At the recent AAAS meeting in Boston, I met Amanda Hendrix from NASA’s Cassini Mission. Dr. Hendrix, a planetary scientist, has been with Cassini since 1999, when Cassini flew by Earth’s Moon. “I became involved with the UVIS (the Ultraviolet Imaging Spectrograph) team to analyze the Moon data. The next year, I began working with the Cassini Project team at JPL as part of the Science Planning team, to plan out the science investigations that would happen during each icy satellite flyby.” Now she uses data from UVIS to study the icy moons of Saturn.

Cassini has returned so many stunning results over the last nine years, I thought I’d get the latest from her. Here’s an excerpt of our email interview.

Where is Cassini right now? What is it studying?

Cassini is in a highly inclined portion of its tour of the system, so that its path is ~60° out of the plane of Saturn’s equator. This provides Cassini’s instruments access to wonderful views of the polar regions of Saturn and Titan, and also a unique perspective on the rings system.

After spending the last couple of years in the equatorial plane, it is great to get some beautiful views of the rings, and to understand how they are evolving on the timescales of a few years. High latitude views of the planet and Titan mean that we can observe critical seasonal variations happening in the Saturn atmosphere (such as the development of the giant “serpent” storm) and the Titan atmosphere (such as the formation of the southern hemisphere polar hood) and on the Titan surface (we can watch for changes in the lakes and seas at the southern and northern polar regions).

Looking for and studying seasonal variations is important because it helps us to piece together the clues to understand solar system processes and will ultimately aid in the study of the formation and evolution of the solar system.

Can you highlight some of Cassini’s recent discoveries?

There are several studies being undertaken to understand the variability (if any) of Enceladus’ activity, and its ice grain and water vapor output, with orbital location. Some models have shown that the gravitational stresses vary, depending on where Enceladus is in its orbit, and this might affect the plume output. So those studies are ongoing and interesting.

On another topic, Cassini images have been used to show that Titan “glows” from deep in its atmosphere, as seen while Titan was in Saturn’s shadow. The likely cause is deeply-penetrating particles (such as cosmic rays) that excite the atmospheric gases. Another discovery is that there could be icebergs—of hydrocarbon ice—floating on the lakes of Titan. This comes from the radar images of the lakes along with calculations that if some amount of Titan atmosphere is contained within the methane ice, it will float rather than sink.

What’s next for Cassini? 

Cassini will remain in the inclined phase of orbits until around February 2015 (it recently passed the peak in inclination and is now heading back down), then it will execute orbits roughly in the equatorial plane (for about a year), and this is when we will have two Dione and three Enceladus flybys. The final close flyby of the moon Rhea took place Saturday, March 9, 2013. We have numerous upcoming Titan flybys to study this intriguing moon and track its seasonal variations.

How much longer will Cassini be operational?

The plan is for Cassini to remain in operation, in orbit at Saturn, until September of 2017. An exciting end-of-mission is being planned, whereby Cassini orbits closer and closer to Saturn, with its orbital periapse (closest point to Saturn in the orbit) between the top of the atmosphere and the inner edge of the D-ring (the innermost ring), at high inclination. Such close passes will tremendously help the instruments on Cassini to measure the internal structure and magnetic field of Saturn, and will allow for a careful measurement of the mass of the rings—which is important in ultimately understanding their age and source! Finally, Saturn’s gravity will capture Cassini and the mission will be over.

What are some of your favorite findings?

The discovery of activity at Enceladus is one of my favorites! That such a small moon puts out so much material, with great effect on the rest of the system, is really astonishing and wonderful. This discovery was great because it was such a multi-instrument discovery and really highlights the utility of synergistic investigations on a mission.

Another one of my favorites is the discovery of liquid lakes on Titan—the only body in the solar system other than Earth with liquid on the surface! The landing of the Huygens probe on the surface of Titan was a really exciting time. Another of my favorite findings was the up-close views of bizarre Iapetus that we obtained during our close flybys with that moon.

Why do the data and images Cassini provides move people so much?

Cassini is such a great mission because the payload includes a complementary instrument suite that allows us to probe nearly every aspect of the Saturn system. The datasets are stunning and moving partly because the Saturn system is very beautiful. The intricate detail revealed in the images is wonderfully mind-boggling!

Recent Cassini image (with Venus hiding in Saturn’s rings): NASA/JPL-Caltech/Space Science Institute

By Zuberoa Marcos

Humanity has landed several rovers on Mars. The next scientific challenge is to land a boat on Titan.

Titan, Saturn’s largest moon, is one of the most interesting destinations in the Solar System for scientists looking for extraterrestrial life. Discovered on March 25, 1655 by the Dutch astronomer Christian Huygens, Titan has the most Earth-like atmosphere. Just as on Earth, it is composed primarily of nitrogen (95%), methane (approximately 3%), and the remaining 2% percent consists of hydrogen, little vapor water, other hydrocarbons and possibly argon. These atmospheric gases are some of the necessary building blocks for life.

In 2005, the Cassini-Huygens mission studied extensively Titan descending via parachute onto its mysterious surface. It confirmed that lakes, seas and rivers exist and cover much of the satellite’s northern hemisphere. However, the chemical composition of the lakes of Titan is still not well determined.

The Titan Lake In-situ Sampling Propelled Explorer (TALISE) project proposes sending a boat-probe to Saturn’s largest moon that could be propelled by paddles, inflatable wheels or screws. The probe would land in the middle of Ligeia Mare—Titan’s biggest lake and then sail for the coast, taking scientific measurements along the way.

“The detection of additional compounds and the investigation of the influence of both photochemistry and the atmosphere on the chemical composition of liquids of Titan’s lakes it is the next step to understand the satellite’s environment, its relationship with the climate and to analyze the possibility of prebiotic compounds” explained the scientists in the abstract of the project presented in the European Planetary Sciences Congress held in Madrid, Spain last month.

The TALISE project is currently being developed in Spain by SENER, an engineering company, and the Centro de Astrobiología, a research center associated with NASA’s Astrobiology Institute. The hovercraft design is still under consideration but they hope to be ready for a future space science mission call for proposals.

Zuberoa Marcos is a former biologist and current science writer based in Barcelona. She writes articles regularly for Science Today.

Surcando los mares de Titán

Por Zuberoa Marcos

La Humanidad ha posado varios rovers sobre la superficie de Marte. El próximo reto científico es que un barco se pose en Titán.

Titán, la luna más grande de Saturno, es uno de los destinos más interesantes del Sistema Solar para los científicos que buscan vida extraterrestre. Descubierto el 25 de marzo 1655 por el astrónomo holandés Christian Huygens, Titán tiene la atmósfera más parecida a la de la Tierra. Al igual que la de nuestro planeta, se compone principalmente de nitrógeno (95%), aproximadamente el 3% es metano y el 2% restante una mezcla de hidrógeno, vapor de agua, otros hidrocarburos y posiblemente argón. Todo estos gases atmosféricos son ladrillos necesarios para construir vida.

En 2005, la misión Cassini-Huygens estudió minuciosamente Titan al descender en paracaídas y posarse en su superficie. Confirmó que un conjunto de lagos, mares y ríos cubren gran parte del hemisferio norte del satélite. Sin embargo, la composición química de los lagos de Titán sigue siendo desconocida.

El proyecto Explorador in situ de los lagos de Titán (TALISE por sus siglás en inglés) propone enviar un barco-sonda propulsado por paletas o ruedas inflables a la luna más grande de Saturno. La sonda aterrizaría en medio del Ligeia Mare, el lago más grande de Titán, y después navegaría por la costa realizando mediciones científicas a lo largo del camino.

“La detección de compuestos químicos adicionales y el estudio de la influencia de la fotoquímica y de la atmósfera en la composición química de los líquidos que forman los lagos de Titán es el siguiente paso para comprender el medioambiente del satélite, su clima y analizar la posible existencia de compuestos prebióticos”, explicaron los científicos en el resumen del proyecto presentado en el Congreso Europeo de Ciencias Planetarias celebrado en Madrid, España, el pasado mes de septiembre.

El proyecto TALISE está siendo desarrollado por la empresa española de ingeniería SENER y el Centro de Astrobiología, un centro de investigación asociado al Instituto de Astrobiología de la NASA y ubicado en las afueras de Madrid. El diseño del barco está aún en estudio, pero los científicos confían en tenerlo listo para la próxima convocatoria de propuestas para futuras misiones espaciales.

Zuberoa Marcos es bióloga molecular y actualmente trabaja como productora de TV y periodista científica. Escribe de forma regular para Science Today.

The scientists used data from NASA’s Cassini, Galileo and New Horizons missions (dating from 1996 to 2009) to search the ring systems of Jupiter and Saturn for patterns of cometary disruptions.

In the case of Jupiter, the ripple-producing culprit was the well-known comet Shoemaker-Levy 9, whose debris cloud hurtled through the thin Jupiter ring system during a kamikaze course into the planet in July 1994. Scientists attribute Saturn’s ripples to a similar object—likely another cloud of comet debris—plunging through the inner rings in the second half of 1983. The researchers believe this comet passed through when Saturn was on the other side of the Sun from Earth.

“We now know that collisions into the rings are very common—a few times per decade for Jupiter and a few times per century for Saturn,” said Mark Showalter of SETI and lead author of the paper on Jupiter. “Now scientists know that the rings record these impacts like grooves in a vinyl record, and we can play back their history later.”

The tightness of the rings’ “grooves” gives clues to when the comet debris came hurling through, according to Nature News:

As time passed, this tilt has become a progressively tighter spiral, meaning that the shorter the ripple’s wavelength, the longer ago it was formed.

(Discover has a great NASA video of the rings becoming tighter with age on their site.)

The ripples also give scientists a measurement of the size of the clouds of cometary debris that hit the rings. In each of these cases, the nuclei of the comets were a few kilometers wide before they likely broke apart.

“Finding these fingerprints still in the rings is amazing and helps us better understand impact processes in our solar system,” said Linda Spilker, Cassini project scientist, based at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “Cassini’s long sojourn around Saturn has helped us tease out subtle clues that tell us about the history of our origins.”

“What’s cool is we’re finding evidence that a planet’s rings can be affected by specific, traceable events that happened in the last 30 years, rather than a hundred million years ago,” said Matthew Hedman, of Cornell and lead author of the Saturn paper. “The solar system is a much more dynamic place than we gave it credit for.”

Image credit: NASA/JPL-Caltech/SETI

Earth

The Gulf oil spill—the number of gallons spilled and the controversy surrounding the damage seems to top many lists this year. Nature even named Jane Lubchenco, head of NOAA, its newsmaker of the year for how she handled the crisis.

Natural disasters often took the front page in 2010 with the Haitian earthquake and the eruption of Eyjafjallajökull topping many lists. The hard-to-pronounce Icelandic volcano also made many of the best science images of the year lists.

DiscoveryNews ends the year on a positive note with “How Humans Helped the Earth in 2010,” a slide show with text concerning recent strides in alternative energy, species and habitat conservation efforts and individual efforts to go green (electric cars, white roofs and saving energy).

For more environmental news of the year, New Scientist’s Short Sharp Science has a great review and the Nature Conservancy has a best/worst list on its site.

Life

Teeny, modified life stole the spotlight this year—the J. Craig Venter Institute’s so-called “synthetic cell” and GFAJ-1—the bacteria that incorporates arsenic into its DNA—or so NASA scientists claimed.  Science writer Carl Zimmer discredited the arsenic bacteria paper on Slate; NASA author Felisa Wolfe-Simon defended herself in Science. Fun stuff!

The spread of pesky bedbugs was number six in Discover’s “Top 100 Science Stories of 2010.”

Nature’s great article this past summer on eradicating mosquitoes was among its readers’ top choices of the year.

Looking for something a little bigger and less controversial? New Scientist has “The coolest animals of 2010,” which includes a scorpion-eating bat and a fly thought to be extinct for over 160 years!

NPR found it was a very good year for Neanderthals—their genome was sequenced, brain examined and diet expanded.

Remarkably, the Census of Marine Life tops the BP oil spill in the Deep Type Flow blog’s biggest marine science stories of the year for its sheer numbers:

…over 500 research expeditions covering every ocean, over 2,500 scientists and the discovery of over 6,000 species new to science and published in over 2600 peer-reviewed papers.

Space

ScienceNow’s most popular story of all time, not just 2010, was “Does Our Universe Live Inside a Wormhole?” A wonderful theory that we also covered last spring.

Exoplanets, in part thanks to the Kepler mission, were all over the news this year—whether it had to do with size, atmosphere or number within a star system. Discover’s interview with local exoplanet hunter (and California Academy of Sciences Fellow) Geoff Marcy made number 11(!) on their 100 top stories list.

A little closer to home, Jupiter’s missing stripe and Neptune’s tale of cannibalism are included in New Scientist’s most popular space stories of 2010.

Our Moon and Saturn’s moons made news throughout the year and the top lists on Universe Today and Wired this week.

Universe Today also included SDO’s new views of the sun in their top stories list. Stunning!

Hubble celebrated its 20^th year in space this year by taking even more beautiful images. Several are included in Bad Astronomy’s “Top 14 Astronomy Pictures of 2010.”

Technology

Electric cars and NASA’s new foray into commercial spacecraft are included in Scientific American’s top ten stories of the year.

The Large Hadron Collider was very busy this year, and topped many lists. Another machine at CERN made news (and also topped Nature’s readers’ choice list) when it was able to capture antimatter for a sixth of a second!

Graphene not only garnered a Nobel Prize this year, the material (and it’s potential) also made news and top science lists of the year.

DiscoveryNews put plastics on their 2010 list—whether its finding new ways of removing plastic from the oceans or engineering smarter plastics.

What was your favorite science story of the year? Share with us by adding it to the comment section below!

Image by Les Stone, International Bird Rescue Research Center/Wikipedia

Saturn’s moons got all sorts of attention. From Enceladus’ warm “Perrier” ocean to the potential for life on Titan, one of the best-known planets in our Solar System enjoyed particular popularity this week.

In the lab, researchers were able to create the building blocks of life in Titan’s atmosphere. From SPACE.com:

In the lab, researchers simulated possible chemical reactions occurring high up in the nitrogen-rich atmosphere of Titan. They found that various complex molecules, such as amino acids and nucleotide bases, could form without much prodding.

Also in the news this week, the idea that perhaps it was the death of a large, early moon around Saturn that formed its lovely rings. From Universe Today:

[Robin] Canup’s new alternative theory is that Titan-sized moon with a rocky core and an icy mantle spiraled into Saturn early in solar system history. Tidal forces ripped off part of the icy mantle, distributing it into what would become the rings.

The Academy’s own Jack Dumbacher made news this week with research on the family tree of extinct passenger pigeons. DNA extracted from century-old museum specimens reveals that the spectacular passenger pigeon was most closely related to other North and South American pigeons, and not to the Mourning Dove, as was previously suspected. You can read more in the abstract, published in this month’s Molecular Phylogenetics and Evolution.

Now for three news items about beer and flirtation…

Italian researchers recently published a protein library of beer, and according to the Discoblog in Discover:

…better knowledge of the proteins that survive brewing could help improve flavor, aroma, and retention of the foamy head so prized by beer drinkers.

Cheers!

And how about Beers in Space? Popular Science had a story this week about a non-profit space research company that is “about to test an Australian beer that’s brewed and bottled especially for consumption in microgravity.” Apparently, due to numbed taste buds and carbonation, regular beer just won’t do.

Finally, our science-geek neighbors at UCSF posted a very funny, must-see YouTube video late last week, “Most Beautiful Girl in the Lab.”

What turned you on in science news this week? Let us know!

As if Saturn wasn’t already considered drop-dead gorgeous. And as if Cassini wasn’t already the luckiest satellite in the skies. Using Cassini’s visual and infrared mapping spectrometer instrument (VIMS), scientists gathered data to create beautiful images and even a video of auroras on the ringed planet. Released just today, these are truly a must see!

Also published today, in the journal Science, independent researchers have calculated the vastness of the BP oil spill by viewing videos of the underwater oil gushing. From Science News:

Crone and Tolstoy used an optical technique known as flow velocimetry. In this approach, the volume of a roiling plume is estimated by using video or a series of photos to measure the movements of a host of distinguishing features over a short period of time. Computers can then calculate likely flow volumes based on the plume’s size and density.

And their numbers exceed the government estimate by about 300,000 barrels (or 12.6 million gallons) of oil.

Earlier this week, scientists published a study in the Proceedings of the National Academy of Sciences (PNAS) describing the affect of dust on Colorado’s snowpack. According to Reuters and Yale Environment 360:

Dust created by intensifying human activities in the southwestern United States has caused snow in the Rocky Mountains to melt earlier over the last 150 years and has reduced runoff into the Colorado River basin by about 5 percent, according to a new study.

For a drought-prone area, this makes a potentially bad situation worse.

So, now for a bit of good news. A month ago, we reported on Conservation International’s launch of a worldwide search for 100 species or so of amphibians that were possibly extinct. This week, they announced three of those species were spotted—two in Africa and one in Mexico. You can read more at the 80beats blog on Discover.

Which science news items caught your eye this week? Let us know!