Asteroid and Comet Impact Hazards

Calculate NEAR's ephemerides for your location during its Jan 22-23 close-encounter with Earth using JPL's on-line system via telnet. (Jan 20, 1998)

• Overview
• Latest news / hot topics
  (as of Jan-22-1998)
• The Spaceguard Survey Report (1992)
• Congressional testimony (1993)
• Congressional statements
• AIAA Position Paper
• List of all known NEOs with orbital elements
• List of future close passages of NEOs
• Report of the NEO Survey Working Group
• Further reading
  
  • NEO impact bibliography of basic references
  • Reviews of recent books
  • Was TWA flight 800 hit by a meteorite?
  • Asteroid and Comet Impact Fact Sheet

Images and Animations

NASA (and others) images of Impacts!

NASA "USE" policy for images/etc.

Related Web Sites

The Space Shield Foundation is a totally private, non-commercial Foundation organized in Russia with international participation. It was established in 1994 mainly as Russian public foundation to promote, support and provide scientific research and technology development on hazards due to space objects (asteroids and comets) impact with the Earth and protection of the planet against such impacts.

LONEOS: The Lowell Observatory Near-Earth Object Search

LONEOS is a system designed to find Earth-crossing asteroids (ECAs) and comets (ECCs), collectively known as near-Earth objects (NEOs). These objects can occasionally collide with Earth sometimes with devastating consequences. Finding large NEOs is the first step in averting a collision.

Space Resources

This is on Space Resources, which is not directly our subject, but it looks like a good page for general NEO stuff.

Near-Earth Asteroid Tracking (NEAT)

NEAT is an autonomous celestial observatory located at the USAF/Ground-based Electro-Optical Deep Space Surveillance (GEODSS) site on Haleakala, Maui, Hawaii. NEAT is a cooperative effort between the National Aeronautics and Space Administration/Jet Propulsion Laboratory and the United States Air Force. It is designed to complete a comprehensive search of the sky for near-Earth asteroids and comets.

Spaceguard UK

At the end of June a proposal concerning the establishment of a coordinating office to study the threat posed to the United Kingdom by the possibility of an impact by an asteroid or a comet was sent to the Minister for Science and Technology and to the Secretary of State for Defence.

The International Workshop Tunguska96

The main purpose of this workshop is to allow scientists from both Western countries and Russia to meet in order to;
1. Assess our current understanding of the Tunguska event as resulting from field research;
2. Review models of the presumed extraterrestrial impact event and inferences about the nature of the projectile body;
3. Discuss the implications of Tunguska on the broader issue of the impact hazard for human civilization. Thus, the program of the workshop has been planned in three day-long sessions.

The Spaceguard Foundation

An association aimed at the protection of the Earth environment against the bombardment of objects of the solar system (comets and asteroids).

Scott Hudson: Asteroid Shapes

In recent years Dr. Steven Ostro of JPL has been able to capture some remarkable delay-Doppler radar images of Earth-crossing asteroids. The best way to get at the information they contain is to use them to form 3D-shape and spin-state models.
Detailed models include:
• 4769 Castalia
  
• 4179 Toutatis
  
• 1620 Geographos (work in progress)
  
• 1991 JX (work in progress)
  

The ABCs of Near-Earth Objects:

Getting to Know Earth's Neighbors (Planetary Society)

What are NEOs? Where do they come from? Do they pose any real threat to Earth? Can they provide viable space resources? All of these questions are now under investigation by planetary scientists.

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The Minor Planet Center

"The MPC is responsible for the collection and dissemination of astrometric observations and orbits for minor planets and comets."

The European Asteroid Research Node (EARN)

"EARN is an informal association of European research groups active in asteroid research. The idea behind this service is to provide a means for easy and fast communication, exchange of data and other information in both observational and theoretical research on asteroids."

Terrestrial Impact Craters

• Subjects include:
  • Terrestrial Impact Craters
    
    • Introduction
      
    • Views of Terrestrial Craters
      
  • Terrestrial Crater Impact List
    
  • Educator's Guide to Impact Craters
    
  • James River, Alberta - Possible Meteorite Impact Crater
    

"Space Telescope Science Institutes'

Comet Shoemaker-Levy 9 Encounters Jupiter"

"..... includes data from the Hubble Space Telescope and other observatories as well as other materials such as simulations and text."

Related Web Pages

A paper by Clark R Chapman. (Southwest Research Institute)

THE SPACEWATCH PROJECT

Under the direction of Dr. Tom Gehrels the University of Arizona's Spacewatch Observatory is now discovering about 2 to 3 near-Earth asteroids (NEAs) per month.

The Impact Catastrophe

"...Theories about 'what happened to the dinosaurs' abound as researchers from many fields attempt to hone in on one of the great mysteries of our planet. Artist Bill Hartmann, a renowned planetary scientist in his own right, has captured one of the most plausible and exciting theories in a series of original paintings....."

Space Mechanics Group: Near Earth Objects

"....The objects (asteroids, comets, meteoroids) whose orbits cross the orbit of the Earth are studied from different points of view."

The KT Event

"....Sixty-five million years ago about 70% of all species then living on Earth disappeared within a very short period. The disappearances included the last of the great dinosaurs. Paleontologists speculated and theorized for many years about what could have caused this mass extinction, known as the K-T event (Cretaceous-Tertiary Mass Extinction event)."

Collisions with Earth

"....A 10-m body typically has the kinetic energy of about five Hiroshima fission bombs, however, and the shock wave it creates can do considerable damage even if nothing but comparatively small fragments survive to reach the ground."

The Collision of Comet Shoemaker-Levy 9 with Jupiter

"... Each explosion produced a plume that reached thousands of kilometers above the cloudtops, placing the plumes far above Jupiter's limb and into direct view from Earth. ..... When the plumes fell back on the atmosphere they were reheated. Embedded dust glowed brightly in the thermal infrared for a period of order ten to twenty minutes, producing the spectacular infrared events seen on Earth."

"Comet Busters"

"....Fortunately, we have more at our disposal than panic in dealing with an intruder from outer space. For the first time in earth's history, one of its species is capable of doing something about an approaching juggernaut, rather than simply taking it like a dinosaur."

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