Erin
Schumacher's summer job for NASA was to look for UFOs. Erin is a
16-year-old high school student from Redondo Beach, California,
attending the California Academy of Mathematics and Science in
Carson. She was one of ten students selected to work at NASA's
Jet Propulsion Laboratory (JPL) in Pasadena as part of the Summer High
School Apprenticeship Research Program, or SHARP.
But is studying UFOs a useful kind of NASA research? Well, it is
when they are "unidentified flashing objects" that appear in
certain images of Earth from space. Erin worked with scientists
on the Multi-angle Imaging SpectroRadiometer (MISR) project to track
down these mysterious features. MISR is one of five instruments
onboard the Earth-orbiting Terra satellite. MISR's nine
separate cameras all point downward at different angles, each camera
in turn taking a picture of the same piece of Earth as the satellite
passes overhead. Viewing the same scene through the atmosphere
at different angles gives far more information about the aerosols,
pollution, and water vapor in the air than a single view would give.
Ground features may also look slightly or dramatically different from
one viewing angle to another.
Erin's job was to carefully examine the pictures looking for any
flashes of light that might be visible from just one of the nine
angles. Such flashes are caused by sunlight bouncing off very
reflective surfaces and can be seen if a camera is pointed at just the
right angle to catch them. Because the satellite data contain precise
locations for each pixel in the images, Erin could figure out exactly
where a flashing object on the ground should be. Her job was
then to figure out exactly what it was that made the flash-in
particular, to see if she could distinguish man-made objects from
natural ones.
When Erin began working at JPL, scientists on the MISR project had
already identified two large flashes out in the middle of the Mojave
Desert in Southern California. These turned out to be from solar
power generating stations. Soon, Erin began finding flashes all
over the place. She learned how to apply her math knowledge to
figuring out how the objects would have to be oriented in order to be
seen by a particular MISR camera. One time, she and a team of MISR
scientists and students went on a field trip to the exact locations of
some flashes, where they found greenhouses, large warehouses with
corrugated metal roofs, a glass-enclosed shopping mall, and a
solar-paneled barn. For some flashes, they could find nothing at all.
Those remain "UFOs" to this day!
Two
cameras on MISR made these images of the same part of the Mojave
Desert. The camera pointed at an angle of 26 forward saw the
flashes from two solar electric power generating stations. These
objects are nearly invisible at the other angle.
Learn more about SHARP at www.nasasharp.com and Earth science
applications of MISR at www-misr.jpl.nasa.gov. Kids can
do an online MISR crossword at
spaceplace.nasa.gov/en/kids/misr_xword/misr_xword1.shtml.
This article was written by Diane K. Fisher. It was provided
by the Jet Propulsion Laboratory, California Institute of Technology,
under a contract with the National Aeronautics and Space
Administration
