Monday, April 25, 2016

Beautiful Celestial Grouping in Pre-Dawn Sky Mon., Tue.



The Moon, Mars, Saturn, and Antares on the mornings of April 24-26, 2016
Beautiful celestial grouping before dawn on Monday
and Tuesday (2016 April 25 and 26).
(Graphic Source: Sky and Telescope Magazine)

By Glenn A. Walsh
Reporting for SpaceWatchtower

Monday and Tuesday mornings (2016 April 25 and 26), before dawn, early risers will be able to view a beautiful quasi-conjunction or celestial grouping of the Moon, two planets (Mars and Saturn), and the bright Star Antares.

Before dawn on Monday and Tuesday, this celestial grouping can be found in the south-southwestern sky.

On Monday morning the four objects will form a sort-of square or diamond with the Moon above the rest. Saturn will be to the left of the Moon, with Mars below the Moon. The bright Star Antares, which is dimmer than the two planets, can be found 5 degrees to the lower left of Mars.

On Tuesday the configuration of the planets and star remain, pretty-much the same. However, Tuesday morning the Moon can be found to the upper left of Saturn. Hence, the Moon, Saturn, and Mars create almost a straight-line, with Antares still to the lower left of Mars.

The Moon is now in its Waning Gibbous Phase, having passed Full Moon (the “Pink Moon”) early Friday morning at 1:24 a.m. Eastern Daylight Saving Time (EDT) / 5:24 Coordinated Universal Time (UTC). As a Waning Gibbous Moon, the Moon now rises very late in the evening, but is in the sky by local Midnight. So, these celestial configurations could also be seen earlier in the morning, as well.

Mars is brightening as it grows closer to the Earth. Currently, Mars has a visual magnitude of about -1.3. Mars will be at opposition (when the Earth lies directly between Mars and the Sun) on May 22 at 7:00 a.m. EDT / 11:00 UTC, when Mars will be visible from Earth from approximately local sunset to approximately local sunrise.

Mars will reach its closest point to Earth, for the next two years, on May 30 at 4:00 a.m. EDT / 8:00 UTC, when Mars will have a visual magnitude of -2.1 and a light-speed distance from Earth of 4.2 light-minutes. This will be the closest Mars has been to the Earth since 2005. In two years (July of 2018), Mars will approach about the closest it ever comes to the Earth.

Saturn is somewhat dimmer than Mars at the visual magnitude of +0.3. Like Mars, it rises in the late evening, but about a half-hour later.

Both Mars and Saturn are now in retrograde motion, with Mars having begun the retrograde motion following the Mars movement becoming stationary (from normal motion) on the evening of April 16 at 10:00 p.m. EDT / April 17 at 2:00 UTC. This means that both planets can be seen, from one night to the next, moving from east to west relative to the background stars. When these planets are in normal or prograde motion, they move from west to east relative to the background stars, from one night to the next.

Antares is the brightest star in the Constellation Scorpius the Scorpion, and hence, the astronomical designation for Antares is Alpha Scorpii. However, Antares is the dimmest of the four objects with an apparent visual magnitude of +0.96. The Constellation Scorpius will be in good view below the two planets, until the sky brightens for dawn.

More on the Moon: Link >>> https://en.wikipedia.org/wiki/Moon

More on Mars: Link >>> https://en.wikipedia.org/wiki/Mars

More on Saturn: Link >>> https://en.wikipedia.org/wiki/Saturn

More on Star Antares: Link >>> https://en.wikipedia.org/wiki/Antares

More on Constellation Scorpius: Link >>> https://en.wikipedia.org/wiki/Scorpius

Source: Glenn A. Walsh Reporting for SpaceWatchtower, a project of Friends of the Zeiss.
              2016 April 25

            May 9 - Safe Public Viewing of Rare Astronomical Event


                                                               Historic 10-inch Siderostat-type Refractor Telescope at Pittsburgh's original Buhl Planetarium and Institute of Popular Science.
        2016: 75th Year of Pittsburgh's Buhl Planetarium Observatory
     Link >>> http://spacewatchtower.blogspot.com/2016/01/astronomical-calendar-2016-january.html

                             Like This Post? - Please Share!

Want to receive SpaceWatchtower blog posts in your inbox ?
Send request to < spacewatchtower@planetarium.cc >..

gaw

Glenn A. Walsh, Project Director,
Friends of the Zeiss < http://buhlplanetarium.tripod.com/fotz/ >
Electronic Mail - < gawalsh@planetarium.cc >
SpaceWatchtower Blog: < http://spacewatchtower.blogspot.com/ >
Also see: South Hills Backyard Astronomers Blog: < http://shbastronomers.blogspot.com/ >
Barnestormin: Writing, Essays, Pgh. News, & More: < http://www.barnestormin.blogspot.com/ >
About the SpaceWatchtower Editor / Author: < http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
SPACE & SCIENCE NEWS, ASTRONOMICAL CALENDAR:
http://buhlplanetarium.tripod.com/#news >
Twitter: < https://twitter.com/spacewatchtower >
Facebook: < http://www.facebook.com/pages/SpaceWatchtower/238017839577841?sk=wall >
Author of History Web Sites on the Internet --
* Buhl Planetarium, Pittsburgh:
  < http://www.planetarium.cc >
* Adler Planetarium, Chicago:
  < http://adlerplanetarium.tripod.com >
* Astronomer, Educator, Optician John A. Brashear:
  < http://johnbrashear.tripod.com >
* Andrew Carnegie & Carnegie Libraries:
  < http://www.andrewcarnegie.cc >
* Civil War Museum of Andrew Carnegie Free Library:
  < http://garespypost.tripod.com >
Duquesne Incline cable-car railway, Pittsburgh:
  < http://inclinedplane.tripod.com >
* Public Transit:
  < http://andrewcarnegie2.tripod.com/transit >

Tuesday, April 19, 2016

Laser Cloaking of Earth From Alien Civilizations?

A 22W laser used for adaptive optics on the Very Large Telescope in Chile. A suite of similar lasers could be used to alter the shape of a planet's transit for the purpose of broadcasting or cloaking the planet. Credit: ESO / G. Hüdepohl
(Image Sources: ESO / G. Hüdepohl)

From: EarthSky.org

In a paper published on Wednesday, 2016 March 30 in Monthly Notices of the Royal Astronomical Society, two astronomers at Columbia University in New York propose that humanity could use lasers to conceal the Earth from searches by advanced extraterrestrial civilizations.

The new work is in line with suggestions by several prominent scientists, including Stephen Hawking, who have cautioned against humanity’s broadcasting its presence to intelligent life on other planets, lest those civilizations be warlike and desirous of Earth resources.

And it’s in line with an abundance of work over past decades in which earthly astronomers have sought distant planets in our Milky Way galaxy. A primary method for finding these exoplanets is the transit method, which is a high-tech search for a minute dip in starlight when a planet moves directly in front of the star it orbits. Transits are the main way that the Kepler mission and similar projects have discovered some 2,000 planets orbiting distant suns. So far, a few tens of these worlds appear to be similar in size to the Earth.

The suggestion for Earth-cloaking by the Columbia astronomers supposes that other civilizations might also try to find Earth-like planets using the transit method.

More - Link >>> https://earthsky.org/space/use-laser-cloaking-to-hide-earth-from-aliens

Sources: Royal Astronomical Society, EarthSky.org .
              2016 April 19.

Related Blog Post ---

"Laser-Propelled Nano-Space Probe to Reach Alpha Centauri in 20 Years?"

2016 April 14.

Link >>> http://spacewatchtower.blogspot.com/2016/04/laser-propelled-nano-space-probe-to.html

 
            May 9 - Safe Public Viewing of Rare Astronomical Event


                                                               Historic 10-inch Siderostat-type Refractor Telescope at Pittsburgh's original Buhl Planetarium and Institute of Popular Science.
        2016: 75th Year of Pittsburgh's Buhl Planetarium Observatory
     Link >>> http://spacewatchtower.blogspot.com/2016/01/astronomical-calendar-2016-january.html

                             Like This Post? - Please Share!

Want to receive SpaceWatchtower blog posts in your inbox ?
Send request to < spacewatchtower@planetarium.cc >..

gaw

Glenn A. Walsh, Project Director,
Friends of the Zeiss < http://buhlplanetarium.tripod.com/fotz/ >
Electronic Mail - < gawalsh@planetarium.cc >
SpaceWatchtower Blog: < http://spacewatchtower.blogspot.com/ >
Also see: South Hills Backyard Astronomers Blog: < http://shbastronomers.blogspot.com/ >
Barnestormin: Writing, Essays, Pgh. News, & More: < http://www.barnestormin.blogspot.com/ >
About the SpaceWatchtower Editor / Author: < http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
SPACE & SCIENCE NEWS, ASTRONOMICAL CALENDAR:
http://buhlplanetarium.tripod.com/#news >
Twitter: < https://twitter.com/spacewatchtower >
Facebook: < http://www.facebook.com/pages/SpaceWatchtower/238017839577841?sk=wall >
Author of History Web Sites on the Internet --
* Buhl Planetarium, Pittsburgh:
  < http://www.planetarium.cc >
* Adler Planetarium, Chicago:
  < http://adlerplanetarium.tripod.com >
* Astronomer, Educator, Optician John A. Brashear:
  < http://johnbrashear.tripod.com >
* Andrew Carnegie & Carnegie Libraries:
  < http://www.andrewcarnegie.cc >
* Civil War Museum of Andrew Carnegie Free Library:
  < http://garespypost.tripod.com >
Duquesne Incline cable-car railway, Pittsburgh:
  < http://inclinedplane.tripod.com >
* Public Transit:
  < http://andrewcarnegie2.tripod.com/transit >

Thursday, April 14, 2016

Laser-Propelled Nano-Space Probe to Reach Alpha Centauri in 20 Years?



Photograph of the spaceship depicted
in the 1960s science-fiction television
series, "Lost in Space," where a family
had launched from Earth in 1997 for a
voyage to a planet orbiting the closest star,
Alpha Centauri. Now, scientists hope to
send an unmanned probe to the Alpha
Centauri star system within a generation.
(Image Source: Pinterest.com )

By Lee Billings, Scientific American

For Yuri Milner, the Russian Internet entrepreneur and billionaire philanthropist who funds the world’s richest science prizes and searches for extraterrestrial intelligence, the sky is not the limit—and neither is the solar system. Flanked by physicist Stephen Hawking and other high-profile supporters in New York, Milner announced his most ambitious investment yet: $100 million toward a research program to send robotic probes to nearby stars within a generation.

“The human story is one of great leaps,” Milner said in a statement released shortly before the announcement. “55 years ago today, Yuri Gagarin became the first human in space. Today, we are preparing for the next great leap—to the stars.”

“Breakthrough Starshot,” the program Milner is backing, intends to squeeze all the key components of a robotic probe—cameras, sensors, maneuvering thrusters and communications equipment—into tiny gram-scale “nanocraft.” These would be small enough to boost to enormous speeds using other technology the program plans to help develop, including a ground-based kilometer-scale laser array capable of beaming 100-gigawatt laser pulses through the atmosphere for a few minutes at a time, and atoms-thin, meter-wide “light sails” to ride those beams to other stars. Each pinging photon of light would impart a slight momentum to the sail and its cargo; in the microgravity vacuum of space, the torrent of photons unleashed by a gigawatt-class laser would rapidly push a nanocraft to relativistic speeds.

"Without new methods of propulsion we simply cannot get very far," Hawking said at the announcement. "Light is the most pragmatic technology available."

Deployed by the thousands from a mothership launched into Earth orbit, each nanocraft would unfurl a sail and catch a laser pulse to accelerate to 20 percent the speed of light—some 60,000 kilometers per second. Using a sophisticated adaptive-optics system of deformable mirrors to keep each pulse coherent and sharp against the blurring effects of the atmosphere, the laser array would boost perhaps one orbiting nanocraft per day. Each laser pulse would contain as much power as that produced by a space shuttle rocketing into orbit.

The array would need to be built at a dry, high-altitude location in the Southern Hemisphere, perhaps on a peak in Chile, South Africa or even Antarctica—somewhere within sight of Breakthrough Starshot’s primary targets: the twin stars of Alpha Centauri, which at 4.37 light-years away make up the nearest neighboring star system to our own. NASA has already sent five spacecraft on trajectories taking them beyond our solar system, although even the fastest of these would require more than 30,000 years to reach Alpha Centauri. The nanocraft would make that same interstellar crossing in just 20 years. With no onboard ability to decelerate, they would briefly gather data about any planets in the Alpha Centauri system and beam it back toward Earth before plunging deeper into interstellar darkness and out of communication range.

More - Link >>> http://www.scientificamerican.com/article/100-million-plan-will-send-probes-to-the-nearest-star1/

More on Project Breakthrough Starshot:
Link >>> https://en.wikipedia.org/wiki/Breakthrough_Starshot

Related Blog Posts ---

"Laser Propulsion: Earth To Mars in 3 Days?" 2016 Feb. 25.

Link >>> http://spacewatchtower.blogspot.com/2016/02/laser-propulsion-earth-to-mars-in-3-days.html

"Supersonic Laser Propulsion." 2014 Nov. 13.

Link >>> http://spacewatchtower.blogspot.com/2014/11/supersonic-laser-propulsion.html


Source: Scientific American Magazine.
              2016 April 14.

            May 9 - Safe Public Viewing of Rare Astronomical Event


                                                               Historic 10-inch Siderostat-type Refractor Telescope at Pittsburgh's original Buhl Planetarium and Institute of Popular Science.
        2016: 75th Year of Pittsburgh's Buhl Planetarium Observatory
     Link >>> http://spacewatchtower.blogspot.com/2016/01/astronomical-calendar-2016-january.html

                             Like This Post? - Please Share!

Want to receive SpaceWatchtower blog posts in your inbox ?
Send request to < spacewatchtower@planetarium.cc >..

gaw

Glenn A. Walsh, Project Director,
Friends of the Zeiss < http://buhlplanetarium.tripod.com/fotz/ >
Electronic Mail - < gawalsh@planetarium.cc >
SpaceWatchtower Blog: < http://spacewatchtower.blogspot.com/ >
Also see: South Hills Backyard Astronomers Blog: < http://shbastronomers.blogspot.com/ >
Barnestormin: Writing, Essays, Pgh. News, & More: < http://www.barnestormin.blogspot.com/ >
About the SpaceWatchtower Editor / Author: < http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
SPACE & SCIENCE NEWS, ASTRONOMICAL CALENDAR:
http://buhlplanetarium.tripod.com/#news >
Twitter: < https://twitter.com/spacewatchtower >
Facebook: < http://www.facebook.com/pages/SpaceWatchtower/238017839577841?sk=wall >
Author of History Web Sites on the Internet --
* Buhl Planetarium, Pittsburgh:
  < http://www.planetarium.cc >
* Adler Planetarium, Chicago:
  < http://adlerplanetarium.tripod.com >
* Astronomer, Educator, Optician John A. Brashear:
  < http://johnbrashear.tripod.com >
* Andrew Carnegie & Carnegie Libraries:
  < http://www.andrewcarnegie.cc >
* Civil War Museum of Andrew Carnegie Free Library:
  < http://garespypost.tripod.com >
Duquesne Incline cable-car railway, Pittsburgh:
  < http://inclinedplane.tripod.com >
* Public Transit:
  < http://andrewcarnegie2.tripod.com/transit >

Friday, April 8, 2016

Long-Distance AM Radio Reception At Risk?



AM radio stations, particularly powerful stations, often transmit hundreds of miles at night due to "Sky-Wave" radio propagation, where the radio signal bounces off of the ionosphere portion of the Earth's atmosphere. (Image Source: ccrane.com )

By Glenn A. Walsh
Reporting for SpaceWatchtower

Since 1920 November 2, with the first broadcast of the world's first commercial radio station, KDKA-AM in Pittsburgh (although, the very first broadcast came from atop the Westinghouse plant in the suburb of East Pittsburgh), many AM radio stations have been heard hundreds of miles from their transmitters at night.

However, the U.S. Federal Communications Commission (FCC) has proposed new rules which could cause great interference to the many powerful radio stations that broadcast for hundreds of miles between sunset and sunrise. The FCC proposes to allow other radio stations with lower powers, on the same or adjacent frequencies to the powerful stations, be allowed to increase their time of operation (i.e. allow these stations to operate between sunset and sunrise) and / or increase their transmission power level. This will increase interference to the more powerful stations, making it more difficult for the more powerful stations to be heard hundreds of miles away.

Normally, during daytime hours, AM radio signals use “Ground-Wave” radio propagation, whereby the ground is used to propagate the radio signal. For most AM radio stations, which are only licensed to use 5,000 watts of power or less, these radio stations are heard only within a 30 to 50 mile radius. The most powerful 50,000 watt AM radio stations can be heard within a hundred miles or further in the daytime.

Between sunset and sunrise, AM radio stations, particularly the most powerful, 50,000 watt radio stations, can be heard hundreds of miles from the radio station transmitter, due to, what is known as, “Sky-Wave” or “skip” radio propagation. Instead of just hugging the ground, radio waves also reflect off of a portion of the atmosphere called the ionosphere, back to the Earth hundreds of miles from the transmitter.

The ionosphere exists about 50 to 620 miles / 80 to 1000 kilometers above the Earth's surface. In the ionosphere, air is ionized by photons from the Sun and by cosmic rays. Ionospheric conditions can be disrupted by solar flares, particularly during times of high sunspot activity. Then, long-distance radio propagation can be degraded, and in some rare instances, enhanced.

The lower levels of the ionosphere largely disappear at night (and sometimes, very briefly, during a daytime Solar Eclipse), when not being bombarded by solar radiation. Hence, the refractive layer of the ionosphere is much higher allowing AM radio waves to be reflected back to the Earth hundreds of miles away.

Higher frequency radio signals, including those of FM radio stations and television stations, cannot, normally, use “Sky-Wave” radio propagation. These signals, which normally do not bounce off of the ionosphere back to the ground, completely penetrate the ionosphere and continue into Outer Space; although, under extreme ionization conditions, sometimes these stations can also be heard hundreds of miles away. These stations are normally received, generally, within the "line-of-sight" of the transmitter.

Short-wave radio stations, particularly, take advantage of “Sky-Wave” transmissions. At short-wave frequencies, radio transmissions can be heard thousands of miles away. In extreme ionization events, sometimes AM radio stations can, also, be heard at such distances.

At the dawn of commercial radio broadcasting, AM radio stations were mostly built in the larger cities of the country, with very few stations existing in rural areas or the mountainous areas, particularly in the west. So, the FCC (originally known as the FRC, Federal Radio Commission) created a special class of radio station, which was originally called a “Clear-Channel” station. The FCC had allocated a “Clear-Channel” radio frequency to have only one, or sometimes two, radio stations operating on that particular frequency from sunset to sunrise. In the case of a "Clear-Channel" with two nighttime stations, usually one would broadcast from the East Coast while the other broadcast from the West Coast; this distance seemed far enough away to minimize interference.

At night, such "Clear-Channel" stations would have virtually no interference from other stations on their frequency. All other radio stations operating on that particular “Clear-Channel” radio frequency were required to sign-off and leave the air at sunset, and not return to the air until sunrise.

So, using “Sky-Wave” transmissions, at night nearly every inch of American soil could be served by one or more of these "Clear-Channel" stations. This allowed thousands of Americans, who had no radio station to listen to during the daylight hours, an opportunity at night to get up-to-the-minute news, weather forecasts, and information particularly of interest to farmers.

Today, most major cities in this country have one or two, and sometimes more, very powerful AM radio stations, which can be heard hundreds of miles from their transmitters at night. In addition to Pittsburgh's KDKA, some of the better known of these AM radio stations include WWVA in Wheeling, WWKB in Buffalo, WHAS in Louisville, WGY in Schenectady, WTIC in Hartford, WBZ in Boston, WBAL in Baltimore, WRVA in Richmond, WSB in Atlanta, WCCO in Minneapolis, KMOX in St. Louis, WWL in New Orleans, WBAP in Ft. Worth, KOA in Denver, and KSL in Salt Lake City.

Some cities have several such powerful stations including WCBS, WBBR, WABC, and WOR in New York City; KYW and WPHT in Philadelphia; WLW and WCKY in Cincinnati; WSM and WLAC in Nashville; WBBM, WSCR, and WGN in Chicago; KNBR and KGO in San Francisco; and KNX and KFI in Los Angeles.

With 50,000 watts of transmitting power (the highest power level allowed for AM radio stations in the United States), the stations originally known as “Clear-Channel” radio stations are now classified as “Class A” radio stations by the FCC. Over the years, the FCC has allowed some lower-power stations, which operate on a "Clear-Channel" but are not Class A stations, to stay on later at night or start broadcasting earlier in the morning (at a power level lower than their normal daytime power level), so long as these stations do not interfere with the more powerful “Clear-Channel” stations.

Now, the FCC wants to eliminate all rules that forbid interference with Class A radio stations, by other radio stations on the same or adjacent frequencies. Over the last few years, the FCC has solicited public comments on this proposal. Final public comments were due last month.

Former radio station General Manager Glenn A. Walsh submitted public comments last month opposing the FCC plan. According to Mr. Walsh, "The major advantage of AM radio is long-distance broadcasting. If you create more interference for stations which have been successfully providing a good long-distance service for nearly a century, you are degrading the most valuable aspect of AM radio!"

In his public comments, Mr. Walsh added, "If your goal is more and better local radio stations, it would be far better to increase the size of the FM radio band, which provides the best local service and cannot provide a long-distance service."

In the 1970s, Mr. Walsh served as General Manager of a small, educational radio station near White Sulphur Springs, West Virginia, WLCR-AM Carrier Current, at a Summer camp for boys and girls called Camp Shaw-Mi-Del-Eca. Mr. Walsh taught the campers radio theory and radio station operation, and several of the campers went-on to acquire a FCC Third Class Commercial Radiotelephone License with Broadcast Endorsement.

Public Comments to the FCC from Glenn A. Walsh, regarding the proposed elimination of rules preventing interference to Class A radio stations:
Link >>> http://apps.fcc.gov/ecfs/comment/view;ECFSSESSION=4n8PWxTQ6WJZ2L2h92R0nNJ5V5Q1XfwLSKlqPSvrx1RxY3v6Dnqb!634993814!-322446565?id=60001513703

More on Sky-Wave Radio Propagation: Link >>> https://en.wikipedia.org/wiki/Skywave

More on Clear-Channel AM Radio Stations, including a List of All Clear-Channel Stations:
Link >>> https://en.wikipedia.org/wiki/Clear-channel_station

More on Educational Radio Station WLCR-AM Carrier Current, near White Sulphur Springs, West Virginia: Link >>> http://johnbrashear.tripod.com/wlcr.html

2015: 95th Anniversary of the World's First Commercial Radio Station, KDKA-AM in Pittsburgh:
Link >>> http://spacewatchtower.blogspot.com/2015/11/astronomical-calendar-2015-november.html

Source: Glenn A. Walsh Reporting for SpaceWatchtower, a project of Friends of the Zeiss.
              2016 April 8.

                                                               Historic 10-inch Siderostat-type Refractor Telescope at Pittsburgh's original Buhl Planetarium and Institute of Popular Science.
        2016: 75th Year of Pittsburgh's Buhl Planetarium Observatory
     Link >>> http://spacewatchtower.blogspot.com/2016/01/astronomical-calendar-2016-january.html

                             Like This Post? - Please Share!

Want to receive SpaceWatchtower blog posts in your inbox ?
Send request to < spacewatchtower@planetarium.cc >..

gaw

Glenn A. Walsh, Project Director,
Friends of the Zeiss < http://buhlplanetarium.tripod.com/fotz/ >
Electronic Mail - < gawalsh@planetarium.cc >
SpaceWatchtower Blog: < http://spacewatchtower.blogspot.com/ >
Also see: South Hills Backyard Astronomers Blog: < http://shbastronomers.blogspot.com/ >
Barnestormin: Writing, Essays, Pgh. News, & More: < http://www.barnestormin.blogspot.com/ >
About the SpaceWatchtower Editor / Author: < http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
SPACE & SCIENCE NEWS, ASTRONOMICAL CALENDAR:
http://buhlplanetarium.tripod.com/#news >
Twitter: < https://twitter.com/spacewatchtower >
Facebook: < http://www.facebook.com/pages/SpaceWatchtower/238017839577841?sk=wall >
Author of History Web Sites on the Internet --
* Buhl Planetarium, Pittsburgh:
  < http://www.planetarium.cc >
* Adler Planetarium, Chicago:
  < http://adlerplanetarium.tripod.com >
* Astronomer, Educator, Optician John A. Brashear:
  < http://johnbrashear.tripod.com >
* Andrew Carnegie & Carnegie Libraries:
  < http://www.andrewcarnegie.cc >
* Civil War Museum of Andrew Carnegie Free Library:
  < http://garespypost.tripod.com >
Duquesne Incline cable-car railway, Pittsburgh:
  < http://inclinedplane.tripod.com >
* Public Transit:
  < http://andrewcarnegie2.tripod.com/transit >

Friday, April 1, 2016

Astronomical Calendar: 2016 April



A giant mosaic of the Crab Nebula, a remnant of bright Supernova SN 1054 recorded by
Chinese astronomers in A.D. 1054 as a "guest star," imaged by NASA's Hubble Space Telescope.
Astronomers Without Borders declares April as Global Astronomy Month:
Link >>> http://www.astronomerswithoutborders.org/global-astronomy-month-2016.html
and April 20 as the World Night in Defence of Starlight:
Link >>> http://www.astronomerswithoutborders.org/gam2015-programs/program-schedule/166-gam2015/programs1/949-world-night-in-defence-of-the-starlight434.html
(Image Sources: Wikipedia.org , By NASA, ESA, J. Hester and A. Loll (Arizona State University) - HubbleSite: gallery, release., Public Domain, https://commons.wikimedia.org/w/index.php?curid=516106 )


Astronomical Calendar for 2016 April: 
Link >>> http://buhlplanetarium4.tripod.com/astrocalendar/2016.html#apr

Source: Friends of the Zeiss.
              2016 April 1.
                                              

                                                               Historic 10-inch Siderostat-type Refractor Telescope at Pittsburgh's original Buhl Planetarium and Institute of Popular Science.

        2016: 75th Year of Pittsburgh's Buhl Planetarium Observatory
Link >>> http://spacewatchtower.blogspot.com/2016/01/astronomical-calendar-2016-january.html

                             Like This Post? - Please Share!

Want to receive SpaceWatchtower blog posts in your inbox ?
Send request to < spacewatchtower@planetarium.cc >..

gaw

Glenn A. Walsh, Project Director,
Friends of the Zeiss < http://buhlplanetarium.tripod.com/fotz/ >
Electronic Mail - < gawalsh@planetarium.cc >
SpaceWatchtower Blog: < http://spacewatchtower.blogspot.com/ >
Also see: South Hills Backyard Astronomers Blog: < http://shbastronomers.blogspot.com/ >
Barnestormin: Writing, Essays, Pgh. News, & More: < http://www.barnestormin.blogspot.com/ >
About the SpaceWatchtower Editor / Author: < http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
SPACE & SCIENCE NEWS, ASTRONOMICAL CALENDAR:
< http://buhlplanetarium.tripod.com/#news >
Twitter: < https://twitter.com/spacewatchtower >
Facebook: < http://www.facebook.com/pages/SpaceWatchtower/238017839577841?sk=wall >
Author of History Web Sites on the Internet --
* Buhl Planetarium, Pittsburgh:
  < http://www.planetarium.cc >
* Adler Planetarium, Chicago:
  < http://adlerplanetarium.tripod.com >
* Astronomer, Educator, Optician John A. Brashear:
  < http://johnbrashear.tripod.com >
* Andrew Carnegie & Carnegie Libraries:
  < http://www.andrewcarnegie.cc >
* Civil War Museum of Andrew Carnegie Free Library:
  < http://garespypost.tripod.com >
* Duquesne Incline cable-car railway, Pittsburgh:
  < http://inclinedplane.tripod.com >
* Public Transit:
  < http://andrewcarnegie2.tripod.com/transit >

Sunday, March 27, 2016

Will Christians Agree to Fix the Date of Easter?

Full moon in the darkness of the night sky. It is patterned with a mix of light-tone regions and darker, irregular blotches, and scattered with varying sizes of impact craters, circles surrounded by out-thrown rays of bright ejecta.
For centuries, the Full Moon phase of the Moon figured prominently in the annual calculation
of the date of Easter. However, this could possibly change within the next decade.
(Image Sources: Wikipedia.org , By Gregory H. Revera - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=11901243 )

By Glenn A. Walsh
Reporting for SpaceWatchtower

Since the beginning, Astronomy has been used to calculate the date of Easter. In the 1930s and 1940s, a planetarium show explaining how Astronomy helped to calculate the date of Easter was shown to the public at several of the early planetaria, including Pittsburgh's original Buhl Planetarium and Institute of Popular Science.

However, in January a leading theologian announced that several Christian denominations may soon reach an agreement to fix the date of Easter, once and for-all.

The Most Reverend Justin Welby, the Archbishop of Canterbury of the Church of England, said he has been in on-going discussions with the Catholic, Coptic, and Orthodox churches regarding the selection of a fixed date for Easter. In addition to Archbishop Welby, these discussions included Pope Francis, the Coptic Orthodox Pope Tawadros II, and the Ecumenical Patriarch Bartholomew I, head of the Greek Orthodox Church.

Last June, Pope Francis told a global gathering of priests in Rome, "we have to come to an agreement" regarding a common date for Easter. According to the Catholic News Agency, he joked that right now one Christian could tell another, "When did Christ rise from the dead? My Christ rose today, and yours next week."

Archbishop Welby said the agreed-upon date for Easter would probably be the second or third Sunday of April. However, changing the date of Easter may not occur for a decade or more. Secular governments would have to approve the change, and calendar and almanac publishers would have to be given advance notice of the date of implementation of such a change.

Actually, the effort to fix the date for Easter is nothing new. According to Archbishop Welby, "Equally, I think the first attempt to do this was in the 10th century." Others note that this is one of the longest running controversies of Christianity, possibly dating back as far as the 2nd century.

Currently, Easter is one of the moveable feasts, with the date determined by a lunisolar calendar, similar to the Hebrew Calendar. The difficulty in calculating Easter is due to the fact that our civil calendar does not match astronomical cycles.

A combination of Hebrew, Roman, and Egyptian calendars, along with local culture and customs, all contributed to the Easter calculations we have today. The Egyptians based their calendar on the cycle of the Sun, which was adopted by Roman, and later, Christian cultures. The Hebrew Calendar is based partly on the lunar cycle (the Islamic Calendar is also based on the Moon). The Easter calculations become complicated when both lunar and solar calendars are used, combined with the fact that different Christian sects use different mathematical formulas.

Jesus Christ's death and resurrection occurred during the Jewish holiday of Passover (which begins on the night of a Full Moon, immediately after the Vernal Equinox), according to the Christian Bible. However, this led to confusion of what date to celebrate Easter, with Christians celebrating the holiday on different dates.

In the year A.D. 325, the First Council of Nicaea of the Roman Catholic Church established only two rules for the annual determination of Easter: independence from the Jewish Calendar and worldwide uniformity. The rules for actual calculation of the date of Easter took centuries to work-out.

Calculating the date of Easter caused several controversies, partly because some Christians did not want Easter to be associated with the Jewish Passover. In at least one case, violence accompanied such a controversy.  In attempting to calculate the date of Easter, from astronomical observations, the 5th century astronomer and mathematician, Hypatia of Alexandria, was murdered by a clique of Bishop Cyril's zealots, according to the Church historian Socrates Scholasticus.

In 725, an English monk, the Venerable Bede (later known as Saint Bede) made the general rule for determining the date of Easter, by stating, “The Sunday following the full Moon which falls on or after the equinox will give the lawful Easter.” However, the Ecclesiastical rules are more specific.

Easter was determined to occur on the first Sunday, after the Ecclesiastical or Paschal Full Moon (actually determined to be the 14th day of an Ecclesiastical lunar month; this date could be a couple days away from the actual Full Moon), which occurs on or soonest after the Vernal Equinox (which is fixed as March 21, even if this Spring Equinox occurs on March 19 or 20, which often happens).

Traditional Easter is celebrated by most Western Christian sects today, March 27, the earliest the holiday has been celebrated in several years. Actually,  Easter was also on March 27 in 2005 and on March 23 in 2008. One of the reasons for the early Easter, this year, is due to the use of the Gregorian Calendar, a reform introduced by Pope Gregory XIII in 1582. By the Gregorian Calendar, Easter always falls between March 22 and April 25, within about seven days of the actual, astronomical Full Moon. The most common date for Easter, in the Gregorian Calendar, is April 19.

Orthodox or Eastern Catholic churches do not celebrate Easter, this year, until May 1, one of the latest dates this feast day can occur. These churches continue to use the Julian Calendar to calculate Easter and other feast days including Christmas (January 7). By the Julian Calendar, the March 21 date of the Equinox is equated with April 3 (in our current century), when converted to the Gregorian Calendar used as the civil calendar of all nations where the Orthodox Christianity is predominant. Then, Easter always falls between April 4 and May 8 of the Gregorian Calendar. The Julian Calendar Full Moon is always several days after the astronomical Full Moon, hence, the Orthodox Easter is often later, relative to the visible Moon phases, than the Western Easter.

Due to the need to use Astronomy to calculate the date of Easter and other moveable feasts, the Roman Catholic Church has supported an astronomical observatory for several centuries. The Vatican Observatory, originally established as the Observatory of the Roman College of Rome in 1774, is now located in Castel Gandolfo, Italy. The Holy See, since 1993, also operates the Vatican Advanced Technology Telescope at the Mount Graham International Observatory in southeastern Arizona.

If the date of Easter is ever fixed, Astronomy will no longer be part of this particular determination. But of course, even if Easter is designated as a certain Sunday in April, Astronomy will still be needed for the determination of the civil calendar for the actual date Easter falls on each year.

                                 Internet Links to Additional Information

More on Easter: Link >>> https://en.wikipedia.org/wiki/Easter

More on a Lunisolar Calendar: Link >>> https://en.wikipedia.org/wiki/Lunisolar_calendar

More on an Ecclesiastical Full Moon:
Link >>> https://en.wikipedia.org/wiki/Ecclesiastical_full_moon 

More on the Gregorian Calendar: Link >>> https://en.wikipedia.org/wiki/Gregorian_calendar

More on the Julian Calendar: Link >>> https://en.wikipedia.org/wiki/Julian_calendar

More about Hypatia of Alexandria ---
Link 1 >>> https://en.wikipedia.org/wiki/Hypatia
Link 2 >>> http://booksandjournals.brillonline.com/content/journals/10.1163/15700720-12341264

More on the petition to designate March 20 (Vernal Equinox) to commemorate the life of Hypatia:
Link >>> https://www.change.org/p/canada-s-parliament-commemorating-the-first-female-astronomer-hypatia-of-alexandria

More about the Vatican Observatory: Link >>> https://en.wikipedia.org/wiki/Vatican_Observatory

Related Blog Posts ---

"Dim Penumbral Lunar Eclipse Early Wed. Morning" (During March Full Moon). 2016 March 22.

Link >>> http://spacewatchtower.blogspot.com/2016/03/dim-penumbral-lunar-eclipse-early-wed.html

 

"Fly-By of Twin (?) Comets Heralds Beginning of Spring." 2016 March 20.

Link >>> http://spacewatchtower.blogspot.com/2016/03/fly-by-of-twin-comets-heralds-beginning.html  


Source: Glenn A. Walsh Reporting for SpaceWatchtower, a project of Friends of the Zeiss.
              2016 March 27.

                                                               Historic 10-inch Siderostat-type Refractor Telescope at Pittsburgh's original Buhl Planetarium and Institute of Popular Science.
        2016: 75th Year of Pittsburgh's Buhl Planetarium Observatory
Link >>> http://spacewatchtower.blogspot.com/2016/01/astronomical-calendar-2016-january.html

                             Like This Post? - Please Share!

Want to receive SpaceWatchtower blog posts in your inbox ?
Send request to < spacewatchtower@planetarium.cc >..

gaw

Glenn A. Walsh, Project Director,
Friends of the Zeiss < http://buhlplanetarium.tripod.com/fotz/ >
Electronic Mail - < gawalsh@planetarium.cc >
SpaceWatchtower Blog: < http://spacewatchtower.blogspot.com/ >
Also see: South Hills Backyard Astronomers Blog: < http://shbastronomers.blogspot.com/ >
Barnestormin: Writing, Essays, Pgh. News, & More: < http://www.barnestormin.blogspot.com/ >
About the SpaceWatchtower Editor / Author: < http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
SPACE & SCIENCE NEWS, ASTRONOMICAL CALENDAR:
http://buhlplanetarium.tripod.com/#news >
Twitter: < https://twitter.com/spacewatchtower >
Facebook: < http://www.facebook.com/pages/SpaceWatchtower/238017839577841?sk=wall >
Author of History Web Sites on the Internet --
* Buhl Planetarium, Pittsburgh:
  < http://www.planetarium.cc >
* Adler Planetarium, Chicago:
  < http://adlerplanetarium.tripod.com >
* Astronomer, Educator, Optician John A. Brashear:
  < http://johnbrashear.tripod.com >
* Andrew Carnegie & Carnegie Libraries:
  < http://www.andrewcarnegie.cc >
* Civil War Museum of Andrew Carnegie Free Library:
  < http://garespypost.tripod.com >
Duquesne Incline cable-car railway, Pittsburgh:
  < http://inclinedplane.tripod.com >
* Public Transit:
  < http://andrewcarnegie2.tripod.com/transit >

Tuesday, March 22, 2016

Dim Penumbral Lunar Eclipse Early Wed. Morning


Photographs of a Penumbral Lunar
Eclipse in January of 1999 shows the
dimming of the Southern Hemisphere
of the Moon (left photo) compared to
the Moon seen outside of the Earth's
shadow (right photo).
(Image Sources: Wikipedia.org , By
SockPuppetForTomruen (talk) - I
created this work entirely by myself.
Transferred from en.wikipedia, Public
Domain, https://commons.wikimedia.org/
w/index.php?curid=17097701 )

By Glenn A. Walsh
Reporting for SpaceWatchtower

Early on Wednesday Morning, 2016 March 23, very observant viewers may be able to see a dim Penumbral Eclipse of the Moon or Lunar Eclipse.

A Penumbral Eclipse of the Moon is dimmer than a Partial Eclipse of the Moon. During an eclipse of the Moon, the Earth's solar shadow shines on part or all of the Moon, at the time of the Full Moon. The Earth actually casts two shadows: the main and darker Umbral Shadow along with the secondary and dimmer Penumbral Shadow.

In the case of a Total Lunar Eclipse, the Earth's Umbral Shadow completely envelops the Moon. In the case of a Partial Eclipse of the Moon, only part of the Moon is covered by the Umbral Shadow. In the case of a Penumbral Eclipse of the Moon, only the dimmer Penumbral Shadow covers part or all of the Moon.

Of course, weather conditions have to be clear to have a chance to see this eclipse. A Lunar Eclipse or Eclipse of the Moon is the type of eclipse which is safe to look at with the naked-eyes, binoculars, and telescopes. However, the shading of the Moon during such a Penumbral Eclipse is extremely subtle, and not everyone may be able to tell when the eclipse is occurring.

The entire eclipse could be visible to viewers in western North America, Hawaii, Alaska, eastern Australia, New Zealand, Japan, and the Pacific Ocean. Part of the eclipse, before local moon-set, would be visible in eastern North America and South America. Parts of central and eastern Asia could experience part of the eclipse after local moon-rise. Europe and Africa will not experience this eclipse at all.

                                                       Times of Eclipse Phases
             (EDT = Eastern Daylight Saving Time; UTC = Coordinated Universal Time)

Penumbral Lunar Eclipse Begins:                                   5:39:28 a.m. EDT / 9:39:28 UTC
Greatest Penumbral Lunar Eclipse:                                7:47:13 a.m. EDT / 11:47:13 UTC
Moon Phase - Full Moon:                                                 8:01 a.m. EDT / 12:01 UTC
Penumbral Lunar Eclipse Ends:                                      9:54:54 a.m. EDT / 13:54:54 UTC

Special Note: Although the times given for the beginning and ending of the Penumbral Eclipse are the correct times, it is highly unlikely that the beginning and ending can be viewed visually. Observations of when the Penumbral Eclipse is first visible, and when the Eclipse is no longer visible, would be valuable to Science. On average, a Penumbral Eclipse is only visible a half-hour before until a half-hour after the time of greatest eclipse.

And, that bright star-like object near the Moon is the planet Jupiter.

More on the Penumbral Lunar Eclipse of 2016 March 23 ---
Link 1 >>> http://eclipse.gsfc.nasa.gov/LEplot/LEplot2001/LE2016Mar23N.pdf
Link 2 >>> https://en.wikipedia.org/wiki/March_2016_lunar_eclipse

More about a Lunar Eclipse or Eclipse of the Moon:
Link >>> https://en.wikipedia.org/wiki/Lunar_eclipse

Source: Glenn A. Walsh Reporting for SpaceWatchtower, a project of Friends of the Zeiss.
              2016 March 22.

                                                               Historic 10-inch Siderostat-type Refractor Telescope at Pittsburgh's original Buhl Planetarium and Institute of Popular Science.
        2016: 75th Year of Pittsburgh's Buhl Planetarium Observatory
                     Link >>> http://buhlplanetarium2.tripod.com

                             Like This Post? - Please Share!

Want to receive SpaceWatchtower blog posts in your inbox ?
Send request to < spacewatchtower@planetarium.cc >..

gaw

Glenn A. Walsh, Project Director,
Friends of the Zeiss < http://buhlplanetarium.tripod.com/fotz/ >
Electronic Mail - < gawalsh@planetarium.cc >
SpaceWatchtower Blog: < http://spacewatchtower.blogspot.com/ >
Also see: South Hills Backyard Astronomers Blog: < http://shbastronomers.blogspot.com/ >
Barnestormin: Writing, Essays, Pgh. News, & More: < http://www.barnestormin.blogspot.com/ >
About the SpaceWatchtower Editor / Author: < http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
SPACE & SCIENCE NEWS, ASTRONOMICAL CALENDAR:
http://buhlplanetarium.tripod.com/#news >
Twitter: < https://twitter.com/spacewatchtower >
Facebook: < http://www.facebook.com/pages/SpaceWatchtower/238017839577841?sk=wall >
Author of History Web Sites on the Internet --
* Buhl Planetarium, Pittsburgh:
  < http://www.planetarium.cc >
* Adler Planetarium, Chicago:
  < http://adlerplanetarium.tripod.com >
* Astronomer, Educator, Optician John A. Brashear:
  < http://johnbrashear.tripod.com >
* Andrew Carnegie & Carnegie Libraries:
  < http://www.andrewcarnegie.cc >
* Civil War Museum of Andrew Carnegie Free Library:
  < http://garespypost.tripod.com >
Duquesne Incline cable-car railway, Pittsburgh:
  < http://inclinedplane.tripod.com >
* Public Transit:
  < http://andrewcarnegie2.tripod.com/transit >