Bill sisk's radar blanker manual (.pdf) . ... ipp : Inter Pulse period. ... A radar blanker synchronizes with the ipp of a radar and generates a blanking pulse that is high while the radar rfi is present in our system. ... The observatory has a radar blanker for the airport "FAA" radar and for the iridium satellites (they can be considered radars since they have an 50% uplink, downlink duty cycle). ... The iridium blank output from the iridium supplied box is synced with the uplink cycle. ...

Sixty-five million years ago, about 70 percent of all species then living on Earth disappeared within a very short period. ... Paleontologists speculated and theorized for many years about what could have caused this mass extinction, known as the K-T event (Cretaceous-Tertiary Mass Extinction event). ... The Alvarez team suggested that the enhancement was the product of a huge asteroid impact. ... Sulfuric acid aerosols may have cooled Earth for years. ... Appendix C ...

Turning the Camera Skyward . A reconfigured camera can take wide-field exposures of astronomical objects (constellations, the Milky Way, zodiacal light, moving artificial satellites, meteor showers, variable stars, etc.) to reveal much fainter objects and structures than seen by naked eye. ... This picture reveals objects more than 2.5 times fainter than can be seen by the naked eye, including not only stars but also the Orion nebula (M42), where new stars are being born. ...

Astronomy Discussion Forums . Forums: . ... Venus Transit - jhuggins - June 3, 2012 - 19:45 UTC . ... New Theory Of Relativity [Nwobu's Effect] - rayhugh - August 21, 2010 - 16:58 UTC . ... Comet 2003/K4 - jaypa - August 5, 2004 - 02:30 UTC . xt8i - leonard - March 9, 2004 - 07:51 UTC . ... Saturn and others - leonard - November 12, 2003 - 06:39 UTC . ... observations of mars - leonard - August 21, 2003 - 03:09 UTC . ... Hi Thom - leonard - August 21, 2003 - 03:23 UTC . ... www.astronomy.net . ...

... Moon . ... Earth Satellites . ... M42 Orion Nebula (M42) showing complete nebulous complex, including M43, and the combined emission/reflection nebulous complex consisting of NGC 1973, NGC 1975, NGC 1977 (left of frame).( ... Our next spooky spectacle is not too far away as its hiding around the right foot of Orion, at the bright blue supergiant star of Rigel shining like a torch in the dark, and this stellar torch lights up a mischievously secret nebula, IC2118 or the Witch Head Nebula ! ...

... Home Articles Observing Resources for Amateur Astronomers ? Part 1: Beginning Observers Observing Resources for Amateur Astronomers ? Part 4: Magazines and Miscellany . ... Observing Resources for Amateur Astronomers - Part 1: Beginning Observers . Observing Resources for Amateur Astronomers - Part 2: Intermediate Observers . Observing Resources for Amateur Astronomers - Part 3: Advanced Observers . Observing Resources for Amateur Astronomers - Part 4: Magazines and Miscellany . ...

... Tonight's Sky . ... Observing . ... Get to Know the Night Sky . ... Get ready for Comet PANSTARRS т?? 2013's first naked-eye comet . ... If predictions hold true т?? never a sure thing when it comes to comets making their first trip through the inner solar system т?? the comet will be a superb object through binoculars and probably an impressive naked-eye sight. ... Although PANSTARRS likely wonт??t get as bright as 1997's Comet Hale-Bopp (pictured) did, it lets us see the major components of a...

... In this talk I will briefly review the constraints posed by the distributions of nitrogen and its isotopes in primitive Solar System materials on its chemical evolution. I will explore the journey of nitrogen and different possible pathways from the interstellar medium through protoplanetary disks to forming planets. ... I will outline our current knowledge of the water vapor and ice distribution in protoplanetary disks. ... Water in the early Earth. ... dust and ice. ... 500K) water vapor. ...

... Recherche dans le site : . Ciel Espace, le magazine qui vous guide toujours plus loin . ... des pages consacr†йes †а la publication de vos photos Mais c'est aussi une vraie communaut†й avec laquelle partager votre passion et nourrir votre curiosit†й. Accueil Un Iridium dans une conjonction Lune-Jupiter . ... Pour savoir comment observer et photographier les satellites Iridium, retrouvez notre article €л La saison des satellites †йtincelants €Ё dans le num†йro de juin de €л Ciel & Espace €Ё . ...

Grazing incidence imaging from 10 to 40 keV Martin Elvis, Daniel G. Fabricant, and Paul Gorenstein The prospects for imaging x rays at energies from 10 to 40 keV with grazing incidence optics are explored. ... The reflectivity of a sample of iridium-coated float glass was measured at small grazing angles (25-5 min of arc) at energies of 8,17, and 26 keV. ... The grazing angle at 30 keV is -10 min of arc. ... At 10-min of arc grazing angle the reflectivity they measured drops sharply beyond 10 keV. ...

Imaging performance of the XMM ­Newton X­ ray telecopes B. Aschenbach a , U. Briel a , F. Haberl a , H. BrЁauninger a , W. Burkert a , A. Oppitz a , P. Gondoin b and D. Lumb ... Giessenbachstrasse, 85740 Garching, Germany b European Space Research and Technology Center, 2200 AG Noordwijk, The Netherlands ABSTRACT The in­ orbit imaging performance of the three X­ ray telescopes on board of the X­ ray astronomy observatory ... XMM­Newton Wolter Type I X­ray telescope characteristics. ...