Saturday, February 14, 2015

EXTRATERRESTRIAL MEMES: In Search Of Another Earth - NASA Wants To Send A Submarine To Titan's Seas And Pleiades Supercomputer Searches Kepler Mission Database For Habitable Alien Moons!

February 14, 2015 - SPACE - In a sneak peek of a possible future mission to Saturn’s moon Titan, NASA has showcased their vision of a robotic submersible that could explore the moon’s vast lakes of liquid methane and ethane.


NASA Wants to Send a Submarine to Titan's Seas

NASA

Studying Titan is thought to be looking back in time at an embryonic Earth, only a lot colder. Titan is the only moon in the solar system to have a significant atmosphere and this atmosphere is known to possess its own methane cycle, like Earth’s water cycle. Methane exists in a liquid state, raining down on a landscape laced with hydrocarbons, forming rivers, valleys and seas.

Several seas have been extensively studied by NASA’s Cassini spacecraft during multiple flybys, some of which average a few meters deep, whereas others have depths of over 200 meters (660 feet) — the maximum depth at which Cassini’s radar instrument can penetrate.

So, if scientists are to properly explore Titan, they must find a way to dive into these seas to reveal their secrets.

At this year’s Innovative Advanced Concepts (NIAC) Symposium, a Titan submarine concept was showcased by NASA Glenn’s COMPASS Team and researchers from Applied Research Lab.

Envisaged as a possible mission to Titan’s largest sea, Kracken Mare, the autonomous submersible would be designed to make a 90 day, 2,000 kilometer (1,250 mile) voyage exploring the depths of this vast and very alien marine environment. As it would spend long periods under the methane sea’s surface, it would have to be powered by a radioisotope generator; a source that converts the heat produced by radioactive pellets into electricity, much like missions that are currently exploring space, like Cassini and Mars rover Curiosity.

Communicating with Earth would not be possible when the vehicle is submerged, so it would need to make regular ascents to the surface to transmit science data.

But Kracken Mare is not a tranquil lake fit for gentle sailing — it is known to have choppy waves and there is evidence of tides, all contributing to the challenge. Many of the engineering challenges have already been encountered when designing terrestrial submarines — robotic and crewed — but as these seas will be extremely cold (estimated to be close to the freezing point of methane, 90 Kelvin or -298 degrees Fahrenheit), a special piston-driven propulsion system will need to be developed and a nitrogen will be needed as ballast, for example.

This study is just that, a study, but the possibility of sending a submersible robot to another world would be as unprecedented as it is awesome.

Although it’s not clear at this early stage what the mission science would focus on, it would be interesting to sample the chemicals at different depths of Kracken Mare.

“Measurement of the trace organic components of the sea, which perhaps may exhibit prebiotic chemical evolution, will be an important objective, and a benthic sampler (a robotic grabber to sample sediment) would acquire and analyze sediment from the seabed,” the authors write (PDF). “These measurements, and seafloor morphology via sidescan sonar, may shed light on the historical cycles of filling and drying of Titan’s seas. Models suggest Titan’s active hydrological cycle may cause the north part of Kraken to be ‘fresher’ (more methane-rich) than the south, and the submarine’s long traverse will explore these composition variations.”

A decade after the European Huygens probe landed on the surface of Titan imaging the moon’s eerily foggy atmosphere, there have been few plans to go back to this tantalizing world. It would be incredible if, in the next few decades, we could send a mission back to Titan to directly sample what is at the bottom of its seas, exploring a region where the molecules for life’s chemistry may be found in abundance.


WATCH: Exploring the depths of Kracken Mare.



- Discovery News.


NASA's Pleiades Searching Kepler Mission Database for Habitable Alien Moons

The Daily Galaxy via HEK 


A team of 21st-century explorers working for the Hunt for Exomoons with Kepler (HEK) project, based at Harvard University, are searching for exomoons using data from NASA’s Kepler mission and the Pleiades supercomputer at the NASA Advanced Supercomputing (NAS) facility at NASA’s Ames Research Center. The discovery of exomoons—moons situated beyond our own solar system—would add to the growing list of celestial objects detected by the Kepler telescope that could potentially harbor life in some form.

In the quest to find the first exomoon, HEK astronomers led by David Kipping at the Harvard-Smithsonian Center for Astrophysics have devised a unique, systematic computational approach that requires 5.2 million processor hours on Pleiades.

Using their in-house LUNA light curve modeling algorithm and a massively parallel sampling algorithm called MultiNest, the project team simulates billions of possible star-planet-moon configurations and compares the results to the actual Kepler data to look for a good match. So far, the team has surveyed 56 of about 400 identified Kepler planet candidates that could have a detectable exomoon.

Surveying the remaining 340 planet candidates would require about 50,000 hours of processing time per object and would take nearly a decade to complete on smaller computers. Utilizing NASA’s powerful Pleiades system—which performs over 3 quadrillion calculations per second—will speed up this computationally expensive process, reducing the processing time to 30,000 hours per object. Over the next two years, the team will survey the remaining candidates for exomoons by performing photo-dynamical analysis of the public data from Kepler, consuming about 10 million processor hours on Pleiades. Their results will be used to determine the occurrence rate of Earth-like moons. - Daily Galaxy.



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