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Stardust Mission Makes First-Ever Return To Comet
RedEaredSlider writes "NASA's Stardust probe made its closest approach to comet Tempel-1 on Monday night, marking the first time a comet has ever been revisited by a spacecraft. The mission, formally called Stardust-NeXT, for New EXploration of Tempel-1, was launched on its way in 2006. On Monday night it came within 181 kilometers (112 miles) of the comet, taking pictures and measuring the amount and composition of dust in the comet's coma, the plume of gas that surrounds it. It approached the comet at about 10.6 kilometers (6.7 miles) per second, making it one of the fastest probes that has yet flown. Stardust made its closest approach at 11:39 p.m. Eastern and after that, swung around its high-gain antenna towards Earth to transmit its data. The comet and spacecraft are about 336 million kilometers (209 million miles) away, so signals take a full 18 minutes to get to Earth."
http://www.nasa.gov/mission_pages/stardust/news/stardust20110214d.html if you can't stand those damn add-infested pages. Also has better images.
I'm not sure, but its probably quoted in an inertial frame relative to the solar system barycenter. However, its conceivable that it could be quoting the relative velocity of one object to the other (i.e. the distance between the two of them was changing at a rate of 10.6 km/s).
Most things nearby each other in Earth orbit are in similar orbits and thus have fairly low relative speeds. However, if you have polar or retrograde vehicles passing near conjuction with more typical near equatorial objects, then the typical LEO orbital velocity of ~7.8 km/s could produce similar speeds. However, in those cases you're not trying to take pictures of one with the other so it doesn't make much difference.
7.6 km x 4.9 km. So somewhere in between a baseball stadium and Hawaii.
A small town may be the best 'library of congress' to use.
Scanning through some of the releases on http://www.jpl.nasa.gov/news/stardust/ "NASA's Stardust-NExT mission took this image of comet Tempel 1 at 8:40 p.m. PST (11:40 p.m. EST) on Feb 14, 2011, from a distance of approximately 946.05 trillion kilometers (587.85 trillion miles). The comet was first visited by NASA's Deep Impact mission in 2005." 587.85 trillion miles? ( See http://en.wikipedia.org/wiki/Trillion for both defintions ) This would put it 6,314,828 A.U., or about 23 times the 4.365 Light years ( 276,041 A.U.) distance to Alpha Centauri. ... or maybe it is just damn fine imaging! :-)
Good point. A little google arithmetic and wikipedizing and I come up with Rosenheim, Bavaria. That town's area is a close approximation of the area marked out by your dimensions (37.22 km^2 for the town v. 37.24 km^2 for the rock).
So, henceforth the maximal surface area coverage ("Lay it flat on the ground; how much ground does it cover?") will be designated with a non-SI unit "Rosenheims". Tempel-1 is very close to one Rosenheim.
Welcome to the Panopticon. Used to be a prison, now it's your home.
I used to work at a small robotics company in NYC, that worked on NASA projects. We were building a drilling device that would be part of a lander that was supposed to go to Tempel 1. But NASA/JPL scrapped it in favor of Deep Impact (smashing into the comet instead of landing on it).
So instead of having a spacecraft land on the comet, drill 1 meter into it, take a sample and return the sample to Earth (yes it was ambitious), they opted for smashing into it with Deep Impact and fly bys/dust collection with Stardust.
I'm not really bitter, really. It was fun/cool working there, but I was disappointed that NASA switched things up on us.
from the summary: "181 kilometers (112 miles) miles"
what the hell is a kilometer mile?
A kilometer mile is about 0.62 mile miles.
The enemies of Democracy are
I'm not sure, but its probably quoted in an inertial frame relative to the solar system barycenter.
In that case it is a very slow probe since the orbital velocity of the earth vs. the solar system centre of mass is about 30km/s.
Tempel-1 was the comet that the Deep Impact probe visited (and impacted) on July 4 2006. So this is a different spacecraft (Stardust-NExT) returning to that same comet after its close approach to the sun. The fact that its a return is interesting because we've never seen how a comet changes after perihelion (where all the volatility peaks), or in fact seen any indication of how comets change at any time. Since they are the most dynamic bodies in the solar system, this is highly valuable science.