|
|
|
  |
| Sunday, 22 May 2005 |
 |
|
 |
Junior Observer |  |
| News Business Features Editorial
|
New insights into galaxies
Called the Hubble Ultra Deep Field (HUDF), this reveals the first galaxies to emerge from the so-called "dark ages," the time shortly after the Big Bang when the first stars reheated the cold, dark universe. The new image should offer new insights into what types of objects reheated the universe long ago. This historic new view is actually two separate images taken by Hubble's Advanced Camera for Surveys (ACS) and the Near Infrared Camera and Multi-object Spectrometer (NICMOS). Both images reveal galaxies that are too faint to be seen by ground-based telescopes. The combination of ACS and NICMOS images will be used to search for galaxies that existed between 400 and 800 million years after the Big Bang. The HUDF field contains an estimated 10,000 galaxies. In ground-based images, the patch of sky in which the galaxies reside (just one-tenth the diameter of the full Moon) is largely empty. Located in the constellation Fornax, the region is below the constellation Orion. The final ACS image is studded with a wide range of galaxies of various sizes, shapes, and colours. In vibrant contrast to the image's rich harvest of classic spiral and elliptical galaxies, there is a zoo of oddball galaxies littering the field. Some look like toothpicks; others like links on a bracelet. A few appear to be interacting. Their strange shapes are a far cry from the majestic spiral and elliptical galaxies we see today. These oddball galaxies chronicle a period when the universe was more chaotic. Order and structure were just beginning to emerge. Installed in 2002, during the last servicing mission to the Hubble telescope, the ACS has twice the field of view and a higher sensitivity than the older workhorse camera, the Wide Field Planetary Camera 2, installed during the 1993 servicing mission. The NICMOS sees even farther than the ACS. The NICMOS reveals the farthest galaxies ever seen, because the expanding universe has stretched their light into the near-infrared portion of the spectrum. The NICMOS may have spotted galaxies that lived just 400 million years after the birth of the cosmos. The entire HUDF was also observed with the advanced camera's "grism" spectrograph, a hybrid prism and diffraction grating. The grism spectra have already yielded the identification of about a thousand objects. Included among them are some of the intensely faint and red points of light in the ACS image, prime candidates for distant galaxies.
Hubble's ACS allows astronomers to see galaxies two to four times fainter than Hubble could view previously, and is also very sensitive to the near-infrared radiation that allows astronomers to pluck out some of the farthest observable galaxies in the universe. This will hold the record as the deepest-ever view of the universe until ESA, together with NASA, launches the James Webb Space Telescope in 2011. Courtesy - NASA *********** India's mission to the moon Do you believe our neighbouring country is planning to land on the moon in another three years time? Well, whether you believe it or not, India recently launched a remote sensing satellite and announced that it was the first step of their mission to land on the moon, in 2007. The launch of CARTOSAT-1 was the first this year for India. The rocket that carried CARTOSAT-1 was built in India and a version of the rocket called the Polar Satellite Launch Vehicle (PSLV), will be used in India's first mission to the moon expected in 2007 or 2008. According to news reports, the Polar Satellite Launch Vehicle (PSLV) lifted off from a new pad at the Satish Dhawan Space Centre in Sriharikota, India and placed the CARTOSAT-1 satellite into orbit 18 minutes later. The 1.5-ton spacecraft, built by the Indian space agency ISRO, is designed to produce stereo imagery of the Earth with resolutions of 2.5 metres per pixel for use in cartography. The PSLV also carried a small secondary payload, Hamsat; the 42.5-kg satellite will serve as an amateur radio relay. Experts say that the CARTOSAT-1, carried by a rocket made in India, signals an effort by India to get into the profitable business of satellite launch services and using space technology for rural and urban development. CARTOSAT-1, which is intended to reach an orbit of 618 km (384 miles) above earth, represents the highest payload carried so far by the PSLV. The satellite mounted with two cameras for "stereographic" imaging can take photos of cars on the ground, though not their number plates. It can capture visual features down to 2.5 metres (8 ft 2 inches) across, officials of the Indian Space Research Organisation (ISRO) said. India, which has launched 10 remote sensing satellites since 1988 in addition to several broadcast satellites, aims to use CARTOSAT-1 to help urban and rural planning, land and water management, relief operations and environmental assessments. |
|
| News | Business | Features
| Editorial | Security
| Politics | Produced by Lake House |
Are you curious to know about the latest galaxy news? Well, then we
have some interesting news for you. Astronomers at the Space Telescope
Science Institute recently revealed the deepest portrait of the visible
universe ever achieved by humankind. 
Based on those identifications, some of these objects are among the
farthest and youngest galaxies ever seen. The grism spectra also
distinguish among other types of very red objects, such as old and dusty
red galaxies, quasars, and cool dwarf stars. 
