SoylentNews is people
SoylentNews
Asteroid threats seems only taken seriously when the last close call is fresh in memory. But it didn't last long enough to establish consistent funding. On March 23, 1989, when an asteroid 300 meters in diameter called 1989FC passed within 684 000 kilometers from Earth. New York Times wrote, "In cosmic terms, it was a close call." This event also woke up the powers that were after this arguably close brush with total annihilation. The US Congress asked NASA to prepare a report on the threat posed by asteroids. The document from 1992, "The Spaceguard Survey: Report of the NASA International Near-Earth-Object Detection Workshop," was rather bleak.
If a large Near-Earth Object (NEO) were to hit the Earth, the report said, its denizens could look forward to acid rain, firestorms, and an impact winter induced by dust being thrown kilometers into the stratosphere. After reports from the National Research Council made it clear that meeting the discovery requirement outlined in the Congressional mandate was impossible given the lack of program funding, NEOO got a tenfold budget increase from 2009 to 2014. Yet it still faces a number of difficulties. An audit of the program released September 2014 described the NEOO program as "a one-man operation that is poorly integrated and lacking in objectives and oversight".
Original Submission
(Score: 1) by Absolutely.Geek on Wednesday July 01 2015, @12:39AM
I just did a quick calculation of the kenetic energy of an inro astroid of 300m in diameter traveling at 46000mph reletive to Earth....I was thinking 300m isn't really that big in the scheme of things....turns out that KE=44.5GT of TNT.
This is assuming pure iron (density of 7870kg/m^3). But still even if the density is 1/2 that of iron; we are still talking 10's of GT in energy release for a modest sized impactor. Once the size goes to the km diameter range things look bleak.
Don't trust the police or the government - Shihad: My mind's sedate.
(Score: 3, Interesting) by stormwyrm on Wednesday July 01 2015, @01:50AM
Here's a good link for actual computations: http://www.lpl.arizona.edu/tekton/crater_c.html [arizona.edu]
Your asteroid would make a crater 8 km wide or so. Your energy calculations seem to be a little off though. Kinetic energy is "only" about 10 gigatons TNT (4.45×1019 J) for pure iron. Enough to make an 8 km wide crater where it lands if it hit at a 90° angle. Even if your impactor were only made of ice (1000 kg / m3), we're still talking 1.3 gigatons, still quite enough to cause vast, worldwide destruction.
Numquam ponenda est pluralitas sine necessitate.
(Score: 2) by stormwyrm on Wednesday July 01 2015, @03:34AM
Numquam ponenda est pluralitas sine necessitate.
(Score: 1) by Absolutely.Geek on Wednesday July 01 2015, @10:40PM
Thanks that is a cool calculator. I get about 6GT. Still for a "small" impactor that is devistating.
Don't trust the police or the government - Shihad: My mind's sedate.