Wednesday, January 27, 2021

Most Stable Laser Signal Through Atmosphere Could Help Prove Einstein Theory

                         https://buhlplanetarium2.tripod.com/bio/einstein/Einstein-Leo-1934AAAS.jpg

 A new atmospheric laser link could help prove, more precisely than ever before, Albert Einstein's General Theory of Relativity This 1934 photograph shows Dr. Einstein (right) visiting the exhibit booth of the Amateur Astronomers Association of Pittsburgh (AAAP) at the annual conference of the American Association for the Advancement of Science in Pittsburgh. To the front-left of Dr. Einstein is Leo J. Scanlon, AAAP Co-Founder (1929), constructor of the world's first all-aluminum, astronomical observatory dome (1930), and one of the first two Buhl Planetarium lecturers (1939).
(Image Sources: AAAP, Scanlon Family Collection; Photo Reproduction: © Copyright David Smith)

By Glenn A. Walsh

Reporting for SpaceWatchtower

Scientists have developed a world record for the most stable transmission of a laser signal through the atmosphere. A research team from the International Centre for Radio Astronomy Research (ICRAR) and The University of Western Australia (UWA) reached this milestone by combining Australia's 'phase stabilisation' technology with advanced self-guiding optical terminals.

This new technology now allows laser signals to be sent, point-to-point, without any atmospheric interference. The paper introducing this new technology was issued on January 22 in the journal, Nature Communications.

Lead author Benjamin Dix-Matthews, a PhD student at ICRAR and UWA, said that this new technique basically eliminates turbulence from the atmosphere.

In a news release from ICRAR, Mr. Dix-Matthews said, "We can correct for atmospheric turbulence in 3D, that is, left-right, up-down and, critically, along the line of flight.

"It's as if the moving atmosphere has been removed and doesn't exist. It allows us to send highly-stable laser signals through the atmosphere while retaining the quality of the original signal."

Dr Sascha Schediwy, ICRAR-UWA senior researcher, highlighted new applications possible with this new technology: "If you have one of these optical terminals on the ground and another on a satellite in space, then you can start to explore fundamental physics. Everything from testing Einstein's theory of general relativity more precisely than ever before, to discovering if fundamental physical constants change over time."

He added that there are practical uses in Earth science and geophysics: "For instance, this technology could improve satellite-based studies of how the water table changes over time, or to look for ore deposits underground."

Additionally, he emphasized the great increase in the amount and security of data that could now be transferred between the Earth and satellites: "Our technology could help us increase the data rate from satellites to ground by orders of magnitude. The next generation of big data-gathering satellites would be able to get critical information to the ground faster."

This research was originally developed to synchronize incoming signals for the Square Kilometre Array Telescope which is set to be constructed in Western Australia and South Africa.

 Internet Links to Additional Information ---

International Centre for Radio Astronomy Research (ICRAR): Link >>> https://en.wikipedia.org/wiki/International_Centre_for_Radio_Astronomy_Research 

 University of Western Australia (UWA): Link >>> https://en.wikipedia.org/wiki/University_of_Western_Australia

Square Kilometre Array Telescope: Link >>> https://en.wikipedia.org/wiki/Square_Kilometre_Array

Related Blog Posts ---

"100 Years Ago: U.S. Scientist Questions Evidence Proving General Theory of Relativity." Wed., 2019 Nov. 13.

Link >>> https://spacewatchtower.blogspot.com/2019/11/100-years-ago-us-scientist-questions.html

 

"Book: "Einstein for Anyone: A Quick Read"" Thur., 2016 Dec. 15.

Link >>> https://spacewatchtower.blogspot.com/2016/12/book-einstein-for-anyone-quick-read.html 


"Centennial: Einstein's General Theory of Relativity." Wed., 2015 Nov. 25.

Link >>> https://spacewatchtower.blogspot.com/2015/11/centennial-einsteins-general-theory-of.html 


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

                 Wednesday, 2021 January 27.

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gaw

Glenn A. Walsh, Informal Science Educator & Communicator:
Link >>> http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/
Electronic Mail: < gawalsh@planetarium.cc >
Project Director, Friends of the Zeiss: Link >>> http://buhlplanetarium.tripod.com/fotz/
SpaceWatchtower Editor / Author: Link >>> http://spacewatchtower.blogspot.com/
Formerly Astronomical Observatory Coordinator & Planetarium Lecturer, original Buhl Planetarium & Institute of Popular Science (a.k.a. Buhl Science Center), Pittsburgh's science & technology museum from 1939 to 1991.
Formerly Trustee, Andrew Carnegie Free Library and Music Hall, Pittsburgh suburb of Carnegie, Pennsylvania.
Author of History Web Sites on the Internet --
* Buhl Planetarium, Pittsburgh: Link >>>  http://www.planetarium.cc  Buhl Observatory: Link >>>  http://spacewatchtower.blogspot.com/2016/11/75th-anniversary-americas-5th-public.html
* Adler Planetarium, Chicago: Link >>> http://adlerplanetarium.tripod.com
* Astronomer, Educator, Optician John A. Brashear: Link >>> http://johnbrashear.tripod.com
* Andrew Carnegie & Carnegie Libraries: Link >>> http://www.andrewcarnegie.cc

Wednesday, January 20, 2021

Venus Surprises in Day-time Sky Shortly After Lincoln's 2nd Inaugural

A large crowd in front of a large building with many pillars

Photograph of the second Presidential Inauguration of Abraham Lincoln on 1865 March 4, on the east portico of the U.S. Capitol Building, the expansion of which was nearly completed including a much more prominent dome. January 20 Inaugurations of the President of the United States did not begin until 1937, with the 1933 January 23 adoption of the 20th Amendment to the United States Constitution.

(Image Sources: Wikipedia.org, By Alexander Gardner - This image is available from the United States Library of Congress&#039;s Prints and Photographs divisionunder the digital ID ppmsca.23718.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., Public Domain, https://commons.wikimedia.org/w/index.php?curid=38086507)

By Glenn A. Walsh

Reporting for SpaceWatchtower

As we celebrate the Inauguration of the 46th President of the United States of America, Joseph R. Biden, Jr. (second Pennsylvania native to be elected U.S. President), we remember an interesting astronomical occurrence observed by Inaugural attendees, including Abraham Lincoln, shortly after the second Inauguration of the 16th U.S. President.

According to Chuck Bueter, writing in Nightwise.org on 2017 January 6, although clouds and rain dominated the Saturday morning of 1865 March 4, as the Inauguration ceremonies of Abraham Lincoln proceeded, the clouds parted and the planet Venus dominated a crystal-clear blue sky!

Two members of President Lincoln's body-guard detail, during the Inauguration proceedings, corroborated the sudden appearance, and notice by Inauguration attendees, of Venus in the post-Inaugural sky:

According to MrLinconsWhiteHouse.org, Sergeant Smith Stimmel wrote:

Soon after the President concluded his address, he entered his carriage, and the procession started up Pennsylvania Avenue to the White House, the escort from our Company following next to his carriage. Shortly after we turned onto Pennsylvania Avenue, west of the Capitol, I noticed the crowd along the street looking intently, and some were pointing to something in the heavens toward the south. I glanced up in that direction, and there in plain view, shining out in all her starlike beauty, was the planet Venus. It was a little after midday at the time I saw it, possibly near one o’clock; the sun seemed to be a little west of the meridian, the star a little east. It was a strange sight. I never saw a star at that time in the day before or since. The superstitious had had many strange notions about it, but of course it was simply owing to the peculiarly clear condition of the atmosphere and the favorable position of the planet at that time. The President and those who were with him in the carriage noticed the star at the same time.

In GilderLehrman.org, the second body-guard added:

When Mr. Lincoln delivered his second inaugural address, I had the privilege of standing within twenty feet of him....It had rained a great deal during the forenoon, and clouds overcast the sky as the presidential party and the Senate came out on the east portico. While the ceremonies were in progress the clouds suddenly parted, and, although it was about midday, Venus was seen clearly shining in the blue sky. The attention of the immense throng was directed to it.

Even famous poet Walt Whitman, then covering the Inauguration for The New York Times, mentioned the Venus appearance in his news report.

In his book, Celestial Sleuth: Using Astronomy to Solve Mysteries in Art, History and Literature, Donald W. Olson gives possible explanations why Venus would have been so noticeable on that special day in American history. He argues that the morning rains may have cleansed the Washington sky of city air pollution, allowing Venus to appear brighter in the afternoon sky.

He also notes that, at that particular time of the year, Venus was near maximum elongation, meaning that the planet's distance in the sky from the Sun was nearly the farthest possible. The Sun's glare would have made it more difficult to see Venus in the day-time sky, if the Sun and Venus had appeared closer in the sky.

Viewing Venus in the day-time sky with naked-eyes (one-power) is possible for anyone. However, the sky has to be clear and deep-blue with good astronomical seeing (steadiness of the air), and it is best if Venus is far from the Sun as viewed in the sky. And, usually, you need to know where to look in the sky for Venus, as it is very rarely obvious to naked-eyes in the day-time sky, as it was on that day in 1865.

If you try to find Venus in the day-time sky using binoculars or a telescope, BE VERY CAREFUL NOT TO ACCIDENTALLY AIM THE BINOCULARS OR TELESCOPE AT THE SUN! LOOKING AT THE SUN WITH BINOCULARS OR A TELESCOPE COULD CAUSE MAJOR EYE DAMAGE AND POSSIBLE BLINDNESS !!!

During President Lincoln's second Inauguration, the President delivered, what many people consider, one of his best speeches. This address, which historian Mark Noll places "among the small handful of semi-sacred texts by which Americans conceive their place in the world," is inscribed on the Lincoln Memorial on the National Mall in Washington, D.C.

It was a little more than a month later, at 7:22 a.m. on 1865 April 15, that Abraham Lincoln died from a gun-shot wound suffered the previous evening at Washington's Ford's Theatre. This was just six days after the American Civil War came to a conclusion, with the victory of the Union Army at Appomattox Courthouse, Virginia.

Internet Links to Additional Information ---

 "Looking Up At The Inauguration" (Nightwise.org): Link >>> https://www.nightwise.org/single-post/2017/01/06/Looking-Up-At-The-Inauguration

1864 U.S. Presidential Election: Link >>> https://en.wikipedia.org/wiki/1864_United_States_presidential_election 

Abraham Lincoln: Link >>> https://en.wikipedia.org/wiki/Abraham_Lincoln 

Related Blog Posts ---

 

"Science & U.S. Presidents." Mon. 2020 Feb. 17.

Link >>> https://spacewatchtower.blogspot.com/2020/02/science-us-presidents.html

 

"Presidents' Day: The Astronomy President." Mon., 2014 Feb. 17.

Link >>> https://spacewatchtower.blogspot.com/2014/02/presidents-day-astronomy-president.html

 

"JFK: Loss of the Man Who Sent Us to the Moon." Fri., 2013 Nov. 22.

Link >>> https://spacewatchtower.blogspot.com/2013/11/jfk-loss-of-man-who-sent-us-to-moon.html

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

                 Wednesday, 2021 January 20.

                             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, Informal Science Educator & Communicator:
Link >>> http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/
Electronic Mail: < gawalsh@planetarium.cc >
Project Director, Friends of the Zeiss: Link >>> http://buhlplanetarium.tripod.com/fotz/
SpaceWatchtower Editor / Author: Link >>> http://spacewatchtower.blogspot.com/
Formerly Astronomical Observatory Coordinator & Planetarium Lecturer, original Buhl Planetarium & Institute of Popular Science (a.k.a. Buhl Science Center), Pittsburgh's science & technology museum from 1939 to 1991.
Formerly Trustee, Andrew Carnegie Free Library and Music Hall, Pittsburgh suburb of Carnegie, Pennsylvania.
Author of History Web Sites on the Internet --
* Buhl Planetarium, Pittsburgh: Link >>>  http://www.planetarium.cc  Buhl Observatory: Link >>>  http://spacewatchtower.blogspot.com/2016/11/75th-anniversary-americas-5th-public.html
* Adler Planetarium, Chicago: Link >>> http://adlerplanetarium.tripod.com
* Astronomer, Educator, Optician John A. Brashear: Link >>> http://johnbrashear.tripod.com
* Andrew Carnegie & Carnegie Libraries: Link >>> http://www.andrewcarnegie.cc

Monday, January 4, 2021

Astro-Calendar: 2021 Jan. / Circle of Planets: Jupiter, Saturn, Mercury

 Chart of twilit sky with three labeled bright dots close to the ground.

Last month Jupiter and Saturn provided a Great Conjunction to evening viewers. Jupiter and Saturn are still nearby, joined by Mercury in mid-January for a Circle of Planets (2.3-degree Circle peaks Sun., Jan. 10, 7:00 a.m. EST / 12:00 UTC, but only visible just after local sunset). Mercury, always near the Sun and setting shortly after local sunset, can only be seen shortly after sunset in the west-southwest sky. This Circle of Planets will set around 6:00 p.m. local time. So, try to find it as soon as it gets dark.

Later in the month, around January 21, also in the southwestern sky shortly after sunset can be seen the waxing gibbous Moon sliding past a conjunction of Mars and Uranus. Uranus is very dim; binoculars or a telescope may be necessary.

Remember, all celestial observations are weather-permitting.

More information: Link >>> https://earthsky.org/astronomy-essentials/visible-planets-tonight-mars-jupiter-venus-saturn-mercury

(Graphic Source: EarthSky.org)

Astronomical Calendar for 2021 January ---
Link >>> https://buhlplanetarium4.tripod.com/astrocalendar/2021.html#jan

 Related Blog Post ---

"Astro-Calendar: 2020 Dec. / Great Conjunction: Jupiter & Saturn on Winter Solstice."

Tuesday, 2020 December 1 .

Link >>> https://spacewatchtower.blogspot.com/2020/12/astro-calendar-2020-dec-great.html


Source: Friends of the Zeiss.
            Monday, 2021 January 4.

                             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, Informal Science Educator & Communicator:
Link >>> http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/
Electronic Mail: < gawalsh@planetarium.cc >
Project Director, Friends of the Zeiss: Link >>> http://buhlplanetarium.tripod.com/fotz/
SpaceWatchtower Editor / Author: Link >>> http://spacewatchtower.blogspot.com/
Formerly Astronomical Observatory Coordinator & Planetarium Lecturer, original Buhl Planetarium & Institute of Popular Science (a.k.a. Buhl Science Center), Pittsburgh's science & technology museum from 1939 to 1991.
Formerly Trustee, Andrew Carnegie Free Library and Music Hall, Pittsburgh suburb of Carnegie, Pennsylvania.
Author of History Web Sites on the Internet --
* Buhl Planetarium, Pittsburgh: Link >>>  http://www.planetarium.cc  Buhl Observatory: Link >>>  http://spacewatchtower.blogspot.com/2016/11/75th-anniversary-americas-5th-public.html
* Adler Planetarium, Chicago: Link >>> http://adlerplanetarium.tripod.com
* Astronomer, Educator, Optician John A. Brashear: Link >>> http://johnbrashear.tripod.com
* Andrew Carnegie & Carnegie Libraries: Link >>> http://www.andrewcarnegie.cc

Sunday, December 20, 2020

Mon.: Winter Begins & Great Conjunction: Jupiter & Saturn; Tue: Ursid Meteors

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 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 Operations Manager of the original Buhl Planetarium & Institute of Popular Science / Buhl Science Center (Pittsburgh's science & technology museum from 1939 to 1991) 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


Despite the Nor'Easter a few days ago, which blanketed much of the Northeastern United States with up-to a foot of snow or more, Winter begins on Monday. On the same day comes the Great Conjunction, the closest view from Earth of the two largest planets in our Solar System since 1623. And, the annual Ursid Meteor Shower peaks on Tuesday.

The season of Winter, in the Northern Hemisphere of Earth, begins at the moment of the Winter / December Solstice, early Monday Morning, 2020 December 21 at 5:02 a.m. Eastern Standard Time (EST) / 10:02 Coordinated Universal Time (UTC). This moment also marks the astronomical beginning of the Summer season in the Southern Hemisphere.

The Great Conjunction of 2020, where the planets Jupiter and Saturn almost appear to touch, as viewed from Earth (Jupiter passes just 0.1 degree south of Saturn), occurs less than four hours after the Solstice, on Monday Morning, 2020 December 21 at 9:00 a.m. EST / 14:00 UTC.

Early in the evening marks the First Quarter Primary Phase of Earth's Moon: Monday Evening, 2020 December 21 at 6:41 p.m. EST / 23:41 UTC. And, this year's Winter Solstice marks the 52nd anniversary of the launch of Apollo 8, the first human mission to the Moon. Apollo 8 astronauts Frank Borman, James Lovell, and William Anders launched from Cape Canaveral, Florida on 1968 December 21 at 7:51 a.m. EST / 12:51 UTC, entered lunar orbit early on the morning of Christmas Eve, orbited the Moon ten times, and returned to Earth on 1968 December 27.

Almost exactly 24 hours after the Winter Solstice will mark the peak time for the annual Ursid Meteor Shower. This meteor shower peaks Tuesday Morning, 2020 December 22 at 4:00 a.m. EST / 9:00 UTC.


                                               Winter Solstice 2020


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 late Summer or early Autumn).

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, are 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 17th 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 Continent, 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.


                                               The Great Conjunction of 2020


The Great Conjunction of Jupiter and Saturn will occur on the day of the Winter Solstice only about three hours after the moment of the Winter Solstice: Monday Morning, 2020 December 21 at 9:00 a.m. EST / 14:00 UTC.. Although the actual conjunction event occurs in the daytime sky for much of North America, the two planets will appear nearly as close on the evening before and the evening of the event.

As viewed from Earth, bright Jupiter (Apparent Visual Magnitude: -2.0) will pass only 0.1 degree (1/5 diameter of the Earth's Moon) south of the much dimmer Saturn (Saturn is only 10 per-cent as bright as Jupiter - Apparent Visual Magnitude: +0.6) at the moment of the conjunction event. On the evening of the Winter Solstice, the two planets will appear so close (one of the rare occasions when both planets can be seen in the field-of-view of a telescope or binoculars), they may appear as one bright object.

The two planets will be easily visible, shortly after local sunset in the southwestern sky. Even though a conjunction occurs for only one moment, Jupiter and Saturn will be very close for several days in December, as well as close for the next few months. So, if clouds prevent a view of the event on the night of the Winter Solstice, the two planets will continue their dance in the sky for awhile, as they are now dancing together in the sky every evening as we approach the actual conjunction event.

Saturn will appear just above and a little to the left of Jupiter. As both are planets, with visible disks, they do not twinkle as do stars. And, although Saturn will be much dimmer than Jupiter, Saturn will appear as bright as most of the bright stars visible.

Of course, as with all celestial observations, viewing the Great Conjunction will be weather-permitting.

Although the two planets will appear close in the sky, they actually will be 456 million miles / 733.86 million kilometers apart. Saturn is nearly twice as far from the Earth as is Jupiter.

Jupiter, the fifth planet from the Sun, takes 12 years to make one solar orbit, while Saturn, the sixth planet from the Sun, takes 30 years to orbit the Sun. This is why Jupiter and Saturn have a conjunction, from the viewpoint of an observer on Earth, once every 19.6 years on average; although, some Great Conjunctions are much closer than others.

The last conjunction of these two planets was on 2000 May 28. Great Conjunctions will also occur on Halloween, 2040 (October 31) and 2060 April 7. However, the next time a really close Great Conjunction of these two planets occur will be on 2080 March 15.

Jupiter and Saturn were still fairly close to each other, as viewed from Earth, on the night of the dedication of the rather unique 10-inch Siderostat-type Refractor Telescope in Pittsburgh's original Buhl Planetarium and Institute of Popular Science on 1941 November 19 (First Light through this telescope was the planet Saturn, that evening). A 1941 Great Conjunction had occurred several months earlier on 1941 February 20.

The 2020 event will be the closest conjunction of Jupiter and Saturn since 1623 July 16 (only 14 years after Galileo used his first telescope to view the two planets). In fact, the greatest observable conjunction of Jupiter and Saturn came on 1226 March 4, when only naked-eye (one-power) observations would have been possible. As with 2020, the actual time of conjunction in 1226 came during daytime hours, when, even if Jupiter could have been found, Saturn would not have been visible. However, the evenings near the day of conjunction would have shown a brilliant “double-star”.

A famous 17th century astronomer, Johannes Kepler, pointed-out that a conjunction between Jupiter and Saturn occurred on 7 B.C. May 27, near the time of the birth of Jesus Christ. Although this is a possible explanation for the Star of Bethlehem, Johannes Kepler actually preferred a nova / supernova hypothesis for the star that allegedly led the Magi to the Christ child.


                                              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.


Internet Links to Additional Information ---

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

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

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

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

Great Conjunction: Jupiter & Saturn: Link >>> https://en.wikipedia.org/wiki/Great_conjunction 

Great Conjunction of 2020: Link >>> https://earthsky.org/astronomy-essentials/great-jupiter-saturn-conjunction-dec-21-2020 

Computer representation: positions of Jupiter & Saturn on night of dedication (1941 November 19): 10-inch Siderostat-type Refractor Telescope in Pittsburgh's original Buhl Planetarium and Institute of Popular Science. Jupiter & Saturn 1941 Great Conjunction: 1941 February 20: Link >>> https://spacewatchtower.blogspot.com/2020/12/astro-calendar-2020-dec-great.html 


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

                 Sunday, 2020 December 20.

                             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, Informal Science Educator & Communicator:
Link >>> http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/
Electronic Mail: < gawalsh@planetarium.cc >
Project Director, Friends of the Zeiss: Link >>> http://buhlplanetarium.tripod.com/fotz/
SpaceWatchtower Editor / Author: Link >>> http://spacewatchtower.blogspot.com/
Formerly Astronomical Observatory Coordinator & Planetarium Lecturer, original Buhl Planetarium & Institute of Popular Science (a.k.a. Buhl Science Center), Pittsburgh's science & technology museum from 1939 to 1991.
Formerly Trustee, Andrew Carnegie Free Library and Music Hall, Pittsburgh suburb of Carnegie, Pennsylvania.
Author of History Web Sites on the Internet --
* Buhl Planetarium, Pittsburgh: Link >>>  http://www.planetarium.cc  Buhl Observatory: Link >>>  http://spacewatchtower.blogspot.com/2016/11/75th-anniversary-americas-5th-public.html
* Adler Planetarium, Chicago: Link >>> http://adlerplanetarium.tripod.com
* Astronomer, Educator, Optician John A. Brashear: Link >>> http://johnbrashear.tripod.com
* Andrew Carnegie & Carnegie Libraries: Link >>> http://www.andrewcarnegie.cc

 

Monday, December 7, 2020

Lasers Help Large Chile Telescope Provide Better Stellar Images

 at first glance, this image looks both awesome and intimidating, with the enormous beams of light resembling some terrible cosmic weapon fortunately, that is not the case this eso picture of the week shows something far more benign — a mixture of gas, dust, and powerful lasers among the largest nebulae in the southern night sky, the carina nebula is a perfect viewing target for eso’s very large telescope vlt in this image, the nebula appears as a stunning pink cloud in the clear sky above eso’s paranal observatory in chile, home of the vlt the carina nebula is a vast cloud of dust and gas — this gas is ionised and made to glow by the stars within the nebula itself  the cutting edge adaptive optics facility installed on one of the 82 metre unit telescopes uts of the vlt is in full operation here the orange laser beams are sent from the uts into the atmosphere where they excite sodium particles, causing them to glow this creates artificial ‘stars’ that can be used to measure the blurring effects caused by earth’s atmosphere, which are then corrected by the telescope

Image issued by the European Southern Observatory, which graphically illustrates the use of lasers to provide a clearer image of the Carina Nebula, one of the brightest nebulae in the night sky.

(Image Source: European Southern Observatory: Gerhard Hudepohl)

By Glenn A. Walsh

Reporting for SpaceWatchtower

Powerful lasers are helping the Very Large Telescope Array (VLT) at the European Southern Observatory (ESO) in Chile provide crisper images of the night sky. The lasers aid computers in mitigating normal distortion of Earth's atmosphere.

Located in the Atacama Desert in northern Chile, the VLT is one of the world's most advanced telescopes. It consists of four Unit Telescopes, each with 27-foot / 8.2-meter mirrors, which can change configuration to adapt to turbulence in the Earth's atmosphere.

Atmospheric turbulence has always been a major problem of ground-based telescopes. This turbulence, which causes stars to twinkle, often blurs observations of far away stars, nebulae, and galaxies.

Lasers now aid in the resolution of this turbulence problem. High-tech adaptive optics, attached to the VLT, point and fire powerful lasers toward a target area of the sky astronomers wish to observe. Although a small amount of this laser light may some day reach the star, nebula, or galaxy being observed (at the speed of light, for most celestial objects this would take quite a long time), the laser is not meant to go further than our atmosphere.

Sodium particles in Earth's upper atmosphere are excited by the laser beams. These sodium particles then glow as artificial "stars."

The glowing particles are then used as reference “stars” by VLT computers, to measure the distortion of that particular part of Earth's atmosphere. The computers can then adapt telescope optics to receive telescopic images almost as clear as images from a space telescope.

This laser technology has allowed the VLT to claim several astronomical firsts ---

> First image of a planet outside of our Solar System.

> First to track individual stars around the super-massive black hole at the center of our Milky Way Galaxy.

> First to observe the dim glow of the farthest known Gamma Ray Burst.

 Internet Links to Additional Information ---

Very Large Telescope (VLT): Link >>> https://en.wikipedia.org/wiki/Very_Large_Telescope 

European Southern Observatory (ESO): Link >>> https://en.wikipedia.org/wiki/European_Southern_Observatory

Turbulence: Link >>> https://en.wikipedia.org/wiki/Turbulence

Laser: Link >>> https://en.wikipedia.org/wiki/Laser

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

                 Monday, 2020 December 7.

                             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, Informal Science Educator & Communicator:
Link >>> http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/
Electronic Mail: < gawalsh@planetarium.cc >
Project Director, Friends of the Zeiss: Link >>> http://buhlplanetarium.tripod.com/fotz/
SpaceWatchtower Editor / Author: Link >>> http://spacewatchtower.blogspot.com/
Formerly Astronomical Observatory Coordinator & Planetarium Lecturer, original Buhl Planetarium & Institute of Popular Science (a.k.a. Buhl Science Center), Pittsburgh's science & technology museum from 1939 to 1991.
Formerly Trustee, Andrew Carnegie Free Library and Music Hall, Pittsburgh suburb of Carnegie, Pennsylvania.
Author of History Web Sites on the Internet --
* Buhl Planetarium, Pittsburgh: Link >>>  http://www.planetarium.cc  Buhl Observatory: Link >>>  http://spacewatchtower.blogspot.com/2016/11/75th-anniversary-americas-5th-public.html
* Adler Planetarium, Chicago: Link >>> http://adlerplanetarium.tripod.com
* Astronomer, Educator, Optician John A. Brashear: Link >>> http://johnbrashear.tripod.com
* Andrew Carnegie & Carnegie Libraries: Link >>> http://www.andrewcarnegie.cc

Tuesday, December 1, 2020

Astro-Calendar: 2020 Dec. / Great Conjunction: Jupiter & Saturn on Winter Solstice

http://buhlplanetarium4.tripod.com/1941.bmp

This computer representation shows the positions of Jupiter and Saturn at the time of the dedication of the 10-inch Siderostat-type Refractor Telescope in Pittsburgh's original Buhl Planetarium and Institute of Popular Science on 1941 November 19. Earlier that year, Jupiter and Saturn had a Great Conjunction on 1941 February 20. (Image Sources: Friends of the Zeiss, Francis G. Graham, Professor Emeritus of Physics, Kent State University)

This month, another Great Conjunction of Jupiter and Saturn will occur on the day of the Winter Solstice, December 21, only about 3 hours after the Solstice. Bright Jupiter will be only 0.1 degree (1/5 diameter of the Earth's Moon) south of Saturn! That evening, the two planets will appear so close (one of the rare occasions when both planets can be seen in the field-of-view of a telescope), they may appear as one bright object, weather-permitting.
The last conjunction of these two planets was in 2000; a conjunction of Jupiter and Saturn usually happens about once every 19.6 years. The 2020 event will be the closest conjunction of Jupiter and Saturn since 1623 (only 14 years after Galileo used his first telescope to view the two planets). In fact, the greatest observable conjunction of Jupiter and Saturn came in 1226. Although 17th century astronomer Johannes Kepler pointed-out that a conjunction between Jupiter and Saturn occurred near the time of the birth of Jesus Christ, a possible explanation for the Star of Bethlehem, Johannes Kepler actually preferred a nova / supernova hypothesis for the star that allegedly led the Magi to the Christ child. The next time such a close conjunction of these two planets occur will be on 2080 March 15.

More information: Link >>> https://earthsky.org/astronomy-essentials/great-jupiter-saturn-conjunction-dec-21-2020

 

Astronomical Calendar for 2020 December ---
Link >>> http://buhlplanetarium4.tripod.com/astrocalendar/2020.html#dec

 Related Blog Post ---

"Astro-Calendar: 2020 Nov. / Centennial: Commercial Radio Broadcasting."

Sunday, 2020 November 1.

Link >>> https://spacewatchtower.blogspot.com/2020/11/astro-calendar-2020-nov-centennial.html


Source: Friends of the Zeiss.
            Tuesday, 2020 December 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, Informal Science Educator & Communicator:
Link >>> http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/
Electronic Mail: < gawalsh@planetarium.cc >
Project Director, Friends of the Zeiss: Link >>> http://buhlplanetarium.tripod.com/fotz/
SpaceWatchtower Editor / Author: Link >>> http://spacewatchtower.blogspot.com/
Formerly Astronomical Observatory Coordinator & Planetarium Lecturer, original Buhl Planetarium & Institute of Popular Science (a.k.a. Buhl Science Center), Pittsburgh's science & technology museum from 1939 to 1991.
Formerly Trustee, Andrew Carnegie Free Library and Music Hall, Pittsburgh suburb of Carnegie, Pennsylvania.
Author of History Web Sites on the Internet --
* Buhl Planetarium, Pittsburgh: Link >>>  http://www.planetarium.cc  Buhl Observatory: Link >>>  http://spacewatchtower.blogspot.com/2016/11/75th-anniversary-americas-5th-public.html
* Adler Planetarium, Chicago: Link >>> http://adlerplanetarium.tripod.com
* Astronomer, Educator, Optician John A. Brashear: Link >>> http://johnbrashear.tripod.com
* Andrew Carnegie & Carnegie Libraries: Link >>> http://www.andrewcarnegie.cc

 

Sunday, November 15, 2020

Live Web-cast Sun. Night: Historic SpaceX, 1st Operational Astronaut Launch

Crew-1 rocket on pad
Photograph of the SpaceX Crew Dragon capsule on top of a Falcon 9 rocket, which will be launched Sunday. The Crew-1 mission will launch three NASA astronauts and one Japanese astronaut to the International Space Station (ISS) on Sunday evening.

By Glenn A. Walsh

Reporting for SpaceWatchtower

Web-casts and cable-casts are set for coverage of the historic launch, rescheduled to Sunday evening, of three NASA astronauts and one Japanese astronaut bound for the International Space Station (ISS), using the SpaceX Crew Dragon capsule. This first regular operational, Crew-1 mission was originally scheduled for Saturday evening.

SpaceX, founded in 2002 by billionaire tech entrepreneur Elon Musk, plans to launch the astronauts toward the International Space Station on Sunday Evening, 2020 November 15 at 7:27 p.m. Eastern Standard Time (EST) / November 16, 0:27 Coordinated Universal Time (UTC).

The launch had been originally scheduled for Saturday Evening, 2020 November 14 at 7:49 p.m. EST / November 15, 0:49 UTC. However, the launch was delayed due to concerns regarding on-shore winds and to enable recovery of the first stage booster, which is planned to be reused to launch the Crew-2 mission next year. The booster is expected to land on the recovery ship about nine minutes after launch.

The launch will occur from Launch Complex 39A at the John F. Kennedy Space Center, at Cape Canaveral on Merritt Island, Florida. This is the same launch pad which saw the launch of the Apollo missions to the Moon, 1968 to 1972, and the Space Shuttle missions beginning on 1981 April 12; Space Shuttle missions concluded on 2011 July 21.

NASA-TV, available through the NASA Internet web-site, will provide live coverage of the launch, beginning on Sunday at 3:15 p.m. EST / 20:15 UTC (Internet link to the NASA-TV web-page near the end of this blog-post). NASA will provide continuous coverage - more than 30 hours - of the pre-launch, launch, docking and arrival activities for the first crew rotation flight of the SpaceX Crew Dragon spacecraft on a Falcon 9 rocket following certification by NASA for regular flights to the Space Station. The Crew Dragon capsule is scheduled to dock with the ISS at approximately 11:00 p.m. EST on Monday, 2020 November 16 / November 17, 4:00 UTC.

Coverage of the launch will also be available on two cable television channels: Discovery and Science. Chances are good that the three major cable news channels, CNN, MSNBC, and Fox News Channel may also provide coverage at the actual time of launch.

As of Saturday evening, the U.S. Air Force 45th Weather Squadron determined that weather conditions provided a 50 per-cent favorable chance of a launch of Crew-1 on Sunday evening.

The very first SpaceX astronaut mission to the ISS was a demonstration mission, launching two astronauts, on May 30. While the demonstration mission in May was short, this first operational mission will have the four astronauts stay on the ISS for about a half-year.

This Crew-1 flight will include Mission Commander Michael Hopkins (NASA), Pilot Victor Glover (NASA), Mission Specialist Shannon Walker (NASA), and Mission Specialist Soichi Noguchi (Japan Aerospace Exploration Agency – JAXA). Victor Glover, a Navy test pilot who is launching on his first space mission, will be the first African-American to have an extended stay on the International Space Station.

Crew-1 is the first crew rotation flight of a U.S. commercial spacecraft with astronauts to the Space Station following the spacecraft system’s official human rating certification.

 NASA-TV Web-Page for SpaceX Launch: Link >>> https://www.nasa.gov/multimedia/nasatv/#public

Internet Links to Additional Information ---

 SpaceX Crew-1 Mission -

Link 1 >>> https://blogs.nasa.gov/commercialcrew/ 

Link 2 >>> https://en.wikipedia.org/wiki/SpaceX_Crew-1 

Crew Dragon Capsule: Link >>> https://en.wikipedia.org/wiki/SpaceX_Dragon_2#Crew_Dragon

Falcon 9 Rocket: Link >>> https://en.wikipedia.org/wiki/Falcon_9 

SpaceX: Link >>> https://en.wikipedia.org/wiki/SpaceX 

NASA: Link >>> https://en.wikipedia.org/wiki/NASA

Related Blog-Posts ---

"UPDATE: Web & Cablecasts: Historic SpaceX Astronaut Launch Sat. Afternoon."

Wed., 2020 May 27.

Link >>> https://spacewatchtower.blogspot.com/2020/05/web-cablecasts-historic-spacex.html 

 

"SpaceX Public, On-Line Simulator: Docking w/ Space Station." Tue., 2020 May 19.

Link >>> https://spacewatchtower.blogspot.com/2020/05/spacex-public-on-line-simulator-docking.html 

 

"Astro-Calendar: Jan. / SpaceX Crew Dragon Test Launch Jan. 11." Thur., 2020 Jan. 2. 

 Link >>> https://spacewatchtower.blogspot.com/2020/01/astro-calendar-jan-spacex-crew-dragon.html 

 

"Web-Cast: 1st Test Launch of SpaceX Falcon Heavy Rocket Tue. Afternoon."

Tue., 2018 Feb. 6.

Link >>> https://spacewatchtower.blogspot.com/2018/02/web-cast-1st-test-launch-of-spacex.html

 

NASA Orion Spacecraft: Near-Perfect Test Mission After Day-Delay." Fri., 2014 Dec. 5.

Link >>> https://spacewatchtower.blogspot.com/2014/12/nasa-orion-spacecraft-near-perfect-test.html

 

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

                 Sunday, 2020 November 15.

                             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, Informal Science Educator & Communicator:
http://buhlNo Friends of the Zeiss: < http://buhlplanetarium.tripod.com/fotz/ >
SpaceWatchtower Editor / Author: < http://spacewatchtower.blogspot.com/ >
Formerly Astronomical Observatory Coordinator & Planetarium Lecturer, original Buhl Planetarium & Institute of Popular Science (a.k.a. Buhl Science Center), Pittsburgh's science & technology museum from 1939 to 1991.
Formerly Trustee, Andrew Carnegie Free Library and Music Hall, Pittsburgh suburb of Carnegie, Pennsylvania.
Author of History Web Sites on the Internet --
* Buhl Planetarium, Pittsburgh: < http://www.planetarium.cc >                                                               Buhl Observatory: < http://spacewatchtower.blogspot.com/2016/11/75th-anniversary-americas-5th-public.html >
* 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 >