Saturn's Hyperion: A Moon With Odd Craters

What lies at the bottom of Hyperion's strange craters? Noone knows. To help find out, Cassini took this image, containing unprecedented detail, as the spacecraft swept past the sponge-textured moon in late 2005.

The image shows a remarkable world strewn with strange craters and odd surfaces. At the bottom of most craters lies some type of unknown dark material. Inspection of the image shows bright features indicating that the dark material might be only tens of meters thick in some places. Hyperion is about 250 kilometers across, rotates chaotically, and has a density so low that it might house a vast system of caverns inside

Big Spherules near Victoria

This frame from the microscopic imager on the Mars Exploration Rover Opportunity shows spherules up to about 5 millimeters (one-fifth of an inch) in diameter. The camera took this image during the 924th Martian day, or sol, of Opportunity's Mars-surface mission (Aug. 30, 2006), when the rover was about 200 meters (650 feet) north of Victoria Crater.

Opportunity discovered spherules like these, nicknamed "blueberries," at its landing site in "Eagle Crater," and investigations determined them to be iron-rich concretions that formed inside deposits soaked with groundwater. However, such concretions were much smaller or absent at the ground surface along much of the rover's trek of more than 5 kilometers (3 miles) southward to Victoria. The big ones showed up again when Opportunity got to the ring, or annulus, of material excavated and thrown outward by the impact that created Victoria Crater. Researchers hypothesize that some layer beneath the surface in Victoria's vicinity was once soaked with water long enough to form the concretions, that the crater-forming impact dispersed some material from that layer, and that Opportunity might encounter that layer in place if the rover drives down into the crater.

Echoes from the Edge

Variable star V838 Monocerotis lies near the edge of the Milky Way Galaxy, about 20,000 light-years from our sun. Still, ever since a sudden outburst was detected in January 2002, this enigmatic star has taken the center of an astronomical stage. As astronomers watch, light from the outburst echoes across pre-existing dust shells around V838 Mon, progressively illuminating ever more distant regions.

This stunning image of swirls of dust surrounding the star was recorded by the Hubble Space Telescope in September 2006. The picture spans about 14 light-years. Astronomers expect the expanding echoes to continue to light up the dusty environs of V838 Mon for at least the rest of the current decade. Researchers now have found that V838 Mon is likely a young binary star, but the cause of its extraordinary outburst remains a mystery.

Saturnian Psychedelia

This psychedelic view of Saturn and its rings is a composite made from images taken with the Cassini spacecraft wide-angle camera using spectral filters sensitive to wavelengths of infrared light. The image was acquired on Dec. 13, 2006 at a distance of approximately 822,000 kilometers (511,000 miles) from Saturn. Image scale is 46 kilometers (28 miles) per pixel.

Cat's Eye Nebula

Three thousand light-years away, the Cat's Eye Nebula, a dying star throws off shells of glowing gas. This image from the Hubble Space Telescope reveals the nebula to be one of the most complex planetary nebulae known. In fact, the features seen in the Cat's Eye are so complex that astronomers suspect the bright central object may actually be a binary star system. The term planetary nebula is misleading; although these objects may appear round and planet-like in small telescopes, high resolution images reveal them to be stars surrounded by cocoons of gas blown off in the late stages of stellar evolution.

NGC 602 and Beyond.

Near the outskirts of the Small Magellanic Cloud, a satellite galaxy some 200 thousand light-years distant, lies the young star cluster NGC 602. Surrounded by natal gas and dust, NGC 602 is featured in this Hubble image of the region. Fantastic ridges and undulating shapes strongly suggest that energetic radiation and shock waves from NGC 602's massive young stars have eroded the dusty material and triggered a progression of star formation moving away from the cluster's center. At the estimated distance of the Small Magellanic Cloud, the picture spans about 200 light-years, but a tantalizing assortment of background galaxies are also visible in the sharp Hubble view. The background galaxies are hundreds of millions of light-years or more beyond NGC 602.

Unfathomable

This scale comparison shows "the true place" of Earth and our Sun among the various giants of the universe. It is simultaneously sobering and mind-boggling experience.
First series of images starts with a Death Star, to further emphasize the futility of vain pride and ambition.

"We simply do not understand our place in the universe
and have not the courage to admit it"
-- Barry Lopez (American writer, b.1945)


"Really, the fundamental, ultimate mystery - the only thing you need to know to understand the deepest metaphysical secrets - is this: that for every outside there is an inside and for every inside there is an outside, and although they are different, they go together."
-- Alan Watts


"The universe is like a safe to which there is a combination.
But the combination is locked up in the safe."
-- Peter De Vries


"If the whole universe has no meaning, we should never have found out that it has no meaning: just as, if there were no light in the universe and therefore no creatures with eyes, we should never know it was dark. Dark would be without meaning."
-- C.S. Lewis


The Universe is a big place populated by stars and thoroughly confused humans.

Black Hole Grabs Starry Snack.

This artist's concept shows a supermassive black hole at the center of a remote galaxy digesting the remnants of a star. NASA's Galaxy Evolution Explorer had a "ringside" seat for this feeding frenzy, using its ultraviolet eyes to study the process from beginning to end.

The artist's concept chronicles the star being ripped apart and swallowed by the cosmic beast over time. First, the intact sun-like star (left) ventures too close to the black hole, and its own self-gravity is overwhelmed by the black hole's gravity. The star then stretches apart (middle yellow blob) and eventually breaks into stellar crumbs, some of which swirl into the black hole (cloudy ring at right). This doomed material heats up and radiates light, including ultraviolet light, before disappearing forever into the black hole. The Galaxy Evolution Explorer was able to watch this process unfold by observing changes in ultraviolet light.

The area around the black hole appears warped because the gravity of the black hole acts like a lens, twisting and distorting light.

Cosmic Epic Unfolds in Infrared

This majestic view, taken by NASA's Spitzer Space Telescope, tells an untold story of life and death in the Eagle Nebula, an industrious star-making factory located 7,000 light-years away in the Serpens Sonstellation. The image shows the region's entire network of turbulent clouds and newborn stars in infrared light.

The color green denotes cooler towers and fields of dust, including the three famous space pillars, dubbed the "Pillars of Creation," which were photographed by NASA's Hubble Space Telescope in 1995 (right of center; see http://www.nasa.gov/mission_pages/spitzer/multimedia/ssc2007-01b.html for exact location).

But it is the color red that speaks of the drama taking place in this region. Red represents hotter dust thought to have been warmed by the explosion of a massive star about 8,000 to 9,000 years ago. Since light from the Eagle Nebula takes 7,000 years to reach us, this supernova explosion would have appeared as an oddly bright star in our skies about 1,000 to 2,000 years ago.

According to astronomers' estimations, the explosion's blast wave would have spread outward and toppled the three pillars about 6,000 years ago (which means we wouldn't witness the destruction for another 1,000 years or so). The blast wave would have crumbled the mighty towers, exposing newborn stars that were buried inside, and triggering the birth of new ones.

STEREO's First View of the Sun.

Loops of highly charged particles burst from the sun's surface in this image, taken on Dec. 4, 2006. Among the first images taken by STEREO, the image shows the sun's roiling surface and atmosphere at temperatures around one million Kelvin (1.8 million degrees Fahrenheit).

The charged particles, mostly extremely hot protons and electrons, create a strong magnetic field that pulls the particles into the loops seen here. Over time, magnetic stress builds in the sun's atmosphere until the energy is released in a massive explosion. The explosion sends a giant cloud of charged particles (a coronal mass ejection) and x-ray solar flares hurtling into space with a force comparable to a billion megaton nuclear bombs. When the charged particles and x-rays bombard the Earth, they can disrupt communications and power systems and are a threat to satellites and astronauts in space.

Understanding the difference between harmful and harmless coronal mass ejections is one of the biggest questions that scientists studying the face of the sun. Currently, scientists only see ejections in one dimension. To understand how solar storms travel through the solar systems, scientists need a three-dimensional view of the storms.

STEREO, launched on Oct. 25, 2006, consists of observation systems orbiting the sun in front of and behind the Earth. Just as our two eyes give us a three-dimensional view of the world, the views provided by each STEREO system can be combined to provide a three-dimensional view of the sun. Though the first STEREO images were taken in early December, the two systems won't be in position to give three dimensional images until April 2007.

Cyclones in Tandem

A cyclone is a low-pressure area of winds that spiral inwards. Although tropical storms most often come to mind, these spiraling storms can also form at mid- and high latitudes. Two such cyclones formed in tandem in November 2006. MODIS, flying onboard NASA's Terra satellite, took this picture on Nov. 20. This image shows the cyclones south of Iceland. Scotland appears in the lower right. The larger and perhaps stronger cyclone appears in the east, close to Scotland.

Cyclones at high and mid-latitudes are actually fairly common, and they drive much of the Earth's weather. In the Northern Hemisphere, cyclones move in a counter-clockwise direction, and both of the spiraling storms in this image curl upwards toward the northeast then the west. The eastern storm is fed by thick clouds from the north that swoop down toward the storm in a giant "V" shape on either side of Iceland. Skies over Iceland are relatively clear, allowing some of the island to show through. South of the storms, more diffuse cloud cover swirls toward the southeast.

White Dwarf Stars

Pushing the limits of its powerful vision, NASA's Hubble Space Telescope uncovered the oldest burned-out stars in our Milky Way Galaxy. These extremely old, dim "clockwork stars" provide a completely independent reading on the age of the universe.

The ancient white dwarf stars, as seen by Hubble, are 12-13 billion years old. Because earlier Hubble observations show that the first stars formed less than 1 billion years after the universe's birth in the big bang, finding the oldest stars puts astronomers well within arm's reach of calculating the absolute age of the universe.

Though previous Hubble research sets the age of the universe at 13-14 billion years based on the rate of expansion of space, the universe's birthday is such a fundamental and profound value that astronomers have long sought other age-dating techniques to cross-check their conclusions.

Globular clusters are the first pioneer settlers of the Milky Way. Many coalesced to build the hub of our galaxy and formed billions of years before the appearance of the Milky Way's magnificent pinwheel disk. Today 150 globular clusters survive in the galactic halo. The globular cluster M4 was selected because it is the nearest to Earth, so the intrinsically feeblest white dwarfs are still apparently bright enough to be picked out by Hubble.

Dazzling Dunes.

As NASA's Mars Exploration Rover Opportunity creeps farther into "Endurance Crater," the dune field on the crater floor appears even more dramatic. This false-color image taken by the rover's panoramic camera shows that the dune crests have accumulated more dust than the flanks of the dunes and the flat surfaces between them. Also evident is a "blue" tint on the flat surfaces as compared to the dune flanks. This results from the presence of the hematite-containing spherules, or "blueberries", that accumulate on the flat surfaces.

Sinuous tendrils of sand less than 1 meter (3.3 feet) high extend from the main dune field toward the rover. Scientists hope to send the rover down to one of these tendrils in an effort to learn more about the characteristics of the dunes. Dunes are a common feature across the surface of Mars, and knowledge gleaned from investigating the Endurance dunes may apply to similar dunes elsewhere.

Before the rover heads down to the dunes, rover drivers must first establish whether the slippery slope that leads to them is firm enough to ensure a successful drive back out of the crater. Otherwise, such hazards might make the dune field a true sand trap.