23 December 2005

HST Hits '05

The Hubble Space Telescope continues to impress, delivering yet another year of breathtaking imagery. With 2005 being nearly history I thought I'd share my favorites.




Credit: NASA, ESA, and The Hubble Heritage Team (STScI/AURA); Full press release

The Hubble Space Telescope's latest image of the star V838 Monocerotis (V838 Mon) reveals dramatic changes in the illumination of surrounding dusty cloud structures. The effect, called a light echo, has been unveiling never-before-seen dust patterns ever since the star suddenly brightened for several weeks in early 2002.

The illumination of interstellar dust comes from the red supergiant star at the middle of the image, which gave off a pulse of light three years ago, somewhat similar to setting off a flashbulb in a darkened room. The dust surrounding V838 Mon may have been ejected from the star during a previous explosion, similar to the 2002 event.
The echoing of light through space is similar to the echoing of sound through air. As light from the stellar explosion continues to propagate outwards, different parts of the surrounding dust are illuminated, just as a sound echo bounces off of objects near the source, and later, objects further from the source. Eventually, when light from the back side of the nebula begins to arrive, the light echo will give the illusion of contracting, and finally it will disappear.





Credit: NASA, ESA, J. Clarke (Boston University), and Z. Levay (STScI)
Full press release

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.





Credit: NASA, ESA, S. Beckwith (STScI), and The Hubble Heritage Team (STScI/AURA)

The graceful, winding arms of the majestic spiral galaxy M51 (NGC 5194) appear like a grand spiral staircase sweeping through space. They are actually long lanes of stars and gas laced with dust.
This sharpest-ever image of the Whirlpool Galaxy, taken in January 2005 with the Advanced Camera for Surveys aboard NASA's Hubble Space Telescope, illustrates a spiral galaxy's grand design, from its curving spiral arms, where young stars reside, to its yellowish central core, a home of older stars. The galaxy is nicknamed the Whirlpool because of its swirling structure.




Credit: NASA, ESA, and The Hubble Heritage Team (STScI/AURA ); Full press release

Appearing like a winged fairy-tale creature poised on a pedestal, this object is actually a billowing tower of cold gas and dust rising from a stellar nursery called the Eagle Nebula. The soaring tower is 9.5 light-years or about 57 trillion miles high, about twice the distance from our Sun to the next nearest star.

Stars in the Eagle Nebula are born in clouds of cold hydrogen gas that reside in chaotic neighborhoods, where energy from young stars sculpts fantasy-like landscapes in the gas. The tower may be a giant incubator for those newborn stars. A torrent of ultraviolet light from a band of massive, hot, young stars [off the top of the image] is eroding the pillar.

The starlight also is responsible for illuminating the tower's rough surface. Ghostly streamers of gas can be seen boiling off this surface, creating the haze around the structure and highlighting its three-dimensional shape. The column is silhouetted against the background glow of more distant gas.

The edge of the dark hydrogen cloud at the top of the tower is resisting erosion, in a manner similar to that of brush among a field of prairie grass that is being swept up by fire. The fire quickly burns the grass but slows down when it encounters the dense brush. In this celestial case, thick clouds of hydrogen gas and dust have survived longer than their surroundings in the face of a blast of ultraviolet light from the hot, young stars.




Credit: NASA, ESA, The Hubble Heritage Team (STScI/AURA), J. Bell (Cornell University) and M. Wolff (Space Science Institute); Full press release
NASA's Hubble Space Telescope snapped this picture of Mars on October 28, within a day of its closest approach to Earth on the night of October 29. Hubble astronomers were also excited to have captured a regional dust storm on Mars that has been growing and evolving over the past few weeks.




Credit: NASA, ESA, J. Hester and A. Loll (Arizona State University)
Full press release

This is a mosaic image, one of the largest ever taken by NASA's Hubble Space Telescope of the Crab Nebula, a six-light-year-wide expanding remnant of a star's supernova explosion. Japanese and Chinese astronomers recorded this violent event nearly 1,000 years ago in 1054, as did, almost certainly, Native Americans.

The orange filaments are the tattered remains of the star and consist mostly of hydrogen. The rapidly spinning neutron star embedded in the center of the nebula is the dynamo powering the nebula's eerie interior bluish glow. The blue light comes from electrons whirling at nearly the speed of light around magnetic field lines from the neutron star. The neutron star, like a lighthouse, ejects twin beams of radiation that appear to pulse 30 times a second due to the neutron star's rotation. A neutron star is the crushed ultra-dense core of the exploded star.

Visit the Hubble Heritage Gallery and HubbleSite for a great deal more.

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2 Comments:

Blogger peter said...

The Eagle Nebula what an astonishing pic. SOmeone must have been very cheerful when that one came back from the developers. I have an aunt who would soon get rid of that column of dust, along with sarcastic comments about whoever let 57 trillion miles of it buld up in the first place being a dirty trollop. The Crab Nebula could be a micrograph of a cell: and as for the Dover decision...reeeeeeeeeeeesult!

4:47 AM CST  
Blogger Wolverine said...

Booyah! :-D

9:46 AM CST  

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