Published Jan. 23, 2009|Updated Jan. 23, 2009

In the first major initiative of his presidency, President Obama today dispatched Vice President Joe Biden on what he called "an important and special mission" to Antarctica.

Biden was in the middle of making a joke about Chief Justice John Roberts to members of the press corps when Obama interrupted him with the news.

"Here's how John Roberts sings the National Anthem," Biden was saying. " 'Oh see can you say...' "

Obama, yanking away Biden's microphone, then informed him of the extraordinary journey to the South Pole he was about to undertake.

The president was vague about what the mission to Antarctica would entail, but he did indicate that it could take "up to four years."

While some witnesses to the scene said that Biden seemed surprised by the news, his wife, Dr. Jill Biden, offered another version of events during an appearance later in the day on Oprah.

"Joe was given a choice of places to go and he picked Antarctica," she said. "President Obama said he could also go to the moon or Mars."

Jill Biden's remarks were cut short when President Obama appeared on the set and unplugged her microphone.

Other than the Biden news, Obama's day went as planned, meeting with senior staff, drawing up a budget, and being sworn in as president for the third time.