5 ms·

Why does it need to anchor itself? It's not like it will blow away?

• jarin 12y ago
  It could actually, since there's already outgassing on the comet.
• robin_reala 12y ago
  Newton’s Second (edit: Third) Law. It wants to extend a drill bit into the surface.
  • 3rd3 12y ago
    Third?
    • robin_reala 12y ago
      …oops (apropos username)
• ctdonath 12y ago
  Gravity there is so low that something like a light push may be enough to launch. If anything used to examine the surface makes contact and presses (drill, digger), good-bye lander. Firing the harpoon would also be enough to launch, but at least the hook would grab the surface and pull the lander back down, giving enough pull to drill viable long-term anchors.
  • mVChr 12y ago
    Are there any forces in effect as it gets closer and swings around the sun that might cause it to separate from the comet if there is no further attachment by then?
    • JoeAltmaier 12y ago
      Absolutely! If its attached, its via surface ice. That ice will all melt on close approach to the sun. At some point the probe will drift away.
      • mVChr 12y ago
        Of course, I should have deduced that. Is the harpoon expected to go deep enough to prevent this from happening?
• humanfromearth 12y ago
  It will dig into the surface anyway so it will anchor itself even without the harpoon, if it's on the surface of course. See this video that explains how Philae foots work: https://www.youtube.com/watch?v=-77-Z_DHTlY#t=84 https://www.youtube.com/watch?v=-77-Z_DHTlY#t=84 ESA says it landed gently on the surface: https://twitter.com/esaoperations/status/532575615527170048 https://twitter.com/esaoperations/status/532575615527170048