A sampling of space and solar science items of interest:
On Jan. 19, 2019, just 161 days after its launch from Cape Canaveral Air Force Station in Florida, NASA’s Parker Solar Probe completed its first orbit of the Sun, reaching the point in its orbit farthest from our star, called aphelion. The spacecraft has now begun the second of 24 planned orbits, on track for its second perihelion, or closest approach to the Sun, on April 4, 2019.
** Caves and lava tubes on Mars could provide good locations for early settlements: The many pits/caves of Mars | Behind The Black
That these pits are all in a line, and that they also in line with a shallow straight depression, strongly suggests that they are skylights into a lava tube below. Located to the northwest of Arsia Mons, the southeast-to-northwest trend of the line reinforces this conclusion, suggesting that we are looking at surface evidence of an underground lava tube that flowed down from Arsia Mons, when that giant volcano was active, eons ago.
A giant, spiraling storm in Jupiter’s southern hemisphere is captured in this animation from NASA’s Juno spacecraft. The storm is approximately 5,000 miles (8,000 kilometers) across.
The counterclockwise motion of the storm, called Oval BA, is clearly on display. A similar rotation can be seen in the famous Great Red Spot at the top of the animation.
Juno took the nine images used to produce this movie sequence on Dec. 21, between 9:24 a.m. PST (12:24 p.m. EST) and 10:07 a.m. PST (1:07 p.m. EST). At the time the images were taken, the spacecraft was between approximately 15,400 miles (24,800 kilometers) and 60,700 miles (97,700 kilometers) from the planet’s cloud tops above southern latitudes spanning about 36 to 74 degrees.
Citizen scientists Gerald Eichstädt and Seán Doran created this animation using data from the spacecraft’s JunoCam imager.
JunoCam’s raw images are available for the public to peruse and to process into image products at: http://missionjuno.swri.edu/junocam.
** Curiosity sensors measure local gravity and researchers use the data to estimate local ground densities: ‘Mars Buggy’ Curiosity Measures a Mountain’s Gravity | NASA
In a new paper in Science, the researchers detail how they repurposed sensors used to drive the Curiosity rover and turned them into gravimeters, which measure changes in gravitational pull. That enabled them to measure the subtle tug from rock layers on lower Mount Sharp, which rises 3 miles (5 kilometers) from the base of Gale Crater and which Curiosity has been climbing since 2014. The results? It turns out the density of those rock layers is much lower than expected.
Just like a smartphone, Curiosity carries accelerometers and gyroscopes. Moving your smartphone allows these sensors to determine its location and which way it’s facing. Curiosity’s sensors do the same thing but with far more precision, playing a crucial role in navigating the Martian surface on each drive. Knowing the rover’s orientation also lets engineers accurately point its instruments and multidirectional, high-gain antenna.
By happy coincidence, the rover’s accelerometers can be used like Apollo 17’s gravimeter. The accelerometers detect the gravity of the planet whenever the rover stands still. Using engineering data from the first five years of the mission, the paper’s authors measured the gravitational tug of Mars on the rover. As Curiosity ascends Mount Sharp, the mountain adds additional gravity — but not as much as scientists expected.
“The lower levels of Mount Sharp are surprisingly porous,” said lead author Kevin Lewis of Johns Hopkins University. “We know the bottom layers of the mountain were buried over time. That compacts them, making them denser. But this finding suggests they weren’t buried by as much material as we thought.”
** Sounding rocket flies through the Aurora Borealis after launch from Norway: To Catch a Wave, Rocket Launches From Top of World | NASA –
On Jan. 4, 2019, at 4:37 a.m. EST the CAPER-2 mission launched from the Andøya Space Center in Andenes, Norway, on a 4-stage Black Brant XII sounding rocket. Reaching an apogee of 480 miles high before splashing down in the Arctic Sea, the rocket flew through active aurora borealis, or northern lights, to study the waves that accelerate electrons into our atmosphere.
CAPER-2, short for Cusp Alfvén and Plasma Electrodynamics Rocket-2, is a sounding rocket mission — a type of spacecraft that carries scientific instruments on short, targeted trips to space before falling back to Earth. In addition to their relatively low price tags and quick development time, sounding rockets are ideally suited for launching into transient events — like the sudden formation of the aurora borealis, or northern lights.
For CAPER-2 scientists, flying through an aurora provides a peek into a process as fundamental as it is complex: How do particles get accelerated throughout space? NASA studies this phenomenon in an effort to better understand not only the space environment surrounding Earth — and thus protect our technology in space from radiation — but also to help understand the very nature of stars and atmospheres throughout the solar system and beyond.