Space & Planetary Science: April 2017 Archives

Dawn Observing Ceres; 3rd Reaction Wheel Malfunctions, NASA JPL

"While preparing for this observation, one of Dawn's two remaining reaction wheels stopped functioning on April 23. By electrically changing the speed at which these gyroscope-like devices spin, Dawn controls its orientation in the zero-gravity, frictionless conditions of space."

"The team discovered the situation during a scheduled communications session on April 24, diagnosed the problem, and returned the spacecraft to its standard flight configuration, still with hydrazine control, on April 25. The failure occurred after Dawn completed its five-hour segment of ion thrusting on April 22 to adjust its orbit, but before the shorter maneuver scheduled for April 23-24. The orbit will still allow Dawn to perform its opposition measurements. The reaction wheel's malfunctioning will not significantly impact the rest of the extended mission at Ceres."

SwRI-Led Team Discovers Lull in Mars' Giant Impact History

"The new results reveal that Mars' impact history closely parallels the bombardment histories we've inferred for the Moon, the asteroid belt, and the planet Mercury," Bottke said. "We refer to the period for the later impacts as the 'Late Heavy Bombardment.' The new results add credence to this somewhat controversial theory. However, the lull itself is an important period in the evolution of Mars and other planets. We like to refer to this lull as the 'doldrums.'"

Cassini Completes Final and Fateful Titan Flyby

"NASA's Cassini spacecraft has had its last close brush with Saturn's hazy moon Titan and is now beginning its final set of 22 orbits around the ringed planet."

"The spacecraft made its 127th and final close approach to Titan on April 21 at 11:08 p.m. PDT (2:08 a.m. EDT on April 22), passing at an altitude of about 608 miles (979 kilometers) above the moon's surface."

Marc's note: There are a couple of new images.

Breakthrough Initiatives Summit on Life in the Universe and Space Exploration

"Breakthrough Initiatives today announced its second annual Breakthrough Discuss scientific conference, which will bring together leading astronomers, engineers, astrobiologists and astrophysicists to advance discussion surrounding recent discoveries of potentially habitable planets in nearby star systems. The two days of discussions will focus on newly discovered Earth-like 'exoplanets' in the Alpha Centauri and TRAPPIST-1 planetary systems, and new evidence that these planets could be habitable, as well as their potential as targets for novel methods of space exploration."

Breakthrough Discuss Opens with Lively Sessions Dedicated to the Search for Planets and Life in Our Cosmic Neighborhood, Breakthrough Initiatives

"Peter Michelson emphasized that the last century of scientific investigation has transformed questions about origins from the realm of metaphysics to a place where they can be investigated observationally."

Breakthrough Discuss Conference Closes with Full Day Dedicated to Newly Discovered Exoplanets and SETI, Breakthrough Initiatives

"Breakthrough Initiatives are a suite of scientific and technological programs exploring the big questions around life in the Universe, such as, Are we alone? What are the nearest habitable planets? And can we become an interstellar civilization?"

Keith's note: I had a few thoughts about this official Science March T-shirt design.

New Insights into Ocean Worlds Enceladus and Europa

"Two veteran NASA missions are providing new details about icy, ocean-bearing moons of Jupiter and Saturn, further heightening the scientific interest of these and other "ocean worlds" in our solar system and beyond. The findings are presented in papers published Thursday by researchers with NASA's Cassini mission to Saturn and Hubble Space Telescope. In the papers, Cassini scientists announce that a form of chemical energy that life can feed on appears to exist on Saturn's moon Enceladus, and Hubble researchers report additional evidence of plumes erupting from Jupiter's moon Europa."

Keith's note: correction - "Linda" who made the shrimp comment is not from PAO - she is Dr. Linda Spilker the Cassini Project Scientist. NASA gets all upset when newspapers start to make things up about these upcoming announcements - especially when they start speculating on all sorts of alien life forms that might be on the verge of being announced. NASA PAO constantly complains that they have to shoot down all of the loony speculation. Then someone at NASA starts asking about shrimp on Enceladus in an official capacity at a NASA press event.

Hydrothermal Activity in The Seas of Enceladus: Implications For Habitable Zones,

First posted on 11 April 2017 at 7:16 pm EDT. "On Thursday NASA will announce evidence that hydrothermal activity on the floor of an ice-covered ocean on Saturn's moon Enceladus is most likely creating methane from carbon dioxide. The process is indicative of possible habitable zones within the ocean of Enceladus. But before we go any further, "habitable" does not mean "inhabited". NASA bases this determination on the amount of hydrogen in plumes emanating from the moon's south pole. The large amount of hydrogen is strongly suggestive of a constant hydrothermal process wherein the ocean under the surface of Enceladus is interacting with rock and organic compounds. The amount of hydrogen present is in disequilibrium i.e. if there was not a process that was constantly generating hydrogen the observed hydrogen levels would likely be lower than what is seen. Something is pumping it out."

NASA News Conference on Oceans Beyond Earth, NASA

"NASA will discuss new results about ocean worlds in our solar system from the agency's Cassini spacecraft and the Hubble Space Telescope during a news briefing 11 a.m. PDT (2 p.m. EDT, 18:00 UTC) on Thursday, April 13. These new discoveries will help inform future ocean world exploration -- including NASA's upcoming Europa Clipper mission planned for launch in the 2020s -- and the broader search for life beyond Earth."

Keith's note: I just love the media advisories NASA issues such as this one for tomorrow's "NASA to Reveal New Discoveries in News Conference on Oceans Beyond Earth" press event. They are always filled with names, affiliations, specific instruments, buzz words, tantalizing hints, etc. This makes it so much easier for me to use Google, preprint servers, and simple journalistic tools like email and phone calls to figure out what NASA is going to announce. Who needs embargoed papers? NASA loves to make the media play connect the dots. And if you follow these missions, then its even easier to play.

This advisory includes the sentence "NASA will discuss new results about ocean worlds in our solar system from the agency's Cassini spacecraft and the Hubble Space Telescope" and lists participants including "Hunter Waite, Cassini Ion and Neutral Mass Spectrometer team lead at the Southwest Research Institute (SwRI) in San Antonio, Chris Glein, Cassini INMS team associate at SwRI".

Duh "ocean worlds", "Cassini" - they are talking about Enceladus. Hmm ... 2 people who work with the "Cassini Ion and Neutral Mass Spectrometer". Let's do some Googling. Ah "Enceladus Flyby 21 (E-21): Deepest Dive Through the Plume" which says "1. Confirm presence of molecular hydrogen (H2). This measurement will be accomplished using Cassini's sensor that sniffs the gases in the plume (called INMS). Confirmation of H2 would be an independent line of evidence that hydrothermal activity is taking place in the Enceladus ocean, on the seafloor. Amount of H2 Cassini measures would reveal how much hydrothermal activity is going on in the ocean. This has implications for the amount of energy available for creating a habitable environment in the ocean". This instrument's data is posted by NASA here: Cassini (INMS) level 1A high and the low sensitivity counter (Data archive), PDS/PPI, NASA

And "William Sparks" from STSCI is listed. That's easy: he looks at plumes erupting from Europa. He just completed 14891 - Confirming the ice plumes of Europa "We propose a campaign to image Europa in transit against Jupiter close to the April 2017 opposition, in order to maximize spatial resolution, sensitivity, and time sampling. These measurements have the potential to profoundly influence a topic of fundamental scientific importance and of great strategic interest to NASA. If the ice plumes of Europa arise from the deep ocean, we have gained access to probably the most astrobiologically interesting location in the Solar System." He has also completed 14112 - Monitoring the ice plumes of Europa, 13829 - The ice plumes of Europa, and 13620 - Probing the atmosphere of a transiting ocean world: are there ice fountains on Europa?

So its all about ice world/ocean world plumes folks. Bingo.

Keith's note: The artists at JPL who created the farewell video for Cassini must have seen "Wanderers" - and "Interstellar". If so, it shows. That's OK. This JPL creation sets a new standard for displaying what NASA missions have done and the true scale of the vistas these probes would see if we humans were not constantly telling them what to look at. The more of these videos NASA makes, the more it will explain itself to more people, and the stronger its support amongst the populace will be. Watch both videos. One is a prequel. Oh and the Interstellar clip is a must-see as well. We will one day see these things with our own eyes.



Monthly Archives

About this Archive

This page is an archive of entries in the Space & Planetary Science category from April 2017.

Space & Planetary Science: March 2017 is the previous archive.

Space & Planetary Science: May 2017 is the next archive.

Find recent content on the main index or look in the archives to find all content.