Here’s an explanation and defense of the Catholic dogma on the Assumption of Mary into Heaven, (which is a Holy Day of Obligation, so don’t forget to celebrate at Mass!)
what is it about Jesus’ ascension that is unique? Well, the fact that he ascended is unique. Mary did not ascend to heaven. She was assumed. There is a big difference. Jesus ascended by his own divine power as he prophesied he would in John 2:19-21: “Destroy this temple, and in three days I will raise it up . . . he spoke of the temple of his body.” Mary was powerless to raise herself to heaven; she had to be assumed. The same could be said of all Christians. Jesus raised himself from the dead. Christians will be entirely passive when it comes to their collective “resurrection.”