Wallpaper: Cassini’s Latest View of Saturn

Image credit: NASA/JPL
Four months before its scheduled arrival at Saturn, the Cassini- Huygens spacecraft sent its best color postcard back to Earth of the ringed world. The spacecraft is expected to send weekly postcards, as it gets closer to the ringed giant.

The view from Cassini shows Saturn growing larger and more defined as the spacecraft nears a July 1, 2004, arrival date. On February 9, Cassini’s narrow angle camera, one of two cameras onboard the spacecraft, took a series of exposures through different filters, which were combined to form the color image released today.

“We very much want everyone to enjoy Cassini’s tour of this magnificent planetary system,” said Dr. Carolyn Porco, leader of the Cassini imaging science team at the Space Science Institute in Boulder, Colo. “And I can say right now the views out the window will be stunning.”

Cassini was 69.4 million kilometers (43.2 million miles) from Saturn when the images were taken. The smallest features visible in the image are approximately 540 kilometers (336 miles) across. Finer details in the rings and atmosphere than previously seen are beginning to emerge and will grow in sharpness and clarity over the coming months. The thickness of the middle B ring of Saturn, and the comparative translucence of the outer A ring, when seen against the planet, as well as subtle color differences in the finely-banded Saturn atmosphere, are more apparent.

“I feel like a kid on a road trip at the beginning of our tour,” said Dr. Dennis Matson, project scientist for the Cassini-Huygens mission to Saturn and its largest moon Titan. “We’ve been driving this car for nearly 3.5 billion kilometers (2.2 billion miles) and it’s time to get off and explore this ringed world and its many moons. I can hardly wait, but in the meantime, these weekly color images offer a glimpse of our final destination.”

In the coming months, imaging highlights will include near daily, multi-wavelength imaging of Saturn and its rings; imaging of Titan beginning in April; Titan movie sequences starting in late May, when the resolution exceeds that obtainable from Earth; and a flyby of Saturn’s distant moon, Phoebe, in June, at a spacecraft altitude of 2,000 kilometers (1,243 miles).

Through Cassini, about 260 scientists from 17 countries hope to gain a better understanding of Saturn, its famous rings, its magnetosphere, Titan, and its other icy moons. “Cassini is probably the most ambitious exploration mission ever launched and is the fruit of an active international collaboration,” said Dr. Andre Brahic, imaging team member and professor at Universit? Paris 7-Denis Diderot, France. “It should be the prelude of our future, the exploration of our surroundings by humanity.”

Cassini will begin a four-year prime mission in orbit around Saturn when it arrives July 1. It will release its piggybacked Huygens probe about six months later for descent through Titan’s thick atmosphere. The probe could impact in what may be a liquid methane ocean.

JPL, a division of the California Institute of Technology in Pasadena, manages the mission for NASA’s Office of Space Science, Washington. The Space Science Institute is a non-profit organization of scientists and educators engaged in research in astrophysics, planetary science, Earth sciences, and in integrating research with education and public outreach. Cassini- Huygens is a cooperative mission of NASA, the European Space Agency and the Italian Space Agency.

For the first image and other weekly images on the Internet each Friday, visit:

http://www.nasa.gov/

http://saturn.jpl.nasa.gov

http://ciclops.org/

For information about Cassini-Huygens on the Internet, visit:

http://saturn.jpl.nasa.gov/

Original Source: NASA/JPL News Release

Wallpaper: Spitzer’s Valentine Rose

Image credit: NASA/JPL
Out of the dark and dusty cosmos comes an unusual valentine ? a stellar nursery resembling a shimmering pink rosebud. This cluster of newborn stars, called a reflection nebula, was captured by state-of-the-art infrared detectors onboard NASA’s new Spitzer Space Telescope, formerly known as the Space Infrared Telescope Facility.

The Valentine’s Day image is available online at http://www.spitzer.caltech.edu and http://photojournal.jpl.nasa.gov/catalog/PIA05266.

“The picture is more than just pretty,” said Dr. Thomas Megeath, principal investigator for the latest observations and an astronomer at the Harvard Smithsonian Center for Astrophysics, Cambridge, Mass. “It helps us understand how stars form in the crowded environments of stellar nurseries.”

Located 3,330 light-years away in the constellation Cepheus and spanning 10 light-years across, the rosebud-shaped nebula, numbered NGC 7129, is home to some 130 young stars. Our own Sun is believed to have grown up in a similar family setting.

Previous images of NGC 7129 taken by visible telescopes show a smattering of hazy stars spotted against a luminescent cloud. Spitzer, by sensing the infrared radiation or heat of the cluster, produces a much more detailed snapshot. Highlighted in false colors are the hot dust particles and gases, respectively, which form a nest around the stars. The pink rosebud contains adolescent stars that blew away blankets of hot dust, while the green stem holds newborn stars whose jets torched surrounding gases.

Outside of the primary nebula, younger proto-stars can also be seen for the first time. “We can now see a few stars beyond the nebula that were previously hidden in the dark cloud,” said Megeath.

In addition, the findings go beyond what can be seen in the image. By analyzing the amount and type of infrared light emitted by nearly every star in the cluster, scientists were able to determine which ones support the swirling rings of debris, called circumstellar discs, which eventually coalesce to form planets. Roughly half of the stars observed were found to harbor discs.

These observations will ultimately help astronomers determine how stellar nurseries shape the development of planetary systems similar to our own.

Launched on August 25, 2003, from Cape Canaveral Air Force Station, Florida, the Spitzer Space Telescope is the fourth of NASA?s Great Observatories, a program that also includes the Compton Gamma Ray Observatory, Chandra X-ray Observatory and Hubble Space Telescope.

JPL manages the Spitzer Space Telescope mission for NASA’s Office of Space Science, Washington, D.C. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. JPL is a division of Caltech.

Additional information about the Spitzer Space Telescope is available at http://www.spitzer.caltech.edu.

Original Source: NASA/JPL News Release

Wallpaper: Olympus Mons

Image credit: ESA
View from overhead of the complex caldera (summit crater) at the summit of Olympus Mons on Mars, the highest volcano in our Solar System.

Olympus Mons has an average elevation of 22 km and the caldera has a depth of about 3 km. This is the first high-resolution colour image of the complete caldera of Olympus Mons.

The image was taken from a height of 273 km during orbit 37 by the High Resolution Stereo Camera (HRSC) on ESA?s Mars Express on 21 January 2004. The view is centred at 18.3?N and 227?E. The image is about 102 km across with a resolution of 12 m per pixel. South is at the top.

This complementary 3D view shows the Olympus Mons volcano in its entirety, to put the caldera images in context. It has been derived from the Mars Orbiter Laser Altimeter (MOLA) topographic data superimposed with the Mars Orbiter Camera (MOC) wide-angle image

Original Source: ESA News Release

Wallpaper: Hubble’s View of M64

Image credit: Hubble
A collision of two galaxies has left a merged star system with an unusual appearance as well as bizarre internal motions. Messier 64 (M64) has a spectacular dark band of absorbing dust in front of the galaxy’s bright nucleus, giving rise to its nicknames of the “Black Eye” or “Evil Eye” galaxy.

Fine details of the dark band are revealed in this image of the central portion of M64 obtained with the Hubble Space Telescope. M64 is well known among amateur astronomers because of its appearance in small telescopes. It was first cataloged in the 18th century by the French astronomer Messier. Located in the northern constellation Coma Berenices, M64 resides roughly 17 million light-years from Earth.

At first glance, M64 appears to be a fairly normal pinwheel-shaped spiral galaxy. As in the majority of galaxies, all of the stars in M64 are rotating in the same direction, clockwise as seen in the Hubble image. However, detailed studies in the 1990’s led to the remarkable discovery that the interstellar gas in the outer regions of M64 rotates in the opposite direction from the gas and stars in the inner regions.

Active formation of new stars is occurring in the shear region where the oppositely rotating gases collide, are compressed, and contract. Particularly noticeable in the image are hot, blue young stars that have just formed, along with pink clouds of glowing hydrogen gas that fluoresce when exposed to ultraviolet light from newly formed stars.

Astronomers believe that the oppositely rotating gas arose when M64 absorbed a satellite galaxy that collided with it, perhaps more than one billion years ago. This small galaxy has now been almost completely destroyed, but signs of the collision persist in the backward motion of gas at the outer edge of M64.

This image of M64 was taken with Hubble’s Wide Field Planetary Camera 2 (WFPC2). The color image is a composite prepared by the Hubble Heritage Team from pictures taken through four different color filters. These filters isolate blue and near-infrared light, along with red light emitted by hydrogen atoms and green light from Str?mgren y.

Original Source: Hubble News Release

Photo Gallery: Mars Express First Image

Here’s a 1024×768 resolution wallpaper of the amazing first photograph of Mars taken by the European Space Agency’s Mars Express spacecraft. The stereoscopic image was taken on January 14, 2004 by Mars Express when it was 275 kilometres above the Valles Marineris – a 1700 km long by 65 km wide canyon that runs across the surface of Mars.

Photo Gallery: Southwest of Spirit’s Landing Site

This image mosaic was taken by the Mars Spirit rover while it was still sitting on its landing platform – the direction is to the southwest of the landing site. The landscape is very flat, scattered with small rocks and occasional shallow depressions; the narrow peak of a hill is visible seven to eight kilometres away. The image was taken using Spirit’s Panoramic Camera.