... The Round Earth . ... Aristarchus around 270 BC derived the Moon's distance from the duration of a lunar eclipse (Hipparchus later found an independent method). ... Let R be the radius of that circle and T the time it takes the Moon to go around once, about one month. ... Viewed from Earth, a "new Moon" (occuring between the time a thin crescent is last seen before sunrise and the time one is seen shortly after sunset) happens when the Moon in its apparent motion around the sky overtakes the Sun. ...

... Hubble Detects Faster-Than-Light Motion in Galaxy M87 . ... Click on image for larger version. (100kB GIF) Sequence of Hubble images showing apparent motion at six times the speed of light in the galaxy M87. ... The slanting lines track the moving features, and the speeds are given in units of the velocity of light ``c." The images were made between 1994 and 1998 with the Faint Object Camera on the Hubble Space Telescope. ... PHOTO CREDIT: John Biretta, Space Telescope Science Institute. ...

Compilation of distance measurements . HyperLeda home | Documentation | Search by name | Search near a position | ... SQL Search | Search an object in the distance catalogue . This catalog (table a007 in the database) presents the compilation of published distance mesurements using photometric distance indicators. Photometric modulus. Error of modulus measurement. The method used to determine the distance is coded for each measurement as follow: . HyperLeda . ...

. Previous slide . Next slide . Back to first slide . View graphic version .

... This distance is equivalent to 3.26 light years. ... The Universe was now a large place and the intrinsic energy output of the stars had to be huge in order that their light could reach us. ... Newton implicitly assumes space is flat . ... An Orbit in Curved Space This is a prediction made by General Relativity and confirmed by direct observation of Mercury. The Ant Universe in Flat Space . ... Hubble noticed a correlation between recessional velocity and distance. ...

... Posts tagged ?Mahalanobis distance? ... It bears the name of its inventor, Prasanta Chandra Mahalanobis. ... Therefore, under different names, I believe that the Mahalanobis distance is frequently applied in exploring and analyzing astronomical data. ... MADS] Mahalanobis distance? Tags: LDA , MADS , Mahalanobis , Mahalanobis distance , multivariate , outliers , PCA . ... 6 Comments . ... Entries RSS . ... vlk on [MADS] Parallel Coordinates . ... Entries (RSS) and Comments (RSS) . ...

... In 1930, Trumpler noticed that linear diameters (LD) of open clusters increase with distance (D) from the Sun. ... Since that time, the interstellar absorption has become one of the best studied factor in astrophysics, and we may hope that current OCL distance scales are free from this LD-D correlation. To verify if this is the case we have chosen several modern OCL distance scales and test them with the same clusters and the same angular diameters that Trumpler had used back in 1930. ...

. Winds speeds on the platform. Polarized power from the panels. Rfi . Standing waves created by moving the tiedowns. standing waves can ruin observations but they are great tools for measuring distance (if you can generate an artificial src). Oscillations in the platform. previous first

... Home Education Classes AAA Winter Astronomy Class: Measuring Distances in Space тАУ Dec 2015 тАУ Feb 2016 . ... Classes . AAA Fall Astronomy Class: Astronomy Basics тАУ October-November 2015 . AAA Winter Astronomy Class: Measuring Distances in Space тАУ Dec 2015 тАУ Feb 2016 . AAA Spring Astronomy Class: The Physics of Astronomy тАУ February - March 2016 . ... This MonthтАЩs Sky тАУ April 2016 . ... Dec. ... Observing Resources for Amateur Astronomers - Part 1: Beginning Observers . ...

Hipparchus (and possibly Aristarchus before him) also derived the Moon's distance from the duration of a lunar eclipse . Because the Earth casts a much larger shadow than the Moon, such an eclipse usually darkens the entire Moon, for several hours. ... If the Sun is assumed to be very distant, and if the Moon crosses the middle of the shadow (if not, corrections must be made), the width of the shadow is expected to be about 2r , twice the Earth's radius r . ... Last updated 4 February 1999 Moon. ...