Carnival of Space 348

The Carnival of Space 348 is up at Aartscope

Meridiani Journal – The sea of Enceladus: Cassini confirms underground ocean on Saturn’s geyser moon

Researchers have discovered a deep saltwater ocean on one of the many small moons that orbit Saturn, leading scientists to conclude it is the most likely place in the solar system for extraterrestrial life to be found.

Gravitational field measurements taken by Nasa’s Cassini space probe revealed that a 10km-deep ocean of water, larger than Lake Superior, lurks beneath the icy surface of Enceladus at the moon’s south pole.

David Stevenson, a planetary scientist at the California Institute of Technology in Pasadena, said the body of water was so large it “may extend halfway or more towards the equator in every direction. It might even extend all the way to the north.”

An artist’s impression of the interior of Saturn’s moon Enceladus, based on data from the Cassini space probe suggesting the moon contains a water ocean beneath its south pole. Illustration: Nasa/JPL-Caltech

Understanding the interior structure of 500 km-diameter Enceladus has been a top priority of the Cassini mission since plumes of ice and water vapour were discovered jetting from ‘tiger stripe’ fractures at the moon’s south pole in 2005.

Science Cassini Plumbs the Depths of the Enceladus Sea

Science – The Gravity Field and Interior Structure of Enceladus

Orbiting Saturn, Cassini had “tasted” the plumes of salty water that spew from Enceladus’s south polar region, so scientists had growing confidence that the plumes tap briny liquid water tens of kilometers beneath the surface. Now, analyses of Cassini measurements of undulations in Enceladus’s gravity field point to a 10-kilometer-thick layer of water beneath the south polar region, if not the entire moon.

Universe Today – The sudden and unexpected outage of a crucial tracking radar that is mandatory to insure public safety, has forced the scrub of a pair of launches planned for this week from Cape Canaveral, FL, that are vital to US National Security, United Launch Alliance, SpaceX and NASA

Human hopes of reaching stars other than the Sun are currently limited by the maturity of advanced propulsion technologies. One of the few candidate propulsion systems for providing interstellar flight capabilities is nuclear fusion. In the past many fusion propulsion concepts have been proposed and some of them even explored in high detail (Project Daedalus), however, as scientific progress in this field has advanced, new fusion concepts have emerged that merit evaluation as potential drivers for interstellar missions. Plasma jet driven Magneto-Inertial Fusion (PJMIF) is one of those concepts. PJMIF involves a salvo of converging plasma jets that form a uniform liner, which compresses a magnetized target to fusion conditions. It is an Inertial Confinement Fusion (ICF)-Magnetic Confinement Fusion (MCF) hybrid approach that has the potential for many benefits over both ICF and MCF, such as lower system mass and significantly lower cost.

According to Portland State University anthropologist Cameron Smith, any 2000 year long Worldship journey would have to carry a minimum of 10,000 people to secure the success of the endeavor. And a starting population of 40,000 would be even better, in case a large percentage of the population died during during the journey.

Adam Crowl and Crowlspace details “Sail-Beam” or “Macron Beam” propulsion of humans in spaceships to about 4.5% of lightspeed. Quarter-wave sails made of Carbon Nano-Tubes (CNTs) can achieve high speeds by slingshotting near the sun and then pushed by the solar energy of the Sun. Dropping to 0.019 AU, the final velocity is 5.6% of light – dropping to 0.00465 AU (skimming the photosphere) would allow a speed of over 0.11c (11% of lightspeed), but the material might not be up to the beating. Crewed vehicles would not endure the extreme acceleration – 84,000 gee at peak – so the speeds that might be achieved by solar-sailing star-travelers would be limited to 1,000 year flights to Alpha Centauri, with just 17 gee peak acceleration.

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