Winter Begins; Ursid Meteors Peak Friday

This diagram shows the position of the Earth, in relation to the Sun, at the time of the Winter Solstice, as well as the other solstice and equinoxes of the year, in Earth's Northern Hemisphere.
(Graphic Source: ©1999, Eric G. Canali, former Floor Manager of Pittsburgh's original Buhl Planetarium and Institute of Popular Science and Founder of the South Hills Backyard Astronomers amateur astronomy club; permission granted for only non-profit use with credit to author.)

By Glenn A. Walsh

Reporting for SpaceWatchtower

The season of Winter, in the Northern Hemisphere of Earth, begins at the moment of the Winter / December Solstice, Thursday, 2017 December 21 at 11:28 a.m. Eastern Standard Time (EST) / 16:28 Coordinated Universal Time (UTC)---the moment of the posting of this blog-post. This moment also marks the astronomical beginning of the Summer season in the Southern Hemisphere.

Almost 24 hours later, Friday morning will mark the peak time for the annual Ursid Meteor Shower; of course dark skies are needed to actually see meteors. This meteor shower peaks Friday, 2017 December 22 at 10:00 a.m. EST / 15:00 UTC.

                                               Winter Solstice 2017

In etymology, the word solstice comes from the Latin terms sol (Sun) and sistere (to stand-still). In ancient times, astronomers / astrologers / priests recognized that one day of the year when the Sun would appear to reach its lowest point in the sky for the entire year. The motion of the Sun's apparent path in the sky (what is known astronomically today as the Sun's declination) would cease on this day, and the Sun would appear to stand-still, before reversing direction.

With our Gregorian Calendar, this usually occurs on, or very close to, December 21. In ancient times, when people used the Julian Calendar, the Winter Solstice was on, or very close to, December 25, what we now know as Christmas Day. Mid-Winter festivals, at the time of the Winter Solstice, were common in ancient times. Instead of competing with these traditions, the early Roman Catholic Church Christianized the Winter festivals by observing the birth of Jesus Christ on December 25 (the actual birth date of Jesus was probably in September).

Today, we know that, while the Sun does have motions, it is actually the motion of the Earth, tilted on its axis 23.44 degrees from the plane of our Solar System while revolving around the Sun, that causes the Earth's seasons. Hence, as the Earth arrives at the point in its orbit around the Sun, where the south polar axis is most directly inclined toward the Sun (thus, the Sun appears at its lowest point for the year in the Northern Hemisphere sky) around December 21, this marks the Winter Solstice in the Northern Hemisphere (and the Summer Solstice in the Southern Hemisphere).

Alternately around June 21, the Summer Solstice marks the beginning of Summer in the Northern Hemisphere (and this date also marks the Winter Solstice, which is the beginning of Winter in the Southern Hemisphere) as the Earth reaches the point in its orbit where the north polar axis is most directly inclined toward the Sun.

The day of the December Solstice is the only time of the year when the Sun reaches the point of Local Solar Noon at the South Pole. Conversely, it is also the only time of the year when Local Solar Midnight occurs at the North Pole. And, of course, it is the reverse during the June Solstice: the only time the Sun reaches the point of Local Solar Noon at the North Pole and the only time when Local Solar Midnight occurs at the South Pole.

Although the Winter months in the Northern Hemisphere are known for the year's coldest weather, the Earth is actually at the point in its orbit closest to the Sun (astronomically known as the point of perihelion) on or very near January 2. The Earth is farthest from the Sun, each year shortly after the Northern Hemisphere's Summer Solstice, on or very near July 5 (the point of aphelion).

Solar radiation, and hence heat from the Sun, to warm an Earth hemisphere depends on the length of daylight and the angle of the Sun above the horizon. The tilt of the planet's axis toward the Sun determines the additional and more direct solar radiation received by a planet's northern or southern hemisphere, and hence, the warmer season of the respective hemisphere.

The Earth's perihelion in January and aphelion in July is due to the elliptical nature of the Earth's orbit around the Sun. Perihelion and aphelion would not occur if the Earth's orbit was a true circle.

Since the Earth is closest to the Sun near the beginning of the Northern Hemisphere's Winter Season, the Earth, then, moves faster in its orbit around the Sun than it moves in July, making the Northern Hemisphere's Winter a shorter season than Summer. Winter will last for only 89 days, while this past-Summer lasted nearly 93 days. This is one of the observed consequences of Johannes Kepler's Laws of Planetary Motion, which he published at the beginning of the 17^th century.

The day of the Winter Solstice is known as the “shortest day of the year” and the “longest night of the year” as the Sun shines on the Northern Hemisphere for the shortest length of time for the entire year, on this day. For this reason, Homeless Persons' Memorial Day is commemorated on December 21.

Interestingly, the climate of a locale in the Southern Hemisphere is, on average, slightly milder than a location at the same latitude in the Northern Hemisphere, because the Southern Hemisphere has significantly more ocean water and much less land. Water warms-up and cools-down more slowly than does land. The only exception is the Antarctic, which is colder than the Northern Hemisphere's Arctic region, possibly because most of the Arctic region is covered with water (although, often frozen water on the surface, but liquid water beneath the ice) while Antarctica is mostly a land mass.

                                              Ursid Meteor Shower

Almost 24 hours after the Winter Solstice comes the peak of the annual Ursid Meteor Shower, which actually begins on December 17 and usually lasts about a week ending December 24, 25, or 26. The Ursids seem to comprise a narrow stream of debris originating from Comet Tuttle. Hence, it is difficult to see Ursid meteors outside of a 12-hour window before and after the peak, where possibly 12 meteors per-hour could be seen, under ideal conditions.

The Ursid Meteor Shower is so-named because most meteors appear to radiate from a point near the Star Beta Ursae Minoris (apparent meteor shower radiant) in the Constellation Ursa Minor (better known as the asterism the “Little Dipper”), which is the brightest star in the bowl of the Little Dipper. Some people call these meteors “Ursids,” in an attempt to emphasize that their apparent radiant is Ursa Minor, not Ursa Major (the asterism the “Big Dipper”).

However, you should not, necessarily, be looking only at the Little Dipper when looking for meteors in this shower. Meteors can appear in any part of the sky at any time (although a meteor's tail may tend to point back toward the radiant).

Of course meteor showers, like all celestial observations, are weather-permitting. If there are more than a few clouds in the sky, meteors will be much more difficult to find. Clear skies are not always available in the skies of late Autumn and early Winter. And, it is always best to get away from city lights, for the opportunity to see the smaller, dimmer meteors. As always, the best time to view any meteor shower is between local midnight and local dawn, when the Earth is actually rotating into the stream of meteoric debris.

Binoculars and telescopes are not very useful for finding meteors. Meteors streak across the sky in a very short period of time, far too short to aim binoculars or a telescope. So, the best way to view a meteor shower is to lie on a blanket or beach towel on the ground, or use a reclining a chair, outdoors in an area with a good view of the entire sky (with few obstructions such as buildings, trees, or hills), and keep scanning the entire sky.

So, if you go out to see the Ursid Meteor Shower, start looking for meteors around local midnight, or perhaps a little later. Make sure you have a good site where you can see most of the sky, and that sky is relatively clear. Be sure to dress properly for the early morning temperatures, now that we are at the very beginning of Winter.

And, you want to go out ahead of time, before you actually start looking for meteors, to get your eyes accustomed to the dark sky. Dark-adapting your eyes for meteor-watching could take up to a half-hour.

Special Thanks: Eric G. Canali, former Floor Manager of Pittsburgh's original Buhl Planetarium and Institute of Popular Science and Founder of the South Hills Backyard Astronomers amateur astronomy club.

Internet Links to Additional Information ---

More on the Winter Solstice:
Link 1 >>> http://scienceworld.wolfram.com/astronomy/WinterSolstice.html
Link 2 >>> http://en.wikipedia.org/wiki/Winter

More on a Solstice: Link >>> http://en.wikipedia.org/wiki/Solstice

Popular Winter Planetarium Sky Shows Shown at Pittsburgh's original Buhl Planetarium and Institute of Popular Science (1939 to 1991), including full scripts of each show:
The Star of Bethlehem >>> http://buhlplanetarium3.tripod.com/skyshow/bethlehem/
The Stars of Winter >>> http://buhlplanetarium3.tripod.com/skyshow/winter/

More on calendars ---
       Gregorian Calendar: Link >>> http://en.wikipedia.org/wiki/Gregorian_calendar
       Julian Calendar: Link >>> http://en.wikipedia.org/wiki/Julian_calendar

More on the Ursid Meteor Shower: Link >>> http://en.wikipedia.org/wiki/UrsidsA

More on the Homeless Persons' Memorial Day:
Link >>> http://nationalhomeless.org/about-us/projects/memorial-day/

Source: Glenn A. Walsh Reporting for SpaceWatchtower, a project of Friends of the Zeiss.
             2017 December 21.

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Glenn A. Walsh, Project Director, Friends of the Zeiss: < http://buhlplanetarium.tripod.com/fotz/ >
& SpaceWatchtower Editor / Author: < http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
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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 >

Nano-Space Probes to Star Alpha Centauri by Laser-Sail ?

One possible concept for a Laser-sail mounted on a nano-space probe, which could reach
the Alpha Centauri star system, possibly as early as mid-century.
(Image Sources: Wikipedia.org , By Kevin Gill from Nashua, NH, United States - Solar Sail, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=42599221 )

By Glenn A. Walsh

Reporting for SpaceWatchtower

Last month, SpaceWatchtower talked about Lasers in Space ? (posted November 13; reference Internet link near the end of this blog-post). Today, SpaceWatchtower looks at a very ambitious proposal to use Lasers for space propulsion, for very small space probes to reach nearby star systems.

Known as Breakthrough Starshot, this is one of four projects in Breakthrough Initiatives. The other three projects are ---

• Breakthrough Watch – Astronomical program to produce new technologies to help determine if life exists on Earth-like planets in nearby solar systems.
• Breakthrough Listen – Search for radio and optical signals from extra-terrestrial civilizations.
• Breakthrough Message – Competition to create a message about Earth, life, and humanity that could be transmitted, received, and understood by an extra-terrestrial civilization. This project includes a public debate regarding the ethics of sending messages beyond the Earth.

Breakthrough Initiatives was launched “in 2015 by Yuri and Julia Milner to explore the Universe, seek scientific evidence of life beyond Earth, and encourage public debate from a planetary perspective,” according to the Breakthrough Initiatives Internet web-site. A Russian entrepreneur, venture capitalist, and physicist, Yuri Milner has invested several hundred million dollars into these projects.

Pete Worden, former University of Arizona Astronomy Professor, NASA Ames Research Center Director, and Brig. General of the United State Air Force, was introduced as the new Breakthrough Prize Foundation Chairman (and Executive Director of Breakthrough Initiatives and Breakthrough Starshot) at a news conference held at the Royal Society in London when Breakthrough Initiatives was announced on 2015 July 20 (46^th anniversary of the U.S. Apollo 11 mission, which included the first persons to land and walk on the Moon). Almost a year later on 2016 April 12 (the 55^th anniversary of the Russian Vostock 1 mission, which included the first person to enter Outer Space and orbit the Earth, and the 35^th anniversary of the first launch of the U.S. Space Shuttle), the Breakthrough Starshot project was announced at an event in New York City.

Breakthrough Starshot is a research and engineering project which envisions sending nano-space probes, called “StarChips,” to nearby star systems. In addition to a much closer look at nearby stars, a major objective of such a mission would be to fly past, and possibly photograph, any Earth-like worlds that may exist in the star system.

Each StarChip would be a very small, centimeter-sized vehicle weighing only a few grams. From a “mother-ship” in Earth orbit, 1000 of these StarChips would be launched toward the target star system.

Each StarChip would include 4 sub-gram-scale digital cameras, 4 sub-gram-scale central processing units, 4 sub-gram-scale photonic Laser thrusters, 150-milligram atomic battery (powered by plutonium-238 or americium-240), protective coating (to protect from dust collisions and atomic particle erosion), and a Laser light-sail (no larger than 13 x 13 feet / 4 x 4 meters).

A square-kilometer phased-array of ground-based, 10-kilowatt Lasers would then focus Laser-light on each StarChip's Laser-sail. It is estimated that the Lasers would accelerate each StarChip to the target speed within ten minutes. A Laser-sail on each StarChip may be circular, with a diameter of 5 meters.

Propulsion of these spacecraft by Laser-sail will not be easy or inexpensive. Hence, the necessity to have all on-board equipment miniaturized and engineered to survive the rigors of high-speed interstellar travel.

A Laser with a gigawatt of power (approximating the output of a large nuclear power plant) would be necessary to power 1000 such space probes during a single deployment. And, atmospheric turbulence would add difficulty to focusing Laser-light onto the Laser-sails.

In the literature I read regarding this project, there was no mention of whether a Laser in Earth orbit could solve the atmospheric turbulence problem. Of course, some national governments may be concerned with having such a strong Laser in Earth orbit, assuming the technical problems with such an installation could be overcome.

The Alpha Centauri trinary star system, being the closest star system to Earth, is the logical first target of such spacecraft. The 1960s science-fiction television series, “Lost in Space,” portrayed a crewed U.S. space mission launched in 1997 with the goal of being the first such Earth mission to reach a habitable planet outside of our Solar System, one orbiting Alpha Centauri.

Alpha Centauri (which includes the stars Alpha Centauri A & B) is 4.37 light-years from Earth. The third star in the system which is even closer to Earth, Proxima Centauri, is 4.25 light-years from Earth.

Proxima Centauri is of particular interest to scientists. In August of 2016, the European Southern Observatory announced the discovery of an exo-planet a little larger than Earth and within the habitable zone of Proxima Centauri. Known as Proxima Centauri b, it is the closest known exo-planet to Earth.

At the beginning of this year, Breakthrough Initiatives entered into an agreement with the European Southern Observatory to provide funding for upgrades to the Observatory's Very Large Telescope (VLT) in Chile. It is hoped that such upgrades will help find additional planets in the Alpha Centauri star system. Due to its location in the sky, which prevents most of Earth's Northern Hemisphere viewers from directly seeing it, Alpha Centauri can best be studied by observatories in the Southern Hemisphere.

The StarChip nano-spacecraft would be propelled by Lasers toward the Alpha Centauri star system at speeds of between 15 per-cent and 20 per-cent of the Speed of Light (Speed of Light: 186,282 statute miles per second / 299,792 kilometers per second). At that speed, each StarChip would take between 20 and 30 years to reach Alpha Centauri.

While in the Alpha Centauri star system, data would be transmitted back to Earth using a compact Laser communication system. The Laser-sail would be used as the transmitting antenna and the Earth-based Laser propulsion array would be the receiver. At 4.37 light-years away, then Laser communication would take 4.37 years to reach Earth.

Once a successful mission to Alpha Centauri is completed, technology may advance far enough to attempt to send StarChips to even farther star systems. With currently conceived StarChips technology, star systems that may be within reach of such an effort would include ---

• Sirius A (brightest star in the night sky), 8.58 light-years from Earth; StarChips travel time: 68.90 years.
• Procyon A, 11.44 light-years from Earth; StarChips travel time: 154.06 years.
• Vega, 25.02 light-years from Earth; StarChips travel time: 167.39 years.
• Altair, 16.69 light-years from Earth; StarChips travel time: 176.67 years.

Other possible uses for StarChips include ---

• Exploration in our Solar System.
• Detection of asteroids that cross Earth's orbit, that risk hitting the Earth sometime in the future.
• Launch of a “Genesis” probe (proposed by German physicist Claudius Gros) to establish a biosphere of unicellular microbes on otherwise only transiently habitable exo-planets (such a Genesis probe would only travel at 0.3 per-cent of the Speed of Light, so the probe could be decelerated when it reached the target exo-planet by way of a magnetic sail).

Yuri Milner has provided Breakthrough Starshot an initial funding of $100 million for research into how to engineer such an ambitious proposal. He currently estimates that the entire Breakthrough Starshot project may cost between $5 and $10 billion. He believes the first StarChips could launch as early as the year 2036.

Special Note: Last month, SpaceWatchtower talked about Lasers in Space ? (posted November 13; reference Internet link near the end of this blog-post), which included information regarding the-then just-launched NanoRacks CubeSats satellites, which will help set-up a Laser-based, high-speed data communication system in Outer Space. Andrea Boyd (International Space Station Flight Operations Engineer at the European Astronaut Centre in Cologne, Germany) commented, on the November 13 post, saying that the International Space Station already has two operating Laser systems: optical [Optical Payload for Lasercomm Science (OPALS)] and LIDAR [Cloud-Aerosol Transport System (CATS)] (reference Internet links to more information on these two Laser systems near the end of this blog-post).

Internet Links to Additional Information ---

Breakthrough Starshot---
Link 1 >>> http://breakthroughinitiatives.org/initiative/3
Link 2 >>> https://en.wikipedia.org/wiki/Breakthrough_Starshot

Star Alpha Centauri: Link >>> https://en.wikipedia.org/wiki/Alpha_Centauri

Star Proxima Centauri: Link >>> https://en.wikipedia.org/wiki/Proxima_Centauri

Exo-Planet Proxima Centauri b: Link >>> https://en.wikipedia.org/wiki/Proxima_Centauri_b

Optical PAload for Lasercomm Science (OPALS) on the International Space Station (ISS):
Link >>> https://www.nasa.gov/mission_pages/station/research/experiments/861.html

Cloud-Aerosol Transport System (CATS) on the International Space Station (ISS):
Link >>> https://cats.gsfc.nasa.gov/

Related Blog Posts ---

"Lasers in Space ?" 2017 November 13.

Link >>> http://spacewatchtower.blogspot.com/2017/11/lasers-in-space.html

 

"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

Source: Glenn A. Walsh Reporting for SpaceWatchtower, a project of Friends of the Zeiss.
             2017 December 7.

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gaw

Glenn A. Walsh, Project Director, Friends of the Zeiss: < http://buhlplanetarium.tripod.com/fotz/ >
& SpaceWatchtower Editor / Author: < http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
Electronic Mail - < gawalsh@planetarium.cc >
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South Hills Backyard Astronomers Blog: < http://shbastronomers.blogspot.com/ >
Barnestormin Blog: Writing, Essays, Pgh. News, etc.: < http://www.barnestormin.blogspot.com/ >
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: 2017 December

The largest and closest Full Moon of 2017 comes on December 3 at 10:47 a.m. EST / 15:47 UTC;
some people refer to this as a so-called "Super-Moon." Consequently, large tides along ocean coast-lines are predicted due to a Lunar Perigee the next day, at 4:00 a.m. EST / 9:00 UTC. This particular photograph shows the "Super-Moon" of 2016 November 14.
(Image Sources: Wikipedia.org , By Tomruen - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=53147136 )

Astronomical Calendar for 2017 December: 
Link >>> http://buhlplanetarium4.tripod.com/astrocalendar/2017.html#dec

 Related Blog Post ---

"Astronomical Calendar: 2017 November." 2017 Nov. 1.

Link >>> https://spacewatchtower.blogspot.com/2017/11/astronomical-calendar-2017-november.html

Source: Friends of the Zeiss.
              2017 December 1.

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Glenn A. Walsh, Project Director, Friends of the Zeiss: < http://buhlplanetarium.tripod.com/fotz/ >
& SpaceWatchtower Editor / Author: < http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
Electronic Mail - < gawalsh@planetarium.cc >
Astronomy Links: < http://buhlplanetarium.tripod.com/#astrolinks >
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TransportWatchtower Blog: < http://transportwatchtower.blogspot.com  >
South Hills Backyard Astronomers Blog: < http://shbastronomers.blogspot.com/ >
Barnestormin Blog: Writing, Essays, Pgh. News, etc.: < http://www.barnestormin.blogspot.com/ >
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 >

Lasers in Space ?

The U.S. Navy's USS Ponce amphibious transport ship with the world's first active Laser Weapons System (LaWS). Will spacecraft someday possess such a system?

(Image Sources: Wikipedia.org , By U.S. Navy photo by John F. Williams - This Image was released by the United States Navy with the ID 141115-N-PO203-057 (next).This tag does not indicate the copyright status of the attached work. A normal copyright tag is still required. See Commons:Licensing for more information.বাংলা | Deutsch | English | español | euskara | فارسی | français | italiano | 日本語 | 한국어 | македонски | മലയാളം | Plattdüütsch | Nederlands | polski | português | Türkçe | українська | 中文 | 中文（简体）‎ | +/−, Public Domain, https://commons.wikimedia.org/w/index.php?curid=37235168 )

By Glenn A. Walsh

Reporting for SpaceWatchtower

Since the first Lasers were built in the 1960s, science-fiction television programs and motion pictures, such as Star Trek and Star Wars, portrayed Lasers or Laser-type weaponry in Outer Space. In the case of Star Trek, the weapons are called Phasers, as Star Trek creator Gene Roddenberry felt that Lasers would be superseded by more advanced weaponry by the 23^rd century.

Are such Laser weaponry in use today? Will Laser weapons be used in Outer Space in the near future? While American, Chinese, and Russian militaries continue developing Lasers, for terrestrial as well as Outer Space defense-related applications, advanced communication networks using Lasers are being tested by NASA for use in Outer Space.

Of course, most people are aware that the United States started a major research program into a space-based, defense shield using Lasers in the 1980s, after U.S. President Ronald Reagan announced creation of the Strategic Defense Initiative (SDI) in a speech to the American people on 1983 March 23. Most Democrats opposed the project, led by U.S. Senator Ted Kennedy, who called the project “Star Wars.”

However many people are unaware that in response to SDI, the Union of Soviet Socialist Republics (name used for Russia for most of the 20^th century) tried launching the first component of an experimental, orbital, unstaffed Laser battle-station on the evening of 1987 May 15. However, upon reaching orbit, the satellite containing this component started tumbling in orbit. Then, due to a software error, instead of going into a higher orbit, the engines fired with the satellite pointed in the wrong direction—down! The satellite soon re-entered the atmosphere, over-heated, broke-apart, and fell into the Pacific Ocean. The failure of such an expensive component convinced Kremlin leaders to cancel the rest of the project.

In 2014, the U.S. Navy deployed the world's first active Laser Weapons System (LaWS) on the USS Ponce amphibious transport ship in the Persian Gulf. The LaWS cost $40 million to develop, but costs only one dollar per shot! While the LaWS is primarily designed to attack aircraft and small boats, a second-generation system is being developed to target missiles.

The USS Ponce is scheduled to be decommissioned next year. The future of this particular LaWS installation is unclear, as it is not scheduled to be moved to a new vessel.

Last week, the U.S. Air Force gave a $26.3 million contract to Lockheed Martin “for the design, development, and production of a high power fiber laser,” for use on a fighter jet aircraft by 2021.

In August, the U.S. Army's Advanced Test High Energy Asset (ATHENA, for the Greek Goddess of Wisdom) Laser weapon underwent successful testing at the White Sands Missile Range in New Mexico. And in June, the U.S. Army successfully tested a high-energy Laser weapon system on an AH-64 Apache attack helicopter.

In July, Russia announced plans to deploy powerful Laser weapons on its sixth-generation MiG-41 fighter jet aircraft, to destroy missiles. However, their Laser system is still in the concept stage and is not expected to be available until 2035.

Current American and Russian plans to deploy Lasers in Outer Space are unclear. However, reports this year indicate that China is developing first-strike Space-Lasers designed to destroy NATO satellites. These would be both ground-based Laser weapons, along with Laser weapons on a staffed, Chinese space-station (during the Cold War, the Soviet Union considered and rejected placing such weapons on a staffed Salyut Space Station). Some believe a five-ton chemical Laser could be operational by the Chinese military, possibly by 2023.

However, high-speed data communication is where Lasers are making a strong impact in Outer Space today. On Sunday morning (November 12), NASA and aerospace launch firm Orbital ATK launched new satellites which could greatly advance the speed of data networks in Space and on Earth, perhaps eventually including the Internet, using Lasers instead of radio links. It is expected that the new Laser links could create 200 megabits per second (Mbps) connections.

The two, NanoRacks CubeSats satellites are being sent to the International Space Station (ISS) during an ISS re-supply mission. The twin satellites will be deployed from the ISS using one (of two) of their NanoRacks CubeSats Deployers.

Orbital ATK's Antares rocket with the Cygnus CRS OA-8E spacecraft (titled the SS Gene Cernan for the last man to walk on the Moon, who died in January) had a flawless launch (despite a five-minute delay due to a couple boats wandering into the launch zone) from NASA's Wallops Island Flight Facility on the Eastern Shore of Virginia. The SS Gene Cernan will take two days to reach the ISS. It is the eighth mission (of ten Orbital ATK re-supply flights under the current contract with NASA) to re-supply the International Space Station. The launch had been expected on November 11, but was delayed when an aircraft inadvertently strayed into the launch zone.

Internet Links to Additional Information ---

U.S. Navy's Laser Weapons System -
Link 1 >>> https://en.wikipedia.org/wiki/Laser_Weapon_System
Link 2 >>> http://www.cnn.com/2017/07/17/politics/us-navy-drone-laser-weapon/index.html

Mackie, Thomas. "Lazer equipped NASA satellites to revolutionise your internet speed when launched TODAY."
Sunday Express, London 2017 Nov. 12.
Link >>> http://www.express.co.uk/news/world/878501/nasa-nasa-satellites-space-technology-space-agency-new-technology-tech-revolution

Hansen, Drew. "Lockheed to develop jet-mounted laser for the Air Force."
Washington Business Journal 2017 Nov. 9.
Link >>> https://www.bizjournals.com/washington/news/2017/11/09/lockheed-to-develop-jet-mounted-laser-for-the-air.html

Sicard, Sarah. "The U.S. Army's Deadly Laser Just Took a Major Step Forward." Column: The Buzz.
NationalInterest.org / Task and Purpose 2017 Oct. 5.
Link >>> http://nationalinterest.org/blog/the-buzz/the-us-armys-deadly-laser-just-took-major-step-forward-22619

Sharkov, Damien. "Russian Military Plans Missile Killing Laser for Next-Generation Warplanes."
Newsweek 2017 July 27.
Link >>> http://www.newsweek.com/russia-plans-missile-killing-laser-next-generation-warplanes-does-it-work-642906

Judson, Jen. "US Army tests laser on Apache helicopter."
DefenseNews.com 2017 June 26.
Link >>> https://www.defensenews.com/2017/06/26/us-army-tests-laser-on-apache-helicopter/ 

Oliphant, Vickie. "China’s new space lasers to take out satellites leaving west at mercy of Beijing missiles."
Sunday Express, London 2017 March 12.
Link >>> http://www.express.co.uk/news/world/778100/China-developing-lasers-destroy-enemy-satellites-futuristic-light-war-militarise-space

Day, Dwayne A. and Robert G. Kennedy III
"Soviet Star Wars, The launch that saved the world from orbiting laser battle stations."
Air & Space Smithsonian Magazine 2010 January.
Link >>> https://www.airspacemag.com/space/soviet-star-wars-8758185/?page=1

Related Blog-Posts ---

"Nano-Space Probes to Star Alpha Centauri by Laser-Sail ?" 2017 Dec. 7.

Link >>> https://spacewatchtower.blogspot.com/2017/12/nano-space-probes-to-star-alpha.html

"NASA Laser Com-System Miniaturized & Improved Data Precision." 2015 Oct. 24.

Link >>> http://spacewatchtower.blogspot.com/2015/10/nasa-laser-com-system-miniaturized.html

 

"Lunar Laser Com-System Sets Data Transmission Record." 2013 Oct. 24.

Link >>> http://spacewatchtower.blogspot.com/2013/10/lunar-laser-com-system-sets-data.html

 

"Video: Laser Shoots Down Missile." 2013 May 15.

Link >>> http://spacewatchtower.blogspot.com/2013/05/video-laser-shoots-down-missile.html

 

"Laser Weapon Funding from Science Fiction Book?" 2013 Jan. 27.

Link >>> http://spacewatchtower.blogspot.com/2013/01/laser-weapon-funding-from-science.html

Source: Glenn A. Walsh Reporting for SpaceWatchtower, a project of Friends of the Zeiss.
             2017 November 13.

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gaw

Glenn A. Walsh, Project Director, Friends of the Zeiss: < http://buhlplanetarium.tripod.com/fotz/ >
& SpaceWatchtower Editor / Author: < http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
Electronic Mail - < gawalsh@planetarium.cc >
Astronomy Links: < http://buhlplanetarium.tripod.com/#astrolinks >
Science Links: < http://buhlplanetarium.tripod.com/#sciencelinks >
SpaceWatchtower Twitter News Feed: < https://twitter.com/spacewatchtower >
SpaceWatchtower Blog: < http://spacewatchtower.blogspot.com/ >
LibraryWatchtower Blog: < http://librarywatchtower.blogspot.com >
TransportWatchtower Blog: < http://transportwatchtower.blogspot.com  >
South Hills Backyard Astronomers Blog: < http://shbastronomers.blogspot.com/ >
Barnestormin Blog: Writing, Essays, Pgh. News, etc.: < http://www.barnestormin.blogspot.com/ >
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 >

Centennial: Mt. Wilson Observatory's 100-inch Hooker Telescope

Image of the observatory with the historic 100-inch Hooker Reflector Telescope on Mount Wilson in Los Angeles County, California.
(Image Source: Los Angeles Times, Photographer: Francine Orr)

By Glenn A. Walsh

Reporting for SpaceWatchtower

The historic, 100-Inch Hooker Reflector Telescope, at Mount Wilson Observatory in Los Angeles County, California, marks 100 years of discoveries today (November 3). It was the night / early morning of 1917 November 2 to 3 that First Light shone through the Hooker Telescope.

In fact, 100 years ago as of the hour of the posting of this blog-post, 2017 November 3 at 3:00 a.m. Pacific Standard Time (PST) / 7:00 a.m. Eastern Daylight Saving Time (EDT) / 11:00 Coordinated Universal Time (UTC), it is believed to be the time the actual First Light occurred.

[It would be another year before the first Daylight Saving Time would be established in America, due to the United States entry into World War I. Daylight Saving Time proved unpopular to many people, particularly those in the rural areas. Hence Congress repealed Daylight Saving Time shortly after the end of World War I.]

[The international time scale used by scientists, based on the time at the Royal Observatory in Greenwich, London, England, is known as Coordinated Universal Time. At the time the Hooker Telescope began scientific research, this time was known as Greenwich Mean Time (although for Greenwich Mean Time, the day began at Noon).]

Actually, there is some dispute as to the exact time of First Light, and whether it occurred on November 2 or November 3 (or even November 1). The object viewed through the telescope is also in dispute.

The first attempt at First Light seems to have occurred on the evening of November 2, when the telescope was pointed toward Jupiter. However, the image was quite poor, and the astronomers in attendance [George Ellery Hale (first Mount Wilson Observatory Director), Walter S. Adams (second Mount Wilson Observatory Director), George W. Ritchey (also telescope-maker), Francis G. Pease (also designer of the Hooker Telescope), and Ferdinand Ellerman] feared the mirror may be defective (as happened in 1990 after the orbiting of the Hubble Space Telescope).

However, the telescope dome had been open most of the day, for construction workers to finish their work. The scientists decided the observatory interior, including the mirror, was not cool enough for proper observations. So, they agreed to allow the mirror to cool and come back later.

When George Hale and Walter Adams returned at around 3:00 on the morning of November 3, they pointed the new telescope at the bright star Vega (although the star viewed is in dispute). They saw a very sharp image of this celestial object, which is considered the actual First Light.

The dispute in the date of the First Light is due to Walter Adams' later recollection that First Light was on the evening of November 1 to 2, while the diary of George Hale and the post-dated telescope log of night assistant Wendell P. Hoge stated that First Light was on the night of November 2 to 3.

However, most astronomical research did not really get underway until 1918, when the construction of the telescope was completely finished.

Mount Wilson Observatory Director George Ellery Hale was a very ambitious astronomer. By 1908, Mount Wilson Observatory already had the largest, operational telescope in the world, a 60-Inch reflector telescope. A larger 72-Inch reflector telescope, built in 1845 in Parsonstown, Ireland, remained in use until about 1890 and was partly dismantled in 1908.

However, Director Hale was not satisfied. He wanted an even larger telescope. In fact, even before the 60-Inch telescope could be tested, a 4.5-ton disk for the mirror of a 100-Inch telescope had been cast.

A good friend of Director Hale, local businessman John D. Hooker, pledged $45,000 for an 84-Inch (later increased to 100-Inch) glass mirror disk, along with the equipment and facilities to create such a large mirror. Now, Dr. Hale had to find the money (more than $500,000) to build an observatory building to house this new, giant telescope and other needed facilities.

Mr. Hooker's gift only covered 10 per-cent of the total cost of the project. And, the Carnegie Institution of Washington, which owned and operated Mount Wilson Observatory, could not help. Their endowment was needed to maintain their existing research departments.

However, Dr. Hale found an enthusiastic supporter: industrialist and philanthropist Andrew Carnegie, who had created the Carnegie Institution of Washington! Even from his early days as a steel entrepreneur, Andrew Carnegie had greatly appreciated the importance of science and technology.

Mr. Carnegie's science philanthropy had begun in 1895 with the opening of Pittsburgh's Carnegie Museum of Natural History, which he enhanced in 1907 with, what has become, one of the world's best collections of dinosaur skeletons. He had also helped astronomer and telescope-maker John A. Brashear complete a new, 3-dome Allegheny Observatory in Pittsburgh, with all of the steel donated by the Carnegie Steel Company.

Andrew Carnegie had visited Mount Wilson Observatory in 1910 [the same year he donated an 11-Inch Brashear refractor telescope to the Carnegie Institute of Technology in Pittsburgh (today's Carnegie Mellon University), so the students could see Halley's Comet] and had been quite impressed with the 60-Inch reflector telescope. In 1911, Mr. Carnegie donated another $10 million to the Carnegie Institution of Washington. The donation came with a suggestion: “I hope the work at Mount Wilson will be vigorously pushed, because I am so anxious to hear the expected results from it. I should like to be satisfied before I depart, that we are going to repay to the old land some part of the debt we owe them by revealing more clearly than ever to them the new heavens.”

Once completed, the Hooker Telescope did not disappoint. Astronomer Edwin Hubble, for whom the Hubble Space Telescope is named, used the telescope to prove that Andromeda was not just a nebulae in our galaxy as scientists had concluded, but a whole separate galaxy of stars—one of thousands of separate galaxies.

Six years later, Dr. Hubble and Milton Humason used the Hooker Telescope to discover that the Universe is expanding, and they measured the expansion and the size of the Universe. In the 1930s, Fritz Zwicky found evidence for Dark Matter and Seth Nickolson discovered two more Moons of Jupiter (numbers 10 and 11). In the 1940s, Walter Baade used the telescope to find two different types of Cepheid Variable Stars, which led to a new estimate for the size of the Universe, double the estimate Dr. Hubble had calculated.

The 100-Inch Hooker Reflector Telescope was the world's largest reflector telescope from 1917 to 1949. In 1949, the 200-Inch Hale Reflector Telescope at Palomar Observatory in San Diego County, California, named after George Ellery Hale, became the largest telescope in the world.

In the 1980s after ending Mount Wilson Observatory's research program, the institution became a public observatory operated by the Mount Wilson Institute (but still owned by the Carnegie Institution for Science). The Institute sells telescope time to private groups, as well as providing educational tours to local youth groups and to the general public.

Special Thanks: Marilyn E. Morgan, Mount Wilson Observatory.

Internet Links to Additional Information ---

Good photograph of 100-inch Hooker Reflector Telescope:
Link >>> http://spacewatchtower.blogspot.com/2017/11/astronomical-calendar-2017-november.html

100-inch Hooker Reflector Telescope  --
Link 1 >>> http://amazingspace.org/resources/explorations/groundup/lesson/scopes/mt_wilson/
Link 2 >>> https://en.wikipedia.org/wiki/Mount_Wilson_Observatory#Hooker_telescope
Building the Telescope: Link >>> https://www.mtwilson.edu/building-the-100-inch-telescope/

Mount Wilson Observatory, Los Angeles County CA --
Link 1 >>> https://www.mtwilson.edu/
Link 2 >>> https://en.wikipedia.org/wiki/Mount_Wilson_Observatory

Khan, Amina.
"At Mt. Wilson, scientists celebrate 100th birthday of the telescope that revealed the universe."
Los Angeles Times 2017 November 1.
Link >>> http://www.latimes.com/science/la-sci-sn-mt-wilson-centennial-20171101-htmlstory.html

Nicholson, Don and Bob Eklund. "First Light Doubts on Mount Wilson."
Reflections, Mount Wilson Observatory, Mount Wilson Institute. Fall Quarter / 2017 September,
Page 3.
Link >>> http://buhlplanetarium.tripod.com/MtWilson/Reflections_Sept_2017Rev_screenres.pdf

Morgan, Marilyn. "The Amazing Mister Carnegie."
Reflections, Mount Wilson Observatory Association Winter Quarter / 2005 December.
(Includes photo of Andrew Carnegie and George Ellery Hale at Mount Wilson Observatory in 1910 March)
Link >>> http://andrewcarnegie.tripod.com/astro/Reflections-Dec2005.pdf

Source: Glenn A. Walsh Reporting for SpaceWatchtower, a project of Friends of the Zeiss.
             2017 November 3.

                             Like This Post? - Please Share!

            More Astronomy & Science News - SpaceWatchtower Twitter Feed:
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                Want to receive SpaceWatchtower blog posts in your in-box ?
                Send request to < spacewatchtower@planetarium.cc >.

gaw

Glenn A. Walsh, Project Director, Friends of the Zeiss: < http://buhlplanetarium.tripod.com/fotz/ >
& SpaceWatchtower Editor / Author: < http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
Electronic Mail - < gawalsh@planetarium.cc >
Astronomy Links: < http://buhlplanetarium.tripod.com/#astrolinks >
Science Links: < http://buhlplanetarium.tripod.com/#sciencelinks >
SpaceWatchtower Twitter News Feed: < https://twitter.com/spacewatchtower >
SpaceWatchtower Blog: < http://spacewatchtower.blogspot.com/ >
LibraryWatchtower Blog: < http://librarywatchtower.blogspot.com >
TransportWatchtower Blog: < http://transportwatchtower.blogspot.com  >
South Hills Backyard Astronomers Blog: < http://shbastronomers.blogspot.com/ >
Barnestormin Blog: Writing, Essays, Pgh. News, etc.: < http://www.barnestormin.blogspot.com/ >
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: 2017 November

                                                
The night / early morning of November 2 to 3 marks the centennial of First Light for the historic 100-inch Hooker Reflector Telescope at Mount Wilson Observatory in Los Angeles County, California. This telescope was the world's largest reflector telescope from 1917 to 1949.
(Image Sources: Ken Spencer, Wikipedia.org)

Astronomical Calendar for 2017 November: 
Link >>> http://buhlplanetarium4.tripod.com/astrocalendar/2017.html#nov

 Related Blog Post ---

"Astronomical Calendar: 2017 October." 2017 Oct. 1.

Link >>> https://spacewatchtower.blogspot.com/2017/10/astronomical-calendar-2017-october.html

Source: Friends of the Zeiss.
              2017 November 1.

                             Like This Post? - Please Share!

            More Astronomy & Science News - SpaceWatchtower Twitter Feed:
            Link >>> https://twitter.com/spacewatchtower

        Astronomy & Science Links: Link >>> http://buhlplanetarium.tripod.com/#sciencelinks

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

gaw

Glenn A. Walsh, Project Director, Friends of the Zeiss: < http://buhlplanetarium.tripod.com/fotz/ >
& SpaceWatchtower Editor / Author: < http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
Electronic Mail - < gawalsh@planetarium.cc >
Astronomy Links: < http://buhlplanetarium.tripod.com/#astrolinks >
Science Links: < http://buhlplanetarium.tripod.com/#sciencelinks >
SpaceWatchtower Twitter News Feed: < https://twitter.com/spacewatchtower >
SpaceWatchtower Blog: < http://spacewatchtower.blogspot.com/ >
LibraryWatchtower Blog: < http://librarywatchtower.blogspot.com >
TransportWatchtower Blog: < http://transportwatchtower.blogspot.com  >
South Hills Backyard Astronomers Blog: < http://shbastronomers.blogspot.com/ >
Barnestormin Blog: Writing, Essays, Pgh. News, etc.: < http://www.barnestormin.blogspot.com/ >
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 >

250th Anniversary: Astronomy Helps Create Mason-Dixon Line

                                     
This photograph shows Pete Zapadka, a member of the Amateur Astronomers Association of Pittsburgh (AAAP), leaning on the Cornerstone Monument at the precise geographic location of the southwest corner of the Commonwealth of Pennsylvania--the official end of the Mason-Dixon Line. Although due to Native American territory disputes, astronomers Charles Mason and Jeremiah Dixon never saw this site; their portion of the Mason-Dixon Line Survey ended prematurely 23 miles short of this site, 250 years ago today (October 18). Philadelphia clock-maker and astronomer David Rittenhouse placed this monument and completed the Mason-Dixon Line Survey in 1784.
(Image Source: Amateur Astronomer Pete Zapadka)                            

By Glenn A. Walsh

Reporting for SpaceWatchtower

On this date 250 years ago (1767 October 18), astronomers Charles Mason and Jeremiah Dixon completed surveying most of the southern boundary of Pennsylvania [separating from the colonies of Maryland and Virginia (now the state of West Virginia)], what became the most famous boundary in U.S. history: the Mason-Dixon Line. Although contracted to survey to, what is now, the southwest corner of the Commonwealth of Pennsylvania, local Native Americans prevented the survey of the last 23 miles of the boundary line. Philadelphia clock-maker and astronomer David Rittenhouse headed a survey team which finished surveying those last 23 miles in 1784.

The whole idea behind the Mason-Dixon Line began with a colonial land dispute between two influential British families. In 1632, English King Charles I gave a grant of land, in the American Colonies, to Cecilius Calvert. The grant for what would become the colony of Maryland provided land north of Virginia and south of the 40^th parallel. Today, the City of Pittsburgh is located at the 40^th parallel, so this land grant included much of what is now southern Pennsylvania.

In 1681, King Charles II provided a second land grant to William Penn for what would become the Province of Pennsylvania. Although it did mention that the southern boundary of this land grant would be the 40^th parallel, much of the rest of the delineation of the land grant was convoluted and confusing. Hence, the Penn Family interpreted the grant to include land north of the 39th parallel.

.

The Penn and Calvert families both claimed the land between the 39^th and 40^th parallels. And, since the thriving City of Philadelphia was within these two latitudes, this made the dispute even more contentious. However, such land disputes were common in the 17^th and 18^th centuries, as there had been little actual surveying in America and maps and land grants were often quite vague.

The Penn and Calvert families tried to convince the settlers of the disputed region that they lived in Pennsylvania or Maryland, respectively—and, they should pay taxes to the appropriate colony. Most colonists did not care which colony they lived in; but, they did not want to pay taxes to both colonies!

After several decades, the dispute actually led to war between Pennsylvania and Maryland! What became known as Cresap's War (named for Thomas Cresap, a Maryland partisan who had moved into, what is now York County, Pennsylvania, part of the disputed territory) was a series of skirmishes between the two colonies. Also known as the Conojocular War, militias from both Maryland and Pennsylvania fought for about a year or so, until King George II enacted a cease-fire in 1738.

In 1750, King George II created a formal truce between the two colonies. This truce granted most of the disputed territory to Pennsylvania. However, no one knew where the actual boundary line between the two colonies was located. So, in 1763 the Penn and Calvert families agreed to pay for a boundary survey. Well known English astronomers and surveyors Charles Mason and Jeremiah Dixon were hired to conduct this survey.

Charles Mason had been employed by the Royal Society in Greenwich, England to observe the stars and the Moon, and create lunar tables that could be used to determine longitude. Jeremiah Dixon was a surveyor, trained by a renowned maker of high-precision astronomical instruments, John Bird.

Mason and Dixon traveled through the wilderness of early Pennsylvania, Maryland, Delaware, and Virginia, using the stars to create the boundary line, now known as the Mason-Dixon Line. The boundary began 15 miles south of the southern-most tip of the City of Philadelphia.

The east-west, 233-mile line formed the southern boundary of Pennsylvania with Maryland, and for the area west of the beginning of the Potomac River, Virginia. Of course, during the American Civil War this section of Virginia seceded from the Commonwealth of Virginia and became the state of West Virginia.

They also surveyed the 83-mile western boundary of Delaware [then considered the 3 “Lower Counties on the Delaware” (New Castle, Kent, and Sussex) of the Province of Pennsylvania], separating, what would become, the second smallest state of the Union from Maryland.

At one-mile intervals, Mason and Dixon laid mile-marker stones all along the surveyed route. On the north side of the marker was chiseled the letter P for Pennsylvania; on the south side of the marker is the letter M for Maryland. As a five-mile marker, the stone included the Penn Family Coat of Arms on the north side of the stone and the Calvert Family Coat of Arms on the south side of the stone.

Each stone was a huge block of limestone, 3.5 to 5 feet long, weighing 300 to 600 pounds. These stones had come from a quarry in southern England. Mason and Dixon carried these stones with them, during the survey, using a horse and wagon.

Many of these stones survive. However, some are missing. For instance, one stone was hit by a snow-plow in January of 1996, and it was pushed down into a farmer's field. After more than 200 years, this particular stone now sits in a farmer's barn.

As the surveyors entered the Allegheny Mountains, they did not always lay stones at one-mile intervals. Instead, they created groupings of rocks or cairns as mile-markers.

Even in the 18^th century, surveying was not a new science. However, it was quite an achievement to survey a new boundary line in rugged terrain, often harsh weather, and with the constant risk of attack from Native Americans.

It usually took a couple of weeks, at least, for each set of astronomical observations for a particular mile-marker. They would spend clear-sky nights (of course, they could not work during cloudy nights) taking observations of stars, sometimes in very cold weather. They would have to lie on their backs and look through a 6-foot long telescope, measuring angles between stars and a north-south meridian line.

However, they did use state-of-the-art equipment. Jeremiah Dixon's mentor, John Bird, developed the Zenith Sector they used, which was the most advanced instrument of its day for determining latitude. According to John Bird, it was accurate to within 100 feet.

Scientists and geographers remember the work of Charles Mason and Jeremiah Dixon for two particular contributions to scientific literature:

1. They measured the first degree of latitude in the Americas;
2. They made the first scientific gravity measurements in the Americas.

The Pennsylvania land grant had extended 5 degrees of longitude west of the Delaware River, to the location of the southwest corner of Pennsylvania. Mason and Dixon had been commissioned to survey to the southwest corner of Pennsylvania. However, they never made it that far.

The Native American guides of Mason and Dixon refused to guide them into the territory of their enemy, the Shawnee and Delaware tribes. So, on Sunday, 1767 October 18, Mason and Dixon made their final observations before turning-back to return to Philadelphia, 23 miles short of their goal.

The following entry from Mason and Dixon's Journal, written by Charles Mason, describes setting the final mile-marker of their survey:

“Note: The Sector stood on the top of a very lofty Ridge, but when the Offset was made of 3 Chains 38 Links it fell a little Eastward of the top of the Hills; we therefore extended the true Parallel 3 Chains 80 Links Westward which fell on the top of the said Ridge; there viz. at 233 Miles 17 Chains 48 Links from the Post marked West in Mr. Bryan's Field, we set up a Post marked Won the West Side and heaped around it Earth and Stone three yards and a half diameter at the Bottom and five feet High. The figure nearly conical.”

After setting the last mile-stone, Mason and Dixon remained at the site until Tuesday, 1767 October 20, when their journal reported:

“Began to open a Visto in the True Parallel Eastward.”

Philadelphia clock-maker and astronomer, David Rittenhouse (along with surveyor Andrew Ellicott) completed surveying these last 23 miles in 1784. In addition to his scientific pursuits, University of Pennsylvania Astronomy Professor David Rittenhouse served as Treasurer of Pennsylvania from 1779 to 1787, and on behalf of the Federal Government he founded the U.S. Mint in 1792.

Although Mason and Dixon never reached the southwest corner of Pennsylvania, this was their contracted goal. Hence, the entire boundary line to the southwest corner of Pennsylvania is considered the Mason-Dixon Line. Although the Mason-Dixon Line does not follow an exact line of latitude, it is geographically located at approximately 39 degrees and 43 minutes North Latitude.

Beyond the end of the Mason-Dixon Line, at the southwest corner of Pennsylvania, the line continues west to the Ohio River, forming the boundary line between Marshall and Wetzel Counties in West Virginia. However, this county boundary line was formed by the Virginia Assembly in the latter part of the 18^th century and is not an official part of the Mason-Dixon Line.

In 1786, Andrew Ellicott was commissioned to survey the western boundary line of Pennsylvania (which came to be known as Ellicott's Line), from the end of the Mason-Dixon Line, north, to Lake Erie. Part of this boundary was between Pennsylvania and Virginia; the area of Virginia between Pennsylvania and the Ohio River now contains four counties (Hancock, Brooke, Ohio, and Marshall) in what is now the Northern Panhandle of West Virginia.

North of the location where the Ohio River leaves Pennsylvania, this boundary line codified the boundary between Pennsylvania and the Federal Territory known as the “Ohio Country,” part of the Northwest Territory. This boundary line was important because Pittsburgh and a small part of Western Pennsylvania had originally been considered part of the Ohio Country (an area that had been roughly defined as west of the Allegheny Mountains, north of the Ohio River, and south of Lake Erie). The vast majority of the Ohio Country was admitted to the Union as the State of Ohio on 1803 March 1.

The Mason-Dixon Line has come to be known as the dividing line between the northern United States and the southern United States. This division began as early as 1790 March 1, when the Pennsylvania General Assembly passed legislation banning slavery in the Commonwealth. As Maryland still allowed slavery (as did Delaware and Virginia), by 1804 the Mason-Dixon Line came to be seen as the dividing line between the slave states (in the South) and free states (in the North).

During the first half of the 19^th century, the Mason-Dixon Line came to be known, by slaves fleeing their southern masters, as the line of freedom. The Underground Railroad consisted of abolitionists at secret way-stations who would help African-Americans from the South cross the Mason-Dixon Line on their way to freedom and a new life.

A spiritual song sung by these run-away slaves, “Follow the Drinking Gourd,” helped these mostly illiterate refugees find their way north. The song reminded them to search for the Big Dipper asterism in the night sky, which would help them find the North Star, Polaris.

The Mason-Dixon Line was mentioned during Congressional debates leading to the Missouri Compromise of 1820, which allowed Missouri to enter the Union as a slave state, while Maine entered the Union as a free-soil state. At that time, politicians considered the Mason-Dixon Line, and extending further west along the Ohio River, as the boundary line between slave and free-soil states. The Missouri Compromise legally forbade the admission of states, which had been part of the Louisiana Purchase territories, as slave states if they existed north of Latitude 36 degrees, 30 minutes North (the southern boundary of Missouri); however, the legislation also allowed one exception: Missouri.

When the American Civil War, or War Between the States, erupted in 1861, the Mason-Dixon Line was still considered a dividing line between North and South. But because Washington, DC, a southern city, had been chosen as the site of the new nation's capital (due to the Compromise of 1790, which allowed the Federal Government to pay-off Revolutionary War debts of the states, in return for locating the national capital in the South), the Federal Government refused to allow Maryland to join the Confederate States of America (CSA), even though Maryland (along with pro-Union border states Delaware, Kentucky, and Missouri) continued to allow slavery.

In the middle of the Civil War, 50 counties in western Virginia broke-away from Virginia (which included the state capital, Richmond, as the capital of the Confederacy) to form a new state, West Virginia, which was admitted to the Union on 1863 June 20. On that date, no longer did any portion of the Mason-Dixon Line touch the Commonwealth of Virginia; the section of the Mason-Dixon Line previously bordering Virginia now bordered West Virginia.

Derived from the title, Mason-Dixon Line, and the surname of Jeremiah Dixon, “Dixie” became a name generally identifying the southern United States in the early 19^th century. During the Civil War, it was generally used to refer to the Confederacy.

The song, “Dixie” or “I Wish I Was in Dixie,” probably reinforced the popular notion that Dixie meant the American South. The song became the unofficial anthem of the Confederacy during the Civil War, after being played during the inauguration of Confederate President Jefferson Davis in 1861. Upon hearing of the Confederate General Robert E. Lee's surrender at Appomattox County, Virginia in 1865, U.S. President Abraham Lincoln asked the military band to play “Dixie.”

There is still some dispute regarding who wrote the song, although it seems the song may have been authored by Daniel Emmett, a Northerner from Mount Vernon, Ohio in 1859. It quickly became popular through black-face minstrel shows.

Today, the song “Dixie” is still popular in the South. And, the term Dixie is still used to represent the South. In fact, a popular grocery store chain in the South, known as Winn-Dixie (headquartered in Jacksonville), operates 495 stores in five southern states (Alabama, Florida, Georgia, Louisiana, and Mississippi).

Interestingly, a handsome, 10-story office building in a northern city is called Dixie Terminal. Built in Downtown Cincinnati in 1921, this building is located only dozens of feet from the Ohio River. It was named Dixie Terminal because it was once a streetcar terminal (later commuter bus terminal) for streetcars coming from Dixie--that is, the suburbs of Northern Kentucky.

                                        

Internet Links to Additional Information ---

Photograph of Historical Marker near end of Survey conducted by Mason and Dixon:
Link >>> http://spacewatchtower.blogspot.com/2017/10/astronomical-calendar-2017-october.html

Mason-Dixon Line Survey web-site ExploretheLine, with photos of survey markers:
Link >>> http://www.exploretheline.com/index1.html 

Charles Mason: Link >>> https://en.wikipedia.org/wiki/Charles_Mason 

Jeremiah Dixon: Link >>> https://en.wikipedia.org/wiki/Jeremiah_Dixon 

David Rittenhouse: Link >>> https://en.wikipedia.org/wiki/David_Rittenhouse 
     University of Pennsylvania Astronomy Professor David Rittenhouse inspires the field of stars on 
     the American Flag: Link >>> http://spacewatchtower.blogspot.com/2017/06/240th-anniversary-of-american-flag-why.html

Andrew Ellicott: Link >>> https://en.wikipedia.org/wiki/Andrew_Ellicott

Special Thanks: Amateur Astronomer Pete Zapadka.

Source: Glenn A. Walsh Reporting for SpaceWatchtower, a project of Friends of the Zeiss.
             2017 October 18.

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gaw

Glenn A. Walsh, Project Director, Friends of the Zeiss: < http://buhlplanetarium.tripod.com/fotz/ >
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