Supermoon, Geminid meteor shower tonight


This video says about itself:

Supermoon In December 2016 Will Complete Trifecta

On Dec. 13, 2016, the full moon will be at perigee causing it to look brighter and slightly larger than a usual full moon. This is the third straight month where the full moon can be considered a “Supermoon“. — When, Where and How To See It: here.

From eNatureBlog in the USA:

Don’t Miss Tuesday Night’s Supermoon And Geminid Meteor Shower

Sunday, December 11, 2016 by eNature

December’s skies are busy whether you’re looking for meteors or want to enjoy the bright light of the supermoon. Here’s a quick summary of some exciting end-of-year goings on in this month’s night sky.

Tuesday’s Supermoon

The full moons in October, November and December of this year all are supermoons. According to EarthSky, astrologer Richard Nolle developed the term supermoon more than 30 years ago. The term only began to be used recently, however. Nolle defined a supermoon as “a new or full moon which occurs with the moon at or near (within 90 percent of) its closest approach to Earth in a given orbit.”

The last segment of this year’s supermoon trifecta happens on Tuesday, Dec. 13th. The moon technically will reach its peak fullness at 7:05 p.m. EST, but it will appear full when you look in the sky the night before and shortly after the peak experience.

Geminids Meteor Shower

This month’s supermoon is happening the same night as the peak of the Geminids meteor shower— which is the night of Dec. 13-14. According to NASA, the Geminids are “typically one of the best and most reliable of the annual meteor showers.” The metors usually start to be noticeable around 9 or 10 p.m., making them a favorite for kids to watch because they get going before bedtime.

But because they coincide with the bright, full moon this year, the light of the moon will reduce visibility “five to ten fold,” according to NASA.

Ursids Meteor Shower

The Ursids radiate from the Big Dipper [no, the Little Dipper] or Ursa Minor. They run this year from Dec. 17-23, but the best time to catch meteors according to NASA, will be from midnight on Dec. 21 until about 1 a.m. on Dec. 22. There’s a good, but not guaranteed, chance they’ll also be active on Dec. 23 and Dec. 24 as well.

Are you planning to catch the Supermoon or the Geminids? Let us know how you make out!

EarthSky has a good, in-depth story on the Geminids and how to best see them.

Moon’s lava tubes could be colossal. Caverns might make spacious home for moon colonists. By Thomas Sumner, 9:00am, December 15, 2016: here.

Cassini spacecraft photographs Saturn


This video says about itself:

NASA’s Cassini spacecraft releases first close-up photos of Saturn

7 December 2016

At just 240,000 miles from Saturn‘s north pole, NASA’s Cassini spacecraft snapped some stunning photos. These are the first images of the spacecraft’s new mission, which is taking it closer to Saturn than it has been since it arrived at Saturn in 2004.

By Brandon Russell in the USA, December 10, 2016:

NASA’s Cassini takes breathtaking images of Saturn’s northern hemisphere

NASA’s Cassini has been soaring through the cosmos for nearly 20 years and to celebrate the latest phase of its journey, the intrepid spacecraft has sent scientists new images of Saturn’s northern hemisphere.

The purpose of Cassini’s newest mission phase, called Ring-Grazing Orbits, is to skim past the outer edges of the planet’s main rings, according to NASA. The pictures … which highlight the planet’s hexagon-shaped jet stream, were taken in early December.

“This is it, the beginning of the end of our historic exploration of Saturn,” said Carolyn Porco, Cassini imaging team lead at Space Science Institute. “Let these images—and those to come—remind you that we’d lived a bold and daring adventure around the solar system’s most magnificent planet.”

Cassini will continue its ring-grazing orbits until April 22 of next year, where it will then begin its descent toward the planet’s surface. By September of 2017, Cassini will no longer exist.

The beginning of the end

Cassini launched all the way back in 1997 and has continued to study the Saturn system since arriving in 2004.

Over the years, the orbiter has uncovered a potential ocean on a Saturn moon, and sent back an incredibly beautiful image of a hurricane on the planet, among many other accomplishments.

Saturn’s 10th moon was the first satellite discovered in the modern space age. Excerpt from the January 14, 1967, issue of Science News: here.

Stars get official names


WHAT’S IN A NAME? Names of eight stars in the constellation Orion, plus one (Cursa) in Eridanus, are among the 227 now officially sanctioned by the International Astronomical Union. Picture by Rogelio Bernal Andreo

From Science News:

Gaggle of stars get official names

International Astronomical Union weighs in with formal designations for 227 stars

By Christopher Crockett

1:47pm, December 2, 2016

For centuries, stargazers have known which star was Polaris and which was Sirius, but those designations were by unofficial tradition. The International Astronomical Union, arbiter of naming things in space, has now blessed the monikers of 227 stars in our galaxy. As of November 24, names such as Polaris (the North Star) and Betelgeuse (the bright red star in Orion) are approved.

Until now, there has been no central star registry or guidelines for naming. There are many star catalogs, each one designating stars with different combinations of letters and numbers. That excess of options has left most stars with an abundance of labels (HD 8890 is one of over 40 designations for Polaris).

The tangle of titles won’t disappear, but the new IAU catalog is a stab at formalizing the more popular names. Before this, only 14 stars (included in the 227) had been formally named, as part of the IAU’s contest to name notable exoplanets and the stars that they orbit (SN: 2/6/16, p. 5). One famous star is returning to its ancient roots. The brightest member of Alpha Centauri, the pair of stars that are among the closest to our solar system, is now officially dubbed Rigil Kentaurus, an early Arabic name meaning “foot of the centaur.”

Women in astronomy


This video says about itself:

How a Team of Female Astronomers Revolutionized Our Understanding of Stars

24 February 2016

At the turn of the 19th century, male astronomers mainly studied galaxies, leaving female scientists wide latitude to research and innovate. Indeed they accomplished truly stellar work. Frebel’s book is “Searching for the Oldest Stars: Ancient Relics from the Early Universe“.

From Science News in the USA:

‘The Glass Universe’ celebrates astronomy’s unsung heroines

Women in the 19th century played underappreciated role in mapping and understanding the stars

By Macon Morehouse

8:00am, November 27, 2016

The Glass Universe
Dava Sobel
Viking, $30

In the early 1880s, Harvard Observatory director Edward Pickering put out a call for volunteers to help observe flickering stars. He welcomed women, in particular — and not just because he couldn’t afford to pay anything.

At the time, women’s colleges were producing graduates with “abundant training to make excellent observers,” Pickering wrote. His belief in women’s abilities carried over when he hired staff, even though critics of women’s higher education argued that women “originate almost nothing, so that human knowledge is not advanced by their work.”

Pickering and his “harem” sure proved the critics wrong.

In The Glass Universe, science writer Dava Sobel shines a light on the often-unheralded scientific contributions of the observatory’s beskirted “computers” who helped chart the heavens. By 1893, women made up nearly half of the observatory’s assistants, and dozens followed in their footsteps.

These women toiled tirelessly, marking times, coordinates and other notations for photographic images of the sky taken nightly and preserved on glass plates — the glass universe. These women’s routine mapping of the stars gave birth to novel ideas that advanced astronomy in ways still instrumental today — from how stars are classified to how galactic distances are measured.

Using diaries, letters, memoirs and scientific papers, Sobel recounts the accomplishments of these extraordinary women, going into enough scientific detail (glossary included) to satisfy curious readers and enough personal detail to bring these women’s stories to life.

Sobel traces the origin of the glass universe back to heiress Anna Palmer Draper. The book opens in 1882 with her exulting in hosting a party for the scientific glitterati under the glowing and novel Edison incandescent lights. Her husband, Henry Draper, a doctor and amateur astronomer, had pioneered a way to “fix” the stars on glass photographic plates. The resulting durable black-and-white images revealed spectral lines that could provide hints to a star’s elements — and eventually so much more. Henry’s premature death five days after the party launched Anna’s philanthropic support of the Harvard Observatory and the creation of the glass universe.

Other women featured in the book had a more hands-on impact on astronomy. For instance, Williamina Fleming came to the United States as a maid. But Pickering soon recognized her knack for mathematics. At the observatory, she read “the rune-like lines of the spectra,” Sobel writes, noticing patterns that led to the first iteration in 1890 of the Draper stellar classification system. That system, still used today, was later refined by the observations of other women.

Henrietta Leavitt, a promising Radcliffe College astronomy student slowly going deaf, joined the staff in 1895. While meticulously tracking the changing brightness of variable stars, she noticed a pattern: The brighter a star’s magnitude, the longer it took to cycle through all its variations. This period-luminosity law, published in 1912, became crucial in measuring the distance to stars. It underpinned Edwin Hubble’s law on cosmic expansion and led to discoveries about the shape of the Milky Way, our solar system’s place far from the galactic center and the existence of other galaxies.

The story belongs, too, to Pickering and his successor, Harlow Shapley. Perhaps partly motivated by economics at a time of shoestring budgets — in 1888, women computers earned just 25cents per hour — these men not only recognized, but also encouraged and heralded the women’s talent.

Sobel takes readers through World War II and a myriad of other moments starring women: first woman observatory head; first woman professor at Harvard (of astronomy, of course); discoveries of binary stars, the prevalence of hydrogen and helium in stars, and the existence of interstellar dust. In some cases, it took male astronomers to make those findings stick — the glass universe had a glass ceiling.

After World War II, radio astronomy emerged, and “the days of the human computer were numbered — by zeros and ones,” Sobel writes. Using film to photograph the stars ended in the 1970s. But the glass universe is far from obsolete. The roughly half-million plates hold the ghosts of pulsars, quasars and other stellar phenomena not even imagined when the plates were made. They also offer the promise of more discoveries to come, perhaps by the next generation of women astronomers.

Some pulsars lose their steady beat. New discoveries hint at hidden population of neutron stars. By Christopher Crockett, 9:00am, January 6, 2017: here.

Many galaxies discovered by astronomers


This video says about itself:

Astronomers just discovered one of the most massive objects in the universe hiding behind the Milky Way

23 November 2016

Through the thick fog of our own galaxy, astronomers have spotted an ultimate prize: one of the largest-known structures in the universe. Called the Vela supercluster, the newly discovered object is a massive group of several galaxy clusters, each one containing hundreds or thousands of galaxies. “I could not believe such a major structure would pop up so prominently” after an observation of that region of space, said Renée Kraan-Korteweg, an astrophysicist at the University of Cape Town in South Africa, in a press release. Kraan-Korteweg and her team published their discovery of the supercluster, named after the constellation Vela where it was found, in the Monthly Notices Letters of the Royal Astronomical Society.

From Science News:

Giant gathering of galaxies discovered hiding on far side of Milky Way

Astronomers plan to investigate Vela supercluster’s gravitational tug

By Christopher Crockett

7:00am, November 23, 2016

An immense wall of galaxies, stretching over 380 million light-years, is hiding beyond the far side of the Milky Way.

Dubbed the Vela supercluster, this galactic horde sits about 800 million light-years away in the constellation Vela, researchers report online November 8 in Monthly Notices of the Royal Astronomical Society Letters. Despite its size and relative proximity, Vela has gone unnoticed because it is largely obscured by our own galaxy.

Superclusters — assemblages of groups of galaxies — are among the largest known structures in the universe. Following up on earlier hints that an uncharted supercluster might lurk nearby, Renée Kraan-Korteweg, an astronomer at the University of Cape Town in South Africa, and colleagues scoured a patch of sky bisected by a wall of stars that is part of the Milky Way. Using telescopes in South Africa and Australia, they measured distances to 4,432 galaxies and found that many, to the north and south of the wall, appear to be clumped together.

Vela could help solve a long-standing mystery. The Milky Way and dozens of other galaxies in the immediate neighborhood move together through space. Gravity from known superclusters can account for some of that motion, but not all of it. Astronomers don’t yet know the mass — and hence the gravitational influence — of Vela, but it could be partly responsible for nudging us along.

Star-starved galaxies fill the cosmos. As researchers find hundreds of galaxies with scarce starlight, questions pile up. By Christopher Crockett
11:00am, November 29, 2016: here.

More meteorites on moon than expected


CRATER CRAZE Images captured by the Lunar Reconnaissance Orbiter from 2009 to 2015 revealed 222 new impact craters (in yellow) on the moon. Red dots are new craters whose impacts were observed from Earth

From Science News:

Surprising number of meteoroids hit moon’s surface

Lunar images reveal over 200 new craters and about 47,000 undiscovered ‘splotches’

By Emily DeMarco

8:00am, November 16, 2016

The moon is one tough satellite. With no atmosphere, it endures a barrage of incoming asteroids and comets that pit its surface with a constellation of craters. A new map (above) reveals 222 recent impact craters (in yellow), 33 percent more than simulations predicted. Scientists spotted the features by analyzing about 14,000 pairs of before-and-after images captured by the Lunar Reconnaissance Orbiter from 2009 to 2015. (Red dots note new craters whose impacts were observed from Earth.)

The craters — up to 43 meters in diameter — were probably formed by small meteoroids crashing into the crust. Using the image pairs, the researchers created ratio images, which highlight how the impacts alter the reflectance of the moon’s surface. That perspective illuminated the starburst debris patterns around the craters.

The scientists also found about 47,000 “splotches,” faint marks several to tens of meters across. Most result from secondary debris being jettisoned by impacts and spattering the surface, the researchers propose in the Oct. 13 Nature.

Those splotches would “churn” the upper two centimeters of lunar soil in about 81,000 years, more than 100 times faster than previous predictions that didn’t include the smudges, researchers say. That revelation could improve interpretations of remote-sensing data and help engineers design equipment to better withstand the occasional speckling of soil, says study coauthor Mark Robinson, a planetary geologist at Arizona State University in Tempe. “All of the images we’re taking … and the discoveries we’re making are feeding forward into future human exploration of the moon,” he says.

Supermoon, 14 November 2016


This video from the USA says about itself:

14 October 2016

Nothing beats a bright and beautiful “supermoon.” Except maybe, three supermoons! 2016 ends with a trio of full moons at their closest points to Earth.

From eNatureBlog in the USA:

Don’t Miss Monday’s Supermoon

Tuesday, November 08, 2016 by eNature

November’s full moon is special this year.

It’s not only a supermoon — which looks larger to skywatchers than a “regular” full moon — it will be the closest full moon to Earth since January 1948! NASA says we won’t see a full moon this large again until Nov. 25, 2034.

The full moon officially happens next Monday at 8:52 A.M. Eastern Standard Time. So it won’t be visible along the East Coast at the exact moment of fullness, but it will on the West Coast.

So What Makes The Moon Look So Big?

Because the moon’s orbit around Earth is an elliptical shape the moon can be closer or farther from the Earth’s surface depending on where it is in its orbit. The point when our lunar companion is closest to Earth is called perigee. Apogee is the opposite—when the moon is at its furthest point from Earth.

This month, the perigee occurs Nov. 14 at about 6 A.M. EST— within two hours of the moon becoming officially full — meaning that we will see an extra-super, perigee full moon.

So Just How Close Is The Moon?

The distance between Earth and the moon ranges from 221,208 miles at its closest approach to 252,898 miles at its farthest. That’s a difference of about 32,000 miles.

This month, perigee (and the full moon) occurs at 221,524 miles between Earth and the moon, just 316 miles from its nearest possible location. So you can see why the moon will look so big!

What Exactly Is A “Supermoon”

Astrologer Richard Nolle defined the term back in 1979, but its use has really taken off in the past few years. It often it seems that every moon is a supermoon in breathless headlines on the internet, but the term has a very specific meaning.

Nolle specifically defined a “supermoon” as a new or full moon that occurs when the moon is within 90 percent of its closest approach to Earth in a given orbit. And this week’s full moon occurs when the moon is within 99% of its closest approach, so it clearly meets the definition.

But It’s Not All Happening In The Sky

The supermoon also has an impact on coasts and bays. From November through February, the highest tides, known as “king tides”, sweep along the shores during full moons.

The sun is the closest to Earth during those months and the combined gravity of it and the moon working together increases tidal ranges during that time. The tides get even higher during “supermoons” simply because the moon is that much closer to Earth than it normally is.

So When To Look For The Supermoon

On the East Coast , the nearly-full moon rises at 4:30 P.M. this Sunday afternoon , while the sun sets at around 5:00 P.M. The following morning, the moon sets at 6:36 A.M. — so if you scoot out of bed around 5 A.M., you’ll see the moon low in the western sky plump and full. The full moon rises Monday evening at 5:30 p.m., so look for it close to the eastern horizon.

The timing is similar for other parts of the country, the Naval Observatory provides rise and set times for the moon and sun.

The next perigee full moon occurs Dec. 1, the third such moon in an October-November-December lunar trifecta. After that, there will be a perigee full moon on Jan. 1-2, 2018, when the moon and the Earth will be 221,559 miles apart.

So don’t miss out next week!