CASSINI MISSION UPDATE
14 August 2008
In a feat of interplanetary sharpshooting, NASA’s Cassini spacecraft has pinpointed precisely where the icy jets erupt from the surface of Saturn’s geologically active moon Enceladus.
New carefully targeted pictures reveal exquisite details in the prominent south polar “tiger stripe” fractures from which the jets emanate. The images show the fractures are about 300 meters (980 feet) deep, with V-shaped inner walls. The outer flanks of some of the fractures show extensive deposits of fine material. Finely fractured terrain littered with blocks of ice tens of meters in size and larger (the size of small houses) surround the fractures.
“This is the mother lode for us,” said Carolyn Porco, Cassini imaging team leader at the Space Science Institute, Boulder, Colo. “A place that may ultimately reveal just exactly what kind of environment — habitable or not — we have within this tortured little moon.”
Continue reading ‘Cassini Pinpoints Source of Jets on Saturn’s Moon Enceladus’
NASA PRESS RELEASE
30 July 2008
NASA scientists have concluded that at least one of the large lakes observed on Saturn’s moon Titan contains liquid hydrocarbons, and have positively identified the presence of ethane. This makes Titan the only body in our solar system beyond Earth known to have liquid on its surface.
Scientists made the discovery using data from an instrument aboard the Cassini spacecraft. The instrument identified chemically different materials based on the way they absorb and reflect infrared light. Before Cassini, scientists thought Titan would have global oceans of methane, ethane and other light hydrocarbons. More than 40 close flybys of Titan by Cassini show no such global oceans exist, but hundreds of dark lake-like features are present. Until now, it was not known whether these features were liquid or simply dark, solid material.
“This is the first observation that really pins down that Titan has a surface lake filled with liquid,” said Bob Brown of the University of Arizona, Tucson. Brown is the team leader of Cassini’s visual and mapping instrument. The results will be published in the July 31 issue of the journal Nature.
Continue reading ‘Water Water Everywhere (Even on Titan)’
NASA MISSION UPDATE
PASADENA, Calif.—NASA’s Cassini mission is closing one chapter of its journey at Saturn and embarking on a new one with a two-year mission that will address new questions and bring it closer to two of its most intriguing targets—Titan and Enceladus.
On June 30, Cassini completes its four-year prime mission and begins its extended mission, which was approved in April of this year.
Among other things, Cassini revealed the Earth-like world of Saturn’s moon Titan and showed the potential habitability of another moon, Enceladus. These two worlds are primary targets in the two-year extended mission, dubbed the Cassini Equinox Mission. This time period also will allow for monitoring seasonal effects on Titan and Saturn, exploring new places within Saturn’s magnetosphere, and observing the unique ring geometry of the Saturn equinox in August of 2009 when sunlight will pass directly through the plane of the rings.
“We’ve had a wonderful mission and a very eventful one in terms of the scientific discoveries we’ve made, and yet an uneventful one when it comes to the spacecraft behaving so well,” said Bob Mitchell, Cassini program manager at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “We are incredibly proud to have completed all of the objectives we set out to accomplish when we launched. We answered old questions and raised quite a few new ones and so our journey continues.”
Continue reading ‘Cassini Begins Teen Years With Brand New Mission, Bitchin’ Attitude’
NASA PRESS RELEASE
Four students have won the Cassini Scientist for a Day contest, with most choosing Rhea, Saturn’s second-largest moon, as the best place for scientists to study using NASA’s Cassini spacecraft.
Contest participants had to choose one of three target areas for Cassini’s camera: Saturn’s moon Enceladus, Rhea, or a section of Saturn’s rings that includes the tiny moon Pan. The students had to write an essay explaining why their chosen snapshot would yield the most scientific rewards, and the winners were invited to discuss their essays with Cassini scientists via teleconference.
The essays were judged by a panel of Cassini scientists, mission planners, and the education and outreach team at NASA’s Jet Propulsion Laboratory, Pasadena, Calif.
This year’s winners are located in Pennsylvania, Massachusetts and Michigan. Their essays were chosen from 197 essays written by fifth-to-twelfth-grade students across the United States.
Continue reading ‘Students to Become Cassini Scientists, Study Saturn’s Moon Rhea’
A Flagship class Titan explorer balloon. Credit: Jet Propulsion Laboratory
Space.com’s Leonard David reports that NASA and ESA planetary scientists are working out the details on possible flagship-class missions to Jupiter and Saturn that include landers, balloons and a mini-submarine.
“We have the outer planet flagship mission in the [NASA] budget … I do believe it will happen,” said Dr. Fran Bagenal, who heads up the chair of the Outer Planets Assessment Group (OPAG). “I couldn’t have said that four years ago … now I have great confidence that this will happen.”
One mission under review involves two orbiters to study Jupiter and its frozen moon Europa, which scientists believe possesses a subsurface ocean. Russia has proposed a Europa lander for the flight.
The Saturn mission would involve a main spacecraft that would orbit the gas giant and a smaller one to explore its satellite Titan. The Titan vehicle could deploy an atmospheric balloon, surface probes, or a mini-submarine to explore the moon’s methane lakes.
NASA PRESS RELEASE
PASADENA, Calif. – NASA is extending the international Cassini-Huygens mission by two years. The historic spacecraft’s stunning discoveries and images have revolutionized our knowledge of Saturn and its moons.
Cassini’s mission originally had been scheduled to end in July 2008. The newly-announced two-year extension will include 60 additional orbits of Saturn and more flybys of its exotic moons. These will include 26 flybys of Titan, seven of Enceladus, and one each of Dione, Rhea and Helene. The extension also includes studies of Saturn’s rings, its complex magnetosphere, and the planet itself.
“This extension is not only exciting for the science community, but for the world to continue to share in unlocking Saturn’s secrets,” said Jim Green, director, Planetary Science Division, NASA Headquarters, Washington. “New discoveries are the hallmarks of its success, along with the breathtaking images beamed back to Earth that are simply mesmerizing.”
“The spacecraft is performing exceptionally well and the team is highly motivated, so we’re excited at the prospect of another two years,” said Bob Mitchell, Cassini program manager at NASA’s Jet Propulsion Laboratory in Pasadena, Calif.
Continue reading ‘Two More Years! Two More Years! NASA Extends Cassini-Huygens to 2010′
NASA is offering U.S. schoolchildren a chance to control the Cassini spacecraft. The space agency is holding a contest for students in grades 5-12 to decide what part of Saturn the spacecraft will explore for nearly an hour on June 10. Cassini’s Science Planning Team has developed a list of three possible targets.
“You are to weigh all the factors, and after choosing one of the three targets, explain the reasons for your choice in a 500-word essay,” the contest’s website states. “Your decision should be based on which image would yield the most scientific results. Just like actual scientists do, you are to explain what you hope to learn from the image you have selected. The artistic value of the image can be an added bonus to your decision.”
Students can work alone or in groups of up to four. The deadline for submission is May 8 at 3 p.m. Eastern Daylight Time.
NASA Administrator Mike Griffin recently announced that the agency would cut back somewhat on Mars exploration so it can focus the outer planets. The space agency hopes to launch a “flagship” mission to either Jupiter or Saturn while at the same time funding a Mars sample return mission at the end of the next decade.
The big question is: Can NASA afford it all? Taylor Dinerman explores this question in an essay in this week’s edition of The Space Review.
Heat radiating from the entire length of 150 kilometer (95 mile)-long fractures is seen in this best-yet heat map of the active south polar region of Saturn’s ice moon Enceladus. Image credit: NASA/JPL/Space Science Institute
NASA PRESS RELEASE
PASADENA, Calif. — NASA’s Cassini spacecraft tasted and sampled a surprising organic brew erupting in geyser-like fashion from Saturn’s moon Enceladus during a close flyby on March 12. Scientists are amazed that this tiny moon is so active, “hot” and brimming with water vapor and organic chemicals.
New heat maps of the surface show higher temperatures than previously known in the south polar region, with hot tracks running the length of giant fissures. Additionally, scientists say the organics “taste and smell” like some of those found in a comet. The jets themselves harmlessly peppered Cassini, exerting measurable torque on the spacecraft, and providing an indirect measure of the plume density.
“A completely unexpected surprise is that the chemistry of Enceladus, what’s coming out from inside, resembles that of a comet,” said Hunter Waite, principal investigator for the Cassini Ion and Neutral Mass Spectrometer at the Southwest Research Institute in San Antonio. “To have primordial material coming out from inside a Saturn moon raises many questions on the formation of the Saturn system.”
Continue reading ‘Cassini Samples Organic Material at Saturn’s Geyser Moon’
After years of brilliant success studying the Red Planet, scientists and engineers working on NASA’s Mars exploration are getting their just desserts: deep cutbacks in their programs for the next four years.
NASA Administrator Mike Griffin announced last week that he was refocusing the agency’s exploration budget on the outer planets. RedOrbit.com reports that NASA is requesting around $343 million annually for Mars exploration for 2009-12, just over half the $620 million it had estimated just a year ago.
Griffin said the change was spurred by a recent National Research Council report which gave the agency an “A” for its Mars work and a “D” for its exploration of the outer worlds.
“After Mars Science Lab - the current planetary sciences flagship - we are now planning in earnest for an outer planets flagship to Europa, Titan or Ganymede,” Griffin told attendees at the Lunar and Planetary Science Conference in Houston last week.
Continue reading ‘Mars Program Gets an “A”; NASA Slashes Funding’