Planet Mars lies between Earth and Venus. Travelling at approximately 228 billion km per year from Sun to Matahari, Planet Mars can be seen moving outward from its surface.
As its equatorial orbit is circular, so has low altitude, its surface temperature is significantly lower than that of the Moon, giving rise to its classification as a cold planet.
Mars (also referred to as Ares in Greek mythology), one of four planets in our Solar System that orbit around the Sun, was first observed through a telescope by Galileo Galilei in 1610.
Mars, the second-smallest planet after Mercury, boasts an atmosphere containing nitrogen, argon, oxygen and carbon dioxide – similar to that found on Earth – which suggests life could exist there through photosynthesis.
Earth has an average thickness of approximately 3 miles (4.8 km), and its mantle is composed of iron, magnesium, calcium and aluminum – these constituents make up its composition.
This mantle, estimated at about 4.5 billion years old, is composed of molten rock that produces hot plumes of gas that are visible on Mars’s surface. Volcanic eruptions that once existed but no longer produce eruptions may also contribute to these hot gas plumes on Martian surface.
Over time, scientists have searched Mars for evidence of water. Some believe it may have existed on its surface as far back as 4.1 billion years ago; furthermore, its remnants may still be beneath its surface today.
Location of water has significant ramifications when deciding if there is life on a planet, especially since an area of liquid water on its surface would be essential to astronauts transporting supplies between Earth and Mars, and those looking to live on Mars in the future.
Observers have identified numerous features on Mars’ surface, such as craters, dunes and dust devils. These structures reveal information about past activity on its surface while providing insights into Mars’ geology.
Mars is a reddish planet with a thin atmosphere similar to Earth’s Moon and polar ice caps, and boasts some of the largest dust storms in our Solar System, reaching winds speeds over 160 km/h (100 mph).
Mars is less dense than Earth, meaning its atmosphere cannot exchange as much heat with its surface, leading to colder temperatures on Mars than here ranging from -81 deg C in summer and -220 deg C during winter months.
Osczevski notes that this won’t pose a problem for future human colonists since current spacesuits can handle the temperatures on Mars. Furthermore, thin air also prevents martian explorers from experiencing wind chill, which can reduce comfort as it sweeps heat from their bodies back into space.
Osczevski notes it would still be difficult for an explorer to stay warm when exposed to windy conditions typical of global dust storms, such as 15kph winds at -40degC; an exposed Mars explorer would lose 60 times as much heat compared to their Arctic counterpart.
Osczevski believes the Martian atmosphere is so thin that it doesn’t absorb much heat from the sun, thus eliminating a greenhouse effect and thus not creating a greenhouse effect.
Osczevski points out, however, that doesn’t guarantee that Mars won’t be cold: because its distance from the Sun means sunlight takes longer to reach its surface.
Mars’ climate can vary significantly, from warm and sunny sub-tropical regions to cold and rainy conditions in its extreme north. Aside from temperature, there are other factors which affect its environment such as low gravity or dust in its atmosphere which have an effect.
Mars’ atmosphere primarily comprises carbon dioxide. Additionally, however, trace quantities of nitrogen, argon, oxygen and water vapor exist within its boundaries.
Mars has an atmospheric pressure a little below one percent that of Earth, which is an astonishingly low percentage despite being so close to the sun. Surface pressure on Mars averages 7 millibars with deepest basins experiencing pressures as low as 9 mb and Olympus Mons (the tallest mountain on Mars).
At the surface, air travels across our planet through Hadley cell motion. This pattern features rising, warmed air that rises northward before cooling and sinking back toward its original position at the equator at surface level – controlled locally by landforms and planet rotation.
Mars experiences extreme ground heating that produces large-scale winds that transport dust particles up into its upper atmosphere, where they absorb significant heat and promote more wind circulation.
Mars’ atmosphere condenses during winter to form ice caps at each pole. Each spring, these ice caps begin to melt away as some of their mass sublimates back into its original atmosphere.
An obvious difference between Mars and Earth atmospheres is their respective lack of an ozone layer, which provides our atmosphere with protection from UV radiation from the sun that could otherwise damage cells within its upper levels of atmosphere.
Mars and Earth differ significantly in terms of oxygen concentration; scientists discovered in 2003 that Mars’ atmosphere contained one-third less than what exists here on Earth, sparking intense debate as to where all that oxygen had gone.
Mars is an extremely cold planet, where temperatures often dip well below the freezing point of water, creating layers of frost and snow across its surface.
Winter temperatures at Earth’s polar caps can drop well below -20deg Celsius (-29deg Fahrenheit), creating an extremely harsh environment in which any organism that attempts to survive would likely perish.
Mars weather can be hard to predict, making its climate very hard to predict. Latitude and season impact its weather patterns as solar energy strikes different parts of its surface.
Mars shares Earth’s four seasons but can experience dramatic temperature swings throughout each day due to low thermal inertia of its surface, meaning it heats and cools off rapidly with solar radiation.
Mars experiences similar winds to Earth. These range from light winds blowing at just a few miles per hour to massive dust storms that cover thousands of kilometers across its surface and even cause hailstorms.
Auroras, created through interactions between Martian magnetic field and solar radiation, can often be seen on stormy Mars days when there’s an unexpectedly large infusion of solar energy.
Weather will be an immense factor for future human expeditions to Mars, so scientists are making efforts to predict its weather long before people set foot there. This will allow them to plan what resources they’ll require, where to locate them and how best to utilize them.
Life on Mars
Images from Mars have unleashed a flood of speculation about life on its surface. Some researchers believe they have spotted fossilized shrimp, crabs, sea spiders, scorpions and even millipedes; while others insist they have seen living algae and fungi.
NASA’s Curiosity rover made one of the most notable discoveries when they found organic molecules from Gale Crater rocks that may once have held water, possibly once being home to Gale Lake. Though their discovery does not necessarily signify ancient Martian life existed at one point or another, their existence provides key evidence for future explorations.
It also suggests that early Mars could have been an extremely supportive environment for life to arise and flourish, providing plenty of raw ingredients like liquid water on its surface and an airy atmosphere for it to flourish in.
Another astonishing discovery may explain this evidence of life on Mars: Earth-based organisms may have taken the journey from our own planet. Space travel has long been established as an easy means of moving material across galaxies; so this scenario seems plausible.
“The possibility that Earth-borne materials reached Mars is compelling,” according to Mark Asphaug, professor of space sciences and engineering at the University of Colorado Boulder. Asphaug believes impacts between planets may have sent material back and forth allowing more of it to reach Mars than otherwise would have happened.
As such, the prospect of finding evidence of life on Mars remains very real and will mark an unforgettable milestone in science. Should such signs of life surface on our world’s nearest neighbor planet, it will mark a truly astonishing discovery and constitute a true discovery moment!