A large asteroid recently flew close to Earth
businessinsider.com
businessinsider.com
http://www.space.com/35265-newfound-asteroid-buzzes-earth-20...
The idea is to ablate material off of one side of the asteroid using lasers and/or mirroring sunlight to redirect its trajectory. This is better than using a nuclear bomb which risks fragmenting the asteroid. If you intercept early enough it doesn't take much of a change in trajectory to miss Earth.
The USA is apparently retiring from the business of all things progressive and space-oriented, so someone else will have to take up the torch. Right now it looks like the only country with the resources and willpower is China.
I hope some states like California can pitch in and save NASA by funding it directly before it's thrown in the garbage.
On the importance... if human civilization discovers the precise nature of the cosmos and no one is around in 100 years capable of learning about it, does it matter?
Given the current political and social climate I think it's a lot more pragmatic to learn how to organize and preserve our knowledge such that it's as easily decoded and readily available as possible on as large a timescale as we can manage.
"Most of our physical tech stack is read-only executable code: there isn't a civilizational "source code" that shows from first principles how to build up to our current technology layer. For that matter, not even from first principles to turn of the 20th century technology level."
https://www.youtube.com/watch?v=PeROEoimj7I
And here's Primitive Technology man:
https://www.youtube.com/channel/UCAL3JXZSzSm8AlZyD3nQdBA
(Should we leave his videos lying around on clockwork tablets?)
There are aspects of NASA that are more partisan, namely the planetary sciences (which, lately, many conservatives dismiss as agenda-driven climate change science). But there is also overlapping support for funding NASA and DOD/DARPA, which you certainly wouldn't consider progressive causes.
There's also no reason to think it will be 'thrown in the garbage'. NASA funding isn't what it was during the the unique political environment of the space race, but it's funding has been fairly steady since the mid-70s. Again, a steady level with no inflections due to partisan control of government.
The bigger problem is mission-specific funding uncertainty, as many of the missions NASA would like to run take 10 years or more -- too long for politicians to benefit from successes, so there is less individual incentive to fund an ambitious challenge like sending humans to Mars.
As they say, when you're a hard right-wing person reality has a left-wing bias.
And I don't see how it's a bad time for space-oriented stuff in the USA - it hasn't been this good for years! What makes you think NASA is going to get defunded?
Nuking an asteroid would likely just bust it up into smaller chunks that are still going in roughly the same direction. Instead of one threat you now have millions.
Most ideas for using nuclear explosives for asteroid redirection don't involve buryingit into the surface, but rather a "stand-off" explosion that occurs some distance from the asteroid's surface. This would massively heat that side of the asteroid and cause a layer to puff off, acting as reaction mass, and not fracturing the asteroid itself.
And if an asteroid really was blown apart into smaller fragments, that would be an improvement. Even a small relative velocity between fragments would spread them out to a much larger area than the earth's diameter, meaning that fewer would probably hit. Also, smaller meteorites are typically much less destructive than larger ones, measured by weight. It's not linear - one hundred meteors of a hundred tons each is basically harmless, but one ten thousand ton meteor can blow a chunk out of a city. Blowing an asteroid into a 'million fragments' would be a job well done.
It also was spotted: A smallish asteroid zoomed past Earth this morning (Jan. 9), just two days after scientists first spotted the space rock.
Even assuming we had perfect alerting and this was a problem, what action should have been taken considering this is a common occurrence?
https://en.wikipedia.org/wiki/Radar_astronomy#Asteroids_and_...
However, I wasn't aware of the optical methods mitchty was referring to.
It's used for high-res imaging of asteroids that pass close by.
https://en.wikipedia.org/wiki/Sentinel_Space_Telescope
Which was sadly cancelled: http://www.dailymail.co.uk/sciencetech/article-3255059/Nasa-...
But the principle was based off infrared: http://aviationweek.com/space/ball-aerospace-ramps-sentinel-...
The canadian satellite also uses light: https://en.wikipedia.org/wiki/Near_Earth_Object_Surveillance...
Visible light is only one fraction of the spectrum, infrared is far more valuable for detection. Most asteroids are detected via passive observation. Radio waves are not conducive to detecting asteroids.
On the other hand, it's still possible that a long-period comet or rogue planet could come out of nowhere and wipe humanity out. Presumably the odds are extremely remote, judging by the rarity of extinction-level events in the geological record.
An asteroid in an elliptical orbit, for example, could be a civilization killer and might currently be undetectably far away right now.
We are missing a lot right now, and we need to spend money on much better surveys.
An object on such a highly eccentric orbit would be classified as a long-period comet, which I mentioned. Yes, you can argue semantics about whether we might still call such an object an "asteroid" if it had a certain composition or primordial origin (which would be extremely unlikely for such an orbit). But there is no sharp division between asteroid and comment composition (it's a bimodal but smooth continuum) and this isn't relevant for the purposes of tracking such objects.
But that's not what I'm disputing. Asteroids routinely have their orbits mucked with by the planets and get thrown into (1) elliptical orbits, (2) non-planar orbits, and (3) ejected. In the first two cases, we aren't even looking for them because there is so much space that it's not worth trying.
Additionally, it is not true that we have found all dangerous NEO asteroids that are in ordinary orbits. NASA is still running a program whose goal is to find 90% of these [1]. For example, in just the past week they discovered a near-Earth object in excess of 1 km [2].
Of course, that's the problem with not knowing what we don't know. If there are any undiscovered, then we really don't know what percentage we know about. The fields of statistics and probabilities can probably prove me wrong, but I'm used to that.
Note that this is if they were to hit Earth. However, the vast majority of objects that size cannot intercept Earth from their current orbit. Please provide data if you have it, but my understanding is that it's considered extremely unlikely for there to be an Earth-crossing asteroid of sufficient size (> 1 km or so).
Given the nature of orbital mechanics the speeds involved are usually staggeringly large. 20km/s sounds like a lot on a terrestrial basis, but in terms of inter-planetary motion that's downright pedestrian. The Earth itself travels 30km/s around the sun, a relatively leisurely pace as it takes a full year to complete but one orbit.
Something the size of a bus travelling at a high enough rate of speed could do tremendous damage. The Tunguska Event (https://en.wikipedia.org/wiki/Tunguska_event) is presumed to have involved an object between 60-190m in size, and that's a fairly tiny object to track at any distance, akin to trying to spot a football field.