... 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 . ...

... Planets . ... The planets were found using the HARPS instrument on the 3.6m telescope at ESOтАЩs La Silla Observatory. ... A planet in orbit around a star causes the star to regularly move towards and away from observers on Earth. ... One newly discovered planet, HD 85512 b, is best hope found so far for a habitable exoplanet. ... The HARPS team so far have found that about 40% of stars similar to own Sun have at least one planet smaller than Saturn (which is 95 times more massive than Earth). ...

... 2001 February 4 . Welcome to Planet Earth . Credit: Apollo 17 Crew , NASA . Explanation: Welcome to Planet Earth , the third planet from a star named the Sun . The Earth is shaped like a sphere and composed mostly of rock . ... Earth has a single large Moon that is about 1/4 of its diameter and, from the planet's surface, is seen to have almost exactly the same angular size as the Sun . ... Please enjoy your stay on Planet Earth. ... About APOD | ... NASA Technical Rep.: ...

Lectures . ... Home Lectures Lecture Series 2010-2011 Lecture Series 2010-2011 ? Greening the Earth Using Space Resources? by Greg Matloff . ... Lecture Series 2010-2011 . ... Beyond New York City . ... Observing Resources for Amateur Astronomers - Part 1: Beginning Observers . ... A History of the First Forty Years of the Amateur Astronomers Association . ... Amateur Astronomers Medal . ... 2016 Amateur Astronomers Association of New York Designed by Press Customizr Powered by . ...

... 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 . ...

... Bad Astronomy . ... Bitesize Astronomy . ... Bad Astro Store . ... Slacker Astronomy . ... Keep Bad Astronomy close to your heart, and help make me filthy rich. ... Life Under the Moon . ... Seeing Jupiter's Moons . ... Time Zones and the Spherical Earth . A Companion to the Earth? ... December 19, 1999) . ... Big Moon, Little Moon . ... How Big is the Moon? ... 14, 2000) . ... 2008 Phil Plait. ... Subscribe to the Bad Astronomy Newsletter! Talk about Bad Astronomy on the BA Bulletin Board! ...

... It s because some sunlight bounced off the Earth and dimly lit the side of the Moon that is facing away from the Sun. ... Recently, astronomers used earthshine to help in the search for aliens. Signs of life can be found in the quantities of particular gases in a planet s atmosphere, such as oxygen, ozone, methane and carbon dioxide. And astronomers can work out what gases are in a planet s atmosphere by studying the light that bounces off them their planetshine . ...

... Very good telescopic views of Saturn can be expected in the coming days as the ringed planet nears opposition on March 8th, its closest approach to Earth in 2009. ... Lulin and Saturn near Opposition . ... Tracking through the constellation Leo on February 23rd, bright planet Saturn and Comet Lulin were both near opposition -- opposite the Sun in planet Earth's sky. ... Yesterday, Comet Lulin passed its closest to Earth, so that the comet will remain near its brightest over the next few days. ...

... STScI-PRC99-27 A CLOSER ENCOUNTER WITH MARS Taking advantage of Mars's closest approach to Earth in eight years, astronomers using NASA's Hubble Space Telescope have taken the space-based observatory's sharpest views yet of the Red Planet. ... In these views the north polar cap is tilted toward the Earth and is visible prominently at the top of each picture. ... Dark sand dunes that surround the polar cap merge into a large, dark region called Acidalia. ...

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The Sun is our nearest star and the source of energy for life on Earth. ... For centuries astronomers wondered whether they were clouds floating in the Sun's atmosphere, but we now know that they really are huge regions of magnetic field, about as intense as the field at the poles of an iron magnet. ... Such abrupt events were named solar flares , and what made them especially interesting was that occasionally, after a prominent flare, a magnetic storm would erupt on Earth. ...

... Asteroid . ... In case you didn't hear about it, which you probably didn't: On Jan. 7, an asteroid 1,000 feet across -- nearly three times the current diameter of Marlon Brando -- barely missed the Earth, which is most likely your planet of residence. ... What if this asteroid had hit the Earth? ... As it happens, the American Astronomical Society was holding a conference in Washington AT THE VERY SAME TIME as the asteroid nearly hit the Earth. ...

... A glance at the article might leave you assuming that the planet was discovered using a large telescope at a remote, high-elevation location or perhaps by a multi- billion dollar observatory in Earth orbit. Reading on, you may be surprised to find that astronomers actually discovered the planet with a small telescope located not too far from the city of Tucson, Arizona. ... Well, don't give up, because you can observe interesting celestial sights near low-elevation big cities. ...

... Chapter 4: Solar System Targets > 4.4 Observing Windows [Windows] . ... 4.4.1 Default Target Windows . ... In general, ?windows? which define when the target is visible to HST need not be explicitly identified, since these windows will be calculated by the STScI. ... If the target is a surface feature on a body, the times when the feature is within the field of view of the HST (i.e. the feature is on that part of the body ?facing? ... radial velocity of one body relative to another in km/sec . ...

... The first powerful active areas of the new solar cycle have now come into view from Earth ( video, 4.0 MB ). ... Back on 7 May, two space observatories, STEREO (USA) and TESIS/Coronas-Photon (Russia), simultaneously registered a sharp rise in activity on the eastern edge of the solar disk. ... At the present time, TESIS telescopes are tracking these active areas. ... The TESIS observatory ї TESIS: www.tesis.lebedev.ru . ... The First Powerful Areas of the New Solar Cycle (WMV movie, 4.0 MB) . ...

... 9a. Earth orbits Sun? . ... 10a. Scale of Solar Sys. ... If the mean distance of Earth from the Sun is 1 AU ("Astronomical Unit"), then that of Venus is 0.723 AU, of Mercury 0.387 AU and that of Mars is 1.524 AU. ... By noting (1) where on the Sun's disk is the crossing seen, (2) timing its duration at two far-apart points on Earth, and (3) comparing the times, one can calculate the distance to Venus and from it the scale of the solar system. ... One occurred in 1639--too early. ...

... Research . ... NASA's "follow the water" philosophy has led me to study atmosphere-regolith interactions on Mars in search for locations and times where liquid water is available. ... Transient liquid water and water activity at Gale crater Mars. ... Rivera-Valentin, E. G. , Chevrier, V. F., 2015. ... Icarus , 253, 156-158. Lopez Garcia, E. J., Rivera-Valentin, E. G. , Schenk, P. M., Hammond, N. P., Barr, A. C., 2014. ... Icarus , 237, 419-421. ... Chevrier, V. F., Rivera-Valentin, E. G. , 2012. ...

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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... JSC Oral History . NASA History . ... NASA Oral History Project: Earth System Science at 20 . This NASA Oral History Project features recollections from those who significantly contributed to the launch and evolution of Earth System Science. These interviews were gathered as part of the 20th anniversary of the Earth System Science Program. ... NASA Headquarters, Washington D.C. Program Manager , Stratospheric Theory and Data Analysis, Earth Science and Applications Division . ...