The original caption from NASA:
This vertically exaggerated view shows scalloped depressions in Mars’ Utopia Planitia region, one of the area’s distinctive textures that prompted researchers to check for underground ice, using ground-penetrating radar aboard NASA’s Mars Reconnaissance Orbiter.
More than 600 overhead passes with the spacecraft’s Shallow Radar (SHARAD) instrument provided data for determining that about as much water as the volume of Lake Superior lies in a thick layer beneath a portion of Utopia Planitia.
These scalloped depressions on the surface are typically about 100 to 200 yards or meters wide. The foreground of this view covers ground about one mile (1.8 kilometers) across. The perspective view is based on a three-dimensional terrain model derived from a stereo pair of observations by the High Resolution Imaging Science Experiment (HiRISE) camera on the Mars Reconnaissance Orbiter. One was taken on Dec. 25, 2006, the other on Feb. 2, 2007.
The vertical dimension is exaggerated fivefold in proportion to the horizontal dimensions, to make texture more apparent in what is a rather flat plain.
Similar scalloped depressions are found in portions of the Canadian Arctic, where they are indicative of ground ice.
Diagonal striping on this map of a portion of the Utopia Planitia region on Mars indicates the area where a large subsurface deposit rich in water ice was assessed using the Shallow Radar (SHARAD) instrument on NASA’s Mars Reconnaissance Orbiter.
The scale bar at lower right indicates 140 kilometers (76 miles). The violet vertical bars show depth to the bottom of the ice-rich deposit, as estimated from SHARAD passes overhead. Darkest violet indicates a depth of about 550 feet (about 170 meters). Palest violet indicates a depth of about 33 feet (10 meters). The value of 2.8 plus-or-minus 0.8 in the upper right corner denotes the dielectric constant, a property related to radar reflectivity. The value of 14,300 cubic kilometers is an estimate of the volume of water in the deposit. — NASA
Images: NASA/JPL-Caltech/Univ. of Rome/ASI/PSI/Univ. of Arizona
Good news from NASA and the Juno team. The Juno spacecraft is out of safe mode and everything looks good – so far. Once the instruments are back on and stable the team can relax even if only a little. Finding out the cause of the problem is going to be so interesting. Juno is traveling very close to the surface of Jupiter and it is possible exposure to the local environment could be a problem. Time will tell, but for now all is well.
NASA’s Juno spacecraft at Jupiter has left safe mode and has successfully completed a minor burn of its thruster engines in preparation for its next close flyby of Jupiter.
Mission controllers commanded Juno to exit safe mode Monday, Oct. 24, with confirmation of safe mode exit received on the ground at 10:05 a.m. PDT (1:05 p.m. EDT). The spacecraft entered safe mode on Oct. 18 when a software performance monitor induced a reboot of the spacecraft’s onboard computer. The team is still investigating the cause of the reboot and assessing two main engine check valves.
“Juno exited safe mode as expected, is healthy and is responding to all our commands,” said Rick Nybakken, Juno project manager from NASA’s Jet Propulsion Laboratory in Pasadena, California. “We anticipate we will be turning on the instruments in early November to get ready for our December flyby.”
In preparation for that close flyby of Jupiter, Juno executed an orbital trim maneuver Tuesday at 11:51 a.m. PDT (2:51 p.m. EDT) using its smaller thrusters. The burn, which lasted just over 31 minutes, changed Juno’s orbital velocity by about 5.8 mph (2.6 meters per second) and consumed about 8 pounds (3.6 kilograms) of propellant. Juno will perform its next science flyby of Jupiter on Dec. 11, with time of closest approach to the gas giant occurring at 9:03 a.m. PDT (12:03 p.m. EDT). The complete suite of Juno’s science instruments, as well as the JunoCam imager, will be collecting data during the upcoming flyby.
“We are all excited and eagerly anticipating this next pass close to Jupiter,” said Scott Bolton, principal investigator of Juno from the Southwest Research Institute in San Antonio. “The science collected so far has been truly amazing.”
This sounds something like an evolution of a wake to me. I could see the plasma, which I would guess would be rotating, coalesce into spherical masses or “balls”.
Here is the NASA description:
This four-panel graphic illustrates how the binary-star system V Hydrae is launching balls of plasma into space.
Panel 1 shows the two stars orbiting each other. One of the stars is nearing the end of its life and has swelled in size, becoming a red giant.
In panel 2, the smaller star’s orbit carries the star into the red giant’s expanded atmosphere. As the star moves through the atmosphere, it gobbles up material from the red giant that settles into a disk around the star.
The buildup of material reaches a tipping point and is eventually ejected as blobs of hot plasma along the star’s spin axis, as shown in panel 3.
This ejection process is repeated every eight years, which is the time it takes for the orbiting star to make another pass through the bloated red giant’s envelope, as shown in panel 4.
Astronomers found signs of a growing planet around TW Hydra, a nearby young star, using the Atacama Large Millimeter/submillimeter Array (ALMA). Based on the distance from the central star and the distribution of tiny dust grains, the baby planet is thought to be an icy giant, similar to Uranus and Neptune in our Solar System. This result is another step towards understanding the origins of various types of planets.
These observation results were accepted for a publication as Tsukagoshi et al. “A Gap with a Deficit of Large Grains in the Protoplanetary Disk around TW Hya” by the Astrophysical Journal Letters.
To celebrate Hinode’s 10th anniversary, this video from the Japanese Aerospace Exploration Agency (JAXA) and National Astromonical Observatory of Japan (NAOJ) features highlights captured during the satellite’s first decade in space. The Hinode mission is led by JAXA, with participation from NASA and the United Kingdom and European Space Agencies. Credit: JAXA/NAOJ
The power producing solar panels on the Sentinel-1A satellite have been damaged by an impact of some sort. The impacting object was tiny, in the few-millimetres class tiny. The image above from ESA shows the damage.
Even an impact with such a tiny object makes a difference:
A sudden small power reduction was observed in a solar array of Sentinel-1A, orbiting at 700 km altitude, at 17:07 GMT on 23 August. Slight changes in the orientation and the orbit of the satellite were also measured at the same time. — ESA
Sentinel 1A operations have not been impacted. There are in excess of 19,000 bits of known space debris, luckily this one was small.
Ever notice how spacecraft destined to stay in orbit for some period of time always seem to have reflective foil around them? Ever wonder how that could possibly work?
You’re in luck! ESA shows us the state-of-the-art in space insulation:
Blankets of multi-layer insulation (MLI) are used to cover satellite surfaces to help insulate them from orbital temperature extremes. These are the reason that satellites often look as though they’ve been covered in shiny Christmas wrapping.
MLI blankets are made up of multiple layers of very thin, metal-coated plastic film, with low-conducting ‘spacer’ material placed in-between such as silk, nylon or glass-fibre netting. Alternatively, MLI is sometimes deliberately crinkled to minimise any contact between layers.
In the airlessness of space, objects can be hot and cold at the same time, especially if one side is in sunshine and another is in shade. In such conditions, thermal radiation is the main driver of temperature change (rather than convection or conduction), and reflective MLI serves to minimise it.
Thermal control specialists aim to maintain the temperature of the satellite within set limits, to keep electronic and mechanical parts working optimally and to prevent any temperature-triggered structural distortion.
Placing MLI blankets on a satellite body is a skilled art in itself, with complex shapes needing to be created to fit around around edges or joints.