Posted on 02/23/2016 4:25:38 PM PST by BenLurkin
It is believed to have exploded about 18 miles (30km) above the Atlantic Ocean, 6 miles above the troposphere, the atmospheric layer where the Earth's weather occurs.
It is unlikely that anyone saw it, but it was probably picked up by the military, who record atmospheric explosions.
"Impacts like this happen several times per year on average, with most going unseen," Plait said.
It's the much larger impacts that we should be worried about.
Nasa tracks around 12,992 near-Earth objects which have been discovered orbiting within our solar system close to our own orbit.
It estimates around 1,607 are classified as Potentially Hazardous Asteroids.
In September, Paul Chodas, manager of Nasa's Near-Earth Object office at the Jet Propulsion Laboratory in Pasadena, said: "There is no existing evidence that an asteroid or any other celestial object is on a trajectory that will impact Earth.
"In fact, not a single one of the known objects has any credible chance of hitting our planet over the next century."
One such asteroid is 2013 TX68, which poses no threat to Earth, but could get very close to the surface, according to the space agency - although it adds there is a very slim chance of this happening.
(Excerpt) Read more at dailymail.co.uk ...
Chelyabnsk OKski
Great.
I just finished watching 1953’s “The War Of The Worlds.”
I wonder if this mean we are doomed are going to be doomed? An Omen?
Why thanks. Thirty six years on it. Thanks to all the tax payers that payed me too.. :>) It was a lot of fun and a lot of hours and a lot of work.
Another ERMA?
(Easily Recognizable Military Acronym)
You’re welcome for every tax dollar you got from me.
That would probably be one. Penny.
Earn small, pay small! ;^)
I’m glad you enjoyed it. Doing something you love is best.
I enjoyed being a fan and a spectator of the shuttle.
MIL-TFP-41
March 5 is the next known close approach-—asteroid 2013 TX68.
Perhaps you would like us to wave our hands in the air while running in little circles?
Don't fret about the misses. It is the one you don't hear about that gets you.
“In fact, not a single one of the known objects has any credible chance of hitting our planet over the next century.”
But the ones we don’t know about...
After reading your link, decided to Google “images of earth temperature charts for past million years.” Unfortunately, only a few of these charts cover one million years. A lot only go to 400K or 800K or many millions of years. The second link shows one specific chart and it’s site which does cover 800K. [I wish I knew how to transfer over these graphics to FR comments.] Interestingly, there is a strong drop right were one would expect with your linked article. Also interesting is the unusually low drop in atmospheric CO2 (orange line). My question: What is it that causes the periodic drops approximately every 100K years? It looks like we might be due for one soon (10K year+-).
There’s been a lot of time and cash expended on trying to find periodicity and repeating phenom. in the paleontological record, in proxy climate data, that kind of thing. I don’t think of it as a productive use of resources, insofar as there *is* no pattern to (for instance) big impacts.
The objects themselves have random masses, and various origins, which means, over time, their orbits will evolve differently. Every once in a while one crosses paths with the Earth, and if the mass is right, Earth gives it the old come-hither, and *boom*. Same goes for other large bodies, which are more likely to bump into something, just because they’re a tad wider target.
CO2 levels in the Antarctic ice cores (for instance) show that the CO2 levels *rise* a century or more *after* the warming, meaning that the increase in temperature permits more biological activity of all kinds, and voila.
> A geomagnetic reversal is a change in a planet’s magnetic field such that the positions of magnetic north and magnetic south are interchanged. The Earth’s field has alternated between periods of normal polarity, in which the direction of the field was the same as the present direction, and reverse polarity, in which the field was the opposite. These periods are called chrons. The time spans of chrons are randomly distributed with most being between 0.1 and 1 million years[citation needed] with an average of 450,000 years. Most reversals are estimated to take between 1,000 and 10,000 years. The latest one, the Brunhes-Matuyama reversal, occurred 780,000 years ago; and may have happened very quickly, within a human lifetime.[1] A brief complete reversal, known as the Laschamp event, occurred only 41,000 years ago during the last glacial period. That reversal lasted only about 440 years with the actual change of polarity lasting around 250 years. During this change the strength of the magnetic field dropped to 5% of its present strength.[2] Brief disruptions that do not result in reversal are called geomagnetic excursions.
https://en.wikipedia.org/wiki/Geomagnetic_reversal
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