New Venus Images Dazzle With ‘Pancake’ Volcanoes : Space: Magellan spacecraft also reveals mountains and valleys seemingly covered with fool’s gold.

The Magellan spacecraft has sent back dazzling new pictures of the surface of Venus showing mysterious pancake-like volcanoes and mountains and valleys that appear to be covered with gold.

Fool’s gold, that is, not the real stuff. The new images were released one day after the spacecraft broke communications with Earth for the third time, but this time it took only minutes for controllers at the Jet Propulsion Laboratory in Pasadena to regain control. Magellan project manager Anthony Spear said changes in Magellan’s computer software that were radioed to the spacecraft a month ago allowed engineers to resume photographing the surface of Venus within three orbits, compared to several days of lost time after the two earlier incidents.

Engineers and scientists were delighted Friday that controllers had been able to correct the problem so quickly, and they were absolutely enchanted by the images the spacecraft sent back.

Normally, the tortured landscape of Venus--with its volcanoes, craters, mountains and ancient rivers of lava--is hidden from view, but the radar system aboard Magellan pierces through the dense clouds that envelop the planet. The system produces images that look like shots of the Earth from a high-altitude aircraft.

But the scene on Venus is quite different from the blue oceans and green forests seen on Earth.

Photos released by JPL on Friday depict a barren, rugged landscape, pockmarked with huge craters and twisted and torn by dynamic forces that have left the surface of Venus a weathered and foreboding place. Among the most intriguing images is one showing seven pancakes that apparently were formed by a series of oozing volcanic eruptions.

The pancakes measure about 15 miles in diameter and are about 2,500 feet tall, said Magellan project scientist Stephen Saunders. They are startling in their near-perfect symmetry, and they stretch across the Venusian landscape like cookies dropped on a tin plate.

The photo of the pancakes, like the thousands of other images being created at JPL from narrow strips of data collected as Magellan glides around the planet, should help scientists sort out the history of Venus and the dynamic processes that are still reshaping the planet that is most like the Earth.

Saunders said scientists hope to learn something about the consistency of the magma that lies beneath the Venusian surface by studying the tidy string of volcanic pancakes.

Magellan continues to turn up mysteries as well as answers to questions that have troubled scientists for years. For example, some of the images show great fields and mountain slopes that appear to be covered with snow.

“It looks like snow, but we are talking about (a surface temperature) of 700 degrees Fahrenheit, so it certainly isn’t ice,” said Gordon H. Pettengill of the Massachusetts Institute of Technology, principal investigator for radar science.

To investigate this, Pettengill used Magellan’s radar to measure the radiation emitted by the surface of the planet. The “emission,” as it is called, depends mostly on the composition of the surface, and it offers clues to the chemical nature of the material on the ground.

Based on the “emissivity” of the areas that look as though they are covered with snow, Pettengill believes the substance is most likely iron pyrite, also known as fool’s gold.

But that answers one question while posing another.

“We don’t know where it comes from,” if indeed it is iron pyrite, he said. On Earth, the material is associated with volcanic activity, and Venus has plenty of volcanoes, but normally water is also required. Pettengill suggested that the material may form on Venus in the absence of water because of the high temperatures on the planet.

The Magellan images also show what appear to be enormous riverbeds winding through the hills. But these were never rivers like those on Earth. They were once rivers of molten lava, so hot that it burned its way into the surface as it flowed for hundreds of miles, creating scars across a landscape that is void of life.

So far, Magellan has covered more than 18% of the surface of Venus, an area roughly equivalent to all of North and South America.

“We expect to get something like 80% of the planet” in the first phase of the operation, said Spear, the project manager. That is even better than the goal of 70% set before the mission began Sept. 15.

A second phase is to begin May 1, during which Magellan will continue to map the surface of Venus as the planet spins within the spacecraft’s polar orbit. JPL, which manages the Magellan program, is run by Caltech for the National Aeronautics and Space Administration.

Spear said Friday that it is still not known for certain why the spacecraft has severed communications with JPL three times, but the leading candidate is electronic “noise” somewhere in the system.

Every now and then, Spear said, the noise overwhelms the system and “zaps the computer.” At that point, the craft turns its largest antenna away from Earth “and stares at the weeds,” he said.