Total Eclipse of the Sun - February 26, 1998
Fred Espenak, NASA Goddard Space Flight Center

On Thursday, February 26, 1998 a total eclipse of the Sun will be visible
from a 93 mile wide path through South America and the Caribbean. A partial
eclipse will be seen within the much broader path of the Moon's penumbral,
or partial, shadow which includes parts of the United States and eastern
Canada, Mexico, Central and South America.

The Moon's umbral shadow first touches down on Earth just south of the
equator in the Pacific Ocean about 1900 miles southeast of the Hawaiian
Islands (15:46:45 GMT). Even at this extreme position, the total eclipse
lasts nearly one and a half minutes. First landfall occurs shortly after
crossing north of the equator (16:56 GMT) as the shadow engulfs several
members of the Galápagos Islands. The eclipse takes place shortly before
noon with the Sun 69° above the horizon. Unfortunately, none of the islands
are on the center line where the duration of totality is nearly four
minutes. Isla Isabela, Isla Pinta and Isla Marchena are in the path, but
all three islands are uninhabited wildlife sanctuaries with access strictly
controlled by the Ecuadorian government.

After leaving the Galápagos, the umbral path continues on a northeastern
course. The instant of greatest eclipse occurs at 17:28:23 GMT about 400
miles west of Colombia's Pacific coast. At that moment, the Moon's shadow
passes closest to the center of Earth. The length of totality then reaches
its maximum duration of 4 minutes 8 seconds, the Sun's altitude is 76°, the
path width is 93 miles and the umbra's velocity is over 1,300 miles per
hour.

Fifteen minutes later (17:43 GMT), the umbral shadow enters South America
and follows the border between Panama and Colombia. Stretching across the
Isthmus of Panama, the path crosses into northern Colombia where the center
line duration drops below four minutes. After climbing the Andes, the path
sweeps through northwestern Venezuela. The semi-desert vegetation of this
region is a testament to its arid climate. Although Maracaibo lies 30 miles
south of the center line, it manages to enjoy nearly three minutes of
totality. The eclipse occurs here in the early afternoon with the Sun 65°
above the horizon.

The Moon's shadow leaves Venezuela via the Peninsula de Paraguaná and
sweeps across the Caribbean where it encounters five major islands of the
Lesser Antilles. The center line passes directly between Aruba and Curaçao,
but both islands experience as much as 3 1/2 out of a possible 3 3/4
minutes of totality. Aruba's capital Oranjestad witnesses a 3 minute 6
second total phase while the duration in Willemstad, Curaçao is 1 minute 58
seconds. Both islands make good locations for the eclipse since they share
similarly promising weather prospects. Nearby Bonaire is just outside the
88 mile wide path although its northwestern coast will witness a grazing
eclipse with perhaps a dozen seconds of totality.

The track continues across the Caribbean where it engulfs the Leeward
Islands of Montserrat, Antigua and Guadeloupe. Here, the umbra's velocity
increases to over 2,000 miles per hour and the path width drops to 84
miles. Occurring in mid afternoon, the Sun's altitude is 49° at maximum
eclipse. Although the center line passes between Guadeloupe and the other
two islands, all locales enjoy as much as 3 out of a possible 3 1/4 minutes
of totality. While not quite as promising as Aruba and Curaçao, the weather
prospects of this region are still quite favorable.

Leaving the Caribbean Sea, the umbra races across the Atlantic towards
Africa. About 600 miles west of Morocco, the path ends along the sunset
terminator as the shadow falls back into space (19:09:57 GMT). Over course
of 3 hours and 23 minutes, the Moon's umbra travels along an approximately
8,600 mile long path and covers a region comprising 0.3% of Earth's
surface.

Given the ground track for this eclipse, it couldn't occur during a better
time of year. Weather in the Galápagos is controlled by the winds and ocean
currents which are strongly affected by the Intertropical Convergence Zone
(ICZ) passing just north of the archipelago. Although February is one of
the Galápagos' wettest seasons, it's also one of the sunniest. The seeming
contradiction is resolved by the nature of the clouds which are convective
and produce brief periods of heavy showers followed by longer intervals of
abundant sunshine. Statistics at Puerto Baquerizo show that it receives 63%
of the maximum possible sunshine.

Most South American locations are experiencing their dry season and offer
good prospects for clear sky viewing. The northern coast of Venezuela and
the islands of Aruba and Curaçao are particularly favorable. Sunshine
statistics for the region give values of 70 to 80 percent or more of the
maximum possible. Further down the track, sunshine statistics drop slightly
to about 2/3 in the Leeward Islands of Guadeloupe, Antigua and Montserrat.
Considering the time of year and location, many cruise ships that frequent
the Caribbean will be put into service as floating eclipse platforms. Ship
mobility and current weather data could increase the chance of viewing the
eclipse to near certainty. The downside of cruising is that ocean stability
will limit high-magnification photography. Still, most shipboard observers
will be using modest equipment that should yield a satisfactory memento of
the event.

Local circumstances for cities throughout the path are given in Table 1.
All times are given in GMT. The Sun's altitude and azimuth, the eclipse
magnitude and obscuration are all given at the instant of maximum eclipse.

Additional information is available at NASA's 1998 total solar eclipse web
site:

http://planets.gsfc.nasa.gov/eclipse/TSE1998/TSE1998.html

NASA's detailed report on this eclipse (Reference Publication 1383 ) is
available at:

http://umbra.nascom.nasa.gov/eclipse/980226/rp.html


NASA Eclipse Video

The NASA Goddard Space Flight Center's Office of Public Affairs has
prepared a special video including eclipse animations and tips on viewing
the eclipse safely. For more information, contact Wade Sisler at (301)
286-6256.


Other Eclipses During 1998

During 1998, there will be two solar eclipses and three lunar eclipses:

1998 February 26: Total Solar Eclipse
1998 March 13: Penumbral Lunar Eclipse
1998 August 8: Penumbral Lunar Eclipse
1998 August 22: Annular Solar Eclipse
1998 September 6: Penumbral Lunar Eclipse

More information on these eclipses is available at:

http://planets.gsfc.nasa.gov/eclipse/OH/OH1998.html


Solar and Lunar Eclipse Web Site

A special solar and lunar eclipse web site is now available via the Internet at:

http://planets.gsfc.nasa.gov/eclipse/eclipse.html

The site features predictions and maps for all solar and lunar eclipses
well into the 21st century. Special emphasis is placed of eclipses
occurring during the two years with detailed path maps, tables, graphs and
meteorological data. Additional catalogs list every solar and lunar eclipse
over a 3000 year period. Other information includes tips on eclipse
observing, eclipse photography and eye safety. Observer's reports and
photographs from past eclipses are also available.