Beate Czogalla
The Union-Recorder
MILLEDGEVILLE —
Long-time readers of this column will remember the Deep Impact mission that fired a projectile into comet Temple-1 exactly five years ago, with all its nail-biting drama. Unless you are a world-class sniper, hitting a far-off target is quite out of the question for most people. If your target is millions of miles away and you’re dealing with a complex and sometimes finicky spacecraft. It becomes even more of a miracle.
But, you remember, the Deep Impact folks hit the mark and got some awesome footage out of the encounter, and the scientific measurements will provide plenty of research fodder for years to come.
While the impactor part of the spacecraft was, of course, vaporized in the crash, the mothership was still out there, cruising happily along, all dressed up and with nowhere to go.
NASA engineers are masters of recycling, or rather re-purposing. If the hardware still works and there is a chance you can squeeze some extra science out of a mission, you bet they will try everything to keep it going.
And so it was for Deep Impact. Renamed EPOXI/ DIXI (Deep Impact Extended Investigation), it is now on the way to comet Hartley 2.
In order to catch up with the cosmic wanderer, Deep Impact took advantage of a free speed boost from good old planet Earth by executing a gravity-assist maneuver, zipping past at around 19,000 miles distance. That’s closer than a communications relay satellite!
Deep Impact got an extra 3,500 mph speed boost out of the encounter and is now coasting toward its next target.
Hartley 2 was discovered in 1986 by Malcolm Hartley, and with an orbital period of 6.4 years, it’s a rather frequent visitor. It’s also much smaller than Deep Impact’s first destination and a whole lot dustier.
Scientists hope to get close enough to the nucleus to peer past the dust cloud and get a good look at the actual comet. On Nov. 4 this year the instruments on board will have around four hours for the best observation of Hartley — of course they’ll watch it like a hawk before and weeks after the encounter, but for those few hours they expect a truly spectacular view.
Hartley 2 will only be the fourth comet that was closely observed by a man-made explorer, and two of those are credited to Deep Impact.
Suffice it to say we have another technological overachiever on our hands! Stay tuned for updates on the historical meeting later this year.
Meanwhile, browse the EPOXI website at http://epoxi.umd.edu/
Beate Czogalla is the associate professor of theater design in the Department of Music and Theater at Georgia College & State University. She has had a lifelong interest in space exploration and has been a solar system ambassador for the Jet Propulsion Laboratory/ NASA for many years. She can be reached at our_space2@yahoo.com
