The last time NASA visited the Tempel 1 comet, it was with fireworks, on July 4, 2005. On that day, the Deep Impact spacecraft slammed an 820-pound projectile into Tempel 1, excavating a plume of ice and dust.

On Monday night  Valentine’s Day  NASA will return to Tempel 1 but will not bombard it. This time, a different spacecraft, Stardust, will zip past at more than 24,000 miles per hour, taking 72 high-resolution pictures of the comet’s surface.

Stardust will make its closest approach, within 125 miles, at 11:37 p.m. Eastern time.

Tim Larson, the mission’s project manager, said NASA was not deliberately scheduling its missions to coincide with holidays. “That’s just how the orbital mechanics worked out on these,” he said, “although it makes for great P.R.”

Tempel 1 will be the first comet to be seen at close range twice, and scientists will make a then-and-now comparison  one that they expect will reveal a change in topography and tell them more about the inner workings of comets.