https://www.nasa.gov/image-feature/jpl/pia21901/veil-of-ice

Saturn’s rings, made of countless icy particles, form a translucent veil in this view from NASA’s Cassini spacecraft.

Saturn’s tiny moon Pan, about 17 miles (28 kilometers) across, orbits within the Encke Gap in the A ring. Beyond,
we can see the arc of Saturn itself, its cloud tops streaked with dark shadows cast by the rings.

This image was taken in visible light with the Cassini spacecraft narrow-angle camera on Feb. 12, 2016, at a distance
of approximately 746,000 miles (1.2 million kilometers) from Pan.

VIRGO: To vypada (podle tech ryh) jako kus zkameneleho bahna...

ESA Science & Technology: Gaia data help prepare for a rare celestial alignment of Neptune's largest moon
http://sci.esa.int/...ia-data-help-prepare-for-a-rare-celestial-alignment-of-neptune-s-largest-moon/

On 5 October 2017, the largest moon of Neptune will pass in front of a distant star. This rare event will temporarily block the star's light from Earth and provide
an excellent opportunity to study the moon's intriguing atmosphere. Data from ESA's Gaia mission is allowing astronomers to precisely plan their observations.

https://www.nasa.gov/feature/spend-next-new-year-s-eve-with-new-horizons

In just under a year – shortly after midnight Eastern Time on Jan. 1, 2019 – NASA’s New Horizons spacecraft will buzz by the most primitive and most distant object ever explored.
New Horizons’ encounter with Kuiper Belt object 2014 MU69, which orbits a billion miles beyond Pluto, will offer the first close-up look at such a pristine building block of
the solar system – and will be performed in a region of deep space that was practically unknown just a generation ago.

Library of galaxy histories reconstructed from motions of stars | Instituto de Astrofísica de Andalucía - CSIC
http://www.iaa.es/en/news/library-galaxy-histories-reconstructed-motions-stars

The CALIFA survey allows to map the orbits of the stars of a sample of 300 galaxies, a fundamental information to know how they formed and evolved.

Just like the Sun is moving in our Galaxy, the Milky Way, all the stars in galaxies are moving, but with very different orbits: some of the stars have strong rotations,
while others may be moving randomly with no clear rotation. Comparing the fraction of stars on different orbits we can find out how galaxies form and evolve. An international
team of astronomers has derived directly, for the first time, the orbital distribution of a galaxy sample, containing more than 300 galaxies of the local universe. The results,
published in Nature Astronomy, are based on the CALIFA survey, a project developed at Calar Alto Observatory and conceived from the Institute of Astrophysics of Andalusia.

Galaxies are largest structures in the universe, and scientist study how they evolve to understand the history of the universe. Galaxy formation entails the hierarchical
assembly of halos of dark matter (a type of matter that has not been directly observed and whose existence and properties are inferred from its gravitational effects), along
with the condensation of normal matter at the halos´ center, where stellar formation takes place. Stars that formed from a settled, thin gas disk and then lived though dynamically
quiescent times will present near circular orbits, while stars with random motions are the result of turbulent environments, either at birth or later, with galactic mergers.

Proyecto CALIFA: arqueología galáctica en 3D
https://www.youtube.com/watch?v=w67yS68qwto


Thus, the motions of stars in a galaxy are like a history book, they record the information about their birth and growth environment, and it may tell us how the galaxy was formed.
"However, the motion of each single star is not directly observable in external galaxies. External galaxies are projected on the observational plane as an image and we cannot resolve
the discrete stars in it -says Ling Zhu, researcher from the Max Planck Institute for Astronomy who leads the study-. The CALIFA survey uses a recently developed technique, integral
field spectroscopy, which can observe the external galaxies in such a way that it provides the overall motion of stars. Thus, we can get kinematic maps of each galaxy."

The researchers then build models for each galaxy by superposing stars on different types of orbits. By constraining the model with the observed image and kinematic maps, they can
find out the amount of stars moving on different types of orbits in each galaxy. They call it the stellar orbit distribution and, for this study, the team has built models for all
300 galaxies, representative of the general properties of galaxies in the local universe.

The Geometry of Nuclear Black Hole Accretion Diskssu201750 | www.cfa.harvard.edu/
https://www.cfa.harvard.edu/news/su201750

CfA astronomer Anna Pancoast and a team of her colleagues analyzed reverberation mapping data of four AGN to study their geometries and, in particular,
the volume of hot gas known for its rapid motions, the so-called broad line region because the spectral lines have widths corresponding to as much as
three thousand kilometers per second. The scientists find the geometry of this gas, at least in these four AGN, is well-described as coming from thick
disks seen nearly face-on, with median radii from about 1600 AU to 4000 AU, and each with a black hole whose mass is about seventy million solar-masses
(with an estimated precision for each one of about 50%). The new work was successful in modeling the observations and nearly doubles the size of the AGN
sample modeled with this technique. The sample is still small, however, and more observations are being planned.

Supermassive black holes control star formation in large galaxies
https://news.ucsc.edu/2018/01/supermassive-black-holes.html

Astronomers find close correlation between the mass of a galaxy's central black hole and its star formation history

Young galaxies blaze with bright new stars forming at a rapid rate, but star formation eventually shuts down as a galaxy evolves. A new study, published
January 1, 2018, in Nature, shows that the mass of the black hole in the center of the galaxy determines how soon this "quenching" of star formation occurs.

Every massive galaxy has a central supermassive black hole, more than a million times more massive than the sun, revealing its presence through its gravitational
effects on the galaxy's stars and sometimes powering the energetic radiation from an active galactic nucleus (AGN). The energy pouring into a galaxy from an active
galactic nucleus is thought to turn off star formation by heating and dispelling the gas that would otherwise condense into stars as it cooled.

The Plasma Magnet Drive: A Simple, Cheap Drive for the Solar System and Beyond
https://www.centauri-dreams.org/?p=39048