Earth and Space News: Lyrid meteor shower parent body Comet C/1861 G1 (Thatcher)

Showing posts with label Lyrid meteor shower parent body Comet C/1861 G1 (Thatcher). Show all posts

Wednesday, April 18, 2018

2018 Lyrid Meteor Shower Peaks Before Dawn Earth Day, Sunday, April 22

Summary: The 2018 Lyrid meteor shower peaks before dawn Earth Day, Sunday, April 22, but surrounding dates of April 21 and 23 also offer great shower views.

Lyrid meteor shower’s radiant point is near Alpha Lyrae, known as Vega, the brightest star in Lyra the Harp constellation: Bruce McClure and Joni Hall/EarthSky, CC BY SA 3.0 Unported, via Wikimedia Commons

The 2018 Lyrid meteor shower peaks before dawn Earth Day, Sunday, April 22, but great shower views are also possible on the surrounding dates of Saturday, April 21, and Monday, April 23.

Earth’s moon cooperates with visibility of the 2018 Lyrid meteor shower’s peak dates. Saturday’s waxing crescent has approximately 35 percent illumination. The first quarter phases takes over Sunday, April 22, at 21:46 Coordinated Universal Time (5:46 p.m. Eastern Daylight Time). Moonsets occur on all three dates prior to peak viewing hours.

Meteor showers usually derive their name from the constellation from which their meteors appear to originate. The parallel, same-velocity path traveled by a meteor shower’s particles seems, to an observer, to trace back to a single point in the sky.

The point from which meteor shower particles apparently radiate is known as the radiant. The radiant point is actually an illusory effect of perspective, by which eyes interpret parallel objects as converging at a far point or horizon line.

April’s Lyrid meteor shower is named after Lyra the Harp. The Lyrids’ shooting stars have an apparent radiant in proximity to Alpha Lyrae (α Lyr, α Lyrae), the constellation’s brightest star.

Vega is Alphae Lyrae’s popular name. Vega anchors the easternmost angle of the inverted triangle that perches atop Lyra the Harp’s parallelogram.

Vega participates in the Summer Triangle. The inter-, or multi-, constellation asterism comprises Altair (Alpha Aquilae, α Aquilae), Deneb (Alpha Cygni, α Cygni) and Vega, the brightest stars in Aquila the Eagle, Cygnus the Swan and Lyra the Harp, respectively.

Best viewing of the Lyrid meteor shower happens in the Northern Hemisphere. Vega’s location equates to more than 38 degrees north of the imaginary celestial equator that astronomers helpfully project from Earth’s equator outward into space.

EarthSky Tonight’s lead writer, Bruce McClure, explains that, around the Lyrid meteor shower’s maximum, Vega rises above the northeast horizon around 9 or 10 p.m. local time for mid-northern latitudes. Vega’s upward climb is high enough by midnight local time for northern observers to notice Lyrid shooting stars. Before dawn, Vega’s high overhead placement in the northeast-east sky allows for maximum Lyrid visibility, at approximately 10 to 20 meteors per hour.

The American Meteor Society describes the Lyrid meteor shower as a “medium strength shower,” with particle velocity at 30 miles per second (48.4 kilometers per second). Peak zenithal hourly rate (ZHR) of 18 meteors per hour may occur when the radiant is at its zenith, or highest point.

Southern Hemisphere Lyrid seekers in the mid-southern latitudes have viewing possibilities between midnight and dawn. On his Meteor Showers Online website, American amateur astronomer Gary W. Kronk places the radiant in the north-northeast sky. The hourly rate will be lower because Vega perches lower in the Southern Hemisphere skies than in Northern Hemisphere skies.

The annual Lyrid meteor shower, also known as the Lyrids or the April Lyrids, generally shoots meteors between April 16 and April 26. Gary Kronk notes via Meteor Showers Online that British amateur astronomer William Frederick Denning (Nov. 25, 1848-June 9, 1931) observed weak Lyrid activity as early as April 14 annually. Czech-born American astronomer Zdenek Sekanina (born June 12, 1936) indicates that the Harvard Radio Meteor Project, conducted 1961 to 1965 at Havana, Mason County, west central Illinois, detected possible annual Lyrid stream activity as late as May 3.

Earth’s passage through cometary debris causes meteor showers. The Lyrid meteor shower’s parent body is comet C/1861 G1 (Thatcher). NASA’s Solar System Exploration website demystifies comet Thatcher’s alphanumeric prefix. The letter “C” indicates a long period comet, with an orbital period of 200 years or more. Comet Thatcher’s completes an orbit of the sun approximately every 415.5 years.

The number “1861” indicates the year of discovery. The letter “G” represents the first half of April. The number “1” tells that Thatcher was the first cometary discovery during the half-month period.

American amateur astronomer Albert E. Thatcher is credited with discovering his namesake comet in the year of the long period comet’s perihelion, or closest approach, to the sun. Thatcher made his discovery via Columbia University's Rutherford Observatory. His New York City-based discovery Thursday, April 4, 1861, preceded an independent discovery Sunday, April 28, 1861, by Carl Wilhelm Baeker in Nauen, Brandenburg state, northeastern Germany.

The takeaway for the 2018 Lyrid meteor shower’s peak before dawn Earth Day, Sunday, April 22, is that the moon’s waxing crescent April 21 and first quarter April 22 and 23 will have vacated northern skies before peak viewing.

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

Lyrid meteors and the Milky Way; near Lake Tahoe, Hope Valley, California; April 22, 2013; photo by Mark Lissick/Wildlight Nature Photography: Fox Astronautics @FXAstronautics, via Twitter Jan. 23, 2018, @ https://twitter.com/FXAstronautics/status/955914573646712832

For further information:

“2. The Comet Discovered by Mr. Thatcher.” The American Journal of Science and Arts, second series, vol. XXXII (November 1861): 134. New Haven CT: E. Hayes, 1861.
Available via Biodiversity Heritage Library @ https://biodiversitylibrary.org/page/37026463
Available via HathiTrust @ https://hdl.handle.net/2027/inu.32000007831789?urlappend=%3Bseq=150

Arter, T.R. (Terry R.), and I.P. (Iwan P.) Williams. “The Mean Orbit of the April Lyrids.” Monthly Notices of the Royal Astronomical Society, vol. 289, no. 3 (Aug. 11, 1997): 721-728.
Available @ https://academic.oup.com/mnras/article/289/3/721/1001339

“Discovery of a New Comet.” Monthly Notices of the Royal Astronomical Society, Containing Papers, Abstracts of Papers, and Reports of the Proceedings of the Society, From November 1860, to June 1861, vol. XXI, no. 6 (April 10, 1861): 192-193. London, England: Strangeways & Walden, 1861.
Available via HathiTrust @ https://hdl.handle.net/2027/nyp.33433066362348?urlappend=%3Bseq=200

EarthSky. “Find Vega, and Lyrid Meteor Radiant.” EarthSky > Tonight. April 20, 2018.
Available @ http://earthsky.org/?p=3183

Emspak, Jesse. “Lyrid Meteor Shower 2018: When, Where & How to See It.” Space.com > Skywatching. Jan. 23, 2018.
Available @ https://www.space.com/36381-lyrid-meteor-shower-guide.html

Espenak, Fred. “2018 Calendar of Astronomical Events Greenwich Mean Time.” Astro Pixels > Ephemeris.
Available @ http://astropixels.com/ephemeris/astrocal/astrocal2018gmt.html

Fox Astronautics ‏@FXAstronautics. "Lyrid Meteor Shower 2018: When, Where & How to See It: In late April, skywatchers in the Northern Hemisphere will… " Twitter. Jan. 23, 2018.
Available @ https://twitter.com/FXAstronautics/status/955914573646712832

Kronk, Gary. “Lyrids.” Meteor Showers Online.
Available @ http://meteorshowersonline.com/lyrids.html

“The Lyrid Meteors 16 to 25 April.” The Northern Ireland Amateur Astronomy Society > Astronomy > Learning Zone.
Available @ http://www.niaas.co.uk/cms/index.php?option=com_content&view=article&id=12:the-lyrid-meteors

“Lyrid Meteor Shower in 2018.” Time And Date > Sun & Moon > Meteor Showers.
Available @ https://www.timeanddate.com/astronomy/meteor-shower/lyrids.html

“Lyrids.” American Meteor Society > Meteors > Meteor Shower Calendar.
Available @ https://www.amsmeteors.org/meteor-showers/meteor-shower-calendar/

Marriner, Derdriu. “2017 Lyrid Meteor Shower Peaks April 22 and 23.” Earth and Space News. Wednesday, April 19, 2017.
Available @ https://earth-and-space-news.blogspot.com/2017/04/2017-lyrid-meteor-shower-peaks-april-22.html

Marriner, Derdriu. “Lyrid Meteor Shower: April’s Annual Shooting Stars From Comet Thatcher.” Earth and Space News. Friday, April 24, 2015.
Available @ https://earth-and-space-news.blogspot.com/2015/04/lyrid-meteor-shower-aprils-annual.html

McClure, Bruce. “All You Need to Know: Lyrid Meteors.” EarthSky > Astronomy Essentials. April 16, 2018.
Available @ http://earthsky.org/?p=158735

“Moon Phases March 2018.” Calendar-12.com > Moon Calendar > 2018.
Available @ https://www.calendar-12.com/moon_calendar/2018/march

“Observations and Elements of Comet I., 1861. (Extract of a Letter From Mr. Bond to Mr. Carrington.).” Monthly Notices of the Royal Astronomical Society, Containing Papers, Abstracts of Papers, and Reports of the Proceedings of the Society, From November 1860, to June 1861, vol. XXI (May 10, 1861): 215-216. London, England: Strangeways & Walden, 1861.
Available via HathiTrust @ https://hdl.handle.net/2027/nyp.33433066362348?urlappend=%3Bseq=223

“Observations of Comet I. 1861, Made With the Olcott Meridian Circle, at the Dudley Observatory. Observed by G.W. Hough. (Communicated by Professor O.M. Mitchel Through the Astronomer Royal.).” Monthly Notices of the Royal Astronomical Society, Containing Papers, Abstracts of Papers, and Reports of the Proceedings of the Society, From November 1860, to June 1861, vol. XXI, no. 8 (June 14, 1861): 241-242. London, England: Strangeways & Walden, 1861.
Available via HathiTrust @ https://hdl.handle.net/2027/nyp.33433066362348?urlappend=%3Bseq=249

Rao, Joe. “A Brief History of the Lyrid Meteor Shower, Which Peaks Tonight.” Space.com > Skywatching. April 21, 2017.
Available @ https://www.space.com/36550-history-lyrid-meteor-shower-2017.html

Sekanina, Z. (Zdenek). “Statistical Model of Meteor Streams II. Major Showers.” Icarus, vol. 13, no. 3 (November 1970): 475-493.

Wednesday, April 19, 2017

2017 Lyrid Meteor Shower Peaks April 22 and 23

Summary: The 2017 Lyrid Meteor Shower, known popularly as April Lyrids or, simply, Lyrids, peaks Saturday and Sunday, April 22 and 23.

Lyrid Meteor Shower radiant or apparent source; credit NASA Science (science.nasa.gov): Bard Anton Zajac (Bard Anton Zajac), Public Domain, via Flickr

The 2017 Lyrid Meteor Shower, which is also known popularly as Lyrids or April Lyrids, peaks Saturday and Sunday, April 22 and 23.

The Lyrid Meteor Shower takes place annually from around April 16 to April 26. Peak rates usually are centered on April 22.

The 2017 Lyrid Meteor Shower’s peak rates begin to occur beginning around 10:30 to 11 p.m. local time, Saturday, April 22. Best viewing happens early Sunday, April 23, after midnight and before dawn.

Time and Date website (www.timeanddate.com) identifies Northern Hemisphere viewers as favorably located for viewing the April Lyrids. The Lyrids are also viewable by observers in mid-latitudes of the Southern Hemisphere.

The Lyrid Meteor Shower derives its name from Lyra the Harp constellation. The meteor shower’s radiant, or apparent point of origin, lies near Lyra’s eastern border with constellation of Hercules the Hero. Meteors are visible anywhere in the sky, but tracing shooting stars back to their apparent point of origin is helpful in differentiating between annual and sporadic activity. The radiant is not, however, the actual point of origin.

Amateur astronomer Gary W. Kronk orients observers in the Northern Hemisphere to face east-northeast to locate the meteor shower’s radiant east of Lyra the Harp’s brightest star, Vega. Lyra is high above the horizon at midnight local time in mid-northern latitudes worldwide.

Southern Hemisphere observers face north-northeast to locate the Lyrids’ apparent radiant. At about 3 a.m. local time in mid-southern latitudes worldwide, Lyra is above the horizon, though not as high as in the Northern Hemisphere.

Lyra’s brightest star, Vega, shines with unmistakable brightness as the night sky’s fifth brightest star. In the Northern Hemisphere, Altair, brightest star in Aquila the Eagle constellation and the night sky’s twelfth brightest star, appears below the Lyrids’ radiant, diagonally southeast of Vega. In the Southern Hemisphere, Altair resides above the Lyrids’ radiant, diagonally northeast of Vega.

The April 2017 moon cooperates with the Lyrid Meteor Shower’s peak and ending dates via non-competitive phases. The waning crescent, which succeeds Wednesday, April 19’s last quarter phase, segues from Saturday’s 21 percent visibility to Sunday’s 13 percent and reaches new moon blackout by Wednesday, April 26.

The April Lyrids’ shoot across the sky at a medium rate of speed. The American Meteor Society (AMS) times the velocity of the Lyrids’ shooting stars at about 30 miles per second (48.4 kilometers per second).

The Lyrid Meteor Shower displays a usual peak rate of 10 to 20 meteors per hour. Extreme outbursts in the shower’s zenital hourly rate (ZHR) for unknown reasons, at undetermined intervals, have been recorded. Kronk cites maximum hourly rates of 96 on April 21, 1922, in Greece; 112 on April 22, 1945, in Japan; and 90 to 100 on April 22, 1982, in Colorado and Florida.

The Lyrid Meteor Shower of April 20, 1803, illuminated the United States’ east coast with a meteor storm, with an hourly rate of 670 or more, lasting for several hours. A letter from an observer in Richmond, Virginia, published Saturday, April 23, 1803, in the Virginia Gazette, described the outburst as:

“From one until three, those starry meteors seemed to fall from every point in the heavens, in such numbers as to resemble a shower of sky rockets.”

Universe Today contributor David Dickinson notes the prime meteor shower viewing conditions that prevailed in 1803. On April 20, the moon was one day away from the darkness of its new moon phase.

April 2017’s waning crescent lunar phase favors easy viewing of the Lyrid Meteor Shower’s peak date.

Meteor showers mostly originate as debris and dust cast off by comets. The Lyrid Meteor Shower claims Comet C/1861 G1 (Thatcher) as its parent comet. The long period comet roughly takes about 415 years to complete its orbit around the sun.

Gary W. Kronk notes that in 1867 German astronomer Johann Gottfried Galle (June 9, 1812-July 10, 1910) mathematically confirmed Comet Thatcher’s parentage of the annual Lyrid Meteor Shower. Galle also included the April Lyrids’ history, tracing the shower back to March 16, 687 BCE.

The takeaway for the 2017 Lyrid Meteor Shower peak date Saturday evening, April 22, to before dawn, Sunday, April 23, is the favorable shooting star viewing conditions afforded by the moon’s waning crescent phase, only three days away from a new moon blackout.

meteor speeds, with April Lyrids at 110,000 miles per hour, according to NASA Marshall Space Flight Center's Meteoroid Environment Office: NASA/MSFC (Marshall Space Flight Center)/Danielle Moeser, Public Domain, via NASA Blogs

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

Lyrid Meteor Shower radiant or apparent source; credit NASA Science (science.nasa.gov): Bard Anton Zajac (Bard Anton Zajac), Public Domain, via Flickr @ https://www.flickr.com/photos/128032454@N02/20640325510/

meteor speeds: NASA/MSFC (Marshall Space Flight Center)/Danielle Moeser, Public Domain, via NASA Blogs @ https://blogs.nasa.gov/Watch_the_Skies/2014/08/12/live-chat-and-ustream-2014-perseid-meteor-shower/

For further information:

“2017 Lyrids.” Society for Popular Astronomy > Meteor Showers > Activity.
Available @ http://www.popastro.com/meteor/activity/activity.php?id_pag=310

Cooke, William B. (wcooke). “Live Chat and Ustream! 2014 Perseid Meteor Shower.” NASA Blogs > Watch the Skies. Aug. 12, 2014.
Available @ https://blogs.nasa.gov/Watch_the_Skies/2014/08/12/live-chat-and-ustream-2014-perseid-meteor-shower/

Dickinson, David. “The Curious History of the Lyrid Meteor Shower.” Universe Today. Dec. 23, 2015.
Available @ http://www.universetoday.com/101602/the-curious-history-of-the-lyrid-meteor-shower/

Fisher, Willard J. “Records of the Lyrid Meteor Shower of 1803: A Search by the Bond Astronomical Club, With Notes on the Leonids of 1799.” Popular Astronomy, vol. 39 (1931): 256-263.
Available via Harvard ADSABS (NASA Astrophysics Data System Abstracts) @ http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?db_key=AST&bibcode=1931PA.....39..256F&letter=.&classic=YES&defaultprint=YES&whole_paper=YES&page=256&epage=263&send=Send+PDF&filetype=.pdf

Harbaugh, Jennifer. “Lyrid Meteor Shower Peaks Tomorrow, April 22.” NASA > Press Release > Meteor & Meteorites. April 21, 2015. Last updated July 30, 2015.
Available @ https://www.nasa.gov/features/watchtheskies/lyrid-meteor-shower-peaks-tomorrow-april22.html

Kronk, Gary W. “Observing the Lyrids.” Meteor Showers Online.
Available @ http://meteorshowersonline.com/lyrids.html

Lindblad, Bertil A.; V. Porubcan. “Activity of the Lyrid Meteor Stream.” In Lunar and Planetary Institute, Asteroids, Comets, Meteors 1991. Pages 367-370. December 1992.
Available via Harvard ADSABS (NASA Astrophysics Data System Abstracts) @ http://adsabs.harvard.edu/full/1992acm..proc..367L

“Lyrid Meteor Shower in 2017.” Time And Date > Sun & Moon > Meteor Showers.
Available @ http://www.timeanddate.com/astronomy/meteor-shower/lyrids.html

“Lyrids.” American Meteor Society > Meteor Showers > Meteor Shower Calendar.
Available @ http://www.amsmeteors.org/meteor-showers/meteor-shower-calendar/

“Meteors & Meteorites: Lyrids.” NASA Solar System Exploration > Planets > Meteors.
Available @ http://solarsystem.nasa.gov/planets/meteors/lyrids#!

Phillips, Tony. “Look, Listen, Lyrids!” NASA Science > Science News > Science at NASA > 2001. April 18, 2001.
Available @ https://science.nasa.gov/science-news/science-at-nasa/2001/ast19apr_1/