Two beams of light will converge inside Mission Concepción on the afternoon of Aug. 15 and illuminate the altar floor and the Virgin Mary's face on a painting perched on the church wall.
The rare double solar illumination happens every year at the same time and is made possible by a sunbeam that enters through the window above the front door of the church and another ray of light that pierces through the dome window. The public is invited to see the special event, which will occur at 6:30 p.m.
A 7 p.m. mass will follow to commemorate the Feast of the Assumption of the Blessed Virgin Mary, marking the remembrance of her bodily ascension into heaven. Church doors will open at 6 p.m.
"It's a moment for people to see something that is really quite moving, especially inside a church built over 280 years ago," Fr. David Garcia, the pastoral administrator of Mission Concepción and director of the Old Spanish Missions, stated in a press release.
The Assumption of the Blessed Virgin Mary into Heaven is a defined dogma of the Catholic Church and a required belief of all Catholics. The teaching was defined as a dogma in the Munificentissimus Deus, an apostolic constitution written in 1950 by Pope Pius XII.
The Catechism of the Catholic Church summarizes the teaching as follows:
"The Most Blessed Virgin Mary, when the course of her earthly life was completed, was taken up body and soul into the glory of heaven, where she already shares in the glory of her son's resurrection, anticipating the resurrection of all members of his body."
Recent research on Mission Concepción's vaulted dome roof suggests that windows were placed strategically for light to illuminate the main altar and north altar on specific feast days.
Throughout the Southwest, several other old Spanish missions are home to solar illuminations to commemorate special days, but double illuminations like at Mission Concepción are rare.
"Our tour guide and volunteer at the Missions, George Dawson, discovered the illumination about 10 years ago," San Antonio Missions National Historical Park Archaeologist Susan Snow told the Rivard Report. "He read research about the illumination in the California missions and wanted to see if it was true here, so he did his own research and went out with his compass."
Dawson then invited Ruben Mendoza, the researcher he read about, to verify his findings, Snow said.
Mission Concepción, also known as Nuestra Señora de la Purísima Concepción, was founded in 1731 and is considered by some historians to be the oldest unrestored church in the United States.
Colorful, geometric designs used to cover the surface of the church, but time has taken its toll and wind and water erosion have worn away much of the patterns.
The cross-shaped, limestone building has unique Moorish, Native American, and Spanish design influences and original frescos are still visible in several rooms, showcasing a blend of Spanish and indigenous iconography.
To expand their religious reach, missionaries strove to teach Christian beliefs by hosting religious festivals to replace Indian rituals, and carvings of saints and other objects became popular symbols of Catholicism for the native peoples.
For nearly 300 years, the San Antonio Spanish Colonial Missions have been places of worship, and centers of communal and cultural life for Native Americans, settlers, and missionaries alike.
Through their preserved architecture and design elements, the Missions vividly showcase the cultural history of European and indigenous cultures converging in the New World. This is one of the many reasons why on July 5, 2015, the Missions and the Alamo were designated as UNESCO World Heritage sites. They are the first sites to receive the distinction in Texas.
The forthcoming World Heritage Festival, slated for Sept 9-11, aims to bring San Antonians together to commemorate the World Heritage designation of the Missions through performances and educational activities.
For more information about the Mission, call (210)-357-5601.
Top image: Mission Concepción's facade. The bright, colorful patterns have worn off during 300 years of weather and wind erosion. Photo by Iris Dimmick.