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A Year After Chelyabinsk, NASA Readying Asteroid Response Mission
An anonymous reader sends this NASA report: "One year ago, on Feb. 15, 2013, the world was witness to the dangers presented by near-Earth Objects (NEOs) when a relatively small asteroid entered Earth's atmosphere, exploding over Chelyabinsk, Russia, and releasing more energy than a large atomic bomb. ... NASA is now pursuing new partnerships and collaborations in an Asteroid Grand Challenge to accelerate NASA's existing planetary defense work, which will help find all asteroid threats to human population and know what to do about them. In parallel, NASA is developing an Asteroid Redirect Mission (ARM) — a first-ever mission to identify, capture and redirect an asteroid to a safe orbit of Earth's moon for future exploration by astronauts in the 2020s. ... NASA is assessing two concepts to robotically capture and redirect an asteroid mass into a stable orbit around the moon. In the first proposed concept, NASA would capture and redirect an entire very small asteroid. In the alternative concept, NASA would retrieve a large, boulder-like mass from a larger asteroid and return it to this same lunar orbit. In both cases, astronauts aboard an Orion spacecraft would then study the redirected asteroid mass in the vicinity of the moon and bring back samples."
That will be interesting for amateur astronomers as well. I know I would love to check that out
have you seen my sig? there are many others like it but none that are the same
that almost everybody can agree deserves full funding
Armageddon/Deep Impact 2: NASA mission accidentally brings killer asteroid into collision course with earth. Or maybe a documentary on how NASA is using asteroid winter to cancel out global warming. Carefully done, we can kill only a few million poor folks every once in a while to preserve our precious beach front property.
Strange things are afoot at the Circle-K.
500kt is large ever since people figured out how to actually *hit* anything with the darn things.
Back in the 50ies and 60ies you could easily be off by a mile and they'd still call it a bullseye. A few miles off wasn't unusual at all. That's not because they thought this is good, but because they knew it was the best they could do. Thus, in order to destroy a target you can't hit, you had to get a much bigger bomb in the general vicinity of your target. Because you didn't expect to be hit directly, people started building bunkered silos for their bombs and rockets. In order to destroy those, even if you couldn't expect to hit them, you needed even bigger bombs.
The better the targeting, the smaller the bombs became. Then bunker busters were developed that could not only hit a target the size of a few hundred meters size, they could also bury themselves in the ground by some 50m and explode there, with much greater effect in terms of shock waves. These days, a few 100kt is all you need to destroy anything you want.
In fact, for the most part, you don't need any nuclear weapons to destroy most things out there. Simply because of the accuracy of modern weaponry. Part of this is GPS, but since this is likely the first thing to be destroyed in a big war, people developed inertial guidance and other navigation systems that can do without it. Hence, 500kt is a big bomb these days and people are unlikely to build bigger ones for the foreseeable future. If only because it is much more effective hit several targets with a couple of warheads than just one or two with a big one.