NEAR spacecraft to shine brightly Thurs. night

Joan and David Dunham (
Sat, 17 Jan 1998 13:20:50 -0500

            Spacecraft to shine brightly Thursday night

     On Thursday night-Friday morning, January 22-23, the Near Earth 
Asteroid Rendezvous (NEAR) spacecraft will swing by the Earth 
primarily to change its orbital plane to match that of the asteroid 
433 Eros, NEAR's target for an early 1999 rendezvous.  As NEAR 
approaches the Earth, its almost 100 square feet of solar panels 
will be rotated to reflect sunlight to several regions of the 
U.S.A., providing a unique opportunity to see with the naked eye an 
interplanetary spacecraft flying through space.  Although NEAR will 
be about 9000 miles over the North Pacific Ocean at the time, it is 
expected to briefly shine as bright as Capella, among the brightest 
stars in the sky.  These NEAR sunglints will be visible from 1:25 am
to 1:49 am EST January 23rd (10:25 pm to 10:49 pm PST January 22nd), 
about an hour before NEAR's closest approach to the Earth over 300 
miles above the Middle East.  More about NEAR's Earth swingby is 
available in a press release from the Johns Hopkins University's 
Applied Physics Laboratory (APL) available on the Web at
This site lists the following times to see the sunglint:

Areas Most Likely to See NEAR's Sunglint: 

Region                 (Friday Jan. 23) Sunglint Time

s. New England, e. New York*              1:25 am EST
Midwest (s. Ontario, Detroit area)        1:26 am EST
Midwest (Chicago & Kans. City areas)     12:26 am CST
s. Nebr., n. Missouri, central Illinois  12:28 am CST
s. Indiana, Cincinnati, W. Va.            1:28 am EST
e. Virginia, DC area, Md., s. Penn.*      1:29 am EST
Central Va., central N. Car., S. Car.     1:30 am EST
Georgia, central & e. Tenn.*              1:31 am EST
Georgia (again), Florida peninsula        1:32 am EST
Florida peninsula (again)*                1:33 am EST
Louisiana*                               12:35 am CST
eastern Texas*                           12:37 am CST
San Angelo to Midland-Odessa, Texas      12:39 am CST

Region               (Thursday Jan. 22) Sunglint Time

Colorado*                                11:27 pm MST
s. New Mexico, s. Arizona                11:39 pm MST
southern California*                     10:40 pm PST
southern Nevada                          10:41 pm PST
Utah*                                    11:41 pm MST
central Calif. (Fresno area)             10:43 pm PST
n. Calif. (San Francisco-Sacramento)*    10:44 pm PST
Oregon                                   10:45 pm PST
w. Washington state, s.w. Brit. Col.*    10:46 pm PST
Oahu and Maui, Hawaii*                    8:48 pm HST

*These are "targeted" regions that will see the flash for about half 
a minute. Other areas will see the flash for only a few seconds. 
Watch for about three minutes, starting a minute before the listed 

The press release also describes approximately how to find NEAR:

If you are in one of the sunglint regions listed above, look for the 
brightest star above the northwestern horizon, Capella, which will 
be about halfway between the horizon and straight overhead for the 
East Coast, and higher on the West Coast.  Hold your hand at arm's 
length and stretch out your fingers, putting the end of your little 
finger at the top at Capella.  The tip of your thumb, pointing 
straight down from Capella, will mark the approximate location where 
the sunglint will occur in the constellation Perseus, about 20 
degrees below Capella.  The glint should be very noticeable, about 
as bright as Capella.  The press release Web site includes a figure 
illustrating this. 

Hawaii will see the brightest flash, as bright as Sirius, the 
brightest star in the night sky.  The view there will differ from 
other parts of the U.S., with Capella being above the northern 
horizon and the glint being below and to the left of Capella.  

Sky charts for locating the glint areas with binoculars and a map 
showing the path of the glint zone (100 to 200 miles wide, depending 
on the geometry) will soon be on IOTA's Web sites at   and
The U.S.A. map showing the path has no times; use the table above 
for the time for your location.  A version of the map with Universal 
Times will be posted on the IOTA sites either late tonight or 
tomorrow.  A local-time version will be posted either tomorrow or 
Monday, with the best-quality version being posted Monday at the 
NEAR Web site.  Two sky charts are posted, one calculated for the 
Washington-Baltimore area but which can be used for the eastern half 
of the U.S.A., and one for Los Angeles that will be good enough for 
the western half of the country.  Similar charts for about a dozen 
other locations will be posted Monday or Tuesday probably at the 
NEAR site but possibly at the IOTA sites.  Anyone needing a 
preliminary version of one of these charts for other regions for 
publication can contact me to obtain it by fax. 

An animation showing the path of the sunglint can be found on the 
NEAR Web site: 

That site also includes a chart of Perseus showing in more detail
where the sunglint will appear for different cities, suitable for
those who want to find the sunglint location with powerful 
binoculars or telescopes.  That site indicates that it might be
best to see the sunglint with a telescope, but that is misleading; 
it will be easy to see with the naked eye.

NEAR's pointing should be accurate to better than 0.1 deg., less
than a fifth of the diameter of the Sun.  But the solar panels could 
be misaligned with the spacecraft axis by a few tenths of a degree, 
and (unlikely) even as much as a degree.  So observers at least half 
a pathwidth (and maybe more) outside of the predicted path have a 
chance to see at least part of the sunglint.  It may occur in steps 
since NEAR has 4 solar panel arrays, each of which might be 
misaligned a little relative to each other.

Timed observations of the sunglint are sought to try to measure the 
solar panel alignments precisely.  Such observations could be made 
with a camcorder (use manual focus), or visually with a tape 
recorder, like timing a grazing or asteroidal occultation.  Record 
WWV shortwave time signals along with the event for timing.  More
about recording and reporting the sunglint will be distributed later 
and posted on the IOTA Web sites.

David Dunham, IOTA and NEAR Mission Design         January 17, 1998
Telephones:  301-474-4722 at home and 301-953-5609 at APL
E-mail: at home and at APL