Asteroids and comets come in all shapes and sizes—from small pebbles, to larger SUV-sized fragments, to massive asteroids like Ceres, which has a diameter of about 621 miles. Much of the asteroid material that crosses paths with the Earth burns up when it enters the atmosphere. About once every 100 years, though, a fairly large asteroid strikes the Earth.
But how big does an asteroid need to be to cause major destruction? The new "Impact: Earth!" asteroid impact effects calculator will help you find out. The interactive web tool, developed by a Purdue University research team led by Jay Melosh, allows anyone to calculate the potential damage caused by a comet or asteroid striking the Earth. Users input information into several parameter fields, such as the diameter and density of the object, its angle of entry, and the location where it will hit. The calculator then estimates the impact consequences, providing information about debris distribution, ground shaking, size of the resulting crater, and whether a tsunami will be generated.
About 50,000 years ago, an asteroid about 164 feet in diameter scooped out the famous Barringer Crater (Meteor Crater) in northern Arizona. The new calculator estimates that if an asteroid twice as large as that one struck about 20 miles outside Chicago, it would generate impact energy equal to about 97 megatons of TNT—igniting a fireball with a 1-mile radius and triggering a magnitude-6 earthquake about six seconds after the impact.
The largest known impact threat in Earth's near future is the asteroid Apophis, which scientists say has a small chance of striking the planet in 2036. The new calculator will tell you what will happen if Apophis falls in your backyard, Melosh says.
"Impact: Earth" is an update of an earlier impacts calculator that Melosh created with colleagues at the University of Arizona. The new user-friendly version includes more visual components, as well as calculations of tsunamis that would result from ocean impacts. Melosh is also a science team member on NASA's EPOXI mission, which flew to within 435 miles of the comet Hartley 2 yesterday.
So the website not so great of on droid X stupid keyboard pops up like a mad man all the darn time can't see what is going on other than that it look s like this would be really cool can't wait to try it when of hey home from work
This thing has been at a nearby museum in Massachusetts for a while. It even had the same name!
97 megatons. About the same as Krakatoa, which blocked out the sun for months after it blew. I notice it says nothing about the parameter-relative velocity-nor ice and low density material burnoff. Does anyone know how much in resources is being aimed at defining Apophis' trajectory? It's getting much more important every day, as our only ally on the cosmic pooltable is time. Idiot fantasies like 'Armageddon' where the inertia and trajectory of an object the size of Texas is overcome by one nuke at 800 feet might make good TV; but it seems to me that a repetitive series of nuclear strikes aimed at changing an objects trajectory by altering it's spin would be a likelier scenario, providing we have time.