Partial Solar Eclipse Feb. 15 Is First of Three 2018 Solar Eclipses

Summary: The partial solar eclipse Feb. 15 is the first of three 2018 solar eclipses, with all three appearing as partial eclipses for Earth’s observers.

animation of partial solar eclipse Thursday, Feb. 15, 2018: A.T. Sinclair/NASA, Public Domain, via Wikimedia Commons

The partial solar eclipse Feb. 15 is the first of three 2018 solar eclipses, with all three occurring as partial eclipses, as seen from Earth.

The partial solar eclipse Thursday, Feb. 15, 2018, is an event observable in the Southern Hemisphere. EarthSky Tonight’s lead writer, Bruce McClure, notes that 2018’s first partial solar eclipse begins at sunrise over the South Pacific Ocean and ends over the South Atlantic Ocean.

Oceanic viewing of the partial solar eclipse is available in the Southern Ocean as well as parts of the south Atlantic and south Pacific. Continental viewing of partiality emphasizes most of Antarctica and also encompasses southern Brazil, much of Argentina and Chile, southernmost Paraguay and all of Uruguay in southern South America.

The natural phenomenon of a partial solar eclipse involves partial eclipsing, or obscuring, of the solar system’s sun by the moon, as seen from Earth. The lack of straight line alignment of the sun and the moon with Earth occasions the casting of only the light, outer region of the moon’s shadow -- but none of the dark, inner region, known as umbra -- onto the Earth's surface.

February 2018’s partial solar eclipse begins with the first contact between Earth’s surface and the lunar penumbra. Time And Date web site places first contact Thursday at 18:55:51 Coordinated Universal Time (UTC). At 3:51:29 UTC greatest eclipse is expected over Antarctica. Greatest eclipse indicates the instant of closest passage to Earth’s center by the axis of the lunar shadow cone.

The partial solar eclipse ends with the last contact before Earth exits from the moon’s penumbra. Time And Date places last contact at 22:47:08 UTC. February 2018’s partial solar eclipse has a duration of close to four hours (3 hours 51 minutes 17 seconds).

February’s partial solar eclipse occurs as 2018’s second eclipse. The year’s first eclipse happened Wednesday, Jan. 31, as the first of the year’s two total lunar eclipses.

The partial solar eclipse Thursday, Feb. 15, appears as the first of three 2018 solar eclipses, all of which occur as partial solar eclipses. February 2018’s partial solar eclipse takes place as number 11 of 77 partial solar eclipses happening in the 21st century (Monday, Jan. 1, 2001-Friday, Dec. 31, 2100).

The year’s second partial solar eclipse takes place Friday, July 13. The event joins 2018’s first partial solar eclipse as a Southern Hemisphere event. July 2018’s partial solar eclipse favors the Antarctic Ocean, also known as the Southern Ocean, and southern Australia.

The year’s third and final partial solar eclipse happens Saturday, Aug. 11, and claims status as closing eclipse in 2018’s lineup of five eclipses (two total lunar eclipses, three partial solar eclipses). The event favors the Northern Hemisphere, especially northeastern Canada, Greenland, Iceland, northern Europe and northern and eastern Asia.

The Saros cycle groups similar eclipses into families, known as series. A Saros cycle equates to 6,585.3 days (18 years 11 days 8 hours). Two eclipses separated by one Saros share similar geometries, such as occurrence at the same node, ascending or descending, with the moon and at nearly similar distances from Earth.

The two nodes mark the two points of the crossing of Earth’s orbit by the moon’s orbit. The two points reflect the tipping of the lunar orbit by about 5.1 degrees to Earth’s orbit around the sun. The ascending node indicates the lunar passage to the north of Earth’s orbit. The descending node signifies the lunar crossing to the south. Saros 150 eclipses occur at the moon’s descending node.

February 2018’s partial solar eclipse belongs to Saros 150. The partial solar eclipse Thursday, Feb. 15, occurs as number 17 in Saros 150’s lineup of 71 solar eclipses.

Saros 150 dates its first eclipse back to Sunday, Aug. 24, 1729, which occurred as a partial solar eclipse. The event’s greatest eclipse took place at 13:48:20 UT1 (the principal form of Universal Time).

Saros 150’s closing eclipse will occur Thursday, Sept. 29, 2991, as a partial solar eclipse. The event’s greatest eclipse will take place at 05:42:15 UT1.

Saros 150’s lineup features three sequences. A sequence of 22 partial solar eclipses characterizes the cycle from August 1729’s opener to the sequence’s closing partial eclipse Wednesday, April 11, 2108. The second sequence comprises 40 annular eclipses, beginning Monday, April 22, 2126, and ending Friday, June 22, 2829. Saros 150’s third sequence reverts to partial solar eclipses. The sequence of nine partial solar eclipses begins June 12, 2811, and closes Saros 150’s final eclipse Thursday, Sept. 29, 2991.

The partial solar eclipse Thursday, Feb. 15, claims status as the first of three partial solar eclipses and as the first of the year’s two Southern Hemisphere-based solar eclipses.

details of partial solar eclipse Thursday, Feb. 15, 2018: "Permission is freely granted to reproduce this data when accompanied by an acknowledgment: Eclipse Predictions by Fred Espenak, NASA's GSFC," via NASA Eclipse Web Site

Acknowledgment

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

Image credits:

animation of partial solar eclipse Thursday, Feb. 15, 2018: A.T. Sinclair/NASA, Public Domain, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:SE2018Feb15P.gif

details of partial solar eclipse Thursday, Feb. 15, 2018: "Permission is freely granted to reproduce this data when accompanied by an acknowledgment: Eclipse Predictions by Fred Espenak, NASA's GSFC," via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/SEplot/SEplot2001/SE2018Feb15P.GIF

For further information:

“Accuracy of Eclipse Times.” TimeAndDate > Sun & Moon > Eclipses.
Available @ https://www.timeanddate.com/eclipse/accuracy.html

“Eclipses: What Is the Penumbra?” TimeAndDate > Sun & Moon > Eclipses.
Available @ https://www.timeanddate.com/eclipse/penumbra-shadow.html

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

Espenak, Fred. “Five Millennium Catalog of Solar Eclipses.” NASA Eclipse Web Site > Solar Eclipses.
Available @ https://eclipse.gsfc.nasa.gov/SEcat5/SE2001-2100.html

Espenak, Fred. “Glossary of Solar Eclipse Terms.” NASA Eclipse Web Site.
Available @ https://eclipse.gsfc.nasa.gov/help/SEglossary.html

Espenak, Fred. “Key to Catalog of Solar Eclipses.” EclipseWise.
Available @ https://www.eclipsewise.com/solar/SEhelp/SEsarcatkey.html

Espenak, Fred. “Partial Solar Eclipse of 2018 Feb 15.” EclipseWise > Lunar Eclipses > Eclipses During 2018 > Partial Solar Eclipse of February 15.
Available @ https://www.eclipsewise.com/oh/oh-figures/ec2018-Fig02.pdf

Espenak, Fred. “Partial Solar Eclipse of 2018 Feb 15.” NASA Eclipse Web Site > Solar Eclipses > Decade Solar Eclipse Tables > Solar Eclipses: 2011-2020.
Available @ https://eclipse.gsfc.nasa.gov/SEplot/SEplot2001/SE2018Feb15P.GIF

Espenak, Fred. “Partial Solar Eclipse of February 15.” EclipseWise > Lunar Eclipses > Eclipses During 2018.
Available @ https://www.eclipsewise.com/oh/ec2018.html#SE2018Feb15P

Espenak, Fred. “Saros 150.” EclipseWise > Solar Eclipses > Saros Catalog of Solar Eclipses.
Available @ https://www.eclipsewise.com/solar/SEsaros/SEsaros150.html

“February 15, 2018 -- Partial Solar Eclipse.” TimeAndDate > Sun & Moon > Eclipses.
Available @ https://www.timeanddate.com/eclipse/solar/2018-february-15

Marriner, Derdriu. “Jan. 31, 2018, Blue Moon Total Lunar Eclipse Belongs to Saros Cycle 124.” Earth and Space News. Wednesday, Jan. 10, 2018.
Available @ https://earth-and-space-news.blogspot.com/2018/01/super-blue-moon-wednesday-jan-31-is_31.html

McClure, Bruce. “Partial Solar Eclipse on February 15.” EarthSky > Tonight. Feb. 15, 2018.
Available @ http://earthsky.org/?p=271387

“Universal Time.” U.S. Naval Observatory > Astronomical Information Center > Time.
Available @ http://aa.usno.navy.mil/faq/docs/UT.php