Subscribe free to our newsletters via your
. 24/7 Space News .




IRON AND ICE
The Asteroids Are Coming
by Launchspace Staff
Bethesda MD (SPX) May 04, 2009


Scientists have demonstrated that several large NEO impacts in the past have altered both life and the environment. While the probability of a life-ending impact is low, scientists know that potentially critical collisions are inevitable.

This isn't just "buzz" to get you excited about a new movie coming; we really are being buzzed by asteroids and other NEOs (Near Earth Objects), and one day these conjunctions could become collisions! There are lots of NEOs out there orbiting the sun.

Some, like comets, are less worrisome since they are composed primarily of ice and small, rocky particles that dissipate upon entering Earth's atmosphere. Others, however, like asteroids are thought of as minor planets that are large enough to damage Earth and its environment if an encounter should take place.

Astronomers estimate that there are approximately 1100 near Earth asteroids bigger than one kilometer in diameter and more than one million that are larger than 40 meters in diameter. Those smaller than 40 meters tend to burn up in the atmosphere, but the impact of a 40-meter diameter asteroid is equivalent to a three-megaton bomb! One megaton is the equivalent explosive power of one million tons of TNT.

For comparison, the Little Boy atomic bomb dropped on Hiroshima in 1945, exploded with an energy of about 15 kilotons of TNT.

Larger NEOs of about 2 kilometers in size could impart energies in the category of about a million megatons! Such an impact could result in an "impact winter" with global loss of crops and subsequent starvation and disease.

Large impacts could cause mass extinctions of species. And....scientists know that most of the larger asteroids are as yet undetected! How do we detect, and better yet, deflect such large asteroids?

Eventually, one of these will be spotted. And when that happens, who do we call? Right now there is no one to call, because the world has no defense against pending large asteroid encounters! If this is troubling, here is the bad news.

On March 2 of this year, asteroid 2009 DD45 zipped just 41,000 miles above Earth at a speed of 12 miles per second at its closest point to Earth. Amateur astronomers aided professionals at the International Astronomical Union's Minor Planet Center by providing measurements used in refining calculations of the asteroid's orbit.

But, astronomers did not even detect the asteroid until just a couple of days before it zoomed by Earth; far too late to take any preventative action. This was not an isolated incident as many NEOs come this close to Earth and zip by undetected!

Scientists have demonstrated that several large NEO impacts in the past have altered both life and the environment. While the probability of a life-ending impact is low, scientists know that potentially critical collisions are inevitable. Why are we not doing something to mitigate or hopefully prevent such a catastrophic event?

The answer to this question is complicated. As humans, we focus on potential dangers only when they are imminent, or after the fact.

We react when the danger becomes real and the situation becomes urgent. However, deflecting large asteroids is not easy, simple or inexpensive. We do not yet know how to do it, but we do know it will require early detection and long-term investments on a global scale.

We want to start thinking about ways to protect Earth from NEOs and we need your ideas. Please send them to Launchspace and we will publish the better ideas in future articles.

.


Related Links
Launchspace
Asteroid and Comet Mission News, Science and Technology






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle








IRON AND ICE
Dawn Now Fully Reconfigured With New Software
Pasadena CA (SPX) May 01, 2009
The upgraded Dawn spacecraft is now traveling in a new direction in its orbit around the Sun. The mission continues to go smoothly during this long coasting period, scheduled to conclude in June, when powered flight with the ion propulsion system will resume. Dawn has many computers in its onboard crew and one that serves as the captain of the ship. This primary computer's software had bee ... read more


IRON AND ICE
Lawmakers To Honor Space Pioneers

Indian Lunar Orbiter Sends Back Images To Establish Water Presence On Moon

US scientists plan greenhouses on the Moon

NASA Twin Spacecraft May Reveal Secret Of Lunar Origin

IRON AND ICE
NASA, ESA And A Trip To Mars

NASA Selects Future Projects To Study Mars And Mercury

Focused On Phobos

Spirit problems still baffle scientists

IRON AND ICE
Releases Interactive 3-D Views Of ISS And New Mars Rover

NASA Announces Fiscal Year 2010 Budget

NASA Wins Two Webby Awards

NASA Goddard Space Flight Center Celebrates 50 Years Of Scientific Excellence

IRON AND ICE
China Launches Yaogan VI Remote-Sensing Satellite

China Able To Send Man To Moon Around 2020

China To Launch 15 To 16 Satellites In 2009

Macao Donates 14 Million Yuan To Mainland Space Program

IRON AND ICE
New dinner table top priority as ISS expands

Russian Space Freighter Progress M-66 Undocks From ISS

European-Built Node 3 Starts Its Journey To The ISS

Happy US-Russian crew deny 'divorce in space'

IRON AND ICE
Delta II Launch Successful

Planck Mated With The Ariane 5 ECA Launcher

Base Considers Disassembling Historical Launch Complex

Continental Provides New Tires For Payload Transporter

IRON AND ICE
Some planets may fall into their stars

Super-Earth And An Ocean World

Mass Loss Leaves Close-In Exoplanets Exposed To The Core

Lightest Exoplanet Yet Discovered

IRON AND ICE
Boeing Completes PDR For Tracking And Data Relay Satellite Series K-L

Making The Space Environment Safer For Civil And Commercial Users

Virtual mobility for disabled wins Second Life prize

New Book Highlights Success Stories In Satellite Systems




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement