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.

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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

 

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 >

Friday, November 13, 2020

Friday the 13th: Only 2 in Leap Year

 This photograph shows the late children's television host, Fred Rogers, with the
hand-puppet King Friday the 13th, used to prevent children's superstitions. Today
(and every Friday the 13th) is the birthday of King Friday the 13th, the monarch
of the "Neighborhood of Make-Believe" since 1966 on the popular, national children's
television program, "Mister Rogers' Neighborhood," produced by WQED-TV channel 13 
in Pittsburgh. Originally, when WQED-TV premiered in 1954 as the nation's first
community-sponsored, educational television station, King Friday the 13th had been
the king of time on the "Children's Corner" television program's "Calendarland" (hence,
why all royal family names are days-of-the-week !).
(Image Source: Fred Rogers Productions)

By Glenn A. Walsh

Reporting for SpaceWatchtower

Despite the superstition that revolves around the date of Friday the 13th, it is true that the 13th day of the month occurs slightly more often on a Friday, than any other day of the week in the Gregorian Calendar.

Today, 2020 November 13, is the second of two occurrences of Friday the 13th in 2020. The other occurrence this year was in March. There were only two occurrences of Friday the 13th this year, because 2020 is a leap year.

The last time Friday the 13th occurred in November, in 2015, it was the third of three occurrences of Friday the 13th—the most number of such occurrences possible in one calendar year. Of course, the reason there were three such occurrences in 2015 is because the first occurred in February. And, during a non-leap year, the February calendar of days-of-the-week is always repeated in March (then adding days 29, 30, and 31), and then again in November (which also added days 29 and 30), due to the fact that February has precisely four weeks in non-leaps years.

On average, Friday the 13th occurs once every 212.35 days. Any month that begins on a Sunday includes a Friday the 13th. Every calendar year includes at least one Friday the 13th. And, the longest period that can occur without a Friday the 13th is fourteen months: from July to September of the following year which is a non-leap year or from August to October of the following year which is a leap year.

Over the 400-year recurring cycle of the Gregorian Calendar (which contains 146,000 normal days, 97 leap days, 20,871 weeks, and 4,800 months), the number of occurrences of the 13th day of the month on each of the seven days of the week is the following:

Friday – 688

Sunday – 687

Wednesday – 687

Monday – 685

Tuesday – 685

Thursday – 684

Saturday – 684

The superstition surrounding Friday the 13th may have originated in the Middle Ages, with the Biblical story of Jesus' Last Supper where 13 individuals were present, and his Crucifixion the next day, a Friday. One individual present at the Last Supper, Judas (perhaps considered the 13th), would betray Jesus.

Friday, 1307 October 13, the date King Philip IV of France supposedly arrested hundreds of the Knights Templar, may have also contributed to the superstition, but not until the 20th century (although the documentation of this story is quite limited).

The publication of a novel in 1907, Friday the Thirteenth by Thomas W. Lawson, may have popularized the superstition. The novel depicts a Wall Street broker using the superstition to create a financial panic on a Friday the 13th.

Friday the 13th is not the unlucky day in other cultures. In Spanish-speaking countries, Tuesday the 13th is unlucky, partly due to the fall of Constantinople occurring on Tuesday, 1204 April 13. In Italy, Friday the 17th is the unlucky day, with Italians actually considering the number 13 as lucky; more recently, with American and European influences, some Italians now also consider Friday the 13th as unlucky.

However, confirmation bias is considered by psychologists as the reason the Friday the 13th superstition has lasted so long. People remember bad things that happen on a Friday the 13th, while forgetting the other occurrences of Friday the 13th when nothing spectacular happens.

Internet Links to Additional Information ---

 
More on Friday the 13th ---
Mathematics: Link >>> http://scienceworld.wolfram.com/astronomy/FridaytheThirteenth.html
General: Link >>> https://en.wikipedia.org/wiki/Friday_the_13th
History -
   Link 1 >>> http://www.todayifoundout.com/index.php/2013/09/the-origin-of-friday-the-13th-as-an-unlucky-day/
   Link 2 >>> http://www.snopes.com/luck/friday13.asp

How Mister Rogers Made Friday the 13th Less Scary:
Link >>> http://nowiknow.com/how-mr-rogers-made-friday-the-13th-less-scary/

More on King Friday XIII:
Link >>> https://en.wikipedia.org/wiki/Neighborhood_of_Make-Believe#Regular_puppets

More on "Mister Rogers' Neighborhood" & the "Neighborhood of Make-Believe":
Link >>> https://en.wikipedia.org/wiki/Mister_Rogers'_Neighborhood

"The Sky Above Mister Rogers' Neighborhood," a planetarium show produced by Family Communications, Inc. (now The Fred Rogers Company) and the Henry Buhl, Jr. Planetarium and Observatory at Pittsburgh's Carnegie Science Center:
Link >>> https://carnegiemuseums.org/magazine-archive/2003/mayjun/feat5.htm

More about WQED-TV channel 13, the nation's 1st community-sponsored TV station:
Link >>> https://en.wikipedia.org/wiki/WQED_%28TV%29

More on November 13: Link >>> https://en.wikipedia.org/wiki/November_13

Source: Glenn A. Walsh Reporting for SpaceWatchtower, a project of Friends of the Zeiss.                Originally published Friday, 2015 November 13. Updated & re-published Friday, 2020 November 13.

                             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://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
Electronic Mail: < gawalsh@planetarium.cc >
Project Director, 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 >

Sunday, November 1, 2020

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

One of the earliest photographs (circa 1921) of the broadcasting studio of KDKA-AM radio in Pittsburgh (original studio located at the Westinghouse plant in East Pittsburgh). KDKA was the world's first commercial broadcasting station, beginning with its first broadcast: the Harding-Cox U.S. Presidential Election Returns, which commenced at 6:00 p.m. EST / 23:00 UTC on Tuesday, 1920 November 2. Today, KDKA, which now broadcasts 50,000 watts of transmission power on AM 1020, can be heard on the radio at night in 38 states and half of Canada, as well as everywhere, anytime at http://kdkaradio.com. (Image Sources: KDKA, Wikipedia.org, By Austin C. Lescarboura - Radio for Everybody, page 62, Public Domain, https://commons.wikimedia.org/w/index.php?curid=50907768) More Information: Link >>> http://www.pbs.org/wgbh/aso/databank/entries/dt20ra.html 

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

 Related Blog Post ---

"Astro-Calendar: 2020 Oct. / SpaceX Launch & Halloween 'Blue' Moon!"

Thursday, 2020 October 1.

Link >>> https://spacewatchtower.blogspot.com/2020/10/astro-calendar-2020-oct-spacex-launch.html


Source: Friends of the Zeiss.
            Sunday, 2020 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, Informal Science Educator & Communicator:
http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
Electronic Mail: < gawalsh@planetarium.cc >
Project Director, 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 >

Monday, October 19, 2020

Watch Live Tue.: NASA Probe Grabs Asteroid Rocks to Bring Back to Earth

BennuAsteroid.jpg
Asteroid 101 955 Bennu, compiled from 12 images photographed by NASA's OSIRIS-REx mission on 2018 December 2. (Image Sources: NASA, Wikipedia.org, By NASA/Goddard/University of Arizona - https://www.nasa.gov/press-release/nasa-s-newly-arrived-osiris-rex-spacecraft-already-discovers-water-on-asteroid; see also https://www.asteroidmission.org/?attachment_id=12476, Public Domain, https://commons.wikimedia.org/w/index.php?curid=74979917)
 

 

By Glenn A. Walsh

Reporting for SpaceWatchtower

Early Tuesday evening, NASA's OSIRIS-REx probe will “TAG” asteroid Bennu, collecting rocks and dust samples for an eventual return to Earth. On-line, NASA-TV will provide live coverage of the event.

The OSIRIS-REx mission has been in orbit of asteroid 101955 Bennu since 2018 December 3, after launching from Cape Canaveral, Florida on 2016 September 8. It has taken two years to survey and map the asteroid's surface, to determine good sites for the TAG (Touch-and-Go) maneuver.

The asteroid is much rockier than expected. The “Nightingale” site chosen for the landing is only the size of a few parking spaces. If the first TAG does not succeed, OSIRIS-REx has only two other chances to attempt a sample collection, possibly at other sites. To stir-up rocks and dust samples, the probe carries three pressurized nitrogen canisters to fire at the collection site, from the end of the probe's robotic arm, one canister for each collection attempt.

Descending to the surface of Bennu will take about four hours, about the same time as one rotation of the asteroid on its axis. However, after descent, the TAG sample procedure will be quite short: only 16 seconds! After each collection attempt, the space probe will hover above the site to determine if the attempt was successful, before either attempting again or returning to orbit.

After successfully collecting material from Bennu, OSIRIS-REx will slowly launch into orbit of the asteroid, where it will stay for the rest of this year. Next year, OSIRIS-REx will begin the journey home, with the Bennu sample materials, which is expected to take about two years.

OSIRIS-REx is expected to land in the Utah desert on 2023 September 24. The spacecraft and Bennu samples will then be recovered and taken for study by scientists.

Bennu is considered a "rubble pile" asteroid, formed in the deep past, possibly near the time our Solar System was formed. Gravity slowly forced remnants of collisions of material to come together forming this asteroid. Bennu looks something like a spinning top, with a diameter of about 0.33 statute mile / 500 meters.

Bennu has a slight chance of hitting the Earth in the distant future. In fact, NASA ranks Bennu as the second-most likely asteroid to hit Earth, perhaps sometime in the last 25 years of the 22nd century. Although, even this chance is rather remote.

Determining Bennu's orbit of the Sun, which varies, is important for a final determination if the asteroid could impact the Earth sometime in the future. The orbit of Bennu changes due to the heating of the Sun-side of the asteroid, and then this solar energy is dissapated into Outer Space when that side of the asteroid turns away from the Sun. 

Last month, NASA reported that scientists have discovered that some meteorites from the asteroid 4 Vesta have been found on Bennu. “We found six boulders ranging in size from 5 to 14 feet (about 1.5 to 4.3 meters) scattered across Bennu’s southern hemisphere and near the equator,” said Daniella DellaGiustina of the Lunar & Planetary Laboratory, University of Arizona, Tucson. “These boulders are much brighter than the rest of Bennu and match material from Vesta.”

NASA's OSIRIS-REx science team also recently reported that Bennu observations have led to a conclusion that some of the carbon-rich materials of the asteroid could have seeded Earth with the chemicals necessary for the beginning of life. These conclusions came from six studies published in the journals Science and Science Advances on October 8.

Two Japanese missions have accomplished similar asteroid sample return missions in the recent past. The Hayabusa spacecraft returned tiny grains from asteroid 25143 Itokawa in 2010. Hayabusa-2 returned shrapnel from asteroid Ryugu last year.

Live coverage of the event begins on NASA-TV at 5:00 p.m. Eastern Daylight Saving Time (EDT) / 21:00 Coordinated Universal Time (UTC) on Tuesday, 2020 October 20. Touch-down of the spacecraft is expected at about 6:12 p.m. EDT / 22:12 UTC.

NASA-TV: Link >>> https://www.nasa.gov/multimedia/nasatv/index.html#public

Internet Links to Additional Information:

NASA OSIRIS-REx Mission:

Link 1 >>> https://www.nasa.gov/osiris-rex

Link 2 >>> https://en.wikipedia.org/wiki/OSIRIS-REx

Asteroid 101955 Bennu: Link >>> https://en.wikipedia.org/wiki/101955_Bennu 

Asterioid 4 Vesta: Link >>> https://en.wikipedia.org/wiki/4_Vesta

Source: Glenn A. Walsh Reporting for SpaceWatchtower, a project of Friends of the Zeiss.
               Monday, 2020 October 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, Informal Science Educator & Communicator:
http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
Electronic Mail: < gawalsh@planetarium.cc >
Project Director, 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 >

Monday, October 12, 2020

October: Closest View of Mars Until 2035

  Mars appears as a red-orange globe with darker blotches and white icecaps visible on both of its poles.

October is the best month for viewing the planet Mars until September of 2035.This is a true color image of Mars taken by the OSIRIS instrument on the ESA Rosetta spacecraft during its 2007 February 24 fly-by of the planet, from a distance of about 149,129.1 statute miles / 240 000 kilometers.

(Image Sources: European Space Agency, Wikipedia.org, By ESA & MPS for OSIRIS Team MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA, CC BY-SA IGO 3.0, CC BY-SA 3.0-igo, https://commons.wikimedia.org/w/index.php?curid=56489423)

By Glenn A. Walsh

Reporting for SpaceWatchtower

October is the best month to view the planet Mars, due to its closeness to Earth, until September of 2035.

Tuesday (October 13) at 7:00 p.m. Eastern Daylight Saving Time (EDT) / 23:00 Coordinated Universal Time (UTC) will mark the closest Opposition of Mars, when Earth will lie directly between Mars and the Sun. At Opposition, Mars will rise in the eastern sky approximately at local sunset, stay in the sky all night long, and set in the west approximately at local sunrise.

Actually, Mars came the closest to Earth on October 6 at 10:18 a.m. EDT / 14:18 UTC, when the distance between Earth and Mars was about 38.57 million statute miles / 62.07 million kilometers.

Although Mars is not quite as close as will be in 2035, or that it was in 2003 or 2018, it is still close enough for a good show in the sky. This is a good time to take a look at Mars, whether with the naked-eyes (one-power), or observing more detail on the Martian surface with binoculars or a telescope.

So, starting Tuesday (October 13), people can view Mars just about any time once it gets dark, weather-permitting of course. The best time to look for Mars is low in the eastern sky shortly after sunset (as Mars begins to rise). Or, you can look low in the southern sky in the middle of the night (as Mars appears to travel from east to west in the night sky), or low in the western sky just before sunrise (as Mars begins set).

This month, Mars, with an apparent visual magnitude of -2.6, will be the brightest object in the night sky, other than the Moon and the planet Venus. It will even be a little brighter than the planet Jupiter (at about apparent visual magnitude of -2.3), for this month.

You may need a higher elevation, with few obstructions such as trees, buildings, and hills, to see Mars. For most of this month Mars will be approximately +5 degrees declination, north of the celestial equator. But, as mentioned, it will be one of the brightest objects in the night sky this month, glowing with a reddish-orange tint. So, when you do find it, you will, likely, be sure it is Mars.

Close approaches between Earth and Mars occur about every two years, due to the different orbits of the two planets around the Sun. While Earth takes 365.256 days to travel around the Sun, Mars takes 686.98 Earth days / 1.88 Earth years to complete one solar orbit.

Not every close approach of Mars is as close as others. Mars' distance from the Sun varies quite a bit, depending on where Mars is located in its solar orbit. When Mars is closest to the Sun (as it is this month), and at the same time close to the Earth, these are the times when Mars is the closest in distance to the Earth.

Many people may remember the close approach in 2003, when Mars came closer to Earth than it had in 60,000 years. On 2003 August 27, Earth and Mars were only 34.65 million statute miles / 55.76 million kilometers apart.

Two years ago on 2018 July 31, Mars was almost as close as in 2003. At that time Mars came within 35.78 million statute miles / 57.59 kilometers of the Earth.

Set your calendars: Mars will not be closer than in 2003 until 2287 August 28, when it will approach Earth from a distance of 34.60 statute miles / 55.69 kilometers.

The end of this month will mark the 82nd anniversary of the famous radio broadcast, The War of the Worlds. It was on the evening of 1938 October 30, the day before the Cross-Quarter Day of Halloween, that the CBS radio's Mercury Theater on the Air, presented a radio adaptation of the famous H.G. Wells 1898 novel, The War of the Worlds.

Directed and narrated by actor and future filmmaker Orson Welles, the radio drama began as fictional news bulletins regarding the landing in central New Jersey of invaders from the planet Mars. Occurring one day before Halloween, and with war threatening in Europe (less than a year before the beginning of World War II), this radio broadcast caused a public panic as few people heard the disclaimer at the beginning of the program that this was a work of fiction.

Internet Links to Additional Information ---

Planet Mars: Link >>> https://en.wikipedia.org/wiki/Mars 

NASA Missions to Mars: Link >>> https://www.nasa.gov/mission_pages/mars/main/index.html 

More on 1938 Broadcast of The War of the Worlds:

Link >>> http://johnbrashear.tripod.com/wlcr.html#warofworlds 

Related Blog-Posts ---

"NASA Laser Retroreflector Going to Mars on Perseverance Rover.

Wed., 2020 Oct. 7.

Link >>> http://spacewatchtower.blogspot.com/2020/10/nasa-laser-retroreflector-going-to-mars.html

 

"Thur.-AM U.S. Joins China & U.A.E in Race to Mars; Watch Launch Live."

Mon., 2020 July 27.

Link >>> http://spacewatchtower.blogspot.com/2020/07/thur-am-us-joins-china-uae-in-race-to.html

 

"For Students: Mars 2020 Name the Rover Essay Contest By Nov. 1."

 Tue., 2019 Oct. 15.

Link >>> https://spacewatchtower.blogspot.com/2019/10/for-students-mars-2020-name-rover-essay.html

 

"Place Your Name on Mars 2020 Rover Microchip By This Monday, Sept. 30."

Thur., 2019 Sept. 26.

Link >>> https://spacewatchtower.blogspot.com/2019/09/place-your-name-on-mars-2020-rover.html

 

"Spring to Begin: Vernal Equinox on Earth Wednesday & on Mars Saturday!"

Wed., 2019 March 20.

Link >>> https://spacewatchtower.blogspot.com/2019/03/spring-vernal-equinox-begins-march-20.html

 

"'War of the Worlds' Panic Broadcast: 75th Anniversary." Tue., 2013 Oct. 29.

Link >>> http://spacewatchtower.blogspot.com/2013/10/war-of-worlds-panic-broadcast-75th.html 

 

Source: Glenn A. Walsh Reporting for SpaceWatchtower, a project of Friends of the Zeiss.
               Monday, 2020 October 12.

                             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://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
Electronic Mail: < gawalsh@planetarium.cc >
Project Director, 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 >
* 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 >  

Wednesday, October 7, 2020

NASA Laser Retroreflector Going to Mars on Perseverance Rover

small dome called the Laser Retroreflector Array on the Perseverance rover

In the upper left of this image is the Laser Retroflector, which will be located near the center of NASA's Mars Perseverance Rover in the larger image. Some time in the future, a Mars orbiter spacecraft will be able to use a laser to determine the exact location of Perseverance on the Martian surface.

(Image Sources: NASA, Jet Propulsion Laboratory of the California Institute of Technology)


By Glenn A. Walsh

Reporting for SpaceWatchtower

Astronauts on the lunar landing missions of Apollo 11, 14, and 15 installed Laser Retroreflectors on the Moon, so scientists could better determine the distance between Earth and the Moon. Now, NASA is sending a Laser Reflector to Mars, on the Perseverance Rover, for similar scientific experiments.

Laser Retroreflectors are small arrays of special mirrors which reflect a laser beam directly back to its source, as a bicycle reflector reflects traffic light back to the vehicle source. Scientists use Laser Retroreflectors for laser ranging experiments, such as distance between planets or the distance between an object in orbit and a planet. Such experiments can also be used to determine the shape of a planet, the orbit of a planet, and how the planet's orbit changes over time.

In the case of the Laser Retroreflectors left on the Moon, laser beams are directed from Earth to the Moon; scientists measure the time it takes the laser beam to reach the Moon and return to Earth. The result of this experiment has provided detailed data regarding how the Moon is slowly moving farther away from the Earth. At the present time, the Moon is moving 1.49 inches / 3.8 centimeters away from the Earth each year.

Laser ranging experiments, using Apollo-era Laser Retroreflectors, continues to this day.

In the case of Laser Retroreflectors on Mars (smaller than the Laser Retroreflectors left on the Moon), it is currently not possible to conduct laser ranging experiments directly from the Earth, due to the great distance between the two planets. A future Mars orbiter spacecraft will use a laser, not yet developed, to conduct laser ranging experiments from Martian orbit.

Scientists, then, will be able to determine the location of rovers on the surface of Mars. As NASA will know the precise orbit of the spacecraft originating the laser beam, scientists will then be able to derive the laser ranging data sought from the Laser Retroreflector on the Martian surface. This could also make future landings on Mars more precise.

These laser ranging experiments could also provide future proof of Albert Einstein's General Theory of Relativity. As Perseverance is mobile, scientists will be able to receive data from several points of reference on Mars. This will help determine the influence on Mars' orbit from curvature in space-time. This could help scientists understand how gravity shapes our Solar System, and possibly even understand the roles of Dark Matter and Dark Energy in our Universe.

Perseverance will be the first rover on Mars to be equipped with the palm-size Laser Retroreflector Array (LaRA). A smaller Laser Retroreflector was also installed on NASA's Mars InSight Lander, which does not independently move, which landed on Mars on 2018 November 26. A Laser Retroreflector will also be aboard the European Space Agency's (ESA) ExoMars Rover scheduled for launch in 2022.

Perseverance launched toward the Red Planet on July 30, at 7:50 a.m. Eastern Daylight Saving Time (EDT) / 11:50 Coordinated Universal Time (UTC), from the Cape Canaveral Air Force Station in Florida. It is expected to land next February 18, at 3:00 p.m. Eastern Standard Time (EST) / 20:00 UTC, in Mars' Jezero Crater.

Originally titled NASA's Mars 2020 mission, the Perseverance Rover was designed with the assistance of the Curiosity Rover engineering team, to create a more robust Mars rover. The Perseverance Rover will have a major astrobiology mission, as well as investigate the planet's geology. The project is managed for NASA by the Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, California.

During its travels on the planet, Perseverance will collect soil samples and store the samples in special containers. NASA expects to retrieve these sample containers and return them to Earth for scientific analysis, during a potential, future Mars sample-return mission.

 

 Internet Links to Additional Information ---

NASA Mars 2020 Mission: Link >>> https://en.wikipedia.org/wiki/Mars_2020 

NASA Perseverance Rover: Link >>> https://en.wikipedia.org/wiki/Perseverance_(rover) 

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

Image: Laser RetroReflector on the top deck of the Mars InSight space lander, for laser range-finding from Martian orbit and future node in a proposed Mars geophysical network:
Link >>> https://spacewatchtower.blogspot.com/2018/11/astronomical-calendar-2018-november.html

 Planet Mars: Link >>> https://en.wikipedia.org/wiki/Mars

 Related Blog-Posts ---

 

"Thur.-AM U.S. Joins China & U.A.E in Race to Mars; Watch Launch Live."

Mon., 2020 July 27.

Link >>> https://spacewatchtower.blogspot.com/2020/07/thur-am-us-joins-china-uae-in-race-to.html

 

"'InSight' Space Probe to Land on Mars Monday Afternoon." Mon. 2018 Nov. 26.

Link >>> https://spacewatchtower.blogspot.com/2018/11/insight-space-probe-to-land-on-mars.html

 

Source: Glenn A. Walsh Reporting for SpaceWatchtower, a project of Friends of the Zeiss.
              Wednesday, 2020 October 7.

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gaw

Glenn A. Walsh, Informal Science Educator & Communicator:
http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
Electronic Mail: < gawalsh@planetarium.cc >
Project Director, 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 >
* 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 >