Past Images
- Chronological order - past two hours
(1/4-size) plus current image (full-size)
- Reverse-chronological order - current
image (full-size) plus past two hours (1/4-size)
- One-week
archive of past images (filenames only)
- Time-lapse animations, generated in near-real-time. Small-size
versions (160x120 pixels) are available for the past two, four, six, eight, 12, and 24 hours; file sizes range from ~215 KB to ~2.3
MB. Mid-size versions (320x240 pixels) are available for the past two (~762 KB) and four hours (~1.5 MB).
- Composite Xearth/ED-7
24-hour time-lapse animation (~3.5 MB), generated once daily,
showing three panels: a rotating Earth (centered on the subsolar
point); 24-hours of ED-7 images from yesterday, beginning after
midnight; and a fixed Earth (centered on a position south of the
approximate location of ED-7). See also a one-month archive of past composite
animations (filenames only),
including a permanent archive of files from the 1st and
15th of each month (filenames only).
- Time-lapse animation (~20 MB, 320x240 pixels)
showing the annual north-south migration of the nodus shadow at 12 noon
Eastern Standard Time (1 p.m. EDT). The animation is updated once each day
at ~1:10 p.m. ET: the first frame is always 12 noon on 15 February
2004; the last frame is either 12 noon on the previous day (before 1:10
p.m. ET) or 12 noon on the current day. The "movie" looks a little
"jumpy" as a result of changes in the camera position and image caption
text. See also a running
archive of still images from 12 noon ET each day since 15 February
2004 (filenames only).
- Special archives of images
and time-lapse
animations from the March Equinox (Saturday,
20 March 2004). See a side-by-side
comparison of time-lapse animations from 01 February 2004 and 20 March
2004.
 See also special archives of images and time-lapse animations from the
June Solstice (Monday, 21 June 2004), images and time-lapse animations from the
September Equinox (Wednesday, 22 September 2004), and images and time-lapse animations from the
December Solstice (Tuesday, 21 December 2004). See Earth's Seasons -
Equinoxes and Solstices, a four-panel one-year time series of one-day
time-lapse animations (~6.5 MB) from the equinoxes and solstices in 2004:
20 March, 21 June, 22 September, and 21 December.
Time for Reflection...
Two motions--the rotation of the Earth around its axis, and the
revolution of the Earth around the Sun--cause daily- and annual
cycles in the Sun's apparent path across the sky that can be observed
indirectly using a horizontal sundial such as the FCPS/NOVAC
EarthDial (ED-7). For details, see Observing Daily & Annual Cycles of the Sun.
See a
time-lapse animation (our first!) of 26 images spanning 250 minutes (4
hr-10 min), archived from 01 February 2004. Two sizes are available: 160x120 pixels (~370
KB); and 320x240
pixels (~1.4 MB). As you watch the animations, consider the following
question: Why is "clockwise" clockwise? For further thought: Would
"clockwise" be clockwise if mechanical clocks were invented in the
Southern Hemisphere? Hint: In order to answer the preceding
question, see a time-lapse animation (565 KB) of seven images
(560x320 pixels) spanning three hours on 02 March 2004, archived by
ED-11, South Pole, Antarctica.
How do we do it? See Technical Information re: ED-7 Archiving, a
report by Phillip Wherry, ED-7 Technical Consultant.
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