Catholics in Senegal, Africa attend Mass under a tree. The Pontifical Mission Societies of the Philadelphia Archdiocese invite individual Catholics to help build the church — literally and figuratively — in Africa and around the world. (Photo courtesy the Pontifical Mission Societies)

Activities this Sunday at the Cathedral Basilica of SS. Peter and Paul will serve as the capstone to October’s Extraordinary Month of Missions in the worldwide church, and the observance of the Extraordinary Year of Mission in the Archdiocese of Philadelphia.

World Mission Sunday on Oct. 20 will include several special events to which everyone is welcome to attend. All are sponsored by the archdiocesan Pontifical Mission Societies.

The day begins at 10 a.m. with a rosary walk around the cathedral, praying for the intentions of the world. Participants will meet in front of the cathedral and walk to five areas on the block as though visiting various missionary lands and reflecting on them.

Each decade of the mission rosary, marked by a different color, corresponds to an area of the world where the church continues to evangelize. During the rosary walk, participants will hear reflections on missionary activity around the world.

At 11 a.m. Archbishop Charles Chaput will be the main celebrant for the World Mission Sunday Mass, featuring prayers and music from countries around the world, especially those in most need of God’s healing, love and peace.

The Mass is sponsored in part by the archdiocesan offices of Pastoral Care for Migrants and Refugees, Hispanic Catholics and Black Catholics.

A reception will follow at noon at the nearby Archdiocesan Pastoral Center, where guests can taste international foods that are the favorites in various mission lands.

Other activities continuing through the rest of the month are a rosary devotion meant to embrace all people in every continent in prayer, following the daily 12:05 p.m. Mass in the cathedral.

Every weekday from 9 a.m. to 5 p.m. people can pray and write their intentions — and perhaps take a selfie photo – with a 50-foot wooden rosary using colored ribbons symbolizing the church’s mission areas.

Everyone is invited to take part in Sunday’s activities, which are free of charge and open to the public.

The cathedral is located at 18th Street and the Benjamin Franklin Parkway in Philadelphia.