NASA’s TIMED (Thermosphere, Ionosphere, Mesosphere, Energetics and Dynamics)
spacecraft recently observed our atmosphere’s response to a series of strong
solar storms, providing important new information on the final link in the
Sun-Earth Connection (SEC) chain of physical processes connecting the Sun
and Earth.

“Several NASA spacecraft measured this strong activity coming from the Sun.
Now TIMED provides the critical link between what happened on the Sun and
Earth’s response,” says Dr. Sam Yee, TIMED project scientist, from the
spacecraft’s operations center at the Johns Hopkins University Applied
Physics Laboratory in Laurel, Md., and leader of the mission’s science team.

“TIMED allows us to observe the global reaction of our upper atmosphere to
solar activity,” says Dr. Mary Mellott, TIMED program scientist from NASA
Headquarters in Washington. “One of the current puzzles for the Sun-Earth
Connection community is determining why some solar activity has significant
geospace impact and some does not. Being able to monitor the impact so well
with TIMED should allow the scientific community to make significant
progress toward solving this SEC mystery.”

Preliminary TIMED data will be featured in a special session at the Spring
2002 American Geophysical Union meeting, May 31, in Washington, D.C., which
is open to the media. Information about this session can be found at (item SA02). Interested members of the press should
visit for registration information.

Since TIMED’s science mission began in January 2002, science team members
say it has made great strides in helping them learn more about one of
Earth’s least understood atmospheric regions-the Mesosphere and Lower
Thermosphere/Ionosphere-a gateway between Earth’s environment and space.
TIMED is the first of NASA’s Solar Terrestrial Probes missions to globally
study the influences of the Sun and humans on the MLTI region, located
approximately 40-110 miles (60-180 kilometers) above the surface.

“TIMED’s study of short-term events, such as the recent solar storms, will
help us gain a better understanding of the dynamics of this gateway region,”
says Dr. Yee. “But our main goal is to understand the region’s overall
climate through a comprehensive set of global measurements we’re collecting
using TIMED’s 4-instrument suite. With the core data we’ve already
collected, we’ve taken the first step in assessing the region’s global
characteristics and seasonal variations-information that will help us
establish a baseline for future studies.”

Space weather in Earth’s upper atmospheric regions can change as suddenly as
our weather patterns on the ground. It can affect satellite communications
and orbital tracking, spacecraft lifetimes and the reentry of piloted
vehicles. “When a change occurs in one region of our atmosphere, it affects
other regions,” Dr. Yee says. “It’s important that we better understand how
this gateway region responds to various solar inputs, which affect our
atmosphere’s overall energy balance.”

Images and videos of preliminary TIMED data can be downloaded from

The Solar Terrestrial Probes Program Office at NASA’s Goddard Space Flight
Center, Greenbelt, Md., oversees the TIMED mission for the Office of Space
Science at NASA Headquarters in Washington, D.C. The Johns Hopkins
University Applied Physics Laboratory, in Laurel, Md., built and now
operates the spacecraft, leads the project’s science effort and manages the
mission’s Science Data Center for NASA.

For more information about TIMED, visit