NEO Objects and Planetary Defense.

[MeteorWayne]

The Planetary Society blog, by Emily Lakdawalla has a link to a 4 part video from
the 2009 Planetary Defense Conference in Granada, Spain, and includes Alan Harris, Aline Zimmer, Ben Rozitis, Christie Maddock, David Morrison, Mark Boslough, Nick Bailey, Rusty Schweickart, Sougata Pahari, Tejal Thakore, Tomohiro Yamaguchi, William Ailor, and Zeljiko Ivezic.

http://www.planetary.org/blog/article/00002229/

I haven't yet watched it, but will do so shortly.

MW

 

[R1]

I liked the 4 parts. My computer does better with youtube, although once on the Planetary Scociety
page, either format is accessible.

Will the WISE infrared scope due to launch as early as next week be used extensively for years to search
and study NEOs? Iirc, WISE is only a six month mission to map the entire sky with
the small 2 or 3 hundred $million infrared satellite. I also recall no mention of WISE in these 4 videos,
but they did mention the building of a new [stationary] observatory in Chile.

 

[MeteorWayne]

IIRC, WISE has a limited lifetime due to it's use of cryogenic fluid to cool the IR detector. It may be able to operate at far reduced ability afterward. There's a thread in Missions and Launches that discusses the Mission and Launch.

 

[neilsox]

Lasers are expensive to put in solar orbit, but perhaps the best planetary defence. In space the effective range may be about one million miles, so we need to orbit about a million of them to deal with all the NEOs. A few lasers give us partial protection from both NEOs and comets. The laser can be traveling a different direction and speed than the potential city damaging asteroid or comet. During the minutes or hours they are within a million miles of each other, the laser can illuminate a small spot on the surface of the asteroid. With sufficient energy density, a depression is vaporized and behaves like a jet or rocket engine propelling the asteroid in the opposite direction, with high efficiency. The thrust is small, but can be maintained for hours or days, if enough lasers come within a million miles. A tiny change in the asteroid direction and/or speed typically changes a likely hit to a likely miss. A larger change and/or more accurate knowledge of the orbit is needed to assure a miss. Neil

 

[R1]

I suggested docking exploration teams with asteroids such as Apophis long ago,
but it seems that those things are travelling too fast for any man made machine.

The laser idea may be the best. I don't understand how multiple spacecraft can affect
NEOs gravitationally if people cannot even catch up with those things.

 

[MeteorWayne]

BTW, the WISE mission launched today will provide a wealth of information about NEOs and Asteroids:

The closest of WISE's finds will be near-Earth objects, both asteroids and comets, with orbits that come close to crossing Earth's path. The mission is expected to find hundreds of these bodies, and hundreds of thousands of additional asteroids in our solar system's main asteroid belt. By measuring the objects' infrared light, astronomers will get the first good estimate of the size distribution of the asteroid population. This information will tell us approximately how often Earth can expect an encounter with a potentially hazardous asteroid. WISE data will also reveal new information about the composition of near-Earth objects and asteroids -- are they fluffy like snow or hard like rocks, or both?

http://www.nasa.gov/mission_pages/WISE/ ... index.html