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View Full Version : Once in a million years - A comet



Myk Rian
10-16-2014, 9:45 PM
http://news.yahoo.com/once-million-years-comet-buzzing-mars-sun-192054689.html

Mark Bolton
10-16-2014, 10:13 PM
It's funny they dont mention it but many some craft around Mars are being repositioned to hide behind the planet and point critical instruments away from the debris trail.

Would be prime time to be on Mars I'd say.

Tom M King
10-16-2014, 10:23 PM
not too long ago, it was discovered that there are tracks in the interplanetary dust left from comets that have gone through the solar system . it was discovered that planets were dragging interplanetary dust, and then the old trails were found. The math was complicated, but someone noticed that there is an amateur astronomy software that lets you pick a position in the earth's orbit for any day, and that was somehow used as part of the system to bypass a lot of the complicated math to figure out what is what. There are a bunch of REAlly old tracks from a lot of comets. The hope is that this can be used as a method of detecting incoming asteroids, since they will also leave tracks in the dust, and the track is easier to see than the asteroid. This just in the last couple of years. understand that there are people on these forums who are smarter than all these scientists though, so maybe they can explain it better.

Myk Rian
10-17-2014, 11:38 AM
It's funny they dont mention it but many some craft around Mars are being repositioned to hide behind the planet and point critical instruments away from the debris trail.

Would be prime time to be on Mars I'd say.
Yes, they did mention it.
NASA's three orbiters — Mars Odyssey, Mars Reconnaissance Orbiter and newcomer Maven — will be behind the red planet at the time of peak danger. That's a 20-minute-or-so period approximately 1 hours after the closest approach by the comet's nucleus.


The European Space Agency also shifted the orbit of its Mars Express as did India for its Mars Orbiter Mission, or MOM, the country's first interplanetary spacecraft that, like NASA's Maven, arrived last month.

David Weaver
10-17-2014, 11:41 AM
It's funny they dont mention it but many some craft around Mars are being repositioned to hide behind the planet and point critical instruments away from the debris trail.

Would be prime time to be on Mars I'd say.

That article says the speed is 126,000 miles per hour. I can't imagine the amount of energy a dust particle would have at that speed (well, actually we could calculate it pretty easily with a ballistics formula).

I'd hide my tools, too!

(OK, so I calculated it. For each grain of dust weight, that's about 76,000 foot pounds of energy - where a grain is 1/7000th of a pound). 76000 foot pounds is 20-30 times more than a typical centerfire hunting rifle and 200 times as much as a 45 auto. Even particles a tiny fraction of a grain in weight will have significant energy, and we know from ballistics that the damage from high velocity items isn't necessarily proportional to the energy.