12/12/06 STEREO Spacecraft Perigee Pass by Jim Albers

On Dec 12, 2006, the two STEREO (Solar TErrestrial Relations Observatory) spacecraft will perform their last perigee pass before heading out past the Moon, sending one ahead of the Earth and one behind in order to provide views of the Sun from two directions. During this pass, observers on the dark side of the Earth should be able to see the spacecraft using medium to large amateur telescopes.

Image of SETREO A taken by UA astronomer Bill Keel using a 0.9 m SARA telescope on Kitt Peak, AZ

9:14Z 15,300 km range

60s exposure, spacecraft crossed frame in 12s

StereoAsm.jpg (55595 bytes)


Overhead view of trajectories and both spacecraft at 10:25 UTC


Maximum predicted magnitude of Stereo A worldwide

Latitude from -90 to +90 and Longitude from -180 to +180, tick marks every 30 degrees

Color scale on right side of plot from black:15th magnitude to white:9th magnitude

Sun must be < -6 degrees elevation

Includes effects of atmospheric extinction, solar phase angle and range


Maximum predicted magnitude of Stereo B worldwide 


UPDATED 12/9/06  [A-FDF282, B-FDF291] Excel Prediction Spreadsheet (Time, Az, El, RA, Dec, Range, Sun-Sat-Obs angle, Mag Estimate for any location) from Spice (389 kb zip, Uses Visual Basic - Enable Macros)

Originally created by Ted Molczan for Stardust Reentry, range, angle from Jim Albers, magnitude estimate from David Dunham, populated here with STEREO data

Caution, coordinates calculated by spreadsheet may have several tenths of a degree error, so some searching around calculated location(s) may be required.  


David Dunham Stereo Page (News, Spice trajectory files, etc.)

NASA Goddard Stereo Page

JHU/APL Stereo Page


San Jose,CA Finder Charts and Data Plots 


8 - 11 Hrs RA 4 - 8 Hrs RA 0 - 4 Hrs RA
sj_radec_3.gif (19868 bytes) sj_radec_2.gif (20657 bytes) sj_radec_1.gif (15051 bytes)

Azimuth and Elevation

Data Point every 5 minutes

Time - Elevation

Time - Range
stereo_sj_azel.gif (15293 bytes) stereo_sj_tel.gif (17345 bytes) stereo_sj_trng.gif (16286 bytes)

Stereo A, B Spacecraft

B is higher in Dec and rises later

Viewpoint is  San Jose, CA (37.339400 deg, -121.893900 deg, 0.12 km alt)

From 12/4/06 Spice files [ A-FDF241, B-FDF240] on Dunham page



Rob Matson Skymap info and files