Terra | The EOS Flagship

Terra Instruments: ASTER CERES MISR MODIS MOPITT

The Fast Fire Threat

An Unusual Year for Fire in Bolivia

Heavy Snows in Korea

Saturated Northern Australia

Iran’s Lut Desert

A Hazy, Foggy Day in Italy’s Po Valley

Terra: the EOS Flagship

On November 28th, 2024 at 14:20 UTC, one of Terra’s power-transmitting shunt units failed. A response team reviewed Terra’s status, and discussed potential impacts and options. Consequently, the team changed the battery charge rate and reduced spacecraft power demands by placing the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument into Safe Mode. As a result, ASTER data are not currently being collected. All other instruments continue uninterrupted. The engineering team will continue to closely monitor Terra’s power output and provide future updates on ASTER’s status.

Celebrate 25 Years of Terra! Date: 12/18/2024. Time: 3PM - 5:30PM EST. Location: Goddard Space Flight Center Visitor's Center. Join us for light appetizers and cake, as we celebrate Terra's incredible 25-year (and counting) climate record legacy! Can't make it to the event? We'll stream it online! RSVP for more information and live streaming link. nyssa.rayne@nasa.gov — Click the banner above for more information about the event!

Banner that says: "Going to AGU 2024? Join us for Terra's 25th Anniversary Special Sessions! Click the banner for information and links to session agendas." Logos for both Terra's 25th anniversary and AGU 2024 conference also included.

Terra: The EOS Flagship

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

Connecting Earth’s Systems with Terra’s Observations

Examples of each instrument’s capabilities (clockwise): land composition (ASTER), reflected energy (CERES), aerosols (MISR), vegetation snow and ice (MODIS), carbon monoxide (MOPITT)

Important Terra Updates and Information

Direct Broadcast Update (November 2024):
Terra has not been transmitting Direct Broadcast since May 11, 2024, due to a solar array power generation issue limiting our ability to continue all science and provide Direct Broadcast continuously. Unfortunately, there are no plans to resume Terra Direct Broadcast. November 2024 Data Impacts:
Terra successfully completed a multi-day special maneuver to allow for calibration of the MODIS instrument’s diffuser. Data collection from all Terra instruments were briefly interrupted during this process (see specific dates and times below).

Day 1 (11/12/24) – 16:41z – 22:22z
Day 2 (11/13/24) – 12:24z – 21:25z
Day 3 (11/14/24) – 13:01z – 22:04z
Day 4 (11/15/24) – 12:07z – 20:38z A programmatic change in the Terra mission prompted 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.

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 has changed, but the data quality hasn’t! Visit this link to learn more about Terra’s new orbit.

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.

Equator crossing time: 9:59 (mean local time) — **Equator Crossing Time**
9:37 AM (Mean Local Time)

Orbital Altitude 692 km — **Orbital Altitude**
695 KM

(Updated November 2024)

Happy Thanksgiving 2024, from the Terra mission!

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

Past News Features

Terra 2024 Thanksgiving Greetings!November 26, 2024
This year has been a busy one for Terra, with our 25th Anniversary just around the corner! (Learn more and RSVP here!) In the season of thanksgiving, Terra is especially grateful for the following: Thanks again for all of your support over the years! Wishing you all a relaxing holiday full of food and friends!
Terra Views the Eclipse! (April 8)April 5, 2024
You may have heard about the upcoming full solar eclipse, happening this upcoming April 8th, 2024 — but did you know Terra will have one of the “best seats in the house” for viewing this rare celestial experience?! In the United States, the center “totality” shadow of the eclipse will pass from south to north …
Terra Views the Eclipse! (April 8) Read More »
Top 2023 Terra & Earth Observatory StoriesFebruary 20, 2024
Before we kick off an exciting year — full of celebrating Terra’s upcoming 25th Anniversary! — let’s take a moment to look back at the top-viewed monthly Earth Observatory stories featuring the Terra mission from 2023! Click the linked month in each banner to jump down to a brief article summary and image thumbnail. Want …
Top 2023 Terra & Earth Observatory Stories Read More »

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.