Monday, March 14, 2011

Discovery - The End of an Era

(From CBS News) - Read Full Article

Discovery is NASA's oldest flying space shuttle and the most traveled winged spaceship in the fleet. It has flown more missions, and carried more astronaut crewmembers, than any of NASA's other shuttles, agency officials have said.

Here's a by-the-numbers look at Discovery's lasting legacy in space that, according to NASA, will cement the shuttle's place in the fleet's record books:

148,221,675: The number of miles Discovery has traveled after 39 space missions. This is a distance record unmatched among NASA's space shuttle fleet. The miles traveled by Discovery could have carried it to the moon and back more than 288 times, or on 1 1/2 trips to the sun.

40,000: The number of spectators, according to NASA estimates, who watched Discovery's final launch from the Kennedy Space Center in Cape Canaveral, Fla., on Feb. 24, 2011.

17,400: The speed at which Discovery traveled (in miles per hour) to remain in orbit. It's about Mach 25, or five times the speed of a bullet.

5,830: The number of orbits Discovery has flown around the Earth after its final flight. During spaceflight, Discovery completes one orbit around Earth every 90 minutes.

1984: The year Discovery blasted off on its maiden space voyage. Discovery's first flight was NASA's STS-41D mission, which launched on Aug. 30 carrying three communications satellites and an experimental solar array wing. The mission was commanded by astronaut Henry Hartsfield.

365: The number of cumulative days Discovery will have flown in space by the end of its career. Altogether, that's 52 weeks. Put another way, if you were to string all of Discovery's mission's together into one mission, the shuttle would be in space for exactly an entire year.

246: The number of crewmembers Discovery has carried during its space career so far. According to NASA, Discovery has been the ultimate space taxi and carried the most astronauts of any shuttle.

39: The number of missions Discovery will have flown by the time it is retired.

13: The number of times Discovery will have docked with the International Space Station after it is retired.

5: The number of astronauts that marked a first-ever in space when they flew on Discovery. According to NASA, they include: the first female to ever pilot a spacecraft (former astronaut Eileen Collins); the oldest person to fly in space (former astronaut John Glenn); the first African-American to perform a spacewalk (former astronaut Bernard Harris); the first cosmonaut to fly on an American spacecraft (Russian spaceflyer Sergei Krikalev); and the first sitting member of Congress to fly in space (former Utah Senator Jake Garn).

4: The number of years it took to build the space shuttle Discovery. The shuttle was completed in October 1983 in Palmdale, Calif., and was shipped a month later to NASA piggyback atop the agency's modified Boeing 747 shuttle carrier craft. Four is also the maximum number of times the shuttle has flown in space in a single year. In 1985, Discovery set the bar for number of flights by one orbiter in one year.

3: The number of satellites Discovery carried during its first launch. Discovery was also NASA's third space shuttle built for orbital flight. It was built after the shuttles Columbia and Challenger.

2: The number of return-to-flight missions Discovery has flown to help NASA resume shuttle flights. Discovery was the shuttle that flew the STS-26 mission two years after the loss of shuttle Challenger and its crew during launch on Jan. 28, 1986. The shuttle also flew the STS-114 mission that followed the 2003 loss of shuttle Columbia and its seven-astronaut crew. That mission launched in July 2005.

1: The number of actual dockings with Russia's Space Station Mir. Discovery actually visited the Mir station twice. It was the first U.S. shuttle to rendezvous with (but not dock at) Mir in 1995. Its second and last trip to Mir was in 1998, when it actually linked up with the Russian space station..

Saturday, January 22, 2011

Abell 1689

Galaxies Magnified by Galaxy Cluster Abell 1689

Abell 1689 is a galaxy cluster in the constellation Virgo. It is one of the biggest and most massive galaxy clusters known and acts as a gravitational lens, distorting the images of galaxies that lie behind it.[1] It is 2.2 billion light years (670 megaparsec) away from the Earth.

In February 2008, it was announced that one of the lensed galaxies, A1689-zD1, was the most distant yet found.

Thursday, September 23, 2010

Light Echoes From Red Supergiant Star

The earliest beginning of a star is called a nebula. A nebula is a cloud of hydrogen and a few helium atoms hanging in space. Sometimes a nebula just stays at this point, but if the cloud gets thick enough, with enough hydrogen atoms close enough together, it can become a brown dwarf. A brown dwarf is a small star that is not quite big enough, so there is not enough gravity to start the nuclear fusion process. Brown dwarf stars hardly shine at all, but they're not very common either. 

If the brown dwarf succeeds in attracting enough hydrogen atoms and packing them tightly enough together, then it turns into a main-sequence star - an ordinary star like our sun. Nine out of every ten stars you can see from Earth are main-sequence stars. Inside a main-sequence star, the pressure of gravity pushes hydrogen atoms together so they become helium atoms, and the extra energy released by this fusion process shoots out of the star and become heat and sunlight.
The red giant star Betelgeuse
(thanks to Hubble Space Telescope)
A main-sequence star usually doesn't change for several billion years, but eventually it runs out of hydrogen atoms to turn into helium atoms, like a car running out of gas. When this happens, the main-sequence star turns into a supergiant star. These supergiants, or "red giants", are much bigger and cooler than regular stars. Two examples of supergiant stars are Antares and Betelgeuse. Supergiant stars still have nuclear fusion going on inside them, but they change helium atoms into carbon, or carbon into oxygen. A supergiant lasts about one-tenth as long as the main-sequence star did.  (Read more at History for kids)

Monday, August 23, 2010

Spiral Galaxies


A spiral galaxy is a certain kind of galaxy originally described by Edwin Hubble in his 1936 work The Realm of the Nebulae[1] and, as such, forms part of the Hubble sequence. Spiral galaxies consist of a flat, rotating disk containing stars, gas and dust, and a central concentration of stars known as the bulge. These are surrounded by a much fainter halo of stars, many of which reside in globular clusters.

Monday, August 9, 2010

Saturn Aurora


These images reveal the dynamic nature of Saturn's auroras. Viewing the planet's southern polar region for several days, NASA's Hubble Space Telescope snapped a series of photographs of the aurora dancing in the sky. The snapshots show that Saturn's auroras differ in character from day to day, as they do on Earth, moving around on some days and remaining stationary on others. But compared with Earth, where auroral storms develop in about 10 minutes and may last for a few hours, Saturn's auroral displays always appear bright and may last for several days.
The observations, made by Hubble and the Cassini spacecraft, while enroute to the planet, suggest that Saturn's auroral storms are driven mainly by the pressure of the solar wind — a stream of charged particles from the Sun — rather than by the Sun's magnetic field.

The aurora's strong brightening on Jan. 28, 2004 corresponds with the recent arrival of a large disturbance in the solar wind. The image shows that when Saturn's auroras become brighter (and thus more powerful), the ring of light encircling the pole shrinks in diameter.

Seen from space, an aurora appears as a ring of glowing gases circling a planet's polar region. Auroral displays are initiated when charged particles in space collide with a planet's magnetic field. The charged particles are accelerated to high energies and stream into the upper atmosphere. Collisions with the gases in the planet's atmosphere produce flashes of glowing energy in the form of visible, ultraviolet, and infrared light.

Sunday, July 25, 2010

Cats Eye Nebula

From Wikipedia

The Cat's Eye Nebula (NGC 6543) is a planetary nebula in the constellation of Draco. Structurally, it is one of the most complex nebulae known, with high-resolution Hubble Space Telescope observations revealing remarkable structures such as knots, jets, bubbles and sinewy arc-like features. In the center of the Cat's Eye there is a bright and hot star, which around 1000 years ago lost its outer envelope producing the nebula.
It was discovered by William Herschel on February 15, 1786, and was the first planetary nebula whose spectrum was investigated by the English amateur astronomer William Huggins in 1864. The results of the latter investigation demonstrated for the first time that planetary nebulae consist of hot gases, but not stars. Currently the nebula have been observed across the full electromagnetic spectrum, from far-infrared to X-rays.
Modern studies reveal several mysteries. The intricacy of the structure may be caused in part by material ejected from a binary central star, but as yet, there is no direct evidence that the central star has a companion. Also, measurements of chemical abundances reveal a large discrepancy between measurements done by two different methods, the cause of which is uncertain. Hubble Telescope observations revealed a number of faint rings around the Eye, which are spherical shells ejected by the central star in the distant past. The exact mechanism of those ejections, however, is unclear.

The Pleiades

From Wikipedia
In astronomy, the Pleiades, or Seven Sisters (Messier object 45), is an open star cluster containing middle-aged hot B-type stars located in the constellation of Taurus. It is among the nearest star clusters to Earth and is the cluster most obvious to the naked eye in the night sky. Pleiades has several meanings in different cultures and traditions.