Hunter’s Moon 2019


In honour of the full Hunter’s Moon this weekend – timelapse from Adrien Mauduit at Night Lights Films – https://www.youtube.com/channel/UCC0CLzCpM6nuLSAi1JNBjkA

Hunter’s is an autumn moon, the first full moon of fall following the Harvest (full moon closest to the fall equinox) moon. https://earthsky.org/tonight/full-hunters-moon-from-dusk-till-dawn?utm_source=EarthSky+News&utm_campaign=45a5e032e7-EMAIL_CAMPAIGN_2018_02_02_COPY_01&utm_medium=email&utm_term=0_c643945d79-45a5e032e7-393970565

Ponder origin of all named moons at the link below –

https://www.timeanddate.com/astronomy/moon/full-moon-names.html

Open Contest To Name 20 New Moons Of Saturn


Today, Scott Sheppard of Carnegie Institution for Science launched a contest to name 20 newly discovered moons of Saturn. For those keeping score,  Saturn (now with 82 moons) leapfrogged past Jupiter (79 moons) to claim satellite supremacy.

Illustration is courtesy of the Carnegie Institution for Science, Saturn image is courtesy of NASA/JPL-Caltech/Space Science Institute. Starry background courtesy of Paolo Sartorio/Shutterstock.

Dust off history books, brush up on Norse, Gallic and Inuit mythology – between now and December 6, 2019 the contest is open to anyone who follows IAU rules. Follow link below to enter contest.

From Wikipedia –

In 1847 the seven then known moons of Saturn were named by John Herschel. Herschel named Saturn’s two innermost moons (Mimas and Enceladus) after the mythological Greek Giants, and the outer five after the Titans (Titan, Iapetus) and Titanesses (Tethys, Dione, Rhea) of the same mythology. Until then, Titan was known as the “Huygenian (or Huyghenian) satellite of Saturn” and the other moons had Roman numeral designations in order of their distance from Saturn. Subsequent discoverers of Saturnian moons followed Herschel’s scheme: Hyperion was discovered soon after in 1848, and the ninth moon, Phoebe, was named by its discoverer in 1899 soon after its discovery; they were named for a Titan and a Titaness respectively. The name of Janus was suggested by its discoverer, Audouin Dollfus.

Current IAU practice for newly discovered inner moons is to continue with Herschel’s system, naming them after Titans or their descendants. However, the increasing number of moons that were being discovered in the 21st century caused the IAU to draw up a new scheme for the outer moons. At the IAU General Assembly in July 2004, the WGPSN allowed satellites of Saturn to have names of giants and monsters in mythologies other than the Greco-Roman. Since the outer moons fall naturally into three groups, one group is named after Norse giants, one after Gallic giants, and one after Inuit giants. The only moon that fails to fit this scheme is the Greek-named Phoebe, which is in the Norse group.

  • Two of the newly discovered prograde moons fit into a group of outer moons with inclinations of about 46 degrees called the Inuit group. All name submissions for this group must be giants from Inuit mythology.
  • Seventeen of the newly discovered moons are retrograde moons in the Norse group. All name submissions for this group must be giants from Norse mythology.
  • One of the newly discovered moons orbits in the prograde direction and has an inclination near 36 degrees, which is similar to those in the Gallic group, although it is much farther away from Saturn than any other prograde moons. It must e named after a giant from Gallic mythology.

https://carnegiescience.edu/NameSaturnsMoons

Black Hole Visualization


This week NASA’s Goddard Space Flight Center released a black hole visualization. Jeremy Schnittman, astrophysicist specializing in computational modeling of black hole accretion flows enlisted computer software to animate black hole glory. From https://www.nasa.gov/feature/goddard/2019/nasa-visualization-shows-a-black-hole-s-warped-world

Viewed from the side, the disk looks brighter on the left than it does on the right. Glowing gas on the left side of the disk moves toward us so fast that the effects of Einstein’s relativity give it a boost in brightness; the opposite happens on the right side, where gas moving away us becomes slightly dimmer. This asymmetry disappears when we see the disk exactly face on because, from that perspective, none of the material is moving along our line of sight.

Closest to the black hole, the gravitational light-bending becomes so excessive that we can see the underside of the disk as a bright ring of light seemingly outlining the black hole. This so-called “photon ring” is composed of multiple rings, which grow progressively fainter and thinner, from light that has circled the black hole two, three, or even more times before escaping to reach our eyes. Because the black hole modeled in this visualization is spherical, the photon ring looks nearly circular and identical from any viewing angle. Inside the photon ring is the black hole’s shadow, an area roughly twice the size of the event horizon — its point of no return.

“Simulations and movies like these really help us visualize what Einstein meant when he said that gravity warps the fabric of space and time,” Jeremy Schnittman, who created the images at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, said in a statement.

Simulated black hole.

Click in to see more angles. | The black hole is seen nearly edgewise in this new visualization from NASA. The turbulent disk of gas around the hole takes on a double-humped appearance. The black hole’s extreme gravity alters the paths of light coming from different parts of the disk, producing the warped image. “What we see depends on our viewing angle,” NASA said. Image via NASA’s Goddard Space Flight Center/Jeremy Schnittman.

NASA creates stunning new black hole visualization

Hello Again, You Perfect Moon


Somewhere beyond rivulets of torrential rain assaulting the bedroom window, a full, plump harvest moon prickles with sunlit illumination. Consumed by late night melancholy, my heart aches for restorative lunar wonder. Doesn’t matter to me how often I’ve posted this video. I’ll do it again, and again and again because it makes me smile. This is my happy place – have you ever really seen the Moon?

Night Skies And Petroglyphs


From Harun Mehmedinovic and Gavin Heffernan at https://vimeo.com/357143587 – Ancestral Nights. Filmed for Skyglow Project, a crowdfunded endeavor illustrating effects of light pollution on dark skies. Lose yourself in night skies and petroglyphs….

Carvings, structures and petroglyphs captured in this video represent ancient observance of night skies by Native Hawaiians, Paiute people of California and Puebloans of the Southwest.

Concentric white circles filling the sky over large rock with symbols carved into it.

“These petroglyphs and structures reflect the long standing interest in ancient astronomy which grew stronger as many of the tribes went from the hunter-gatherer to the agrarian societal orders. From references to the sun carved in the rock, and interest in using the sun to predict seasons (entire buildings built to serve as sundials and calendars, a critical element in the farming communities) to those of 13 moons (lunar annual calendar), to carvings of stars and constellations, interest in celestial bodies is ever present across the indigenous communities of the United States.” – Harun Mehmedinovic

Twilight


This evening, gloriously bruised skies created a twilight ponder. Twilight struck with realization most of us take her mesmerizing palette for granted. Far from a cosmic constant, twilight requires atmosphere to scatter rays of light in advance and conclusion of a visible Sun above the horizon.

Civil twilight falls when the sun is 6 degrees below the horizon. In the morning this is known as dawn, in the evening, dusk. This is the limit at which twilight illumination is sufficient, under good weather conditions, for terrestrial objects to be clearly distinguished; at the beginning of morning civil twilight, or end of evening civil twilight, the horizon is clearly defined and the brightest stars are visible under good atmospheric conditions in the absence of moonlight or other illumination. In the morning before the beginning of civil twilight and in the evening after the end of civil twilight, artificial illumination is normally required to carry on ordinary outdoor activities.


Nautical twilight begins when the Sun is 12 degrees below the horizon. At the beginning or end of nautical twilight, under good atmospheric conditions and in the absence of other illumination, general outlines of ground objects may be distinguishable, but detailed outdoor operations are not possible, and the horizon is indistinct.


Astronomical twilight defines a Sun 18 degrees below the horizon. Before the beginning of astronomical twilight in the morning and after the end of astronomical twilight in the evening the Sun does not contribute to sky illumination; for a considerable interval after the beginning of morning twilight and before the end of evening twilight, sky illumination is so faint that it is practically imperceptible.

Civil, nautical, astronomical, three clearly defined twilights that forgot to mention – twilight is also a colour, emotion and source of cosmic wonder unique to our planet.

 

How To Name New Moons Of Jupiter


Trust me when I say the International Astronomical Union (IAU) https://www.space.com/29696-international-astronomical-union.html rarely engages the public in astronomical matters. Truth is IAU arrogance rubs many a scientist the wrong way. IAU members have sole authority and discretion in naming astronomical objects and features, but for a stroke of IAU pen Pluto would still call itself planet. Cosmic nomenclature isn’t official until the IAU says so.

In summer 2018 science discovered twelve unknown moons of Jupiter, now the IAU wants help in naming five. Anyone can submit entries, but guidelines are strict. In keeping with Jovian propriety moons of Jupiter are named for characters in Greek or Roman mythology either descended from or lovers of Zeus. Ponder this before referencing ancient mythology – not all moons orbit Jupiter in the same direction. Those orbiting in the same direction (in this case 2 out of 5) require names ending in “a”, opposite rotation require names ending in “e”. Submissions can’t be similar to other cosmic bodies/features or be culturally offensive.

Diagram of Jupiter's moons including five recently-discovered

Anyone up for the challenge has until April 15, 2019 to submit nominations and explain why in a single tweet to @JupiterLunacy tagged #NameJupitersMoons

https://www.space.com/help-name-five-moons-of-jupiter.html