A sampling of recent articles, videos, and images from space-related science news items:

Asteroids

** JAXA Hayabusa2 made a successful 2nd sample grab from asteroid Ryugu on July 11th. The :

From SFN:

The robot explorer’s sampling mechanism works by firing a metal bullet into the asteroid once the probe’s sampler horn, which extends from one side of the spacecraft, contacts the surface. The projectile is designed to blast away rock and dust on the asteroid’s surface, then direct the material through the sampler horn into a collection chamber inside the Hayabusa 2 spacecraft.

This image shows debris thrown up from the surface of Ryugu by the bullet.

Hayabusa2 2nd Touchdown

Image of surface immediately after touchdown. Taken with the Optical Navigation Camera – Wide angle (ONC-W1). Credits: Hayabusa-2 project.

A diagram of the touch-and-go surface sampling operation:

Outline of the 2nd touchdown operation.

Outline of the 2nd touchdown operation.

More about the The 2nd touchdown – JAXA Hayabusa2 project

** Help OSIRIS-REx mission map the rugged surface of the Bennu asteroid  NASA Invites Public to Help Asteroid Mission Choose Sample Site | NASA

Citizen scientists assemble! NASA’s OSIRIS-REx mission to the asteroid Bennu needs extra pairs of eyes to help choose its sample collection site on the asteroid – and to look for anything else that might be scientifically interesting.

Bennu surface

“This image shows a view of asteroid Bennu’s surface in a region near the equator. It was taken by the PolyCam camera on NASA’s OSIRIS-REx spacecraft on March 21 from a distance of 2.2 miles (3.5 km). The field of view is 158.5 ft (48.3 m). For scale, the light-colored rock in the upper left corner of the image is 24 ft (7.4 m) wide. Credits: NASA/Goddard/University of Arizona”

The OSIRIS-REx spacecraft has been at Bennu since Dec. 3, 2018, mapping the asteroid in detail, while the mission team searches for a sample collection site that is safe, conducive to sample collection and worthy of closer study. One of the biggest challenges of this effort, which the team discovered after arriving at the asteroid five months ago, is that Bennu has an extremely rocky surface and each boulder presents a danger to the spacecraft’s safety. To expedite the sample selection process, the team is asking citizen scientist volunteers to develop a hazard map by counting boulders.

“For the safety of the spacecraft, the mission team needs a comprehensive catalog of all the boulders near the potential sample collection sites, and I invite members of the public to assist the OSIRIS-REx mission team in accomplishing this essential task,” said Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona, Tucson.

For this effort, NASA is partnering with CosmoQuest, a project run out of the Planetary Science Institute that supports citizen science initiatives. Volunteers will perform the same tasks that planetary scientists do – measuring Bennu’s boulders and mapping its rocks and craters – through the use of a simple web interface. They will also mark other scientifically interesting features on the asteroid for further investigation.

The boulder mapping work involves a high degree of precision, but it is not difficult. The CosmoQuest mapping app requires a computer with a larger screen and a mouse or trackpad capable of making precise marks. To help volunteers get started, the CosmoQuest team provides an interactive tutorial, as well as additional user assistance through a Discord community and livestreaming sessions on Twitch.

For more info see:

Microgravity Science & Technology R&D

** SpaceX Cargo Dragon to deliver wide range of science and technology experiments to the ISS. Liftoff of mission CRS-18 is currently set for July 21st at 7:35 pm EDT (2335 GMT)

Highlights of Science Launching on SpaceX CRS 18 – July 8, 2019 –

Solar Science

** Sunspot count near zero in June. Faint spots subsequently show signs of start of next cycle: Sunspot update June 2019: Down to zero again, with next cycle making an appearance | Behind The Black

These two visible sunspots for the next solar cycle are very significant. They indicate that we will have an upcoming solar maximum, and are not heading into a grand minimum, when no sunspots are visible for decades.

Their appearance however does not mean that solar minimum is over. On the contrary, the solar cycles typically overlap by one or two years, with new sunspots for the next solar cycle appearing even as the Sun ramps down to minimum and remains relatively inactive for many months.

I cannot deny that I will be disappointed if a grand minimum does not occur. Such an event would have been a wonderful opportunity for solar scientists to get answers to their many questions about the Sun’s solar cycles that today remain unanswered and will likely not be answerable while the Sun follows its behavior of the last three hundred years.

At the same time, if the upcoming solar cycle is weak, as has been predicted by some solar scientists, it will help confirm some theories that try to explain the Sun’s behavior.

ISES Solar Cycle Sunspot Number Progression - NOAA

Check SpaceWeather.com for the daily sunspot count. More solar images and measurements can be found on the Space-for-All page The Sun & Space Weather.

** Astronomy

** Low-luminosity black hole surrounded by unexpected disc of material: Hubble Discovers Mysterious Black Hole Disc – ESA/Hubble

Astronomers using the NASA/ESA Hubble Space Telescope have observed an unexpected thin disc of material encircling a supermassive black hole at the heart of the spiral galaxy NGC 3147, located 130 million light-years away.

Artist’s impression of the peculiar thin disc of material circling a supermassive black hole at the heart of the spiral galaxy NGC 3147, located 130 million light-years away.

The presence of the black hole disc in such a low-luminosity active galaxy has astronomers surprised. Black holes in certain types of galaxies such as NGC 3147 are considered to be starving as there is insufficient gravitationally captured material to feed them regularly. It is therefore puzzling that there is a thin disc encircling a starving black hole that mimics the much larger discs found in extremely active galaxies. 

Of particular interest, this disc of material circling the black hole offers a unique opportunity to test Albert Einstein’s theories of relativity. The disc is so deeply embedded in the black hole’s intense gravitational field that the light from the gas disc is altered, according to these theories, giving astronomers a unique peek at the dynamic processes close to a black hole. 

“We’ve never seen the effects of both general and special relativity in visible light with this much clarity,” said team member Marco Chiaberge of AURA for ESA, STScI and Johns Hopkins Univeristy.

The disc’s material was measured by Hubble to be whirling around the black hole at more than 10% of the speed of light. At such extreme velocities, the gas appears to brighten as it travels toward Earth on one side, and dims as it speeds away from our planet on the other. This effect is known as relativistic beaming. Hubble’s observations also show that the gas is embedded so deep in a gravitational well that light is struggling to escape, and therefore appears stretched to redder wavelengths. The black hole’s mass is around 250 million times that of the Sun. 

** Hubble images show Eta Carinae glowing in red, white, and blue: Hubble Captures Cosmic Fireworks in Ultraviolet | ESA/Hubble

Hubble offers a special view of the double star system Eta Carinae’s expanding gases glowing in red, white, and blue. This is the highest resolution image of Eta Carinae taken by the NASA/ESA Hubble Space Telescope.

Imagine slow-motion fireworks that started exploding nearly two centuries ago and haven’t stopped since then. This is how you might describe this double star system located 7500 light-years away in the constellation Carina (The Ship’s Keel). In 1838 Eta Carinae underwent a cataclysmic outburst called the Great Eruption, quickly escalating to become in 1844 the second brightest star in the sky by April of that year. The star has since faded, but this new view from the NASA/ESA Hubble Space Telescope shows that the spectacular display is still ongoing, and reveals details that have never been seen before.

Telescopes, including Hubble, have monitored the Eta Carinae star system for more than two [centuries]. It has been prone to violent outbursts, including an episode in the 1840s during which ejected material formed the bipolar bubbles seen here. Now, using Hubble’s Wide Field Camera 3 to probe the nebula in ultraviolet light, astronomers have uncovered the glow of magnesium embedded in warm gas (shown in blue) in places they had not seen it before. The luminous magnesium resides in the space between the dusty bipolar bubbles and the outer shock-heated nitrogen-rich filaments (shown in red). The streaks visible in the blue region outside the lower-left lobe are a striking feature of the image. These streaks are created when the star’s light rays poke through the dust clumps scattered along the bubble’s surface. Wherever the ultraviolet light strikes the dense dust, it leaves a long, thin shadow that extends beyond the lobe into the surrounding gas. Eta Carinae resides 7500 light-years away.

Violent mass ejections are not uncommon in Eta Carinae’s history; the system has been blighted by chaotic eruptions, often blasting parts of itself into space. But the Great Eruption was particularly dramatic. The larger of the two stars is a massive, unstable star nearing the end of its life, and what astronomers witnessed over a century and a half ago was, in fact, a stellar near-death experience.

Saturn System

** The latest on Saturn research: The News From Saturn-With Linda Spilker | The Planetary Society

It has been many months since the great Cassini spacecraft plunged into Saturn’s atmosphere and fiery death. Yet the mission lives on as the reams of data and images reveal much more of this beautiful world, its rings, and its moons. Project Scientist Linda Spilker is back with Mat to provide a fascinating update.

** NASA to explore Titan with Dragonfly drone: NASA’s Dragonfly Mission to Titan Will Look for Origins, Signs of Life | NASA

Dragonfly will launch in 2026 and arrive in 2034. The rotorcraft will fly to dozens of promising locations on Titan looking for prebiotic chemical processes common on both Titan and Earth. Dragonfly marks the first time NASA will fly a multi-rotor vehicle for science on another planet; it has eight rotors and flies like a large drone. It will take advantage of Titan’s dense atmosphere – four times denser than Earth’s – to become the first vehicle ever to fly its entire science payload to new places for repeatable and targeted access to surface materials.

Titan is an analog to the very early Earth, and can provide clues to how life may have arisen on our planet. During its 2.7-year baseline mission, Dragonfly will explore diverse environments from organic dunes to the floor of an impact crater where liquid water and complex organic materials key to life once existed together for possibly tens of thousands of years. Its instruments will study how far prebiotic chemistry may have progressed. They also will investigate the moon’s atmospheric and surface properties and its subsurface ocean and liquid reservoirs. Additionally, instruments will search for chemical evidence of past or extant life.

** Saturn’s moon Dione streaked with fracture lines:

NASA JPL:

This close-up view of icy Dione reveals a wonderful variety of surface features that are simultaneously familiar and unlike any other place in the solar system.

Grooves on Saturn moon Dione

Image of Dione’s surface taken during a Cassini flyby. Fine stress fracture lines run parallel across the surface. Credits: NASA JPL

The terrain in this image is located within a 60-kilometer-wide (37-mile) impact crater along the feature called Padua Linea. The western rim of the encompassing crater runs from the middle left to the upper right. The crater’s central peak can be seen at the lower right.

Multiple generations of fractures are visible here. Numerous fine, roughly parallel linear grooves run across the terrain from top to bottom and are interrupted by the larger, irregular bright fractures. In several places, fractures postdate some deposits in the bottoms of craters that are not badly degraded by time. Such a fracture, for example, runs from the center toward the upper right.

Mars

** Watch installation of the wheel modules on the Mars 2020 rover:

A team of engineers at NASA’s Jet Propulsion Laboratory in Pasadena, California, install the legs and wheels — otherwise known as the mobility suspension — on the Mars 2020 rover. The imagery for this accelerated time-lapse was taken on June 13, 2019, from a camera above the Spacecraft Assembly Facility’s High Bay 1 clean room.

** Speaking of wheels, here’s an update on Curiosity’s battered metal treads: Wheel update on Curiosity | Behind The Black

Overall, however, the new damage does not appear significant, considering two years have passed. Their effort to mitigate wheel damage, described in an April 23, 2018 rover team update, seems to be working.

** Curiosity captured from orbit: HiRISE Spots Curiosity Rover at Mars’ ‘Woodland Bay’ | NASA

HiRISE Spots Curiosity Rover at Mars' 'Woodland Bay'

HiRISE camera on the Mars Reconnaissance orbiter captures the Curiosity Rover at Mars’ ‘Woodland Bay’.

** More Mars image analyses from Bob Zimmerman at Behind The Black:

In their research the scientists are not even sure if the erosion we see here was caused by groundwater melting or heating by the arrival of lava from the giant volcano Elysium Mons to the immediate south. All they know for certain is that this terrain that has been significantly changed, meaning that its structure was weak and prone to easy erosion.

The result are geological features seen nowhere on Earth.

Galaxias Colles

Eroded features in the Galaxias Colles region on Mars.

Martian Atypical Pit Craters

These Martian “Atypical Pit Craters” appear to be cave openings.

Plan view of Aurorae Chaos

ESA’s Mars Express image shows a plan view of Aurorae Chaos, a large area of chaotic terrain located in the Margaritifer Terra region on Mars, and comprises data gathered on 31 October 2018 during orbit 18765. The ground resolution is approximately 14 m/pixel and the images are centred at about 327°E/11°S. This image was created using data from the nadir and colour channels of the High Resolution Stereo Camera. The nadir channel is aligned perpendicular to the surface of Mars, as if looking straight down at the surface. North is to the right.

While the newly discovered scarps are mostly at the same latitude, about 55 degrees, the range is widening to the west, suggesting that with time we are going to discover that they exist in a band that circles Mars at this latitude.

Scarp in Mantling Material

Scarps, or steep cliff faces, like the one shown here, can show streaks that indicate subsurface layer of water ice. Credits: HiRISE camera on Mars Reconnaissance Orbiter.

For future colonists, this information is critical, and suggests that the first future bases could very well be located along this band.

Arabia Terra is one of the largest regions of the transition zone between the northern lowlands and the southern highlands. This crater is located, as shown by the red cross in the overview map to the right, near its northern edge, in an area where the descent into the northern lowlands is somewhat abrupt and broken up by large craters and chaos terrain.

Odd Shaped Crater in Arabia Terra

“Odd Shaped Crater in Arabia Terra” – HiRISE camera on MRO.

The crater itself holds numerous geological mysteries. Its shape suggests two impacts of different sizes overlapping each other, but without any remnant of the inner rim of the second impact. Where did that remnant go? Or maybe this wasn’t caused by two impacts, but by one impact that reshaped the surface in this odd and inexplicable way.

Then there is the three teardrop-shaped patterns in the crater’s floor. They look like the brushstrokes of a giant-sized painter. Were they caused by the wind? And if so, why in this pattern?

Planetary geologists could probably come up with a dozen more questions. The number tells us how little we know about Mars.

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