Monday, March 27, 2017

Public Invited to Search for Planets in Other Star Systems

KeckTelescopes-hi.png
W.M. Keck Observatory on Mauna Kea in Hawaii.
(Image Sources: Wikipedia.org , By T. Wynne / JPL - http://planetquest.jpl.nasa.gov/images/keckTelescopes-hi.tif, Public Domain, https://commons.wikimedia.org/w/index.php?curid=4963229 )

By Glenn A. Walsh
Reporting for SpaceWatchtower

Last month, NASA opened an Internet web-site to engage the public in the search for the long-sought “Planet Nine” in the outer reaches of our Solar System. A huge data-set has also been released on the Internet, by a team led by the Carnegie Institution for Science (a.k.a. Carnegie Institution of Washington), inviting the public to help in the search for exo-planets, planets outside of our Solar System.

With a technique called radial velocity being used to help hunt for exo-planets, this data-set is the largest collection of observations utilizing this particular technique. It took more than two decades for the W.M. Keck Observatory on Mauna Kea in Hawaii to collect all of these observations. At an elevation of 13,600 feet / 4,145 meters, Keck's twin telescopes, each with a 10-meter / 33-foot mirror-aperture, saw “first-light” in the mid-1990s.

The huge observation data-set is being made available for public use, along with a computer software package to help process the data and an on-line tutorial of how to use the data-set. With almost 61,000 observations of more than 1,600 nearby stars, scientists are hoping that fresh, public eyes using this user-friendly data-base will bring new results in the search for exo-planets.

Internet links to this data-base, along with tools to assist in its use, are located at the end of this blog-post.

Much of this observation work was done by a spectrometer mounted on the Keck-I Telescope called HIRES. HIRES (High Resolution Echelle Spectrometer), a large and complex instrument of the Keck Observatory, analyzes the light spectra coming into the telescope from the various star systems observed.

"HIRES was not specifically optimized to do this type of exoplanet detective work, but has turned out to be a workhorse instrument of the field", said Steve Vogt of the University of California Santa Cruz, who built the instrument. "I am very happy to contribute to science that is fundamentally changing how we view ourselves in the universe."

Thus far, scientists looking over this data have found more than 100 possible exo-planets, including one orbiting Star GJ-411, the fourth closest star to our Solar System (8.1 light-years from Earth). An academic research paper about this find was recently published in the scientific journal, The Astronomical Journal.

“This is an amazing catalog, and we realized there just aren’t enough of us on the team to be doing as much science as could come out of this dataset,” says Jennifer Burt, a Torres Postdoctoral Fellow in the Massachusetts Institute of Technology’s (MIT) Kavli Institute for Astrophysics and Space Research. “We’re trying to shift toward a more community-oriented idea of how we should do science, so that others can access the data and see something interesting.”

"I think this paper sets a precedent for how the community can collaborate on exoplanet detection and follow-up", said team-member Johanna Teske of Carnegie’s Observatories and Department of Terrestrial Magnetism. “With NASA’s TESS mission on the horizon (scheduled for launch a year from now), which is expected to detect 1000+ planets orbiting bright, nearby stars, exoplanet scientists will soon have a whole new pool of planets to follow up.”

Keck Observatory Observation Data-Base: Link >>> http://home.dtm.ciw.edu/ebps/

Software Package (Downloadable) to Assist with Searching Data-Base:
Link >>> http://www.stefanom.org/console-2/

On-Line Tutorial for use of Software Package: Link >>> http://oklo.org/

Internet Links to Additional Information ---

News Release from the Carnegie Institution for Science:
Link >>> https://carnegiescience.edu/news/team-makes-planet-hunting-group-effort-finds-more-100-candidates

News Release from the Massachusetts Institute of Technology:
Link >>> http://www.rdmag.com/news/2017/02/scientists-make-huge-dataset-nearby-stars-available-public?et_cid=5828674&et_rid=544605860&location=top&et_cid=5828674&et_rid=544605860&linkid=content

Carnegie Institution for Science: Link >>> https://en.wikipedia.org/wiki/Carnegie_Institution_for_Science

W.M. Keck Observatory: Link >>> https://en.wikipedia.org/wiki/W._M._Keck_Observatory 

HIRES - High Resolution Echelle Spectrometer:
Link >>> https://en.wikipedia.org/wiki/W._M._Keck_Observatory#Instruments

TESS: Transiting Exo-Planet Survey Satellite:
Link >>> https://en.wikipedia.org/wiki/Transiting_Exoplanet_Survey_Satellite

Citizen Science Projects: Link >>> http://buhlplanetarium2.tripod.com/FAQ/citizenscience.html

Related Blog Post ---

"Citizen Science: Help NASA Find 'Planet Nine'." 2017 March 10.

Link >>> http://spacewatchtower.blogspot.com/2017/03/citizen-science-help-nasa-find-planet.html


Source: Glenn A. Walsh Reporting for SpaceWatchtower, a project of Friends of the Zeiss.
             2017 March 27.

                             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 >

Sunday, March 19, 2017

Season of Spring Begins Early Monday Morning

http://buhlplanetarium.tripod.com/pix/graphics/solsticeimage008.png
This diagram shows the position of the Earth, in relation to the Sun, at the time of the Vernal Equinox, the official beginning of the Season of Spring, as well as the other solstices and equinox of the year.
(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 Vernal Equinox, which marks the beginning of the Season of Spring in Earth's Northern Hemisphere, occurs for 2017 on Monday Morning, March 20 at 6:29 a.m. Eastern Daylight Saving Time (EDT) / 10:29 Coordinated Universal Time (UTC).

In the Southern Hemisphere, this marks the astronomical beginning of the Season of Autumn.

On the day of Equinox, the Sun appears directly overhead at local Noon on the Equator. At the moment of Equinox, the Northern and Southern Hemispheres of Earth are illuminated equally. And, the time of Equinox is the only time when the terminator (dividing line on Earth between daylight and darkness) is perpendicular to the Equator.

This, and the reason for seasons on Earth in the first place, is due to the fact that Earth rotates on its axis, which is tilted at a 23 degrees, 26 minutes, 13.4 seconds (23.43705 degrees) angle from the plane of the Earth's orbit around the Sun. As the Earth revolves around the Sun, this axial tilt causes one hemisphere of the planet to receive more direct solar radiation during that hemisphere's Season of Summer and much less direct solar radiation a half-year later during that hemisphere's Season of Winter. As mentioned, during an Equinox [about half-way between Summer and Winter (for Autumn or Fall), and about half-way between Winter and Summer (for Spring)] both planetary hemispheres receive an equal amount of solar radiation.

In Latin, Equinox, is defined as equal-night, the day when daylight and darkness are about equal in length. Such actual equal-night never occurs on the actual date of an Equinox on Earth. This is due to the fact that the Sun is so large, in relation to the Earth, and hence, the entire Sun does not appear at actual sunrise, only a portion of the Sun; it takes a few more minutes for the entire Sun to appear above the horizon. Also, due to the refractive nature of Earth's atmosphere, daylight can be seen before the Sun's disk can be observed.

The date of actual equal-night varies by a location's longitude and latitude. At the Earth's Equator, daytime is always longer than night. Hence, the Equator never has equal-night.

While the Vernal Equinox, the true beginning of the Season of Spring, occurs on March 20 at 6:29 a.m. EDT / 10:29 UTC, the literal Equinox for Spring, termed the Spring Equilux, actually occurs each year a few days earlier, usually around March 16 or 17 (depending on the specific location).

The Vernal Equinox is used in the solar calendars of Iran and Afghanistan as the beginning of their calendar year. In ancient times, the Vernal Equinox, then celebrated by the old style calendar on or near March 25, was also the beginning of the calendar year for many ancient civilizations.

An urban legend that has been making the rounds for decades has it that eggs can be stood on their ends only during an Equinox, whether the Vernal Equinox in the Spring or the Autumnal Equinox in the Fall. This is completely false. Depending greatly on the size and shape of the particular egg, eggs can be stood on their ends any day of the year! Astronomy has nothing to do with whether an egg can stand on its end. If an egg can stand on its end on the Equinox (and, due to the shape and size of some eggs, this is not even possible), it can stand the same way any other day of the year.

In the last few years, with the help of the Internet and Social Media, another urban legend has become prevalent. Now it is claimed that brooms can stand on their own, on their bristles, only on an Equinox day. This is also false. Again, as with eggs, if a broom can stand on its bristles by itself (this usually only works with newer brooms, with more even bristles) on an Equinox, it can do so any day of the year!

This year, the Primary Moon Phase of Last Quarter for March occurs just a few hours after the Vernal Equinox: March 20 at 11:58 a.m. EDT / 15:58 UTC.

There is now an effort to have the day of the Vernal Equinox designated to commemorate the life of the first female astronomer, Hypatia of Alexandria, in ancient Egypt: Hypatia Day / Women in Science Day. Astronomical historian Ari Belenkiy, who finished an academic paper in 2016 on the life and death of Hypatia, has started an effort to have the day of the Vernal Equinox, March 20, designated by the Canadian Parliament as a day commemorating Hypatia's life. According to Professor Belenkiy, Hypatia's last days were dedicated to finding the exact time of the Vernal Equinox.

Hypatia was a Greek astronomer, mathematician, and philosopher, daughter of the mathematician Theon Alexandricus, who lived in Alexandria, Egypt during the late 4th and early 5th centuries. At that time Alexandria was part of the Eastern Roman Empire, which had a great rivalry with the Church of Rome. This led to deep divisions in Alexandria.

Due to the fog of time, there is much dispute regarding the events surrounding the death of Hypatia. According to the Church historian Socrates Scholasticus, a clique of Bishop Cyril's zealots killed Hypatia, due to a deep conflict between the Governor and Bishop of Alexandria. Hypatia's astronomical calculations regarding the date of Easter may have set the mob against her.

Although none of Hypatia's writings survive, she is reported to have made significant academic contributions in the fields of Astronomy and Mathematics.

The beginning of Spring also marks the beginning of the National Cherry Blossom Festival held each year in Washington, DC. This festival commemorates the 1912 gift of 3,000 cherry trees from the Mayor of Tokyo to the City of Washington. This year, the festival runs from March 15 through April 16.

Physicians have declared the first week of Spring as Medicine Cabinet Clean-Up Week. They urge families, as part of their annual Spring cleaning, to clean-out the medicine cabinet of old and expired pharmaceuticals which are no longer being used. This would prevent other family members from using these old drugs by accident, or the beginning of drug abuse.

Internet Links to Additional Information ---

Vernal Equinox: Link >>> http://scienceworld.wolfram.com/astronomy/VernalEquinox.html

Season of Spring: Link >>> http://en.wikipedia.org/wiki/Spring_%28season%29

Equinox: Link >>> http://en.wikipedia.org/wiki/Equinox

Earth's Seasons: Link >>> http://en.wikipedia.org/wiki/Season

Tilt of a planet's axis: Link >>> http://en.wikipedia.org/wiki/Axial_tilt

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

Petition to designate March 20 to commemorate the life of Hypatia:
Link >>> https://www.change.org/p/canada-s-parliament-commemorating-the-first-female-astronomer-hypatia-of-alexandria

National Cherry Blossom Festival, Washington:
Link >>> http://www.nationalcherryblossomfestival.org/?id=404

Medicine Cabinet Clean-Up Week: Link >>> http://www.prnewswire.com/news-releases/include-medicine-cabinets-on-your-spring-cleaning-list-300042760.html

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.

Source: Glenn A. Walsh Reporting for SpaceWatchtower, a project of Friends of the Zeiss.
             2017 March 19.

                             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 >
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 >

Friday, March 10, 2017

Citizen Science: Help NASA Find 'Planet Nine'


This is an artist's concept of a cool, Brown-Dwarf Star, a type known as a "Y-Dwarf," which is one possibility of being the proposed Planet Nine. Such "Y-Dwarf" stars are the coldest star bodies known, with temperatures that can be cooler than the human body! Hence, such an object in the Outer Solar System would be very difficult to find, as it would generate or reflect very little light.
(Image Source: NASA / Jet Propulsion Laboratory of the California Institute of Technology)

By Glenn A. Walsh
Reporting for SpaceWatchtower

NASA is seeking help from Citizen Scientists – that is, regular people who have not trained to be scientists - to help find the elusive “Planet Nine” (which some people also refer to as Planet X), which scientists are convinced exists in our Outer Solar System. Although the Planet Pluto, originally considered the ninth planet, was re-designated as a “Dwarf Planet” about a decade ago due to its small size, scientists recently hypothesized that one (or possibly more than one) much larger, and very difficult to see, planet is still yet to be found beyond the orbit of Neptune.

NASA has funded a new Internet web-site, titled Backyard Worlds: Planet 9 (Internet link to this web-site at the end of this blog-post), for members of the general public to assist with the search for Planet Nine, and possibly other yet-unfound celestial bodies between the orbit of Neptune and the closest star (not including our Sun) to our Solar System, Proxima Centauri. Proxima Centauri is 4.25 light-years from Earth, and in that distance there possibly is one or more planetary bodies that are very difficult to find.

The data-base used in the Backyard Worlds: Planet 9 web-site comes from a scan of stars in the entire sky, between 2010 and 2011, by NASA's Wide-Field Infrared Survey Explorer (WISE) mission. While it may be difficult to find outer planets using normal light, it is hoped that these objects can be found in a WISE infrared scan.

"There are just over four light-years between Neptune and Proxima Centauri, the nearest star, and much of this vast territory is unexplored," said lead researcher Marc Kuchner, an astrophysicist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "Because there's so little sunlight, even large objects in that region barely shine in visible light. But by looking in the infrared, WISE may have imaged objects we otherwise would have missed."

On the new web-site, public participants can view brief "flip-book" movies of WISE scans of parts of the sky. It is believed that human eyes, looking at these infrared scans, could discern objects more readily than would a computer search-algorithm. There are some things that human eyes can still do better than a computer!

In addition to the possibility of finding Planet Nine, or other possible planets, asteroids / planetoids, or comets,  Brown-Dwarf Stars in the vicinity of our Solar System, some known as "Y-Dwarfs" (somewhat similar to Jupiter), may also be found in this new search. It may actually turn-out that Planet Nine is a Y-Dwarf or Brown-Dwarf.

Once a public participant views these brief movies, if they find an object that seems not to be a normal star, they can contact a Jet Propulsion Laboratory scientist (by flagging a questionable object) about the find. If it turns out that a new planet or a Y-Dwarf or Brown-Dwarf Star has actually been discovered, the citizen scientist(s) who participated in the discovery will be credited in the scientific literature.

So, give the new Backyard Worlds: Planet 9 web-site a try and see if you can find any yet-unchartered worlds. And, if NASA confirms that you did help find a new world, let SpaceWatchtower know (E-Mail address: < spacewatchtower@planetarium.cc >); we will include your name and your new discovery in an up-coming SpaceWatchtower blog-post!

Internet Link to the Backyard Worlds: Planet 9 Web-Site:

Internet Links to Additional Information ---

NASA's Wide-Field Infrared Survey Explorer (WISE) mission:
Link >>> https://en.wikipedia.org/wiki/Wide-field_Infrared_Survey_Explorer

Planet Nine: Link >>> https://en.wikipedia.org/wiki/Planet_Nine

Planet X: Link >>> https://en.wikipedia.org/wiki/Planets_beyond_Neptune

Brown-Dwarf Stars: Link >>> https://en.wikipedia.org/wiki/Brown_dwarf

Y-Dwarf Stars: Link >>> https://en.wikipedia.org/wiki/Brown_dwarf#Spectral_class_Y

"NASA-funded Website Lets the Public Search for New Nearby Worlds."
NASA / Jet Propulsion Laboratory 2017 Feb. 15.
Link >>> https://www.jpl.nasa.gov/news/news.php?feature=6747

More Citizen Science Projects:
Link >>> http://buhlplanetarium2.tripod.com/FAQ/citizenscience.html

Related Blog Posts ---

Walsh, Glenn A.
"Public Invited to Search for Planets in Other Star Systems." Blog-Post.
SpaceWatchtower 2017 March 27.
Link >>> http://spacewatchtower.blogspot.com/2017/03/public-invited-to-search-for-planets-in.html

Walsh, Glenn A.
"Undiscovered 'Planet Nine' May Be Cause of Tilt of Our Solar System." Blog-Post.
SpaceWatchtower 2016 Oct. 22.
Link >>> http://spacewatchtower.blogspot.com/2016/10/undiscovered-planet-nine-may-be-cause.html

Source: Glenn A. Walsh Reporting for SpaceWatchtower, a project of Friends of the Zeiss.
             2017 March 10.

                             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 >
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 >

Wednesday, March 1, 2017

Astronomical Calendar: 2017 March

Image result for images daylight savings time
Daylight Saving Time begins on Sunday Morning, 2017 March 12, at 2:00 a.m. Local
Prevailing Time. (Image Source: Austin College, Sherman TX)

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

 Related Blog Post ---


"Astronomical Calendar: 2017 February." 2017 Feb. 1.

Link >>> http://spacewatchtower.blogspot.com/2017/02/astronomical-calendar-2017-february.html


Source: Friends of the Zeiss.
              2017 March 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 >
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 >