The Tool Desk
Outbyte PC Repair FREERepair Windows errors before they cause bigger problemsFix Now →Outbyte Driver Updater FREEFix the driver behind crashes, sound loss and screen glitchesFind Drivers →iTechGuides is reader-supported. When you buy through links on our site, we may earn an affiliate commission. As an Amazon Associate I earn from qualifying purchases. Learn more
Scientists map Martian mountains by measuring the distance from an orbiting spacecraft to the ground, then calculating surface elevation against a defined reference surface. NASA’s Mars Orbiter Laser Altimeter (MOLA) made those measurements from Mars Global Surveyor and supplied data for global topographic maps. The key distinction: a summit’s elevation above Mars’s mapping datum is not the same as how far a mountain rises above nearby terrain.
How does a spacecraft measure Martian terrain?
MOLA sent laser pulses toward Mars and timed how long reflected light took to return. As NASA explains, “MOLA sends laser pulses toward the planet and measures the precise amount of time before the reflected signals are received back at the instrument.” The travel time gives the distance from the spacecraft to the surface along the instrument’s ground track.
Researchers combine that range with the spacecraft’s known position and orbit to locate the surface return and calculate its radius and elevation. Repeated passes build up profiles along orbital tracks. Those observations can then be adjusted for consistency and assembled into regional or global topographic products. MOLA’s surface-altimetry collection aboard Mars Global Surveyor continued through June 30, 2001, according to NASA Goddard.
Quick wins for a faster PC:
Scan for outdated or missing drivers - takes under a minuteDriver Scan →Clear out junk files and repair common Windows errorsFree Scan →NASA’s elevation-measurement profile describes the pulse-and-return method. The NASA Planetary Data System MOLA metadata catalogs products including planetary radius, areoid, topography, and shot counts.
#1 Best Overall
- Globe Diameter : 24cm / 9.5"
- Item Size : 9.5"D X 14"H X 10"W / D 24cm X H 36cm X W 26cm / Diameter X Height X Width
- Name : Explorer Red Mars Globe, 24cm/9.5"
- Color : Red (Mars surface) / Uses images from NASA
- Base Material : Plastic Dark Brown (ABS)
What is zero elevation on Mars?
Mars has no global ocean, so it has no ocean-defined sea level. MOLA elevations are instead measured relative to the MOLA areoid, a gravity-based equipotential reference surface. A NASA-hosted technical report defines it as the gravitational equipotential whose average value at the equator equals the mean radius determined by MOLA. USGS map documentation likewise describes converting planetary radii into elevations above the areoid using a Martian gravity-field solution.
The areoid serves as a consistent vertical datum for mapping; it is not a literal sea surface, a uniform physical radius, or the foot of any particular mountain. That matters when comparing figures: “elevation above the areoid” and “rise above the surrounding plain” answer different questions.
Rank #2
- Mars in Motion – A Realistic Look at the Red Planet - Golden-red surface tones with volcanic ridges and weathered terrain bring Mars to life. An inspiring piece for space lovers and science fans alike.
- Self-Rotating Technology Powered by Light - MOVA’s patented design silently spins the globe using ambient light and the Earth’s magnetic field — no batteries or cords required.
- Premium Build with Seamless Movement - A fluid-suspended inner globe rotates within a clear acrylic outer shell, offering a smooth, almost magical visual experience.
- Perfectly Sized for Personal Spaces - Measuring 4.5 inches in diameter (about softball size), it fits beautifully on desks, shelves, and side tables as a compact cosmic accent.
- Gift-Worthy for Dreamers and Thinkers - A thoughtful present for science enthusiasts, educators, students, and anyone fascinated by space. MOVA Globes spark imagination and lasting conversations.
What does Olympus Mons’s height mean?
A NASA-hosted technical report gives the peak of Olympus Mons as 21.2 km above the MOLA areoid. This is a summit elevation relative to the mapping datum. It does not state how far the volcano rises above its surrounding plains.
Recommended Free Tools
Local relief depends on the baseline chosen. For a broad shield volcano, defining where the mountain’s base begins can be difficult, so a rise-from-base figure requires a stated definition of that base. Do not treat it as interchangeable with the 21.2 km datum elevation.
Rank #3
- Globe Diameter : 24cm / 9.5"
- Item Size : 9.5"D X 14"H X 10"W / D 24cm X H 36cm X W 26cm / Diameter X Height X Width
- Shipping Size : 52cm X 34cm X 26cm / 20.5"L X 13.4"H X 10.2"W / Length X Height X Width
- Explorer Gray Moon/Red Mars 2 Globe Set, 24cm/9.5"
- Color : Moon Globe - Gray / Mars Globe - Red
How precise are MOLA-based maps?
Figures for accuracy, resolution, and sampling describe different properties and depend on the particular data product. The USGS’s 2003 documentation for its MOLA-derived Topographic Map of Mars (I Map 2782) reports more than 600 million measurements collected during 1999–2001. For that map, it gives average point accuracy originally about 100 m in horizontal position and about 1 m in radius, but total elevation uncertainty of at least ±3 m after accounting for global and regional areoid uncertainty.
The same map uses a 0.015625-degree-per-pixel digital elevation model (64 pixels per degree), equivalent to about 926 m per pixel at the equator. This is grid spacing, not a claim that every pixel contains a direct laser measurement. Track spacing leaves gaps—commonly 1–2 km, with some near-equatorial gaps up to 12 km—and the map fills gaps by interpolation. Coverage is especially sparse above 87° north and below 87° south.
Rank #4
- Globe Diameter : 24cm/9.5"
- Item Size : D 24cm X H 36cm X W 26cm / 9.5""D X 14""H X 10""W / Diameter X Height X Width
- Illuminated : Yes (LED Light Blub DC 5V, USB Cable Type-A(4-Pin) is included.)
- Attention !!! : Charger(Wall adapter) is not included. Enable mobile phone charger.
- The lighting of this globe is not bright with subdued lighting.
- Range measurement: spacecraft-to-surface distance inferred from laser pulse travel time.
- Horizontal position accuracy: how well a measurement’s location is known.
- Elevation uncertainty: uncertainty in height relative to the chosen datum.
- Grid spacing: the spacing of cells in a gridded map; it is not the same as the spacing of direct observations.
These values characterize the cited USGS map product, not every Mars elevation dataset or every individual MOLA shot.
Free tools Windows power users keep installed
One-click scans. No signup required.
How to interpret a Martian mountain-height figure
Before comparing mountain heights, check what the number measures and how it was produced:
- Baseline: Is the value elevation above the MOLA areoid, relief above a nearby plain, or rise from a defined base?
- Data product: Is it a laser-track profile, a gridded elevation model, or another dataset?
- Sampling: Does the location have a direct track observation, or is the mapped value interpolated between tracks?
- Uncertainty and resolution: Keep elevation uncertainty, horizontal position accuracy, and grid spacing separate.
- Processing: Note the data collection period and the adjustments or gridding used for the product.
For Earth-to-Mars comparisons, state the baseline on both sides. A Mars summit elevation above the areoid is not directly equivalent to an Earth mountain’s height above local ground or sea level.
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.
