What happened at the Ascension of Jesus?

The Catechism of the Catholic Church (paragraphs 659-660) says,

“So then the Lord Jesus, after he had spoken to them, was taken up into heaven, and sat down at the right hand of God.” Christ’s body was glorified at the moment of his Resurrection, as proved by the new and supernatural properties it subsequently and permanently enjoys. But during the forty days when he eats and drinks familiarly with his disciples and teaches them about the kingdom, his glory remains veiled under the appearance of ordinary humanity. Jesus’ final apparition ends with the irreversible entry of his humanity into divine glory, symbolized by the cloud and by heaven, where he is seated from that time forward at God’s right hand. Only in a wholly exceptional and unique way would Jesus show himself to Paul “as to one untimely born,” in a last apparition that established him as an apostle.

The veiled character of the glory of the Risen One during this time is intimated in his mysterious words to Mary Magdalene: “I have not yet ascended to the Father; but go to my brethren and say to them, I am ascending to my Father and your Father, to my God and your God.” This indicates a difference in manifestation between the glory of the risen Christ and that of the Christ exalted to the Father’s right hand, a transition marked by the historical and transcendent event of the Ascension.

Who was present at the Ascension of Jesus?

The Scripture definitively names “the eleven disciples,” the inner circle of those who followed Christ. Although Matthew only mentions the eleven Apostles, Judas having defected, we can conjecture that others, including His Mother and other disciples, were likely present, as well. For example, St. Paul tells us that 500 people saw the Lord after His Resurrection, and thus during the forty days. However, we do not know if any of these disciples saw His Ascension.