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Terra has consistently orbited Earth from pole to pole
for over twenty years, collecting important data about Earth's systems.
Crossing the equator at 10:30 am mean local time
allowed Terra's five instruments to collect consistent, simultaneous data,
important to Earth's systems research and applications.
In 2020, Terra completed its final inclination maneuver
using some of its limited fuel supply, to maintain that crossing time.
Since that final inclination maneuver,
Terra has continuously drifted to an earlier equatorial crossing time.
By the Fall of 2022,
Terra's crossing time will be earlier than 10:15 am.
Then, Terra will be lowered to a new orbit
where it will be able to collect valuable data
at an even earlier crossing time.
As Terra's crossing time creeps earlier,
small changes will be noticeable in Terra's data and imagery.
Evidence in imagery of the earlier crossing time
will be visible as longer shadows,
especially in mountain landscapes.
Like in these images of the Grant Range in Nevada.
Meanwhile, as Terra moves closer to Earth
the sensors' views will become narrower
leading to slightly narrower swath widths.
The effect will be most noticeable in ASTER imagery,
but each of Terra's sensors will be affected.
However, the impact on science is expected to be minimal.
In fact, some impacts could prove beneficial to some areas of research,
like land morphology,
surface temperature,
and climate research.
Terra's lengthy legacy of more than two decades of data
will continue to contribute to meaningful research
of Earth's Systems science for years to come.