Asteroid Itokawa

[yevaud]

<b>The Falcon Has Landed</b><br /><br />Joanne Baker<br /><br /><i>Killer asteroids are the stuff of science fiction movies, but the threat from near-Earth asteroids, at least in the long term, is real. Asteroids are small solid bodies, hundreds of meters to many kilometers in size, with rocky, perhaps icy, surfaces. Understanding of what and how they are built may not only someday help us deflect or destroy one on a collision course with Earth, but tell us how Earth was formed. Asteroids preserve within them detritus left over from the debris disk out of which the planets grew some 4.5 billion years ago. Since then, most asteroids have suffered collisions and impacts and often show the scars. Some can even be linked to collected meteorites that were ejected as a result.<br /><br />Enough has been learned about asteroids to group and classify them, but basic questions about their formation remain. Overall chemical compositions can be determined from spectroscopy with ground-based telescopes and compared with meteorite samples, but morphological information requires a closer look. The first close-up pictures of lumpy asteroids Ida and Gaspra were snapped by Galileo on its way to Jupiter, and Eros' weathered surface was probed by NASA's Near Earth Asteroid Rendezvous (NEAR) Shoemaker spacecraft in 2001.<br /><br />The next step requires technically challenging missions designed to land on and return samples from a variety of asteroids. The Japanese Hayabusa mission is the trailblazer. Launched in May 2003 and propelled by an ion-drive engine, in September 2005 Hayabusa reached asteroid Itokawa, a tiny rocky asteroid just 500 m across, whose elliptical orbit crosses the paths of both Earth and Mars.<br /><br />The Hayabusa spacecraft ("hayabusa" means falcon) hovered 20 km above the asteroid and, in November 2005, swooped down to perch for about 30 min on its surface. Whether it managed to grasp any rocks in its robotic talon is not yet known, as the mission scientists had to wr</i> <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[CalliArcale]

I do hope Hayabusa makes it. It would be lovely if the tremendous perseverance of the mission team could pay off. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>