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By Eric Marrapodi, CNN Belief Blog Co-Editor
Washington (CNN) - "You've got something on your forehead."
Every year on Ash Wednesday it's how the awkward conversation begins. A well meaning co-worker points out a black smudge on someone's forehead, not knowing it's supposed to be there.
The smudge is the imposition of ashes, often on the forehead in the shape of a cross. Ash Wednesday marks the beginning of Lenten season, when Christians take time to prepare for Easter through a time of fasting and prayer. The imposition of ashes nears a holy obligation for many Catholics, although technically it is not.
As two prominent Catholic presidential candidates take to the debate stage for the CNN Republican Presidential Debate in Mesa, Arizona, lots of people are asking will they or won't they wear ashes?
In the race for the Republican nomination for the White House, Rick Santorum and Newt Gingrich have made no secret of their Catholic faith.
Santorum was born into a Catholic family and served as an altar boy. A Santorum aide told CNN that Santorum attended Mass Wednesday morning in Mesa, Arizona. He was spotted by CNN's Kevin Bohn after Mass at his hotel with ash on his forehead.
Gingrich converted later in life as an adult to Catholicism. The former House Speaker told CNN's Shawna Shepherd on Wednesday that he would not be going to Mass on Ash Wednesday. Though he said he's been in the past, Gingrich noted that Ash Wednesday is "not a holy day of obligation," referring to days on which Catholics are required to attend Mass.
Gingrich did say he was giving up dessert for Lent, while his wife Callista Gingrich joked that she was giving up "her opinion."
As the presidential hopefuls get ready to take the stage under the lights and pancake makeup on Wednesday night, what's a Catholic candidate to do?
CNN's Belief Blog – all the faith angles to the day's top stories
"There is no regulation or even a suggestion regarding how long the ashes remain," according to Monsignor Rick Hilgartner, the executive director of the U.S. Conference of Catholic Bishops Secretariat of Divine Worship. Hilgartner helps the Catholic church in the United States oversee liturgical matters.
"Sometimes they just don't 'stick' for long, so if someone receives them in the morning they might simply brush off through normal routines later in the day," he said.
The ashes come from palm fronds, or the stems and leaves, used to celebrate Palm Sunday. Palm Sunday marks the beginning of Holy Week when Christians remember Jesus riding into Jerusalem on a donkey and being greeted like a king, with the crowd waving palm fronds and laying their coats on the ground. During Holy Week Christians remember the death and resurrection of Jesus Christ. Easter Sunday marks the end of Holy Week and the end of any Lenten fasts.
In the Catholic tradition parishioners keep the palm fronds in their house all year, until the start of the Lenten season. The church then collects the fronds and burns them to create the ash.
Receiving ashes is a symbolic gesture, said Hilgartner. He notes in different countries the ashes are distributed in different ways. In Italy, for example, ashes are sprinkled over the top of the head. Last year on Ash Wednesday, Pope Benedict XVI received his ashes sprinkled on the top of his head.
"Whatever the method, the symbolic gesture is just that...There is no discussion about what might be 'valid' or 'licit,'" he said.
The ashes are a physical reminder of mortality and a call to live a better life. In the Catholic tradition when they are applied a priest can say, "Remember man, from dust you came and from dust you shall return" or "Repent and believe in the Gospel."
Suppose a Catholic who happened to be running for president needed makeup for a televised debate, Hilgarten says there would be nothing wrong, "if out of necessity the ashes were removed in order to prepare makeup for a public appearance."
"It's not like a tattoo. They could get them and by the time they're doing their debate they could be gone," Monsignor Crosby Kern said. Kern is the pastor at the Saint Louis Cathedral in New Orleans, Louisiana.
"Catholics are not required to get ashes," Kern said. Ash Wednesday is not a Holy Day of Obligation in the Catholic liturgical calender, as Christmas, Easter, and several other days are.
While the New Orleans Police department may be busy on Mardi Gras night clearing Bourbon Street of tourists, Kern said come Ash Wednesday morning the faithful show up en mass to get their ashes.
"We're full at the cathedral. We have three masses and they'll all be full," he said.
While it may not be an obligation, it is an important tradition for millions of Catholics.
In Washington, politicians often are seen with ashes. Most notably in recent years, Vice President Joe Biden has been seen on past Ash Wednesdays with the ash on his forehead.
On Wednesday, President Barack Obama released a statement on Ash Wednesday.
"Today, Michelle and I honor Ash Wednesday with Christians around the country and across the world," the statement said. "This is at once a solemn and joyous occasion, an opportunity to remember both the depths of sacrifice and the height of redemption. We join millions in entering the Lenten Season with truly thankful hearts, mindful of our faith and our obligations to one another."
With Gingrich choosing not to get ashes and Santorum receiving them, the question remains whether Santorum will make an effort to keep them for their time in the national spotlight.
–CNN's Shawna Shepherd, Dana Bash, and Kevin Bohn contributed to this report.
