil A. Armstrong

Astronaut Neil A. Armstrong was born in Wapakoneta, Ohio on August 5, 1930 and passed away at age 82 on August 25, 2012. Armstrong made history on July 20, 1969, when he became the first person to walk on the moon as commander of Apollo 11.
This photograph of Armstrong from the Apollo 11 mission was taken inside the Lunar Module (LM) while the LM rested on the lunar surface. Astronauts Armstrong and Edwin E. Aldrin Jr., lunar module pilot, had already completed their historic spacewalk when this picture was made. Astronaut Michael Collins, command module pilot, remained with the Command and Service Modules (CSM) in lunar orbit while Armstrong and Aldrin explored the moon's surface.

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WATERSPOUTS OVER THE ADRIATIC

The waterspouts were spaced about 1/3 nautical miles apart and the captain was not concerned about boating past the scary-looking yet apparently non-threatening water cyclones. The photo was taken on July 23, 199 and at left center is Othoni Island.
A waterspout is an intense columnar vortex that occurs over a body of water, connected to a cumuliform cloud. In the common form, it is a non-supercell tornado over water.
While it is often weaker than most of its land counterparts, stronger versions spawned by mesocyclones do occur. Waterspouts do not suck up water; the water seen in the main funnel cloud is actually water droplets formed by condensation. While many waterspouts form in the tropics, other areas also report waterspouts, including Europe, New Zealand, the Great Lakes and Antarctica.
Waterspouts have a five-part life cycle: formation of a dark spot on the water surface, spiral pattern on the water surface, formation of a spray ring, development of the visible condensation funnel, and ultimately decay.

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Hubble Space Telescope Finds Source of Magellanic Stream


Astronomers using NASA's Hubble Space Telescope have solved a 40-year mystery on the origin of the Magellanic Stream, a long ribbon of gas stretching nearly halfway around our Milky Way galaxy.
The Large and Small Magellanic Clouds, two dwarf galaxies orbiting the Milky Way, are at the head of the gaseous stream. Since the stream's discovery by radio telescopes in the early 1970s, astronomers have wondered whether the gas comes from one or both of the satellite galaxies. New Hubble observations reveal most of the gas was stripped from the Small Magellanic Cloud about 2 billion years ago, and a second region of the stream originated more recently from the Large Magellanic Cloud.
A team of astronomers, led by Andrew J. Fox of the Space Telescope Science Institute in Baltimore, Md., determined the source of the gas filament by using Hubble's Cosmic Origins Spectrograph to measure the amount of heavy elements, such as oxygen and sulfur, at six locations along the Magellanic Stream. They observed faraway quasars, the brilliant cores of active galaxies, that emit light that passes through the stream. They detected the heavy elements from the way the elements absorb ultraviolet light.
Fox's team found a low amount of oxygen and sulfur along most of the stream, matching the levels in the Small Magellanic Cloud about 2 billion years ago, when the gaseous ribbon is thought to have formed. In a surprising twist, the team discovered a much higher level of sulfur in a region of the stream that is closer to the Magellanic Clouds.

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THE WAITOMO GLOWWORM CAVES

The Waitomo Glowworm Caves attraction is a cave at Waitomo on the North Island of New Zealand, known for its population of glowworms, Arachnocampa luminosa. This species is found exclusively in New Zealand. They are around the size of an average mosquito. This cave is part of the Waitomo Caves system that includes the Ruakuri Cave and the Aranui Cave. [Source]

Geological and volcanic activity has created around 300 known limestone caves in the Waitomo region over the last 30 million years. The Waitomo Glowworm Caves were first explored in 1887 by local Maori Chief Tane Tinorau accompanied by an English surveyor Fred Mace.