... 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 . ...

... Hurricane Paths on Planet Earth . ... The above Earth map shows the path of every hurricane reported since 1851, Although striking, a growing incompleteness exists in the data the further one looks back in time. ... The map also shows that hurricanes never cross -- or even occur very near -- the Earth's equator , since the Coriolis effect goes to zero there, and hurricanes need the Coriolis force to circulate. The Coriolis force also causes hurricane paths to arc away from the equator. ...

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... 2012 May 30 . Looking Back at an Eclipsed Earth . Image Credit: PHL @ UPR Arecibo, NASA , EUMETSAT , NERC Satellite Receiving Station, U. Dundee . Explanation: What's that dark spot on planet Earth? ... The above image of Earth was taken last week by MTSAT during an annular eclipse of the Sun. ... The spot moved across the Earth at nearly 2,000 kilometers per hour, giving many viewers less than two hours to see a partially eclipsed Sun . ... About APOD | ...

Besides the Moon, Earth now has many artificial satellites, put up by us earthlings for a variety of purposes. ... In principle, a satellite could then orbit just above its surface. ... Dividing both sides by m shows that the mass of the satellite does not matter, and leaves . ... Any slower and it loses altitude and hits the Earth ("2"), any faster and it rises to greater distance ("3"). ... This is Kepler's 3rd law , for the special case of circular orbits around Earth. ...

Astronotes Armagh Planetarium's Stellar Blog! ... Armagh Planetarium . ... Alien Life . ... Space Flight . Human Exploration . ... Earth Satellites . ... Science Fiction . ... 4 Comments There are cosmic threats to life on Earth.Hiding in the depths of space are things lethal beyond imagining.One day the End will be nigh for real.A forthcoming conference, part of [ ] . ... Here you will find the latest news and views from the fascinating worlds of astronomy and space exploration. ...

... 22.Reference Frames . ... Inertial Forces . 23a. The Centrifugal Force . ... When calculating the motions of the oceans and the atmosphere, it is much easier to use reference points on the rotating Earth and add a centrifugal force to all equations. ... The rest arises because the Earth is not a perfect sphere: the centrifugal force of its rotation causes its equator to bulge out , making the surface there more distant from the Earth s center and thus weakening the gravitational pull. ...

... Bad Astronomy . ... Every few months, one of a series of questions comes up on the USENET group sci.astro involving tides, or the rotation of the Moon, or the recession of the Moon from the Earth. ... Why the Moon's rotation period is the same as the length of time it takes to orbit the Earth (same as number 1, but phrased differently). ... But when this happens, the time it takes for the Earth to rotate once will be slowed to exactly the same time it takes for the Moon to go around the Earth once! ...

... Tonight's Sky . ... The Magazine . ... Star Atlas . ... An artificial comet holds secrets to Earths life . ... Astronomy for Kids . ... Observing springtime deep-sky objects with a large telescope . ... The planet has extreme temperature swings and perhaps active lava flows. ... A digital supplement to Astronomy magazine. ... Join TravelQuest International with Astronomy and Discover magazines on one of three great tour options surrounding this celestial spectacle . ... Astronomy Magazine . ...

The Earth. ... The middle raiding of the Earth is 6371,032 km, the pole 6356,777 km equatorial - 6378,160 km. The Earth surface area is 510,2 mln km^2, 70,8% of which is the World ocean. ... According to the modern cosmogonical views the Earth was formed 4,6 - 4,7 billions years ago from the protoplanet cloud captured by the Sun. ... The Earth is conditionally divided into 3 parts: a bark a cloak and a core (in the centre). The external layer - the bark is 35 km thick. ... Above the Earth. ...

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... Click on this icon if you would like to see a collection of snapshots of actual pages from the "Other Worlds from Earth" Electronic PictureBook. ... The Other Worlds from Earth Electronic PictureBook is a HyperCardЁ stack designed to run on a color MacintoshЁ computer with at least 2.5 megabytes of available RAM, sufficient hard disk space to contain the Electronic Picturebook, System 7.0, and HyperCard 2.1 or HyperCard Player 2.1. ...