Not all dazzling fireworks displays will be on Earth this Independence Day. NASA hopes to shoot off its own celestial sparks in an audacious mission that will blast a stadium-sized hole in a comet half the size of Manhattan.Yeehaw! Hold my beer and watch this!
Actually, it may not be all that spectacular to a naked eye observer:
The big question is: What kind of fireworks can sky-gazers expect to see from Earth?But the probes are taking pictures of the action.
Scientists do not know yet. But if the probe hits the bull's-eye, the impact could temporarily light up the comet as much as 40 times brighter than normal, possibly making it visible to the naked eye in parts of the Western Hemisphere.
The real action starts in the early morning of July 3 (Eastern time) when the spacecraft separates, releasing an 820-pound copper probe called the "impactor" on a one-way trip straight into the path of the comet. During the next 22 hours, mission control at Jet Propulsion Lab in Pasadena will steer both craft toward Tempel 1.Now we're talking! Hmmm, I'm surprised no ecoweenies have jumped on this.
Two hours before the July 4 encounter, the impactor kicks into autopilot, relying on its self-navigating software and thrusters for the rest of the journey to steer toward the sunlit part of the comet's nucleus so that space and Earth-based telescopes can get the best view.
Meanwhile, the spacecraft - with its high-resolution camera ready - will veer out of harm's way some 5,000 miles away, as it stakes out a ringside seat for recording the collision. The spacecraft will make its closest flyby minutes after impact, approaching within 310 miles.
The collision is expected to occur around 1:52 a.m. EDT when the comet, traveling through space at 6 miles per second, runs over the impactor, which will be shooting some of the most close-up pictures of Tempel 1 up until its death.
Grammier has likened it to standing in the middle of the road and being hit by a semi-truck going 23,000 mph - "you know, just bam!" The energy produced by the crash will be like detonating nearly 5 tons of TNT.