This is Science Friday. I'm Ira Flato.

I'll be seeing you.

I was there yesterday, and I was there with the team as these commands went out into the deep sky,

and I learned this morning that we had not heard back and our beloved opportunity

remained silent. It is therefore that I'm standing here with a sense of deep appreciation

and gratitude that I declare the opportunity mission as complete.

And with it, the Mars Exploration Rover mission as complete.

I'll be looking at the moon, but I'll be seeing you.

That was Thomas Zerbukin, associate administrator for NASA's science mission directorate,

officially declaring opportunity's remarkable 15-year-long mission to be over.

The Mars rover had gone silent since getting caught in a dust storm last summer.

On Tuesday night, the Space Agency made one last attempt to contact the rover,

sending it the Billy Holiday's rendition of I'll be seeing you,

but opportunity did not answer.

Maggie Gert Baker, senior science reporter with 538, is here to talk about sort of a sad occasion.

Hi, Maggie.

Hi, that almost made me cry a little bit in the studio.

I got a little misty myself.

It was almost like a death in the family, was it not?

Yeah. I mean, these rovers are so personable. I mean, they kind of feel like they have faces a little bit, that people get attached to them. You know, they have Twitter presidences.

Everybody really loves these things, and this one was scrappy and tough.

It was only supposed to last for 90 days when it landed in 2004, and instead it ran for 5,352 days,

...