Terra: the EOS Flagship

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A recent programmatic change in the Terra mission is prompting the flight operation staffing to go from 24 hours a day, 7 days a week to 12 hours a day, 7 days a week, with limited operational response when staff are not on site. For more information, see below.

Terra explores the connections between Earth’s atmosphere, land, snow and ice, ocean, and energy balance to understand Earth’s climate and climate change and to map the impact of human activity and natural disasters on communities and ecosystems

Images of five globes, each depicting an example of data collected by Terra instruments, including land composition from ASTER, reflected energy from CERES, vegetation snow and ice from MODIS, aerosols from MISR, and carbon monoxide from MOPITT.


Important Terra Updates and Information

The Terra and Aqua Flight Operation Team (FOT) transitioned fully to Light-Out-Operations (LOOps) on July 7th 2023 at 6am EDT, following successful testing and Ops Readiness Review.

In the LOOps configuration there will not be an on-console engineer working the 12-hour night shift (6pm-6am), but instead system support engineers will be on call during lights out period to respond to red limit alarms as needed.

FOT will no longer attempt to fill science data gaps via Solid State Recorder replays so additional data losses and larger data gaps are expected, though estimated data capture is expected to remain above mission data capture guideline of 95%.

For more information and a list of known Terra and Aqua data gaps due to LOOps, visit this informational page located on the MODIS Adaptive Processing System (MODAPS) website.

Terra data users have expressed the need for weekly updates on Terra’s equator crossing time (in Mean Local Time), as well as orbital altitude. Starting this month, we’ll be adding this information to the Terra homepage and updating it weekly using data provided by the Operations Team. Move your cursor over the chart below to view both Terra’s Mean Local Equator Crossing Time in UTC and orbital altitude for each month through 2026.

Terra’s Orbit Today

Equator Crossing Time

9:59 AM (Mean Local Time)

Orbital Altitude

692 KM

2023 Terra Updates

Click the links below to catch up on all the latest Terra news and updates!

  • (Terra)-fying Tales
    Happy Halloween 2023, from the Terra mission! Enjoy this ‘spooky’ set of (Terra)-fying imagery that highlights some of Earth’s strangest costumes (as well as past NASA Earth Observatory images featuring Terra!)
  • 2023 Terra Updates
    Terra Operational Changes and Data Updates Over the past three years, the Terra mission has performed multiple maneuvers that have led to changes in the satellite’s consistent 20+ year orbit*. Today, Terra continues slowly drifting to an increasingly earlier overpass time and lower altitude. While the orbital changes have had little to no impact on …

    2023 Terra Updates Read More »

  • NASA Celebrates Earth Day!
    April 20th is officially “Earth Day,” and NASA is celebrating with a hybrid event! Join us in-person (if you’re close to Union Station in Washington D.C.) or online! See the official NASA Earth Day website (linked here) or scan the QR code on the graphic below for more information and (free!) registration! (And if you’ll …

    NASA Celebrates Earth Day! Read More »

Past News Features

Terra’s Lower Orbit Virtual Community Forum

NASA’s Terra, Aqua, and Aura Drifting Orbits Workshop Information

Animated Overview of the Request for Information

Terra Begins Drifting. What’s Next?

After more than 20 years orbiting at 705 km above Earth’s surface and routinely crossing the equator at approximately the same time every day, Terra is now drifting. With no maneuvers planned to sustain Terra’s altitude and crossing time, Terra will slowly get closer and closer to Earth – crossing the equator earlier and earlier as time passes. However, despite impacts to some of Terra’s nearly 100 data products, Terra’s five sensors continue to collect meaningful scientific data, producing one of the longest continuous climate data records collected by a satellite. Read more…

Terra: Providing Critical Data to Help Society


Terra’s five sensors help us understand out changing planet and provide critical data used in applications from food security, volcanic monitoring, wildfire safety, public health, and climate modeling. Terra’s twenty years of data continue to contribute to how we understand Earth and how we respond when disasters strike.

Twenty Years of Terra in Our Lives


Terra’s suite of instruments allows us to understand our world well beyond what we knew twenty years ago, when Terra launched. In those twenty years, new applications and contributions to science have been made possible.

There is no question that technology has changed. But, at the same time that our lives on Earth were being shaped by our access to technology, 705 kilometers above us, a satellite was changing how we understood our planet.

For 20 years, Terra, the flagship Earth observing satellite,
has chronicled changes on Earth. Designed and built in the 1980s and 90s, NASA and Lockheed Martin engineers set out to build a satellite that could take simultaneous measurements of Earth’s atmosphere, land, and water. Its mission – to understand how Earth is changing and to identify the consequences for life on Earth. Season after season, Terra data continues to help
us understand how the evolving systems of our planet affect our lives – and how
we can use that data to benefit society. Read more and find resources from our anniversary events, Terra 20 Events

Update on Terra’s New Orbit: Since 2020, Terra has been drifting to an earlier equator crossing time, and in October 2022 was lowered by ~5km in altitude. These changes in orbit did not reduce the data quality of Terra products, and only created minor changes to orbital repeat time and swath width (for some instruments). See Terra’s New Orbit for more information.

Science Visualizations







Ocean Color in Gulf of Alaska