Pope blessed a disabled man who hugged him and kissed his cross in St Peter's Square

Pope Francis is famous for his compassionate nature and is often pictured at his weekly audience in St Peter's Square kissing and hugging his followers.

But today it was his turn to have attention showered on him as a disabled young man was photographed kissing the 77-year-old as well as stroking his cheek and rubbing his head.

The tender moment was captured this morning as the pontiff made his way through the crowds.

Spotting the man, Pope Francis bent down and held his hands to bless him.

The young man kissed the crucifix on a chain around his neck and drew the Pope closer.

The man, whose identity is not known, was clearly encouraged by the Pope's gentle nature, and reached up to kiss him before gently stroking his cheek and rubbing his head.

Every Wednesday, Pope Francis has made it a habit of touring for approximately 30 minutes among the thousands of pilgrims who come to attend the weekly audience and to see him in St Peter's Square, blessing and shaking hands with the most varied groups of people, and often receiving gifts.

But this morning it looked as though he was struggling with the winds  -  his robes blew across his body and at one point at pink balloon floated across the crowd obscuring his face.

Earlier this week Pope Francis said he would be willing to baptise Martians if they came to Earth and asked to become Catholics.

During his daily mass, the leader of the Roman Catholic church said that no one should be denied entry into the church for any reason.

He joked that even if space aliens were 'green men, with a long nose and big ears, like children draw', they deserved to be baptised if they wanted.

'If tomorrow, for example, an expedition of Martians arrives and some of them come to us... and if one of them says, "Me, I want to be baptised!", what would happen?', Francis said, according to AFP.

He added that the early church had an officer charged with welcoming people in to the building, but 'it was never the ministry of the closed door'.

The Pope's comments came as he discussed the passage of the Bible in which St Peter is criticised for baptising non-Jews into the Christian church.

However, they are likely to be seen as a coded jab at Francis' conservative critics who may have objected to his policy of openness towards poor and marginalised groups.

In January, the Pope courted controversy by baptising the child of an unmarried couple in the Sistine Chapel.

Francis' joke about baptising aliens is not the first time that the Catholic church has intervened in the debate over the possibility of extraterrestrial life.

In 2010, Vatican scientist Guy Consolmagno said that although he did not expect to find life on other planets, aliens would be welcome to join the church.

'God is bigger than just humanity,' he said. 'God is also the god of angels.

'Any entity - no matter how many tentacles, it has has a soul.'

And in 2008, the official Vatican newspaper published an article by an astronomer titled 'Aliens Are My Brother', in which an astronomer insisted that it was not irreligious to search for extraterrestrial life. 

The Vatican has its own observatory, with one telescope situated outside Rome and another in Arizona.

The church's interest in astronomy began as a way of calculating the calendar and determining the date of Easter.

Throughout the 20th century, the Vatican became a pioneering force in astronomical research, and photographs of never-before-seen astronomical phenomena were first captured at the papal observatory.