When the White House asked if President Obama could introduce the first episode of the documentary series "Cosmos" earlier this year, host and astrophysicist Neil deGrasse Tyson concluded, "you can't say no to the president.”

Tyson said the show did not ask him to do it, but he concluded the White House was probably trying to ride the media attention the 13-episode series was garnering before its debut on Fox in March. 

"That was their choice. We didn’t ask them," he told Grantland earlier this week. "We didn’t have anything to say about it. They asked us, ‘Do you mind if we intro your show?’ Can’t say no to the president. So he did. He may have been riding the very high media attention that Cosmos had been getting on the ramp-up."

DeGrasse Tyson also speculated the intro could have been a way to curry favor with the scientific community after the White House released its budget.

"That same week, by the way, Obama — the White House — released its budget, which included a reduction in the science spending in NASA," he said.  "So if you look at it politically, rather than gesturally, it’s easy to think of that as a way for him to try to gain points back in the science community, immediately after dropping the science budget for NASA."

In the short introduction, Obama called the United States "a nation of fearless explorers." 

"Open your eyes and open you imagination because the next great discovery could be yours," Obama said at the time. 

Before the series aired the White House showed a preview of the series at the White House Student Film Festival. At the March event Obama, deGrasse Tyson and Bill Nye snapped a selfie together.