Recommended Free Tools
Earth and Mars differ most in their ability to support familiar surface conditions: Mars is about half Earth’s diameter, has a much thinner carbon-dioxide-rich atmosphere, and has only about 38% of Earth’s surface gravity. Mars has water, but today it is found mainly as ice; its thin atmosphere cannot sustain surface liquid water for long. Temperatures vary widely by location and season, so a single figure does not describe either planet’s weather.
Earth and Mars compared at a glance
| Measure | Earth | Mars |
|---|---|---|
| Mean radius | 6,371.0 km | 3,389.5 km |
| Volume relative to Earth | 100% | About 15.1% |
| Near-surface atmosphere | About 78% nitrogen, 21% oxygen, and 1% other gases | Mostly carbon dioxide; approximate composition is 95.3% carbon dioxide, 2.7% nitrogen, and 1.6% argon |
| Mean surface gravity | 9.82 m/s² | 3.73 m/s², or 0.380 of Earth’s |
| Water today | Abundant liquid water at the surface; ocean covers about 71% of the planet | Water exists, especially as ice in polar regions and below the surface; surface liquid water cannot persist for long under current conditions |
| Temperature figures cited by NASA | Black-body temperature: 254.0 K | Black-body temperature: 209.8 K; separate NASA sources give surface temperatures from about −153°C to 20°C, with other source-specific averages and ranges |
The paired radius, volume, gravity, and black-body temperature figures come from NASA Goddard Space Flight Center/NSSDC’s Mars Fact Sheet and Earth Fact Sheet. Atmospheric, water, and surface-temperature descriptions are from NASA’s Facts About Earth, Mars: Facts, and JPL’s Mars at a Glance. The figures are not all the same kind of measurement: the black-body temperatures are modeled comparison values, not weather-station averages.
How big is Mars compared with Earth?
Mars’s mean radius is 3,389.5 km, compared with Earth’s 6,371.0 km, according to NASA Goddard’s paired fact sheets. That makes Mars about 0.532 Earth radii, or roughly half Earth’s diameter. NASA Glenn gives Mars a mean diameter of 6,785 km, about 0.53 Earth’s.
Diameter is not volume. Mars has about 15.1% of Earth’s volume, so it is substantially less than half Earth’s volume. The distinction matters: “half the size” is a useful description of diameter, but not of how much space the planet occupies. NASA notes that Mars’s surface area is nearly the same as Earth’s dry-land area, another way to picture its scale.
#1 Best Overall
- Read Before You Buy — No Video Output: These adapters support charging and USB 2.0 data transfer, but cannot transmit video signals. Except for standard USB webcams (which use USB data only), they are not compatible with HDMI/DisplayPort cables, video-capable USB-C hubs, or docking stations with video output.
- Convert USB-A Ports to USB-C: Designed to connect USB-C earphones, cables, flash drives, card readers, and other USB-C accessories to standard USB-A ports. Plug-and-play with no drivers or software required.
- Aluminum Alloy Housing: Built with a sturdy aluminum alloy shell that aids in heat dissipation and protects against daily wear and scratches. Designed to maintain a stable and secure connection.
- Compact & Travel-Friendly: The ultra-compact design allows the adapter to stay plugged into your device without blocking adjacent ports or adding bulk, reducing wear and tear on your original USB ports.
- 12-Month Warranty: Backed by a 12-month manufacturer warranty for peace of mind. Designed to meet strict quality control standards for reliable everyday performance.
How do the atmospheres compare?
Earth’s air
Earth’s near-surface atmosphere is mostly nitrogen and oxygen: about 78% nitrogen, 21% oxygen, and 1% other gases, according to NASA Science. This composition, together with the atmosphere’s density, is part of the environment in which liquid water and familiar weather persist at the surface.
Mars’s air
Mars has a very thin atmosphere composed chiefly of carbon dioxide. JPL’s InSight press-kit page lists approximate proportions of 95.3% carbon dioxide, 2.7% nitrogen, and 1.6% argon. These are approximate composition figures, not a direct measure of atmospheric pressure. NASA’s Mars facts page and Glenn Research Center describe the Martian atmosphere as thin; its low pressure is why liquid water cannot remain on the surface for long under present conditions.
Rank #2
- 5-in-1 USB-C Hub: Experience comprehensive connectivity featuring a Power Delivery input, two USB-A 2.0 ports, a USB-A 3.0 port, and an HDMI port. (Note: The USB-C power delivery input port is only for connecting an external wall charger to power your laptop and cannot power peripheral devices.)
- 90W Pass-Through Charging: Achieve optimal charging with 90W pass-through power to your laptop, supported by a total input of 100W, with the hub reserving 10W for operational efficiency. (Note: Wall charger not included.)
- Quick Data Transfers: Accelerate your productivity with rapid data transfers using a high-speed 5Gbps USB 3.0 port and two 480Mbps USB 2.0 ports.
- 4K HDMI Display: Enhance your visual experience with a hub capable of delivering 4K resolution at 30Hz in both mirror and extend modes. Please note that this hub is compatible with MacBook (macOS 12 and newer), Windows 10 and 11, ChromeOS, and laptops equipped with DP Alt Mode and Power Delivery. Note: This device is not compatible with Linux.
- What You Get: Anker USB-C Hub (5-in-1, 4K HDMI), welcome guide, 18-month warranty, and our friendly customer service.
Does Mars have water?
Yes. Mars has water today, especially in the form of ice in its polar regions and beneath the surface. It is not accurate to say that Mars has no water. The key difference from Earth is where the water is and whether it can remain liquid at the surface.
NASA Science explains that Mars’s atmosphere is too thin for liquid water to exist for long on the surface. Geological landforms and minerals also indicate that liquid water flowed on ancient Mars, but evidence of a wetter past does not mean the planet has persistent surface lakes or rivers today. NASA Glenn describes surface features consistent with past flowing water and says there are no current lakes or rivers of liquid water on the surface.
Free tools Windows power users keep installed
One-click scans. No signup required.
Rank #3
- Sleek 7-in-1 USB-C Hub: Features an HDMI port, two USB-A 3.0 ports, and a USB-C data port, each providing 5Gbps transfer speeds. It also includes a USB-C PD input port for charging up to 100W and dual SD and TF card slots, all in a compact design.
- Flawless 4K@60Hz Video with HDMI: Delivers exceptional clarity and smoothness with its 4K@60Hz HDMI port, making it ideal for high-definition presentations and entertainment. (Note: Only the HDMI port supports video projection; the USB-C port is for data transfer only.)
- Double Up on Efficiency: The two USB-A 3.0 ports and a USB-C port support a fast 5Gbps data rate, significantly boosting your transfer speeds and improving productivity.
- Fast and Reliable 85W Charging: Offers high-capacity, speedy charging for laptops up to 85W, so you spend less time tethered to an outlet and more time being productive.
- What You Get: Anker USB-C Hub (7-in-1), welcome guide, 18-month warranty, and our friendly customer service.
Earth, by contrast, has abundant surface liquid water: the global ocean covers about 71% of Earth’s surface and contains 97% of its water, according to NASA Science.
How strong is gravity on Mars?
NASA Goddard’s fact sheets report mean surface gravity of 3.73 m/s² on Mars and 9.82 m/s² on Earth. Mars’s value is 0.380 of Earth’s, commonly rounded to about 0.38 g (NASA Glenn rounds it to 0.37 Earth gravity). These figures describe gravitational acceleration at the surface, not a planet’s mass or a person’s weight in every circumstance.
Rank #4
- Dual Converters, Infinite Potential：Includes 2× USB C male to USB A female adapters and 2× USB A male to USB C female adapters. Perfect for a wide range of uses—tablets with Bluetooth keyboards, expand USB ports on macbook, and more. Two different converters for all your daily needs
- Next-Level 10Gbps & 3A Charging: No more slow 480Mbps, this usb to usb c adapter has a transfer speed of up to 10Gbps, allowing you to do more transferring in less time. This usb adapter fits both USB A and USB C charger, supporting up to 3A fast charging
- Upgraded Exquisite Craftsmanship: With an aluminum alloy housing and metal connector, the usbc to usb adapter is extremely durable and sturdy. Rigorously tested to withstand more than 10,000 times of plugging and unplugging, ensuring long-lasting performance
- Broad Compatible: The usb c to usb adapter widely supports all USB C/ USB A devices like laptops, tablets, cellphones, car chargers, and phone chargers. Such as compatible with MacBook Pro/Air 2023/2022, Thunderbolt 4/3 Devices,Apple MagSafe Watch 9/8/7/SE/Ultra, iPad Pro 2022/2021, Samsung Galaxy S23/S20/S10, and iPhone 17/16/15 Pro. Plug and play
- Please Note: To reach 10Gbps speed, keep the cable under 3.3 ft. For USB A Male to USB C adapters, try flipping the USB C connector. USB C Male to USB A adapters support bidirectional 10Gbps transfer within 3.3 ft
For a simple illustration, an object whose Earth weight is 100 units would weigh about 38 units under Mars’s surface gravity, assuming the same object and ignoring other forces. Its mass would not change; only the gravitational force acting on it would be lower.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.How cold is Mars compared with Earth?
Mars is colder overall, but its surface temperature is not one fixed number. NASA Science’s Mars facts page gives an approximate surface-temperature range from about 20°C to about −153°C. JPL’s InSight press-kit page reports an average of −53°C and a range from −128°C during polar night to 27°C near the equator at midday when Mars is closest to the Sun. Those are distinct source-specific descriptions and conditions, not values to combine into a single universal range.
The Tool Desk
Outbyte PC Repair FREERepair Windows errors before they cause bigger problemsFix Now →Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →Best Value
- 5-in-1 Connectivity: Equipped with a 4K HDMI port, a 5 Gbps USB-C data port, two 5 Gbps USB-A ports, and a USB C 100W PD-IN port. Note: The USB C 100W PD-IN port supports only charging and does not support data transfer devices such as headphones or speakers.
- Powerful Pass-Through Charging: Supports up to 85W pass-through charging so you can power up your laptop while you use the hub. Note: Pass-through charging requires a charger (not included). Note: To achieve full power for iPad, we recommend using a 45W wall charger.
- Transfer Files in Seconds: Move files to and from your laptop at speeds of up to 5 Gbps via the USB-C and USB-A data ports. Note: The USB C 5Gbps Data port does not support video output.
- HD Display: Connect to the HDMI port to stream or mirror content to an external monitor in resolutions of up to 4K@30Hz. Note: The USB-C ports do not support video output.
- What You Get: Anker 332 USB-C Hub (5-in-1), welcome guide, our worry-free 18-month warranty, and friendly customer service.
For a planet-to-planet model comparison, NASA Goddard lists black-body temperatures of 209.8 K for Mars and 254.0 K for Earth. A black-body temperature is a modeled quantity; it is not the same as a measured surface-weather average. Use the surface figures when thinking about local conditions, and keep their stated locations, seasons, or source context attached.
What the comparison does—and does not—tell you
- Size: Mars is about half Earth’s diameter, but only about 15.1% of its volume.
- Air: Earth’s near-surface air is chiefly nitrogen and oxygen; Mars’s is chiefly carbon dioxide and much thinner.
- Water: Mars has water, mainly as ice today, and evidence of ancient surface water; it does not have long-lived surface liquid water under present conditions.
- Gravity: Mars’s mean surface gravity is about 38% of Earth’s.
- Temperature: Mars’s temperatures vary by place and season; a black-body figure, an average, and a local extreme are different measures.
NASA’s Mars Quick Facts infographic, published March 23, 2020, is a concise educational comparison resource covering Mars’s size, atmosphere, temperature, and gravity.
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.
