Detecting and Deflecting Meteors

Did you give it some thought before uttering such unfounded assertions?

Where your 100% figure comes from, I wonder..

Time frame starting next second and we not knowing that an object large enough to do great harm world wide is coming is pure nonsense..

Also, last object doing such harm was around 65 million years ago.

Why would another one hit the earth within 20 million years?

Something big just struck Jupiter leaving a scar. Should we be serious about developing the means to detect and deflect meteors headed for the Earth, or are we fairly safe?

Brandon9000 wrote:

Something big just struck Jupiter leaving a scar. Should we be serious about developing the means to detect and deflect meteors headed for the Earth, or are we fairly safe?

This is a tough one. The chance that we'll be hit with a catastrophic impact in the near term (few hundred to few thousand years) is relatively small, and given the pace at which technology improves, it might be reasonable just to continue to let our technology improve along multiple lines until it becomes more feasible to actually deflect large objects.

The other thing to consider is that asteroids aren't the only natural disaster which could devastate us, Supervolcano's (like YellowStone Caldera) can be just as bad and possibly more likely in the near term.

It also depends on whether your primary goal is to protect a particular city (population center) from a particular disaster, or whether you are trying to ensure the survival of the entire human race.

If we're trying to ensure human survival then the ultimate strategy is to make sure all our eggs aren't in one basket (everyone living on Earth), which means that our primary thrust should be to colonize near earth orbit, the moon, mars and the moons of jupiter and saturn. Of course if we do that it'll be just our luck to have a nearby Gamma Ray Burst which will fry the entire solar system. It's a big bad universe out there, we'll never be completely safe.

The question is whether we should do something now, yes or no.

Brandon9000 wrote:

The question is whether we should do something now, yes or no.

Well, if that's all I'm allowed to say in this discussion, then I'll have to flip a coin and go with "No".

I'm much more worried about yellowstones caldera than any meteor.

You're allowed to elaborate, but I'd like to keep sight of the topic.

On May 19, 1996 a 300"500 m asteroid, 1996 JA1, passed within 450,000 km of Earth; it had been detected a few days before.

On March 18, 2004 a 30 m asteroid, 2004 FH, passed within 40,000 km of Earth only a few days after it had been detected. This asteroid probably would have detonated in the atmosphere and posed negligible hazard to the surface, had it been on impact course.

On March 31, 2004, a 6 m meteoroid, 2004 FU162 made the second closest approach on record (closest so far was The Great Daylight 1972 Fireball) with a separation of only 1.02 Earth radii from the surface (6,500 km). Because this object is certainly too small to pass through the atmosphere, it is classed as a meteoroid rather than an asteroid.


Path of risk where 99942 Apophis may impact Earth in 2036.In 2004, a newly discovered 320 m asteroid, 99942 Apophis (previously called 2004 MN4), achieved the highest impact probability of any potentially dangerous object. The probability of collision on April 13, 2029 is estimated to be as high as 1 in 17 by Steve Chesley of NASA's Jet Propulsion Laboratory, though the previously published figure was the slightly lower odds of 1 in 37, calculated in December 2004. Later observations showed that the asteroid will miss the earth by 25,600 km (within the orbits of communications satellites) in 2029, but its orbit will be altered unpredictably in a way which does not rule out a collision on April 13 or 14, 2036 or later in the century. These possible future dates have a cumulative probability of 1 in 45,000 for an impact in the 21st century.

Asteroid 2004 VD17, of 580 m, previously was estimated to have a probability of 1 in 63,000 of striking earth on May 4, 2102 (as of July 2006), with risk 1 on the Torino scale, but further observations lowered the estimate. As of the observation on December 17, 2006, JPL assigns 2004 VD17 a Torino value of 0 and an impact probability of 1 in 41.667 million in the next 100 years.

Asteroid (29075) 1950 DA has a potential to collide with Earth on March 16, 2880. The probability of impact is either 1 in 300 or zero, depending on which one of the two possible directions for the asteroid's spin pole is correct. This asteroid has a mean diameter of about 1.1 km. The energy released by the collision would cause major effects on the climate and biosphere and may be devastating to human civilization.

Asteroid 2007 TU24, with an estimated diameter between 300-500 meters, came very close to earth orbit by 1.4 ld (lunar distance) on January 29, 2008. The orbit of the asteroid is shown on NASA's website.