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

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


                                                              
        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!

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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 >

Laser Cloaking of Earth From Alien Civilizations?

(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


                                                              
        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!

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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 >

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


                                                              
        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 >

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.

                                                              
        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 >

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.
                                              

                                                              

        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 >