Orientation of Roman Catholic Churches in the Philippines


  • Benjamin Jose C. Ambrosio ⋅ PH National Institute of Physics, University of the Philippines Diliman
  • Nathaniel P. Hermosa ⋅ PH National Institute of Physics, University of the Philippines Diliman


The orientation of Christian churches specifically with the rising sun is a well known distinctive feature of their architecture. These orientations tend to align within the solar range of rising directions on the horizon, mostly favoring a range near equinoctial east. We examine 98 Roman Catholic churches, built between 16th and 20th centuries, in the Philippines to uncover if this practice was passed down to countries whose Christian roots were established by Spain. In this paper, we employ the use of geographic information system (GIS) software such as Google Earth and Stellarium to allow geometrically accurate analysis of church altar orientations as well as the azimuths of the sunrise on their respective patron saint's feast day and on both vernal and autumnal equinoxes. Only 22 of the 98 churches in the sample were found to be oriented within the east solar range. Furthermore, our analysis show no preference for canonical nor equinoctial orientations. We explore possible reasons in this paper. We aim to provide contextual insights into how religious traditions permeated into our culture through studying astronomically-motivated alignments of church altars.



Article ID



Poster Session B (Complex Systems, Photonics, and Interdisciplinary Topics)



How to Cite

BJC Ambrosio and NP Hermosa, Orientation of Roman Catholic Churches in the Philippines, Proceedings of the Samahang Pisika ng Pilipinas 39, SPP-2021-PB-21 (2021). URL: https://proceedings.spp-online.org/article/view/SPP-2021-PB-21.