... 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 . ...

M1 image More About M1 Nice Color Picture . ... M16 image More About M16 HST image . ... M31 image More About M31 Nice Color Picture . ... M42 image ; M43 image More About M42/43 Nice Color CCD Picture . M51 image More About M51 Color Image of M51 M51 Supernova . M57 image More About M57 Nice Color CCD Picture Very Deep M57 Image . ... M81 image More About M81 M81 Supernova Ultraviolet Image of M81 More about Ultraviolet Imaging . M82 image More About M82 M82 False Color M82 True Color . ...

... Indeed, one alteration of orbits can be the outright ejection of a planet. When several big planets are orbiting a star under each other's influence, the system is inherently unstable. ... We know of no good reason why the smallest objects with fusion should have the same mass as the smallest objects that can form by themselves. ... 6) Mission Definition . ... I don't think this mission is impossible, and will suggest a definition in a future article in Mercury. ... Good luck! . ...

... Credit: M. Brown ( Caltech ), C. Trujillo ( Gemini ), D. Rabinowitz ( Yale ), NSF , NASA Explanation: Is that a tenth planet? A faint, slowly moving dot discovered by computer shows clear signs of being a deep Solar System object at least as large as Pluto . The object, designated 2003 UB 313 , is currently situated nearly 100 times the Earth-Sun distance -- over twice the average Pluto-Sun distance. ... Since 2003 UB 313 is surely not completely reflective , it could be substantially larger. ...

Astronotes Armagh Planetarium's Stellar Blog! ... Armagh Planetarium . ... Our Galaxy . ... Stars . ... Space Flight . ... This activity is believed to be promoting the unusually high rate of star formation seen in M82. ... Radio image of M82 made with the MERLIN and VLA telescopes. Insets show MERLIN images from April 25th and May 3rd 2009 demonstrating the sudden appearance of the mystery object.€а All images are at a frequency of 5 GHz. ... Mystery object in Starburst Galaxy M82 . ...

... Bad Astronomy . ... Bitesize Astronomy . ... If you thought our tour of the solar system ended with Neptune and Pluto, you are setting your sights way too low. The planets of the solar system mark time relatively close to the Sun compared to interstellar space. Pluto orbits the Sun at an average distance 40 times that of the Earth, yet the nearest star (the Alpha Centauri system) to the solar system is a mind-numbing 260,000 times the distance of the Earth to the Sun. ... 2008 Phil Plait. ...

Discover the cosmos! ... 2005 July 31 . Solar System Object Larger than Pluto Discovered . ... A faint, slowly moving dot discovered by computer shows clear signs of being a deep Solar System object at least as large as Pluto . The object, designated 2003 UB 313 , is currently situated nearly 100 times the Earth-Sun distance -- over twice the average Pluto-Sun distance. ... Since 2003 UB 313 is surely not completely reflective , it could be substantially larger. ... About APOD | ...

The elements of the numbered minor planets are given with respect to the ecliptic and equinox J2000.0. ... In the Table these values are given to 0.01. ... A dash indicates that there is no opposition in 2015. 1 a.u., 1.017 a.u. 1 a.u., q <= 1.017 a.u.), At stands for Aten type ( a . ... It should be noted that all objects included into the Tables of NEAs, Centaurs and transneptunian objects, and some unusual planets can be also found in the Table of elements and opposition dates of all minor planets. ...

... Ever wonder how solar-mass stars form?. ... In order for material to accrete onto a protostar it has to lose angular momentum. The angular momentum of a large natal cloud leads to the formation of a circumstellar disk and inner accretion disk as the cloud collapses. ... Winds generated in the inner disk or close to the stellar surface (we don't know which) expel material along the disk rotation axis. ... This provides the highest resolution observational data on nearby young stars. ...

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 ...

... Tonight's Sky . ... The Magazine . ... Observing . ... Magazine . ... 50 Weirdest Objects . ... The double star 54 Leonis, spiral galaxy NGC 3198, and emission nebula NGC 3199 . ... Astronomy for Kids . ... Observing springtime deep-sky objects with a large telescope . ... Weird Object: Pulsar Planets . ... Get instant access to subscriber content on Astronomy.com! ... Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter. ... Astronomy Magazine . ...

... For moving objects such as asteroids, comets, or planets, it is useful to include ephemeris information, both to provide predicted coordinates for planning observations, and to allow accurate airmass calculations in the reductions. ... These times can be given either as Modified Julian Dates ( ), or as ordinary date strings like 1995 Jan 23.0 . To allow good interpolation, include two ephemeris entries before and two after the interval of observations. ... UT date --- column label: DATE . ...