Rings Gored, Blue "Eye,"and More

Arrows nestled among the fiery reds and oranges of dunes on Saturn's moon Titan depict the sand formations' movements in this image released by NASA's Jet Propulsion Laboratory.

NASA researchers used radar data gathered by the Cassini orbiter over four years to determine the dunes' paths.

The desert-like sand around the moon's midsection is thought to originate from organic haze particles falling from the sky, rather than from rock erosion as on Earth.

The results of the NASA research roughly match previous predictions made by climate models, suggesting that the new data from this study of Titan's sand could someday help scientists better predict the climate of Earth.


Spotted by the Chandra X-ray Observatory, the 200-million-year-old star J0108, seen here in an artist's depiction, is considered the oldest isolated pulsar ever observed using x-ray detection.

Particles spiraling around the star's magnetic fields and heated areas at its magnetic poles are thought to be responsible for the few x-ray emissions still emanating from the pulsar's cooling surface.

Most other pulsars of great age do not convert their dwindling energy into x-rays as well as J0108, which helps explain why it's more than ten times older than the next-oldest pulsar detected by x-ray.


Like a giant blue eye, the Helix planetary nebula gazes from a mere 700 light-years away out of the constellation Aquarius. The giant object spans two light-years--half the distance between our sun and the nearest star.

A planetary nebula is the spectacular last gasp of a sunlike star before it becomes a white dwarf.

The Wide Field Imager at the European Southern Observatory's La Silla Paranal facility in Chile also captured many "cometary knots." These puzzling bodies are the dots appearing around the inside of the ring. Though they've been the objects of much study, the knots are still a mystery to astronomers. What they're not is small--each is about as large as our solar system.

Also visible through Helix's luminous gases is the faint glow of other galaxies.


In an image released Tuesday, the Hubble Space Telescope has spied a trio of galaxies undergoing a cosmic power struggle that could result in a massive intergalactic merger.

Collectively known as the Hickson Compact Group 90, the interacting galaxies are a hundred million light-years away in the constellation Piscis Austrinus. Two of the galaxies are smooth ellipses, but the one in between is a mangled spiral galaxy that's being ripped apart and likely absorbed by its neighbors.

Gravitational forces from this hostile takeover have dragged large groups of stars outside their home galaxies, creating a tenuous band that astronomers believe will ultimately become a separate megastructure tens to hundreds of times as massive as the Milky Way.



Saturn's delicate F ring is rippled by the planet's moon Prometheus periodically "goring" the strands of the ring.

Both Prometheus and the smaller moon Pandora tend to have run-ins with the F ring. (View a video of a collision between Prometheus and the ring.)

Acquired from 620,000 miles (one million kilometers) away by the Cassini spacecraft's visible light camera, the picture also shows a star shining through the ring.