Recommended Free Tools
Some links on this page are affiliate links: if you buy through them we may earn a commission, at no extra cost to you.
NASA’s satellite is not photographing the ocean floor. It is doing something more subtle: measuring tiny variations in sea-surface height caused by the gravitational pull of underwater mountains and ridges. Those measurements are helping scientists infer seamounts, abyssal hills, tectonic structures, and continental margins across vast areas of the ocean.
The satellite is SWOT—the Surface Water and Ocean Topography mission. Its seafloor-mapping results, reported by NASA in March 2025, represent a major improvement in global, satellite-based mapping, but they do not mean the entire ocean floor has been directly surveyed or completely resolved.
What is NASA’s SWOT satellite?
SWOT stands for Surface Water and Ocean Topography. It is an international mission led by NASA and France’s CNES, with contributions from the Canadian Space Agency and the UK Space Agency. NASA’s Jet Propulsion Laboratory leads the U.S. component.
SWOT launched on December 16, 2022, aboard a SpaceX Falcon 9 from Vandenberg Space Force Base in California. Its main purpose is to measure the height and changing condition of Earth’s surface water—including oceans, lakes, rivers, and reservoirs. The mission’s scientific overview is available from NASA’s SWOT mission.
#1 Best Overall
- THE PERFECT BINOCULARS FOR EVERY ADVENTURE: Nature DX 8x42 offers sharp, detailed views in a compact, lightweight frame—ideal for birdwatching, hiking, and everyday adventures.
- 8X MAGNIFICATION: Get detailed views of birds, wildlife, and distant landscapes. 8x power strikes the perfect balance between image stability and the ability to spot fine features from afar.
- 42MM OBJECTIVES LENS: Compact yet capable, the 42mm lenses offer a balance of portability and bright, detailed views for outdoor adventures.
- BRIGHT, SHARP, TRUE-TO-LIFE VIEWS: Fully multi-coated lenses maximize light transmission, while phase-coated BaK-4 prisms enhance contrast and resolution for crisp, color-accurate images in any lighting.
- RUGGED, WEATHER-READY BUILD: The rubber-armored polycarbonate housing shields against bumps and drops. It’s also waterproof and nitrogen-purged to resist fogging in rain, snow, or humidity.
The satellite carries a key instrument called the Ka-band Radar Interferometer, or KaRIn. KaRIn measures the height of water across a wide area rather than producing a conventional photograph of the seabed.
SWOT observes a swath about 120 kilometers wide and follows a 21-day repeat orbit. NASA’s Jet Propulsion Laboratory says the mission can cover approximately 90% of the globe every 21 days, with many areas receiving overlapping measurements more frequently.
How can the ocean surface reveal what lies below?
The process depends on gravity:
- Underwater landforms have mass. A seamount contains more rock than the surrounding seafloor.
- That mass slightly changes the local gravitational field. The gravitational pull is stronger above the seamount than above nearby flatter terrain.
- The ocean surface responds. Water is pulled very slightly toward the extra mass, creating a tiny raised area above the submerged feature.
- SWOT measures the surface change. Repeated observations, combined with geophysical models, allow researchers to infer the likely location and shape of the seafloor feature.
The idea can be summarized as:
seamount → stronger gravity → tiny sea-surface bump → satellite measurement → inferred seafloor feature
These changes are extremely small. SWOT is not seeing through kilometers of seawater, and its radar is not acting as a ground-penetrating scanner. The mission is measuring the ocean surface with exceptional precision and using that surface as evidence of the landscape below.
NASA explains the method and its results in its report on SWOT’s seafloor mapping.
What has the improved map revealed?
SWOT-based research has improved scientists’ ability to identify several kinds of underwater structures.
Rank #2
- Lightweight Small Binoculars: You can throw them into your backpack each day without hesitation. The mini pocket binoculars are totally worth the tiny amount of weight they add to your pack
- Compact Binoculars Clear vision: 8x21 optics binoculars with a 8X magnification and objective lens diameter of 21 mm, What's more is with the large field of view-369ft/1000 yards, you can see the entire visual field for capturing objects easily
- Easy on Focus: Just adjust by Smooth "center-focus knob" and right eye lens. The folding binoculars suitable for both adults and kids binoculars
- Compact Binoculars with BAK4 prism which can keep a good image (while don't forget to adjust the knobs to fit different view distance),made of Mg body and hand figured polishing
- Application: Perfect for adults, kids, concerts, theater, opera, plays, shows, travel, hiking, camping, sport events, bird watching , etc.. The binoculars come with their own neck strap, cleaning cloth and carrying bag
Seamounts
Seamounts are underwater mountains that can influence ocean currents and create important marine habitats. Older satellite-altimetry techniques generally detected very large seamounts—roughly those rising 1 kilometer or more above the seafloor. Under suitable conditions, SWOT can detect features less than half that height.
NASA says the improved observations could increase the estimated number of known or detectable seamounts from approximately 44,000 to as many as 100,000. That is a projection of what the improved data may make possible, not a claim that 100,000 mountains have already been individually confirmed by ship sonar.
Abyssal hills
Abyssal hills are relatively small ridges that cover an estimated 70% of the ocean floor, according to NASA’s account of the research. Their patterns can preserve evidence of how oceanic plates formed and moved.
These hills are not merely decorative features on a map. They can affect deep-ocean turbulence, currents, nutrient movement, and the distribution of organisms in the deep sea.
Continental margins and tectonic patterns
The data also help reveal underwater continental margins—the transition zones between continental and oceanic crust. Parallel bands in the seafloor can record the spreading of tectonic plates and provide clues about Earth’s geological history.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
In this sense, the map is not only a survey of underwater terrain. It is also a record of processes that have shaped the planet over millions of years.
Rank #3
- READY FOR ANY ADVENTURE: The Outland X 8x42 delivers bright, detailed views in a lightweight, pocket-friendly design—perfect for birdwatching, hiking trails, or spontaneous outdoor outings.
- 8X MAGNIFICATION: Spot distant wildlife, birds, and landscapes with ease. The 8x power delivers detailed views while maintaining a steady image—ideal for tracking movement without losing clarity.
- 42MM OBJECTIVE LENS: 42mm lenses deliver bright, high-contrast views in a compact design—perfect for the trail, the park, or wherever your adventures take you.
- BRIGHT, TRUE-TO-LIFE VIEWS: Multi-coated lenses boost light transmission to your eye, while high-quality BaK-4 prisms produce sharp, color-accurate images in a variety of lighting conditions.
- RUGGED, WEATHER-READY BUILD: Rubber-armored polycarbonate housing shields against bumps and drops. Waterproof and nitrogen-purged to prevent fogging in rain, snow, or humidity.
How much better is SWOT than earlier satellite mapping?
The major improvement is a combination of precision, coverage, and repeat observations.
| Method | What it does well | Main limitation |
|---|---|---|
| SWOT and other satellite altimetry | Provides broad global coverage and reveals gravitational signatures of underwater features | Maps the seafloor indirectly and with less local detail than sonar |
| Multibeam ship sonar | Directly measures the seafloor at high local resolution | Ships are expensive, slow, and cannot quickly cover the entire ocean |
SWOT does not make sonar obsolete. Instead, it supplies a global framework: it can identify structures across remote areas and help scientists decide where detailed ship-based surveys would be most valuable.
NASA’s JPL has noted that only about 25% of the seafloor had been directly surveyed by sonar when its March 2025 report was published. That figure refers to direct sonar coverage—not to the percentage of the seafloor for which no satellite-derived information exists at all.
Why does mapping the seafloor matter?
Ocean circulation and climate
Underwater mountains and ridges can redirect deep-ocean currents and increase turbulence. Those effects influence how heat moves through the ocean and how nutrients circulate between deep and shallow water.
Better maps can improve models of:
- Deep-water circulation
- Ocean mixing and tides
- Heat transport
- Nutrient distribution
- Deep-sea ecosystems
SWOT is not directly imaging every deep current. Rather, its seafloor measurements help researchers understand the physical structures that influence those currents.
Plate tectonics
Abyssal hills often form in parallel bands as tectonic plates separate at mid-ocean ridges. Their orientation and distribution can help reconstruct past plate movements and the history of seafloor spreading.
Rank #4
- THE PERFECT BINOCULARS FOR EVERY ADVENTURE: Nature DX 8x42 offers sharp, detailed views in a compact, lightweight frame—ideal for birdwatching, hiking, and everyday adventures.
- 8X MAGNIFICATION: Get detailed views of birds, wildlife, and distant landscapes. 8x power strikes the perfect balance between image stability and the ability to spot fine features from afar.
- 42MM OBJECTIVES LENS: Compact yet capable, the 42mm lenses offer a balance of portability and bright, detailed views for outdoor adventures.
- BRIGHT, SHARP, TRUE-TO-LIFE VIEWS: Fully multi-coated lenses maximize light transmission, while phase-coated BaK-4 prisms enhance contrast and resolution for crisp, color-accurate images in any lighting.
- RUGGED, WEATHER-READY BUILD: The rubber-armored polycarbonate housing shields against bumps and drops. It’s also waterproof and nitrogen-purged to resist fogging in rain, snow, or humidity.
Navigation and infrastructure
More accurate maps can support underwater navigation, submarine route planning, communications-cable installation and maintenance, and the identification of seafloor hazards. They can also contribute to improved earthquake and tsunami-hazard models, although a gravity-based satellite map does not by itself predict a particular earthquake or tsunami.
Free tools Windows power users keep installed
One-click scans. No signup required.
Geological resource studies
Improved maps may help scientists identify geological settings associated with mineral resources. That does not mean SWOT has located commercially recoverable deposits, nor is it a deep-sea mining system. Its contribution is broad geological mapping.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.What SWOT cannot do
The headline “revealing Earth’s hidden depths” is accurate only if it is understood as indirect, satellite-based mapping. SWOT cannot:
- Photograph the ocean floor.
- Scan directly through kilometers of seawater.
- Produce a complete, high-resolution map of every part of the seabed.
- Resolve every slope, crater, fault, sediment layer, or small biological habitat.
- Replace multibeam sonar for detailed local surveys.
The depth and exact shape of features identified through sea-surface gravity signals still require additional calculations and, where possible, ship-based verification. Detection also depends on a feature’s size, depth, shape, ocean conditions, measurement noise, and the quality of the models used to interpret the data.
A satellite map may reveal that a submerged mountain or ridge exists and show its broad structure without describing every detail of its surface.
Crashes, No Sound, or Screen Glitches?
Random freezes, missing sound and display glitches usually trace back to one bad driver. Find and replace yours safely.Free scan · under a minuteWindows Errors? Fix Them Before They Spread
Repair common Windows errors and clear accumulated junk for a smoother, more stable PC - no reinstall needed.Free scan · no reinstallIs this really a NASA discovery?
SWOT is a joint international mission, and the seafloor map was produced by a NASA-supported research team using SWOT data. It is therefore more precise to say that researchers used data from NASA’s international SWOT mission to improve the global map of the seafloor, rather than saying NASA alone discovered every feature shown.
Best Value
- 32mm aperture brings in lots of light so you can see more
- 8x magnification makes objects appear eight times larger
- Great tool for both terrestrial and celestial viewing
- Sliding optical tube makes it easy to focus
The research described by NASA was published in Science in December 2024. The NASA report appeared on March 19, 2025, while the headline that prompted this explanation was published by Daily Galaxy on March 20, 2025.
The bigger scientific payoff
The value of SWOT is not that it has finished mapping the ocean. Its value is that it can make the unknown more visible at planetary scale.
Satellite observations can highlight areas that have received little ship traffic, expose patterns that are difficult to see from isolated sonar tracks, and provide a consistent global framework for future surveys. Researchers can then combine the satellite-derived map with sonar, gravity data, geological observations, and ocean models.
That combination matters because the deep ocean remains incompletely surveyed not only geographically, but also biologically, chemically, and geologically. A better map is a foundation for asking better questions about currents, tectonic history, ecosystems, hazards, and human infrastructure.
The bottom line
NASA’s SWOT satellite is improving our view of Earth’s hidden seafloor by measuring tiny changes in the height of the ocean surface. Those changes reveal gravitational signatures from underwater mountains, abyssal hills, and other structures.
It is a major advance in global satellite-based mapping, but it is not a camera pointed through the ocean and it has not completely mapped the seabed. SWOT and ship-based sonar serve different purposes: the satellite provides broad coverage and discovers patterns, while sonar supplies detailed direct measurements.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
Quick wins for a faster PC:
Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →Repair Windows errors before they cause bigger problemsFix Now →Scan for outdated or missing drivers - takes under a minuteDriver Scan →
