@CM2DD: Ja. vermutlich ist das nur in der Astronomie üblich, wo der Himmel für den Beobachter ja kein dreidimensionales Medium, sondern eine (gekrümmte) zweidimensionale Fläche, auf die alles projiziert wird, ist.
Beginners often have trouble describing distances
on the sky.
http://www.skyandtelescope.com/howto/basics/W...They also made a blink movie of the object showing its motion
on the sky in 3.5 hours.
http://www.skyandtelescope.com/news/3310526.h...Although Venus is currently more than 700 million kilometres from Jupiter, it appears just 2° from the giant planet
on the sky - about four times the width of the full Moon.
http://www.newscientist.com/article/dn16175-r...Their distribution
on the sky could help settle the question of whether the stars were all cast out by the black hole at the centre of the Milky Way, or whether some might have been stolen from a captured dwarf galaxy.
http://www.newscientist.com/article/dn16276-s...Today, we see the faint relic radiation in all directions
on the sky at a temperature of just 3 degrees centigrade above absolute zero, giving a picture of the universe when it was less than one 50,000th of its present age.
http://www.ras.org.uk/news-and-press/72-news2...Rosetta approaches from an area
on the sky at the border between the constellations Leo and Sextans.
http://www.ras.org.uk/news-and-press/89-news2...This robotic telescope network ("RoboNet") would act as a single, fast-reacting telescope, able to observe objects anywhere
on the sky at any time and to follow them 24 hours a day if necessary.
http://www.ras.org.uk/index.php?option=com_co...This map is then used to detect overdensities of galaxies
on the sky which indicate candidate galaxy clusters.
http://aas.org/archives/BAAS/v30n2/aas192/abs...Search for single sources of ultra high energy cosmic rays
on the sky Journal of Cosmology and Astroparticle Physics, 03(2010), 022http://iopscience.iop.org/1475-7516/2010/03/022/Probability for chance coincidence of a gamma-ray burst with a galaxy
on the skyMonthly Notices of the Royal Astronomical Society, 391, 935 (2008)http://onlinelibrary.wiley.com/doi/10.1111/j....Serendipity and the Sloan Digital Sky Survey: Discovery of the Largest Known Planetary Nebula
on the Sky Astrophysical Journal, 599, L37 (2003)http://iopscience.iop.org/1538-4357/599/1/L37/One way to investigate this possibility with the available information is to consider the distributions of the stars
on the sky.
Astronomical Journal, 124, 507 (2002)http://iopscience.iop.org/1538-3881/124/1/507...
