how old was michelangelo when he carved pieta
When Michelangelo set out to create his Pietà, he wanted to create a work he described as “the heart’s image”. 
The structure is pyramidal, and the vertex coincides with Mary’s head. The statue widens progressively down the drapery of Mary’s dress, to the base, the rock of Golgotha. The figures are quite out of proportion, owing to the difficulty of depicting a fully-grown man cradled full-length in a woman’s lap. Much of Mary’s body is concealed by her monumental drapery, and the relationship of the figures appears quite natural. Michelangelo’s interpretation of the Pietà was far different from those previously created by other artists, as he sculpted a young and beautiful Mary rather than an older woman around 50 years of age. 
The lamentation of Christ was a theme popular in Northern European art since the fourteenth century and it traditionally focused on the portrayal of pain through the two figures of Mary and Jesus. But Michelangelo’s interpretation of Mary holding a dead Christ in her arms is remarkable in its devotion to the Renaissance Humanist ideals of physical perfection and beauty. Michelangelo boldly celebrated the intimacy and majesty of a single moment frozen in time, choosing to portray Mary as a chaste and glowing young woman holding the gracefully lifeless body of the Savior across her lap. When we gaze upon this masterpiece itвЂ™s as though MaryвЂ™s outstretched left hand beckons us to share with her, the profound grief caused by the death of her son. Such a subtle and effective compositional device is even more remarkable when we remind ourselves that Michelangelo was only 24 years old when finished his Pieta.
Michelangelo overheard someone remark that it was the work of another sculptor, Cristoforo Solari. Michelangelo then carved MICHAELA[N]GELUS BONAROTUS FLORENTIN[US] FACIEBA[T] (Michelangelo Buonarroti, Florentine, made it) on the sash running across Mary’s breast!
It was concluded that even the smallest crack in the utter perfection of Michelangelo Buonarroti’s Pietà could not have been tolerated.
LOCATION IN SAINT PETER’S BASILICA
This was a special work of art even in the Renaissance because at the time, multi-figured sculptures were rare. These two figures are carved so as to appear in a unified composition which forms the shape of a pyramid, something that other Renaissance artists (e.g. Leonardo) also favored.
Here is perfect sweetness in the expression of the head, harmony in the joints and attachments of the arms, legs, and trunk, and the pulses and veins so wrought, that in truth Wonder herself must marvel that the hand of a craftsman should have been able to execute so divinely and so perfectly, in so short a time, a work so admirable; and it is certainly a miracle that a stone without any shape at the beginning should ever have been reduced to such perfection as Nature is scarcely able to create in the flesh. Such were Michelagnolo’s love and zeal together in this work, that he left his name a thing that he never did again in any other work written across a girdle that encircles the bosom of Our Lady. And the reason was that one day Michelagnolo, entering the place where it was set up, found there a great number of strangers from Lombardy, who were praising it highly, and one of them asked one of the others who had done it, and he answered, “Our Gobbo from Milan.” Michelagnolo stood silent, but thought it something strange that his labors should be attributed to another; and one night he shut himself in there, and, having brought a little light and his chisels, carved his name upon it.
Vasari’s Lives of the Artists
9. Among the most difficult damage to repair was Mary’s eyelid, which took approximately 20 tries before the restorers got it right.
4. The loan of “Pieta” to the 1964 World’s Fair in New York City was a high-security undertaking. A bulletproof enclosure consisting of two and a half tons of Plexiglas ensured the statue’s safety. Electric-powered conveyor walkways kept crowds of viewers moving along.