Feed aggregator

EO

1. Science
2. Earth Observatory
3. Senyar Swamps Sumatra

• Earth
• Earth Observatory
• Image of the Day
• EO Explorer
• Topics
• More Content
• About

  November 30, 2025

Tropical cyclones almost never form over the Strait of Malacca. The narrow waterway separating Peninsular Malaysia from the Indonesian island of Sumatra sits so close to the equator that the Coriolis effect is usually too weak to allow storms to rotate enough to organize into cyclones. But on November 25, 2025, meteorologists watched as a tropical depression intensified into Cyclone Senyar—just the second documented case of a tropical cyclone forming in the strait.

Hemmed in by land on both sides, Senyar made landfall in Sumatra later that day as it made a U-turn and headed east toward Malaysia. As the slow-moving storm passed over Sumatra’s mountainous terrain, it dropped nearly 400 millimeters (16 inches) of rain in many areas, according to satellite-based estimates from NASA’s Global Precipitation Measurement (GPM) mission. (Due to the averaging of the satellite data, local rainfall amounts may differ when measured from the ground.)

The torrent caused extensive flash floods and landslides in Sumatra’s rugged terrain. Streams and rivers rapidly overflowed with sediment-laden, debris-filled waters that swept through villages, cities, and towns. News reports suggest that the damage was worsened by an earthquake that struck on November 27 and the abundance of loose piles of timber in the region that became destructive battering rams in high water. As of December 4, Indonesian authorities reported several hundred deaths and more than 700,000 displaced people.

The OLI-2 (Operational Land Imager-2) on Landsat 9 captured this image of flooding in Aceh and North Sumatra provinces on November 30, 2025. Muddy sediment-filled water appears to have swamped much of Lhoksukon, a town of 40,000 people, and several surrounding villages. 

Other tropical cyclones and monsoon rains hitting Sri Lanka, Thailand, Malaysia, and Vietnam at roughly the same time have also caused extensive destruction in the broader region. According to one estimate from the United Nations Office for the Coordination of Humanitarian Affairs, flooding has affected more than 10.8 million people in the region and displaced more than 1.2 million.

NASA Earth Observatory image by Lauren Dauphin, using Landsat data from the U.S. Geological Survey. Story by Adam Voiland.

References & Resources

• BNPB (2025) News Index. Accessed December 4, 2025.
• India Today (2025, December 2) What made Cyclone Senyar a once-in-a-century weather anomaly in Malacca Strait. Accessed December 4, 2025.
• The Malaysian Reserve (2025, December 3) Death toll from floods, landslides in Indonesia rises to 811. Accessed December 4, 2025.
• NASA Earthdata (2025) Tropical Cyclones. Accessed December 4, 2025.
• The New York Times (2025, December 3) Where Floodwaters Turned Piles of Timber Into Floating Battering Rams. Accessed December 4, 2025.
• ReliefWeb (2025, December 3) Asia and the Pacific: Southeast and South Asia Cyclones and Floods Humanitarian Snapshot (Covering 17 November to 3 December 2025. Accessed December 4, 2025.
• Tsunami and Disasters Mitigation Research Center (2025, November 29) Extreme Rainfall from Tropical Cyclone Senyar Triggers Widespread Flooding and Infrastructure Damage Across Aceh. Accessed December 4, 2025.

Downloads View All November 30, 2025

JPEG (8.43 MB)

You may also be interested in:

Stay up-to-date with the latest content from NASA as we explore the universe and discover more about our home planet.

Monsoon Rains Flood Pakistan 3 min read

Heavy rains and flooding across the country since June 2025 have displaced millions of people, devastated infrastructure, and submerged farmland.

Article Imelda and Humberto Crowd the Atlantic 3 min read

The tropical cyclones are close enough in proximity that they may influence one another.

Article Rokan River Painted by the Tides 2 min read

Tides and sediment form brushstroke-like patterns across the river estuary in eastern Sumatra.

Article 1 2 3 4 Next Keep Exploring Discover More from NASA Earth Science Subscribe to Earth Observatory Newsletters

Subscribe to the Earth Observatory and get the Earth in your inbox.

Earth Observatory Image of the Day

NASA’s Earth Observatory brings you the Earth, every day, with in-depth stories and stunning imagery.

Explore Earth Science

Earth Science Data

An international team has made a significant breakthrough in understanding the tectonic evolution of terrestrial planets. Using advanced numerical models, the team systematically classified for the first time six distinct planetary tectonic regimes. Their work provides a unified theory on the geological evolution of both Earth and Venus.

4 min read

NASA Selects 2 Instruments for Artemis IV Lunar Surface Science

NASA has selected two science instruments designed for astronauts to deploy on the surface of the Moon during the Artemis IV mission to the lunar south polar region. The instruments will improve our knowledge of the lunar environment to support NASA’s further exploration of the Moon and beyond to Mars. 

A visualization of the Moon’s South Pole region created with data from NASA’s Lunar Reconnaissance Orbiter, which has been surveying the Moon with seven instruments since 2009. NASA’s Scientific Visualization Studio/Ernie Wright

“The Apollo Era taught us that the further humanity is from Earth, the more dependent we are on science to protect and sustain human life on other planets,” said Nicky Fox, associate administrator, Science Mission Directorate at NASA Headquarters in Washington. “By deploying these two science instruments on the lunar surface, our proving ground, NASA is leading the world in the creation of humanity’s interplanetary survival guide to ensure the health and safety of our spacecraft and human explorers as we begin our epic journey back to the Moon and onward to Mars.”

After his voyage to the Moon’s surface during Apollo 17, astronaut Gene Cernan acknowledged the challenge that lunar dust presents to long-term lunar exploration. Moon dust sticks to everything it touches and is very abrasive. The knowledge gained from the DUSTER (DUst and plaSma environmenT survEyoR) investigation will help mitigate hazards to human health and exploration. Consisting of a set of instruments mounted on a small autonomous rover, DUSTER will characterize dust and plasma around the landing site. These measurements will advance understanding of the Moon’s natural dust and plasma environment and how that environment responds to the human presence, including any disturbance during crew exploration activities and lander liftoff. The DUSTER instrument suite is led by Xu Wang of the University of Colorado Boulder. The contract is for $24.8 million over a period of three years. 

A model of the DUSTER instrument suite consisting of the Electrostatic Dust Analyzer (EDA)—which will measure the charge, velocity, size, and flux of dust particles lofted from the lunar surface—and Relaxation SOunder and differentiaL VoltagE (RESOLVE)—which will characterize the average electron density above the lunar surface using plasma sounding. Both instruments will be housed on a Mobile Autonomous Prospecting Platform (MAPP) rover, which will be supplied by Lunar Outpost, a company based in Golden, Colorado, that develops and operates robotic systems for space exploration.LASP/CU Boulder/Lunar Outpost

Data from the SPSS (South Pole Seismic Station) will enable scientists to characterize the lunar interior structure to better understand the geologic processes that affect planetary bodies. The seismometer will help determine the current rate at which the Moon is struck by meteorite impacts, monitor the real-time seismic environment and how it can affect operations for astronauts, and determine properties of the Moon’s deep interior. The crew will additionally perform an active-source experiment using a “thumper” that creates seismic energy to survey the shallow structure around the landing site. The SPSS instrument is led by Mark Panning of NASA’s Jet Propulsion Laboratory in Southern California. The award is for $25 million over a period of three years. 

An artist’s concept of SPSS (South Pole Seismic Station) to be deployed by astronauts on the lunar surface.NASA/JPL-Caltech

“These two scientific investigations will be emplaced by human explorers on the Moon to achieve science goals that have been identified as strategically important by both NASA and the larger scientific community”, said Joel Kearns, deputy associate administrator for exploration, Science Mission Directorate at NASA Headquarters. “We are excited to integrate these instrument teams into the Artemis IV Science Team.”

The two payloads were selected for further development to fly on Artemis IV; however, final manifesting decisions about the mission will be determined at a later date. 

Through Artemis, NASA will address high priority science questions, focusing on those that are best accomplished by on-site human explorers on and around the Moon and by using the unique attributes of the lunar environment, aided by robotic surface and orbiting systems. The Artemis missions will send astronauts to explore the Moon for scientific discovery, economic benefits, and build the foundation for the first crewed missions to Mars.

For more information on Artemis, visit:

https://www.nasa.gov/humans-in-space/artemis

Karen Fox / Molly Wasser
Headquarters, Washington
202-358-1600 
karen.c.fox@nasa.gov / molly.l.wasser@nasa.gov

Facebook logo @NASA@NASASolarSystem @NASA@NASASolarSystem Instagram logo @NASA@NASASolarSystem Linkedin logo @NASA Keep Exploring Discover More Topics From NASA

Artemis

Planetary Science

NASA’s planetary science program explores the objects in our solar system to better understand its history and the distribution of…

Earth’s Moon

The Moon makes Earth more livable, sets the rhythm of ocean tides, and keeps a record of our solar system’s…

Solar System

4 min read

NASA Selects 2 Instruments for Artemis IV Lunar Surface Science

NASA has selected two science instruments designed for astronauts to deploy on the surface of the Moon during the Artemis IV mission to the lunar south polar region. The instruments will improve our knowledge of the lunar environment to support NASA’s further exploration of the Moon and beyond to Mars. 

A visualization of the Moon’s South Pole region created with data from NASA’s Lunar Reconnaissance Orbiter, which has been surveying the Moon with seven instruments since 2009. NASA’s Scientific Visualization Studio/Ernie Wright

“The Apollo Era taught us that the further humanity is from Earth, the more dependent we are on science to protect and sustain human life on other planets,” said Nicky Fox, associate administrator, Science Mission Directorate at NASA Headquarters in Washington. “By deploying these two science instruments on the lunar surface, our proving ground, NASA is leading the world in the creation of humanity’s interplanetary survival guide to ensure the health and safety of our spacecraft and human explorers as we begin our epic journey back to the Moon and onward to Mars.”

After his voyage to the Moon’s surface during Apollo 17, astronaut Gene Cernan acknowledged the challenge that lunar dust presents to long-term lunar exploration. Moon dust sticks to everything it touches and is very abrasive. The knowledge gained from the DUSTER (DUst and plaSma environmenT survEyoR) investigation will help mitigate hazards to human health and exploration. Consisting of a set of instruments mounted on a small autonomous rover, DUSTER will characterize dust and plasma around the landing site. These measurements will advance understanding of the Moon’s natural dust and plasma environment and how that environment responds to the human presence, including any disturbance during crew exploration activities and lander liftoff. The DUSTER instrument suite is led by Xu Wang of the University of Colorado Boulder. The contract is for $24.8 million over a period of three years. 

A model of the DUSTER instrument suite consisting of the Electrostatic Dust Analyzer (EDA)—which will measure the charge, velocity, size, and flux of dust particles lofted from the lunar surface—and Relaxation SOunder and differentiaL VoltagE (RESOLVE)—which will characterize the average electron density above the lunar surface using plasma sounding. Both instruments will be housed on a Mobile Autonomous Prospecting Platform (MAPP) rover, which will be supplied by Lunar Outpost, a company based in Golden, Colorado, that develops and operates robotic systems for space exploration.LASP/CU Boulder/Lunar Outpost

Data from the SPSS (South Pole Seismic Station) will enable scientists to characterize the lunar interior structure to better understand the geologic processes that affect planetary bodies. The seismometer will help determine the current rate at which the Moon is struck by meteorite impacts, monitor the real-time seismic environment and how it can affect operations for astronauts, and determine properties of the Moon’s deep interior. The crew will additionally perform an active-source experiment using a “thumper” that creates seismic energy to survey the shallow structure around the landing site. The SPSS instrument is led by Mark Panning of NASA’s Jet Propulsion Laboratory in Southern California. The award is for $25 million over a period of three years. 

An artist’s concept of SPSS (South Pole Seismic Station) to be deployed by astronauts on the lunar surface.NASA/JPL-Caltech

“These two scientific investigations will be emplaced by human explorers on the Moon to achieve science goals that have been identified as strategically important by both NASA and the larger scientific community”, said Joel Kearns, deputy associate administrator for exploration, Science Mission Directorate at NASA Headquarters. “We are excited to integrate these instrument teams into the Artemis IV Science Team.”

The two payloads were selected for further development to fly on Artemis IV; however, final manifesting decisions about the mission will be determined at a later date. 

Through Artemis, NASA will address high priority science questions, focusing on those that are best accomplished by on-site human explorers on and around the Moon and by using the unique attributes of the lunar environment, aided by robotic surface and orbiting systems. The Artemis missions will send astronauts to explore the Moon for scientific discovery, economic benefits, and build the foundation for the first crewed missions to Mars.

For more information on Artemis, visit:

https://www.nasa.gov/humans-in-space/artemis

Karen Fox / Molly Wasser
Headquarters, Washington
202-358-1600 
karen.c.fox@nasa.gov / molly.l.wasser@nasa.gov

Facebook logo @NASA@NASASolarSystem @NASA@NASASolarSystem Instagram logo @NASA@NASASolarSystem Linkedin logo @NASA Keep Exploring Discover More Topics From NASA

Artemis

Planetary Science

NASA’s planetary science program explores the objects in our solar system to better understand its history and the distribution of…

Earth’s Moon

The Moon makes Earth more livable, sets the rhythm of ocean tides, and keeps a record of our solar system’s…

Solar System

Intermediate mass stars experience periods of rapid growth in their late stages of formation. The growing young star emits more radiation that encourages greater accretion. Rather than depleting their protoplanetary disks and preventing gas giants from forming, the opposite is true.

Members of the CDC’s Advisory Committee on Immunization Practices seemed confused about a proposed recommendation for the birth dose of the hepatitis B vaccine

In a recent paper, a team of SETI and astrobiology specialists examines four controversial claims about the existence of extraterrestrial life. From these, they present recommendations for scientists and science communicators when addressing future claims of discovery.

A man has passed away after he received a kidney transplant from a person who had died with undiagnosed rabies, according to U.S. public health officials

The groundbreaking mission designed to observe our Sun and its interactions with Earth celebrates three decades in space this week.

The post The Solar and Heliospheric Observatory Celebrates 30 Years in Space appeared first on Sky & Telescope.

The 10 best fiction books of 2025, explore far-off planets, future climate catastrophes and more

The 10 best nonfiction books of 2025, from the history of replaceable body parts to our AI future

Voters change their opinions after interacting with an AI chatbot – but, encouragingly, it seems that AIs rely on facts to influence people

Voters change their opinions after interacting with an AI chatbot – but, encouragingly, it seems that AIs rely on facts to influence people

Chatbots can measurably sway voters’ choices, new research shows. The findings raise urgent questions about AI’s role in future elections

The AI industry consumes vast amounts of energy, fresh water and investor cash. Now it also needs memory chips - the same ones used in laptops, smartphones and games consoles

The AI industry consumes vast amounts of energy, fresh water and investor cash. Now it also needs memory chips - the same ones used in laptops, smartphones and games consoles

Ten great stories about 10 forgotten female scientists that we hope will inspire middle school readers to pursue their own curiosity and get involved in STEM fields

Over the course of several hours, technicians meticulously connected the inner and outer segments of NASA’s Nancy Grace Roman Space Telescope.

Over the course of several hours, technicians meticulously connected the inner and outer segments of NASA’s Nancy Grace Roman Space Telescope.NASA/Jolearra Tshiteya

Two technicians look up at NASA’s Nancy Grace Roman Space Telescope after its inner and outer segments were connected at the agency’s Goddard Space Flight Center in Greenbelt, Maryland on Nov. 25, 2025. This marked the end of Roman’s construction. After final testing, the telescope will move to the launch site at NASA’s Kennedy Space Center in Florida for launch preparations in summer 2026. Roman  — named after Dr. Nancy Grace Roman, NASA’s first chief astronomer — is slated to launch by May 2027, but the team is on track for launch as early as fall 2026.

See more photos of the completed observatory.

Image credit: NASA/Jolearra Tshiteya

Over the course of several hours, technicians meticulously connected the inner and outer segments of NASA’s Nancy Grace Roman Space Telescope.NASA/Jolearra Tshiteya

Two technicians look up at NASA’s Nancy Grace Roman Space Telescope after its inner and outer segments were connected at the agency’s Goddard Space Flight Center in Greenbelt, Maryland on Nov. 25, 2025. This marked the end of Roman’s construction. After final testing, the telescope will move to the launch site at NASA’s Kennedy Space Center in Florida for launch preparations in summer 2026. Roman  — named after Dr. Nancy Grace Roman, NASA’s first chief astronomer — is slated to launch by May 2027, but the team is on track for launch as early as fall 2026.

See more photos of the completed observatory.

Image credit: NASA/Jolearra Tshiteya