... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... Risks Comparable to NEOs . ... The Increasing Rate of Discovery of Asteroids . ... Comet and Asteroid Collision Probabilities . ... Extreme albedo comets and the impact hazard (PDF Format) . ... Asteroid Impact Animations . ... Workshop on Scientific Requirements for Mitigation of Hazardous Comets and Asteroids - 2002 . ... The Spaceguard Survey Report, 1992 (PDF) . Tsunami from Asteroid/Comet Impacts . ...

... Credit: J. Aasland , Norway Explanation: Does a comet's dust tail always orbit behind it? Since comets rotate, they shed gas and dust in all directions equally. Small ice and dust particles expelled by the comet, however, are literally pushed around by sunlight. ... When the comet is headed inward, sunlight slows down small particles so they orbit behind the comet. When the comet is headed back out though, sunlight speeds them up, so small particles orbit in front of the comet. ...

... April 3, 1997 . Earth, Clouds, Sky, Comet . ... Explanation : Does a comet's dust tail always orbit behind it? ... Small ice and dust particles expelled by the comet, however, are literally pushed around by sunlight. ... When the comet is headed inward, sunlight slows down small particles so they orbit behind the comet. When the comet is headed back out though, sunlight speeds them up, so small particles orbit in front of the comet. ... About APOD > . ...

... Planets . ... Earth Satellites . ... The newly discovered ?mega-Earth? ... Its sibling, the lava world Kepler-10b, is in the background (the two planets? proximity is grossly exaggerated) .€а Kepler-10c has a diameter of about 29 000 km, 2.3 times as large as Earth, and weighs 17 times as much. ... The first mega-earth to be discovered is Kepler-10c which orbits a star lying about 560 light years from the Sun in the constellation Draco. ... Astronomers Find a New Type of Planet: The ?Mega-Earth? ...

Classroom Activity: A Viewgraph Comet . ... This will simulate the Earth's orbit around the Sun. ... Draw several comets along the path with their tails pointing away from the Sun. ... You can create other viewgraphs that have a smaller scale and show several comet orbits or constellations. ... Show how the Earth's orbit is almost circular compared to the comet's. Explain that the Sun is at the focus of the orbits of the planets, asteroids, and comets. ... Actually, comets have two tails. ...

Image credit: Michael Nolan, Arecibo Observatory. These radar images of near-Earth asteroid 2001 SN263 were obtained on 2008 Feb 12 and 13. ... Image from Feb 12 . ... First near-Earth triple asteroid discovered by Arecibo Observatory . ... was discovered this week by astronomers at the sensitive radar telescope at Cornell University?s Arecibo Observatory in Puerto Rico. ... For example, Arecibo has discovered more than half of the near-Earth binary asteroid systems discovered since 1999. ...

The AstroGuide . ... AstroGuide | ... AstroGuide Listing . ... See many more Astronomy Listings by: Category or Alphabet . This project was established in mid-1998 to help coordinate, and provide a focal point for, the study of those comets and asteroids that can approach the Earth's orbit. ... Web Site . ... Unless otherwise specified, web site content Copyright 1994-2016 John Huggins All Rights Reserved . dbHTML," "AstroGuide," "ASTRONOMY.NET" & "VA.NET" . are trademarks of John Huggins ...

... An artificial comet holds secrets to Earths life . ... Supernova showered Earth with radioactive debris . ... Get to Know the Night Sky . ... What is the chance that Earth could pass through the debris field of Comet ISON (C/2012 S1) and get a meteor shower? ... RELATED TOPICS: COMET ISON | COMETS | ... Earth already has passed through Comet ISON s debris field which occurred around January 12, 2014 but no one detected a meteor shower. ... Get instant access to subscriber content on Astronomy.com! ...

Comet C/2006 P1 (McNaught) . ... COMETS . In 2008 the 42 periodical comets will return to perihelions. Comet C/2004 Q2 (Machholz) . ... Comets 8P/Tuttle and 17P/Holmes (at right) . ... Time . ... 1.00 . ... Feb. 2 . ... P/2006 F1 (Kovalsky) . ... P/2001 Q5 (LINEAR-NEAT) . ... P/2000 B3 (LINEAR) . ... 11P/Tempel-Swift-LINEAR . ... P/2001 CV 8 (LINEAR) . ... Note: All time moments are given in Universal Time (UT) units. For Kyiv Local_Time=UT+2 h (and Local_Time=UT+3 h for summer time). ...

... 2000 March 25 . The Earth Also Rises . Credit: The Lunar Orbiter Project , NASA . Explanation: The Lunar Orbiter 1 spacecraft was launched in 1966 to map the lunar surface in preparation for the Apollo moon landings . NASA's plucky robotic explorer performed its job well and pioneered this classic view of the Earth poised above the lunar horizon. The first humans to directly witness a similar scene were the Apollo 8 astronauts . ... About APOD | ... NASA Technical Rep.: ...

... Listed below are questions submitted by users of "The Great Magnet, the Earth" and the answers given to them. ... In "The Exploration of the Earth's magnetosphere" on the magnetic environment of the Earth in space (a few Q duplicated here) . ... 11) Magnetic Shielding . ... 51) Can electricity be generated from the Earth's magnetic field? ... 9) Measuring Earth's magnetic field . ... 6) Reversals of the Earth's field (4 queries) . ... 42) Could generated electricity affect Earth's magnetic field? ...