Princeton Montage

This montage of images shows various astronomical objects at their correct relative sizes as seen from Earth. The Moon, which is small and close to Earth, appears many times larger than the Tadpole Galaxy, which is huge but far away from Earth.

A low resolution version (754 x 1000 pixels) and a medium resolution version (4600 x 6100 pixels, 100 dots per inch) in JPEG format can be found below. The individual images are provided in the next section.

I created this montage for the Princeton University Department of Astrophysics. The high resolution version will be printed out at a size of 46 inches wide by 61 inches high and displayed in their entrance foyer, next to another large mural (at the same angular size) of data from the Sloan Digital Sky Survey.

64 kb
download 		Princeton Montage - Low Resolution JPEG Version

868 kb
download 		Princeton Montage - Medium Resolution JPEG Version
  • File: full_montage_04_100dpi.jpg
  • File size: 868 kilobytes
  • Size in pixels: 4600 x 6100 pixels
  • Resolution: 100 dpi
  • Size in inches: 46 inches x 61 inches
  • File format: JPEG image

Credits:

Moon Image: T.A. Rector, I.P. Dell'Antonio (NOAO / AURA / NSF)
All Other Images: Hubble Space Telescope (STScI / AURA / NASA)
Panel Design and Graphics: J.R. Gott (Princeton) and F.J. Summers (STScI)

A Note on Angular Size

Astronomers use a measure of "angular size" to describe how large an object appears. As its name implies, angular size is an angle measured in degrees (remember that there are 360 degrees in a circle). However, most astronomical objects are much less than a degree in angular size. A degree is subdivided into 60 arc minutes. Each arc minute is further subdivided into 60 arc seconds. So, an arc second (a common angular size in astronomy) is 1/3600th of a degree, and less than a millionth of a circle (1/1,296,000).

A precise description of angular size will specify degrees, arc minutes, and arc seconds. [NOTE: I am being careful here to say "arc minutes" and "arc seconds". Most astronomy texts will not be so careful and will just say "minutes" and "seconds". It can lead to some confusion.] For example, the angular size of the Moon used in the montage is 0 degrees, 31 arc minutes, 36.6 arc seconds.

Individual Images

Provided below are low resolution JPEG format versions of the images used in the montage. For most of the images, higher resolution versions in PNG format (which provides lossless compression compared to JPEG's lossy compression) were used in printing the montage for display. All of these images were cropped as appropriate and then scaled to the correct relative angular size.

Image processing done with the GIMP and ImageMagick.

moon_noao_1000x1000.jpg 64 kb

ss_montage_08_100dpi.jpg    20 kb

hst_montage_08_100dpi.jpg    100 kb

venus_hst_pr1995_16_500x800.jpg 24 kb

mars_jun2001_hst_pr2001_24_800x1000.jpg 40 kb

jupiter_hst_800x800.jpg 48 kb

saturn_oct1998_hst_1000x500.jpg 28 kb

uranus_1997_hst_368x400.jpg 12 kb

neptune_nov1994_hst_248x250.jpg 4 kb

eagle_pillars_hst_1000x986.jpg 88 kb

tadpole_full_acs_frame_924x1000.jpg 76 kb

cl0024_1654_hst_pr96_10_783x1000.jpg 108 kb

hdf_mosaic_full_990x1000.jpg 144 kb

Page last updated on: May 17, 2002