... Bad Astronomy . ... Bitesize Astronomy . ... Last week's Snack talked about how black holes can affect the environment around them in such a way as to be very bright . ... It's a common misconception that black holes always have matter swirling into them. ... As this matter gets closer and closer to the black hole it piles up and a large, fairly flat disk forms. This is called the accretion disk , because matter from this disk accretes (that is, falls in) on the black hole. ... 2008 Phil Plait. ...

... Chain of Impact Craters Suggested by Spaceborne Radar Images . ... From space, astronauts often get the impression that the Earth is small with a thin, fragile layer of atmosphere. ... Galileo Earth Encounter . ... The Earth and Moon were imaged by Mariner 10 from 2.6 million kilometers while completing the first ever Earth-Moon encounter by a spacecraft capable of returning high resolution digital color image data. ... During its flight, the Galileo spacecraft returned images of the Earth and Moon....

... 2008 December 30 . Home from Above . Credit: Expedition 18 Crew , NASA . Explanation: There's no place like home . Peering out of the window of the International Space Station (ISS), astronaut Greg Chamitoff takes in the planet on which we were all born. About 350 kilometers up, the ISS is high enough so that the Earth's horizon appears clearly curved . ... The space station orbits the Earth about once every 90 minutes. ... Note : APOD Editor to Speak in New York on Jan. ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... Although the comet itself never comes dangerously close to the Earth, the particles of dust that it has shed during its many past passages through perihelion found their way into the Earth's atmosphere, appearing as meteors in the cold December sky. ... Animation 1 . ... An Ursid meteor captured by the Armagh Observatory's NE-facing meteor camera in the early morning of 23rd December. ... Meteor Showers Online . ...

... Interstellar Dust Bunnies of NGC 891 . ... Photographs released last week showed clouds forming above Tharsis, a huge bulge on Mars about 4000 kilometers across and 7 kilometers high containing several large volcanoes. ... Asteroids . ... When the Moon's shadow reached out and touched the Earth last month, the result was a Solar Eclipse. Such an eclipse is total only for observers located along a narrow path corresponding to the ground track of the shadow's dark central portion or "umbra". ...

... Gift Center . ... Why do aurorae appear strongest within rings centered on Earth's poles instead of filled-in circles? ... RELATED TOPICS: AURORAE . The visible aurorae result from electrons that move along magnetic field lines from space into the upper atmosphere. ... Just make sure you're registered with the website. Get instant access to subscriber content on Astronomy.com! ... If you are already registered on Astronomy.com, please log in below. ...

Four spacecraft: INTERBALL Tail probe (IB_TAIL), Auroral probe (IB_AUR), POLAR(NASA/ISAS), GEOTAIL (NASA) are considered. Click icons to make large pictures. ... FSP criteria | FSP ASCII file | Four spacecraft . in the FSP situations . ASCII file . ... Magnetic conjugations . ASCII files : . ... The mulisatellites conjugations : . ... The FSP polar diagram . Click hear for more detailed information about each of four orbits. ... IKI RAN | SSC IKI RAN | ...

... December 8, 1996 . Degas Ray Crater on Mercury . ... Explanation : Like the Earth's Moon, Mercury is scarred with craters, testifying to an intense bombardment during the early history of the Solar System. ... In the above mosaic the bright rays emanating from the 27 mile wide Degas crater almost appear to be painted on . The rays consist of light colored material blasted out during the crater's formation. Numerous smaller, younger craters are seen superposed on the Degas crater itself. ...

Astronotes Armagh Planetarium's Stellar Blog! ... Space Flight . ... Earth Satellites . ... Leonid meteors seen from 13 km altitude aboard an aircraft during the 1999 Leonids Multi-Instrument Aircraft Campaign (Leonid-MAC). Comet Tempel-Tuttle provides the cometary debris for the Leonid meteor shower. ... Every 17-19 November Earth crosses Tempel-TuttleтАЩs orbit and the Leonids become visible. With clear, dark skies observers may see 10 to 15 Leonid meteors every hour on those mornings. ...

... The material contained in this Handbook is derived from ground tests and design information obtained by the IDT and the engineering team at JPL, and from on-orbit measurements. ... HST Phase II Proposal Instructions , (Version 8.0, 15 December 1995). ... Calibrating Hubble Space Telescope: Post Service Mission (1995).1 . ... The Imaging Performance of the Hubble Space Telescope , Burrows, C. J., et. al., ... The Performance and Calibration of WFPC2 on the Hubble Space Telescope, Holtzman, J., et al....

... Sun images . ... December : 2015 . ... Image of Sun's photosphere obtained 09.12.2015 at 23:40 UT with HMI instrument on board SDO spacecraft . ... Image of Sun's magnetic field obtained 09.12.2015 at 23:28 UT with HMI instrument on board SDO spacecraft . ... Image of Sun's transition region obtained 09.12.2015 at 23:39 UT with AIA instrument on board SDO spacecraft . Image of Sun's corona . Image of Sun's corona obtained 09.12.2015 at 23:39 UT with AIA instrument on board SDO spacecraft . ...

... EXPN DNO D A T E UT TIME FQ SOURCE CORR-Telescopes VT734 355-MO Dec 21 08:00-21:00 C TAU-A Pointing VT735 356-TU Dec 22 08:00-21:00 C TAU-A Pointing VT736 358-TH Dec 24 09:00-20:00 K ORIONKL Pointing VT737 359-FR Dec 25 09:00-20:00 K ORIONKL Pointing VT738 360-SA Dec 26 09:00-20:00 C 0528+134 Mitk-UD KA SH W018c 364-WE Dec 30 06:00-15:00 L 0552+398 Socr-VLBA W071n 6-WE Jan 06 10:00-17:00 L J0745+10 Mitk-AT HO MP UD SH KA W059e 7-TH ...

... In temperate latitudes, this is a good time to see halos formed by clouds of ice crystals high in the atmosphere where the temperature is always well down below -30 deg. ... The most prominent halos, however, appear quite close to the sun where it can be uncomfortably bright to look. ... In a sense, halos are like rainbows, glories and coronae in that they require the presence of a bright source of light, the Sun or the Moon, and water floating in the air. ...

The Many Streams of the Magellanic Stream . ... As a part of the ongoing GALFA survey we have obtained an H I image of a region located at the tip of the Magellanic Stream. ... Figure 1 shows the velocity field of the tip of the Stream. ... Comparison with numerical simulations by Connors et al. (2006) suggests that a 3-way splitting of the main Stream filament may have taken place due to gravitational interactions between the SMC, the LMC, and the Galaxy. ... 2006) . ...

Target: Venus . The Soviet VEGA Spacecraft Two remarkable "busloads" of automated spacecraft were launched toward Venus by the Soviet Union in December of 1984. Each one contains three separate modules: one lander and one balloon-carried atmosphere probe to be dropped off at Venus in June, 1985, and one major package of instruments which will continue on to encounter Halley's Comet in March, 1986. ... Venus and Earth: A Comparison . Earth . ... in Earth days) . ... 243 Earth days . ...

... Articles | ... Forums . ... 230 deg . 49 deg . ... 130 deg . ... More Info . ... 210 deg . ... 168 deg . ... 249 deg . ... 195 deg . ... 271 deg . ... 110 deg . ... 338 deg . ... July 15 . 247 deg . ... 224 deg . ... 340 deg . ... July Phoenicids (PHE) . ... August 10 . 341 deg . ... 339 deg . ... 307 deg . ... 334 deg . ... 335 deg . ... 286 deg . ... 327 deg . ... 262 deg . ... 102 deg . ... 153 deg . ... 117 deg . ... December 2 . ... 123 deg . ... 100 deg . ... www.astronomy.net . ...

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. ...

The program "Pioneer" . Pioneer - 10", the first space vehicle started in March, 1972 to the Jove, has reached . ... This photo of the Jove was received December, 1, 1973 when space probe " pioneer - 10 " has come nearer to a planet on distance 2,5 million km. ... This photo was received by "Pioneer - 11" December, 6, 1974 from distance 1,1 million km from a planet. ... The picture is received in December, 12, 1974 when "Pioneer - 11" was on distance of 1207 thousand kms from the Jove. ...

THE RELATIVE MONTHLY MEAN SUNSPOT NUMBER ON DECEMBER 2013 HAS MADE Wdec.= 61.4, THAT GIVES FOR 42 MONTH (2012, JUNE) DEVELOPMENT CURRENT 24 CYCLES OF SOLAR ACTIVITY THE SMOOTHED MONTHLY MEAN SUNSPOT NUMBER W*june= 61.7 THE BEGINNING 24 CYCLES OF SOLAR ACTIVITY - I 2009 with W*=1.8 THE MOST PROBABLE TIME OF THE MAXIMUM OF THE CURRENT CYCLE- XI.2012 - III 2013 THE MOST PROBABLE HEIGHT OF THE MAXIMUM - Wmax = 66 - 75. ... NEXT WEEK THE LEVEL OF SUNSPOT ACTIVITY IS EXPECTED TO BE THE HIGH AND AVERAGE. ...

Accretion torques in windaccreting pulsars Nikolay Shakura Sternberg Astronomical Institute Moscow, Russia K.Postnov (SAI), D. Klochkov, V. Doroshenko, V. Suleimanov (IAAT), L. Hjalmarsdotter (SAI) December 2010 HEA-2010 1 Outline Introduction: disc and quasi-spherical accretion Settling accretion regime Spin-up/spin-down torques Specific pulsars Conclusions December 2010 HEA-2010 2 I. Disc and quasi-spherical accretion December 2010 HEA-2010 3 Disc accretion Shakura N.I. Astron. ... 2010 15 III. ...