Touchdown! Philae Successfully Lands on Rosetta’s Comet

We did it! We’re on the comet! At about 9:37 a.m. (CST) Philae touched down on Rosetta’s Comet. After traveling more than 315 million miles (508 million km) the lander’s signal arrived 28 minutes later with the fabulous news. Telemetry is trickling in and the lander’s in great health, but one small concern has arisen. We’ve just learned that the harpoons used to anchor Philae failed to fire. Mission control is considering whether to refire them to make sure the craft is stable.

Philae  postcard. Hey, it made it - a huge congratulations to ESA. Credit: ESA
Philae is now at work on the comet after successfully harpooning itself to the surface. A huge congratulations to ESA! Credit: ESA

One might think that as long as the craft is sitting still on the comet, that will do. Well, maybe. Until it’s anchored, activity from nearby jets or even vaporizing ice beneath it could flip it over. After all, Philae only weighs a gram in 67P/C-G’s gravity field. The harpoons also house the instrument that measures surface density. Presumably, without them we won’t get that data.

ESA's version of a Swiss Army knife, Philae will now probe the comet on many levels. Credit: ESA
ESA’s version of a Swiss Army knife, Philae will now probe the comet on many levels. Credit: ESA

Now that Philae has reached its target, science will begin in earnest. Here’s an illustration that describes each of the probe’s instruments. Be sure to click to enlarge.


16 Replies to “Touchdown! Philae Successfully Lands on Rosetta’s Comet”

  1. Wow!!! It was great to watch, even if my connection dropped out a few times – fortunately not at any crucial time. We can land on a comet so far away but can’t yet guarantee a faultless internet connection!
    So looking forward to what Philae will discover!

  2. Thanks for the timely reporting Bob. I’ve been up since 5 am PST.. waiting and watching as there was no way I could sleep through this! NO!

    Congratulations to ESA – You are an inspiration to us all! GO Rosetta!

  3. Dropped internet signals, a simple processor on Philae no greater than a hand calculator, these are certainly still early days of space travel, like the era of sailing ships. NASA’s Jim Green spoke frankly of colonizing our solar system. These are truly the first steps.

  4. Awesome news! Right on time too! Can’t wipe the huge smile off my face. Looking forward to all the data to come from the surface 🙂

  5. Ehm, maybe not…
    ESA said 10 minutes ago that the cold gas rocket did not work. Neither the anchors on the landing legs. I don’t know about the harpoon, but if it landed gently, isn’t gravity enough to pull it down again?

  6. Far Away,
    One would think it would be enough, but remember, a comet’s surface is active. A nearby jet could easily lift up Philae or topple it. Getting it stable is paramount.

  7. Well done ESA outstanding job, This is giving me the same feeling as the first Moon Landing , One Giant Journey for One Fantastic Endeavour I cant wait for the First Pictures from the surface…..

  8. Bob, you got Rosetta’s travel distance wrong! It travelled MORE THAN 4 BILLION MILES, or MORE THAN SIX BILLION KILOMETERS to reach 67P/C-G. The distance you mentioned is how far it is from Earth now (and diminishing at every moment!). How funny none of the previous comments mentioned this mistake!

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