The robotic spacecraft MESSENGER has run out of fuel. With no way to make major adjustments to its orbit around the planet Mercury, the probe will smash into the surface at more than 8,750 mph (3.91 km/s). The impact will add a new crater to the planet's scarred face that engineers estimate will be as wide as 52 feet (16 meters).
The end is predicted to come at about 3:26 p.m. EDT today.
Editor's note: MESSENGER impacted the surface of Mercury at about 3:26:02 p.m. EDT.