... 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 . ...

nearneighbor - A Nearest neighbor gridding algorithm nearneighbor [ xyzfile ( s ) ] -G out _ grdfile -I x _ inc [ m|c ][/ y _ inc [ m|c ]] -N sectors -R west / east / south / north [ r ] -S search _ radius [ m|c|k|K ] [ -E empty ] [ -F ] [ -H [ nrec ] ] [ -L flag ] [ -V ] [ -W ] [ -: ] [ -bi [ s ][ n ] ] nearneighbor reads arbitrarily located (x,y,z[,w]) triples [quadruplets] from standard ... Default is quadrant search, i.e., sectors = 4]. ... H Input file(s) has Header record(s). ...

... The concerns here are similar to those for observing bright targets; saturation and blooming of the bright companion PSF must not impact the faint target. Also, one may need to consider subtracting the PSF of the bright object, and effects which limit the accuracy of that subtraction. If the bright companion will saturate and bloom, it will be necessary to rotate the CCD so that blooming along the CCD columns does not obliterate the faint target. ...

... NASA's Hubble Space Telescope offers a stunning unprecedented close-up view of a turbulent firestorm of starbirth along a nearly edge-on dust disk girdling Centaurus A, the nearest active galaxy to Earth. A ground-based telescopic view (upper left insert) shows that the dust lane girdles the entire elliptical galaxy. This lane has long been considered the dust remnant of a smaller spiral galaxy that merged with the large elliptical galaxy. ...

Next: Column label: MOONE Up: MOUNTING= 'FORK' Previous: Column label: DEC . The values in this column are the corresponding hour angles of the eastern ``observation'' limits, in decimal degrees. ... Most telescopes read out hours and minutes instead; these should be acceptable inputs to the table-making program, which should do the conversion. ... In some cases, hour angles east of the meridian are read as negative values; in other cases, values will lie between and ( and ). ...