... 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 . ...

... Planets . ... The planets were found using the HARPS instrument on the 3.6m telescope at ESOтАЩs La Silla Observatory. ... A planet in orbit around a star causes the star to regularly move towards and away from observers on Earth. ... One newly discovered planet, HD 85512 b, is best hope found so far for a habitable exoplanet. ... The HARPS team so far have found that about 40% of stars similar to own Sun have at least one planet smaller than Saturn (which is 95 times more massive than Earth). ...

... Today this year's largest group of sunspots will cross the Sun's central meridian. ... The next day, the number of spots in the group reached five, and the day after, on June 2nd, it was possible to count thirteen sunspots on solar disk, which had been clear prior to this. ... This year's two most powerful active areas, which passed across the solar disk at the beginning of May, 2009, are set to appear in the Sun's eastern sector in two days, on June 6th. ...

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... Asteroid . ... In case you didn't hear about it, which you probably didn't: On Jan. 7, an asteroid 1,000 feet across -- nearly three times the current diameter of Marlon Brando -- barely missed the Earth, which is most likely your planet of residence. ... What if this asteroid had hit the Earth? ... As it happens, the American Astronomical Society was holding a conference in Washington AT THE VERY SAME TIME as the asteroid nearly hit the Earth. ...

... Behemoth black hole found in an unlikely place . ... black holes . ... Observing springtime deep-sky objects with a large telescope . ... Could large numbers of black holes account for much of the "dark matter" estimated to exist in our universe? ... NASA, ESA, M.J. Jee and H. Ford (Johns Hopkins University) No, because the universe never had the raw material to grow enough black holes to account for current estimates of dark matter. Get instant access to subscriber content on Astronomy.com! ...

... Monitoring a region around the center of our Galaxy, astronomers have indeed found evidence for a surprisingly large number.. ... NGC 7331 and Beyond . ... Spiral galaxy NGC 7331 is often touted as an analog to our own Milky Way. ... Explosions from White Dwarf Star RS Oph . ... The International Space Station on the Horizon . ... Last week, the STS-121 crew of the Space Shuttle Discovery undocked from the International Space Station (ISS) and returned to Earth. ... Mira: The Wonderful Star . ...

... 2011 June 1 . Earth Rotating Under Very Large Telescopes . ... Explanation: Why is the Earth moving in the above video? ... The video dramatically shows the actual rotation of the Earth, called diurnal motion , in a clear and moving way, as if the camera were floating free in space. The telescopes featured in the video are the Very Large Telescopes (VLT) in Chile , a group of four of the largest optical telescopes deployed anywhere in the world. ... About APOD | ...

... 142,800 Mean density (kg/m^3) .. ... 5.203 Rotation period (length of day in Earth hours).. 9.8 Revolution period (length of year) (in Earth years). 11.86 Obliquity (tilt of axis) (degrees).. 3.08 Orbit inclination (degrees).. 1.3 Orbit eccentricity.. 0.048 Mean surface temperature (K)........................ 120 (cloud tops) Visual geometric albedo.. 0.44 Atmospheric components.............................. 90% hydrogen, 10% helium, .07% methane Rings.. ...

... Users . ... Data Collection and Analysis . ... This particular part of the analysis has been disabled since the code is struggling to cope with the number of users seen this year, in particular the large contingent of people who have re-tweeted NASA. ... Order accounts: by user number (effectively random) by number of tweets (includes retweets) by number of followers by number of followers that also tweeted about AAS225 by number of friends that also tweeted about AAS225 . ... by user number . ...