Mars (also see Are we alone page)
Due to the many Mars Rovers NASA's JPL has put on Mars, the dream of human visitation to the "Red Planet" has become a dream. With NASA and SpaceX both setting their sights on human exploration of Mars. Two science fiction movies that claim to be what a trip to Mars would be like, ''Red Planet" and "The Martian". These and other movies have sparked a public love affair with the idea of space travel beyond the Moon. There is one major problem: these are science fiction and will remain in science fiction. While human technology has increased over the years, the laws of physics have not changed. Earth’s magnetic field protects life from the Sun's deadly radiation. If travelling to Mars, approximately 6 weeks into the 1-year journey, the Sun's lethal solar radiation would kill everyone aboard the craft. Solar radiation includes: X-rays, gamma rays, and high-energy proton storms from solar flares and coronal mass ejections (CMEs). All of these forms of high energy pose deadly risks to life. There is no way to stop these types of radiation on a spacecraft. The movies "Red Planet" and "The Martian" also failed to show what human life on Mars would be like (by pretending there is no deadly radiation). Mars is small, thus there is not enough gravity to walk. The dust on Mars sticks to everything. It is very cold on Mars (global temperature is −81 °F), a greenhouse would not work to grow anything. It is very dry on Mars, Mars's atmosphere has a humidity of 0.03%; Earth's average humidity is about 50% (ranging from 0.36% to 100%). Robots only have a problem with the cold; rovers are shut down during Mars winter. SpaceX announced in February 2026 that it was ending its plan to send humans to Mars. With the new SpaceX Humanoid robots, SpaceX will send these to Mars in place of humans, a wise move.
Note: Links below are to Wikipedia pages.
Mars was not always so cold and dry. The presence of rust on Mars indicates that Mars once had lots of water. We now know that when Mars formed, it had not only water, but a thicker atmosphere and a magnetic field. These Earth-like features did not last; within just a few million years, they were all gone. 1) Mars's small size and lower densitymeans it lacked the gravity to hold on to its atmosphere. Mars's gravity is only 37.5% that of Earth. 2) The lack of gravity with the Mars carbonate catastrophe, and loss of its magnetic field, removed all the water on Mars. Mar's core lacks the potassium-40, uranium, and thorium abundances that Earth's core has, so its core cooled and its magnetic field was lost. Without a large magnetic field, the solar wind (radiation) stripped most of Mars' atmosphere away. But, it is not a matter of if, but a matter of when, the remains of life will be discovered on Mars. Martian rocks ejected into outer space, by impacts, about 7.5 per cent will eventually find their way to Earth. About 1.7 per cent of the rocks escaping Earth’s gravity, from impacts, will wind up on Mars. So ancient Earth life (frozen dry) is on Mars and the Moon.
Mars today:
Mars today is very different from its early history, pre-carbonate catastrophe. Mars today:
Mars's atmosphere is 95% carbon dioxide, 3% nitrogen, 1.6% argon. Earth's atmosphere is 78% nitrogen, 21% oxygen, 0.9% argon, 0.04% carbon dioxide.
Mars has only about 0.7% of the atmospheric pressure of Earth. Mars's atmosphere is about 6.5 millibar, Earth's atmosphere is 1013 millibar. Surface of Mars is like Earth at 100,000 feet (30 kilometres) in the stratosphere.
Mars's atmosphere has a humidity of 0.03%; Earth's average humidity is about 50% (lowest 0.36%, high 100%).
Intense ultraviolet solar radiation, due to thin atmosphere.
Intense solar radiation and cosmic rays due to the lack of a magnetic field. No life can live on Mars, as DNA is destroyed quickly.
Alkaline pH soil at 8.3, due to chlorine in the soil. Earth's average soil pH is about 6.5.
Virtually no oxygen at 0.13%. Earth at about 21% oxygen.
Mars is covered in dry iron oxide dust, has seasonal global dust storms, with a duration of about a month.
Mars's average global temperature is −81 °F (−63 °C; 210 K), Earth's average global is 57 °F (14 °C; 287 K). Greenhouse can work on Mars too cold and radiation.
The seasonal Martian polar ice caps are mostly dry ice, frozen carbon dioxide atmosphere (CO2).
Comets falling on Mars bring some water and ice to Mars. The thin Martian atmosphere means the freezing, evaporation, and boiling point of water is all at the same temperature. Thus, liquid water cannot exist on the surface of Mars.
The solar system’s four rocky planets—Mercury, Venus, Earth, and Mars—have masses (relative to the mass of Earth) of 0.06, 0.81, 1.00 and 0.11, respectively. Notice that Venus and Earth dwarf the other two. Mars, on the other hand, should have a mass similar to Earth’s and Venus’ considering where it formed. Until recently, astronomers lacked a satisfactory explanation for this discrepancy between Mars’ actual mass and its expected mass. Then scientists discovered a mechanism by which Jupiter in the past stole material from the region where Mars formed.
Ext. Link YouTube on Mars
Ext. Link Mars Video update 3-2026
Ref:
Jessica C. E. Irving et al., “First Observations of Core-Transiting Seismic Phases on Mars,” Proceedings of the National Academy of Sciences USA 120, no. 18 (April 24, 2023): id. e2217090120, doi:10.1073/pnas.2217090120.
Irving et al., “First Observations,”
Bonnie J. Berry, David G. Jenkins, and Andrew C. Schuerger, “Effects of Simulated Mars Conditions on the Survival and Growth of Escherichia coli and Serratia liquefaciens,” Applied and Environmental Microbiology 76, no. 8 (April 2010), 2377–86.
Donald M. Hassler et al., “Mars’ Surface Radiation Environment Measured with the Mars Science Laboratory’s Curiosity Rover,” Science 343 (January 2014): 1244797, doi:10.1126/science.1244797.
C. Mileikowsky et al., “Natural Transfer of Viable Microbes in Space,” Icarus 145 (2000), 391-427.
Viking Landers Biology Experiments
Fabrice Gailard and Bruno Scaillet, “The Sulfur Content of Volcanic Gases on Mars,“Earth and Planetary Science Letters 279 (March 15, 2009): 34-43.