... 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 . ...

Russian SHAREABLE DATA CENTER Institute of Solar-Terrestial Physics SB RAS . ... Chirp ionosonde main technical characteristics . ... Linear frequency modulated continuous signals sounding method is relatively simple and has wide application in various special-purpose systems. ... Chirp signals which are applying for ionosphere channel diagnostics usually have10KHz/s -- 1MHz/s. We must point out that under modulation speed increasing there is an increase in noise suppression and resolution power. ...

... Arecibo Observatory took radar images of asteroid 1998 QE2 and its moon as the space rock sailed safely past earth. ... Both the asteroid and its moon passed 6 million kilometers (3.8 million miles) from earth. ... Radar images of asteroid 1998 QE2 (bottom) and its satellite (top) on June 6. ... Radar images of asteroid 1998 QE2 (center) and its satellite (bottom left) on June 7. ... Radar image from June 7 showing the satellite moving past the primary. ...

... HST Phase II Proposal Instructions for Cycle 20 > Chapter 4: Solar System Targets > 4.5 Ephemeris Center [Ephem_Center] . ... HST?s on-board software then computes a correction for the parallax induced by the telescope?s orbit. ... However, HST?s on-board parallax correction may be insufficient for a target closer than 3.8 million kilometers. ... An HST-centric target ephemeris is generated. ... An HST-centric ephemeris should be specified only for very close targets such as the Moon. ...

.

... 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? ...

Astronomy Picture of the Day . ... Alpha Centauri: The Closest Star System . ... The closest star system to the Sun is the Alpha Centauri system. ... The bright stars Alpha Centauri.. The Shuttle Launches an Inflatable Antenna . ... In the Center of 30 Doradus . ... In the center of 30 Doradus lies a huge cluster of the largest, hottest, most massive stars known. ... The largest, most violent star forming region known in the whole Local Group of galaxies lies in our neighboring galaxy the LMC. ...

... 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 . ...

... 8, ``Celestial Mechanics'', 2002 High orbit for the RadioAstron project N. S. Kardashev, B. B. Kreisman, Yu. N. Ponomarev Astro Space Center of the Lebedev Physical Institute, Moscow, Russia RadioAstron project is an international collaborative mission to launch a free flying satellite carrying a 10­meter radio telescope in elliptic orbit around the Earth [1,2]. ... For RadioAstron mission it is proposed to use one K­band circular polarized chan­ nel at fixed frequency 22.232 GHz. ...

An astronaut in low Earth orbit moves in (approximately) a big circle extending around the Earth. ... That can be interpreted as stating that in the astronaut's frame of reference, all bodies are subject to two forces, gravity and the centrifugal force, and the two are in perfect balance, adding up to zero. ... Wheel-shaped space . ... The science-fiction film "2001: A Space Odyssey" featured spinning space station, whose rotation provided the crew with "artificial gravity." ...

... Pre-university education . ... Samara region . ... A small spacecraft Aist-2D , developed by the scientists of Samara State Aerospace University (SSAU) and the experts of the Rocket and Space Centre Progress will see from outer space what is hidden under the thick top of trees and below the Earth's surface. The radar equipment was installed on Aist-2D , which was delivered to the space launcher complex Vostochniy on January 22. ... Tomography of the Earth's ionosphere will also be carried out. ...

... PUL VLBI Analysis Center . ... Pulkovo EOP and Reference Systems Analysis Center (PERSAC) is located at the Pulkovo Observatory . ...