Excerpt from Nightmare Worlds
The New York Times
Friday, March 10, 2006
Where There's Water
Speculations of Life
Enceladus, Saturn's fourth-largest moon
is only 300 miles wide, but NASA's
Cassini spacecraft has spotted plumes of
ice crystals shooting off the moon near
its south pole. That suggests pockets of
liquid water exist near the surface, and
makes Enceladus a new target in the
search for life in the solar system.
I. Houston, Texas. 2006
"This is astonishing." The laconic head of NASA's space probe project rarely put three words together, yet Brad Woodruff's inspection of the Cassini photos had rattled his icy composure. He now presided over a meeting of NASA scientists, engineers, and astronauts in one of the agency's auditoriums, in order to discuss a tiny moon, Enceladus, first discovered by William Herschel in 1789.
Dr. Diane Grimaldi nodded. One of the top two or three astronauts at NASA, she was also a physician and microbiologist/astrobiologist. "I'm sure there's some kind of life on that moon. Liquid water hasn't been found on any extraterrestrial bodies before. So, if there's life in our solar system, it's got to be there. We have to send a team to Enceladus." She pictured herself first off the lander.
Tom Delaney, NASA's preeminent test pilot and commander of three shuttle missions to the ISS, the International Space Station, was less enthusiastic. "So there's water there. Okay, can't have life without water. But because there's water it doesn't mean there's life. Isn't there evidence of water on Mars?"
"There is," replied Diane. "But if water is present on Mars, it's frozen. So, with warm water on Enceladus, and a neighbor like organic-rich Titan, the Saturnian system seems to be the main target for astrobiology."
The Cassini probe had taken seven years to reach the solar system's second largest gas giant, Saturn, and begin exploration of the planet and its moons. Enceladus was a surprise. Compared to Saturn's major moon, Titan, the second largest moon in the solar system, Enceladus seemed an unlikely place for anything that might interest NASA.
"Hold on," said Delaney. "Enceladus is only three hundred miles wide, just a frozen chunk of ice and rock, a piece of junk caught in Saturn's gravity."
"Before you go way off base, Tom, let's review those Cassini photos again," Diane replied as she strode to the lectern and turned on the projector that flashed multiple photographic projections on the panoramic screens. "These Cassini pictures show eruptions of icy crystals from the south polar terrain of the moon, which suggests that pockets of liquid water are near the surface. It's an environment potentially suitable for living organisms." .
She continued to the next set of pictures. "Here's Cassini flying through plumes of ice crystals rising into space from the eruptions. The probe also detected simple carbon based molecules like methane and carbon dioxide ρρρρ suggesting more complicated carbon molecules on the moon's surface or just below, another potential marker for life. This next photo shows the south polar region of Enceladus free of craters as compared to the pockmarked northern hemisphere. So the heat generated isn't due to repeated meteor impacts. Our planetary scientists think that the warm region near the moon's south pole might have been present for billions of years, plenty of time for life to emerge. You see, Tom, everything points to a biological gold mine on this λ piece of junk.' "
"Gwen, tell us your take on Enceladus," said Woodruff.
Dr. Gwen Armstrong, a planetary geologist and the lead scientist assessing the findings from Enceladus, now shared the lectern with Diane. "The data indicates that pockets of liquid water are just below a huge ice pack, and when the ice ruptures, water shoots out, freezes, and becomes ice crystals, similar to Yellowstone's Old Faithful geyser. I think we're seeing geysers. I've no other explanation." A cacophony of voices followed.
Brad Woodruff held up his hand to quiet the group. "Diane, tell us why you think we need to send an expedition to this chunk of ice."
A tall dark haired woman of thirty-five with lively intelligent brown eyes, Diane had been on three shuttle missions to the ISS, and commanded a fourth. She had the respect of colleagues for her quick mind, depth of knowledge, and dedication to NASA. "As most of you know, our astrobiology unit that's been funding research on extraterrestrial life in the solar system and beyond, is having its budget cut in half unless we act promptly. The administration in Washington plans to cut three billion dollars from space science over the next five years to help pay for the completion of the ISS, and to send a crew to our moon. So it's critical we convince Washington of the need for additional funds to explore Enceladus and find out if life exists there. If so, it answers a question that'll change NASA's priorities and those of all space operations across the globe. We've got to go there quickly to prove that life exists beyond Earth. Think what this will mean for the SETI program."
"But maybe there's no life there. I think we should send a robot probe there first," Woodruff said.
"A robot would be better than nothing. But there are too many ways a robot might not collect the correct specimens. This has to be done by humans," Diane replied.
"I'll speak to the big brass," Woodruff said. "I'll do my best. Okay Gang, back to work."
However, interest in Enceladus was suddenly abandoned, and turned to Mars. The Mars Global Surveyor (MGS) and its Mars Orbital Camera (MOC) had been reimaging thousands of gullies looking for water. But data from the Mars Reconnaissance Orbiter could not confirm earlier MOC findings, and it was concluded after two years that dust avalanches had been responsible for pictures suggesting water.
Attention once again turned to Enceladus in the search for extraterrestrial life. A robot was sent to the little moon in 2007 to confirm that the plumes were indeed water. When it landed in 2014, the Enceladus Global Surveyor confirmed that the plumes were primarily water, with small amounts of carbon dioxide, methane, and nitrogen.
And so, the race to Enceladus began.