A sampling of planetary science news:

** Yet more Mars water: A new study finds evidence for a deep groundwater table on Mars: Well water likely available across Mars | Behind The Black

A science paper released today and available for download [pdf] cites evidence from about two dozen deep impact craters located from the equator to 37 degrees north latitude that Mars has a ground ice table at an elevation that also corresponds to other shoreline features.

The third take-away from this paper however is possibly the most important. The evidence suggests that this deep groundwater water table (as ice) almost certainly still exists at all latitudes, though almost entirely underground. From a future explorer’s perspective, this data reinforces the possibility that water will be accessible across much of the Martian surface. All you will have to do is dig a well, something humans have been doing on Earth for eons.

Diagram of surface feature evidence for a deep ground water table

** Curiosity on the move:  The Curiosity rover continues its long slow methodical trek up Mount Sharp – Curiosity Says Farewell to Mars’ Vera Rubin Ridge | NASA

NASA’s Curiosity rover has taken its last selfie on Vera Rubin Ridge and descended toward a clay region of Mount Sharp. The twisting ridge on Mars has been the rover’s home for more than a year, providing scientists with new samples — and new questions — to puzzle over.

On Dec. 15, Curiosity drilled its 19th sample at a location on the ridge called Rock Hall. On Jan. 15, the spacecraft used its Mars Hand Lens Imager (MAHLI) camera on the end of its robotic arm to take a series of 57 pictures, which were stitched together into this selfie. The “Rock Hall” drill hole is visible to the lower left of the rover; the scene is dustier than usual at this time of year due to a regional dust storm.

Curiosity has been exploring the ridge since September of 2017. It’s now headed into the “clay-bearing unit,” which sits in a trough just south of the ridge. Clay minerals in this unit may hold more clues about the ancient lakes that helped form the lower levels on Mount Sharp.

A selfie taken by NASA’s Curiosity Mars rover on Sol 2291 (January 15) at the “Rock Hall” drill site, located on Vera Rubin Ridge. Credits: NASA/JPL-Caltech/MSSS Full image and caption

** Last hope for Opportunity: NASA JPL will try some new techniques in hopes of awakening the long silent Opportunity rover – Rover Team Beaming New Commands to Opportunity on Mars – NASA JPL

Engineers at NASA’s Jet Propulsion Laboratory in Pasadena, California, have begun transmitting a new set of commands to the Opportunity rover in an attempt to compel the 15-year-old Martian explorer to contact Earth. The new commands, which will be beamed to the rover during the next several weeks, address low-likelihood events that could have occurred aboard Opportunity, preventing it from transmitting.

The rover’s last communication with Earth was received June 10, 2018, as a planet-wide dust storm blanketed the solar-powered rover’s location on Mars.

“We have and will continue to use multiple techniques in our attempts to contact the rover,” said John Callas, project manager for Opportunity at JPL. “These new command strategies are in addition to the ‘sweep and beep’ commands we have been transmitting up to the rover since September.” With “sweep and beep,” instead of just listening for Opportunity, the project sends commands to the rover to respond back with a beep.

** Juno midway in Jupiter mission: The Juno spacecraft in December completed its 16th orbit of Jupiter, halfway to the 32 orbit target to complete its primary mission – NASA’s Juno Mission Halfway to Jupiter Science | NASA

“With our 16th science flyby, we will have complete global coverage of Jupiter, albeit at coarse resolution, with polar passes separated by 22.5 degrees of longitude,” said Jack Connerney, Juno deputy principal investigator from the Space Research Corporation in Annapolis, Maryland. “Over the second half of our prime mission — science flybys 17 through 32 — we will split the difference, flying exactly halfway between each previous orbit. This will provide coverage of the planet every 11.25 degrees of longitude, providing a more detailed picture of what makes the whole of Jupiter tick.”

Launched on Aug. 5, 2011, from Cape Canaveral, Florida, the spacecraft entered orbit around Jupiter on July 4, 2016. Its science collection began in earnest on the Aug. 27, 2016, flyby. During these flybys, Juno’s suite of sensitive science instruments probes beneath the planet’s obscuring cloud cover and studies Jupiter’s auroras to learn more about the planet’s origins, interior structure, atmosphere and magnetosphere.

“We have already rewritten the textbooks on how Jupiter’s atmosphere works, and on the complexity and asymmetry of its magnetic field,” said Scott Bolton, principal investigator of Juno, from the Southwest Research Institute in San Antonio. “The second half should provide the detail that we can use to refine our understanding of the depth of Jupiter’s zonal winds, the generation of its magnetic field, and the structure and evolution of its interior.”

** A sampling of recent images from Juno:

**** Juno’s SRU Captures Jupiter Lightning

Juno’s Radiation Monitoring Investigation used the Stellar Reference Unit (SRU) star camera to collect this high-resolution image Jupiter’s northern auroral oval on May 24, 2018 (Perijove 13). Also present in the image are several small bright dots and streaks — signatures of high energy relativistic electrons from polar beams that are penetrating the camera. The large bright dot in the lower right corner of the image is a flash of Jupiter’s lightning. Juno was less than 37,000 miles (60,000 km) from the cloud tops when this SRU image was collected — the closest view of Jupiter’s aurora with a visible light imager.

**** Juno’s Latest Flyby of Jupiter Captures Two Massive Storms

“This image of Jupiter’s turbulent southern hemisphere was captured by NASA’s Juno spacecraft as it performed its most recent close flyby of the gas giant planet on Dec. 21, 2018. This new perspective captures the notable Great Red Spot, as well as a massive storm called Oval BA. The storm reached its current size when three smaller spots collided and merged in the year 2000. The Great Red Spot, which is about twice as wide as Oval BA, may have formed from the same process centuries ago.” – NASA JPL

**** PJ12-83 – Jupiter during Perijove 17

Jupiter during Juno 17th orbit. Credits: Kevin M. Gill at Junocam public image processing gallery

**** Jupiter at home in the Milky Way

“Jupiter at Home in the Milky Way” – Credits: CosmEffect at  Junocam public image processing gallery

See also

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Chasing New Horizons: Inside the Epic First Mission to Pluto