LETS START WITH WHAT WE DO KNOW:

Nasa Has Some Amazing Graphics Here

Equatorial Diameter: 6,792 km
Polar Diameter: 6,752 km
Mass: 6.42 x 10^23 kg (10.7% Earth)
Moons: 2 (Phobos & Deimos)
Orbit Distance: 227,943,824 km (1.52 AU)
Orbit Period: 687 days (1.9 years)
Surface Temperature: -153 to 20 °C
First Record: 2nd millennium BC
Recorded By: Egyptian astronomers

Mars and Earth have approximately the same landmass.
Even though Mars has only 15% of the Earth’s volume and just over 10% of the Earth’s mass, around two thirds of the Earth’s surface is covered in water. Martian surface gravity is only 37% of the Earth’s (meaning you could leap nearly three times higher on Mars).

Mars is home to the tallest mountain in the solar system.
Olympus Mons, a shield volcano, is 21km high and 600km in diameter. Despite having formed over billions of years, evidence from volcanic lava flows is so recent many scientists believe it could still be active.

Only 18 missions to Mars have been successful.
As of September 2014 there have been 40 missions to Mars, including orbiters, landers and rovers but not counting flybys. The most recent arrivals include the Mars Curiosity mission in 2012, the MAVEN mission, which arrived on September 22, 2014, followed by the Indian Space Research Organization’s MOM Mangalyaan orbiter, which arrived on September 24, 2014. The next missions to arrive will be the European Space Agency’s ExoMars mission, comprising an orbiter, lander, and a rover, followed by NASA’s InSight robotic lander mission, slated for launch in March 2016 and a planned arrival in September, 2016.

Mars has the largest dust storms in the solar system.
They can last for months and cover the entire planet. The seasons are extreme because its elliptical (oval-shaped) orbital path around the Sun is more elongated than most other planets in the solar system.

On Mars the Sun appears about half the size as it does on Earth.
At the closest point to the Sun, the Martian southern hemisphere leans towards the Sun, causing a short, intensely hot summer, while the northern hemisphere endures a brief, cold winter: at its farthest point from the Sun, the Martian northern hemisphere leans towards the Sun, causing a long, mild summer, while the southern hemisphere endures a lengthy, cold winter.

Pieces of Mars have fallen to Earth.
Scientists have found tiny traces of Martian atmosphere within meteorites violently ejected from Mars, then orbiting the solar system amongst galactic debris for millions of years, before crash landing on Earth. This allowed scientists to begin studying Mars prior to launching space missions.

Mars takes its name from the Roman god of war.
The ancient Greeks called the planet Ares, after their god of war; the Romans then did likewise, associating the planet’s blood-red colour with Mars, their own god of war. Interestingly, other ancient cultures also focused on colour – to China’s astronomers it was ‘the fire star’, whilst Egyptian priests called on ‘Her Desher’, or ‘the red one’. The red colour Mars is known for is due to the rock and dust covering its surface being rich in iron.

There are signs of liquid water on Mars.
For years Mars has been known to have water in the form of ice. The first signs of trickling water are dark stripes or stains on crater wall and cliffs seen in satellite images. Due to Mars’ atmosphere this water would have to be salty to prevent it from freezing or vaporising.

One day Mars will have a ring.
In the next 20-40 million years Mars’ largest moon Phobos will be torn apart by gravitational forces leading to the creation of a ring that could last up to 100 million years.

–https://space-facts.com/mars/

Mars is also known as the ‘Red Planet’ because, well, it’s red! This signature colour comes from the large amount of a chemical called iron oxide (or ‘rust’ as you might know it) in its rocks and soil.

Mars is the second smallest planet in the solar system after Mercury. With a diameter (distance through the middle) of 6,791 kilometres, it’s roughly half the size of Earth.

It can get pretty cold on Mars –– much colder than our own planet, since it’s further away from the sun. At the equator, temperatures can reach 20°C, but at its poles they can plummet to as low as -140°C. Brr!

Mars is home to the highest mountain in our solar system –– a volcano called Olympus Mons. Standing a whopping 24 kilometres high, it’s about three times the height of Mount Everest!

A day on Mars is 24 hours and 37 minutes –– only a little bit longer than a day on our own planet. A year on Mars, however, is almost twice as long, lasting 687 Earth days! This is because it takes a lot longer than Earth to complete its orbit around the Sun.

Until recently, scientists believed that there was no liquid water on the surface of Mars –– only rocks, soil dust and ice. But… News flash! In 2018, they found evidence of a lake under the planet’s south polar ice cap. Exciting stuff!

–https://www.natgeokids.com/au/discover/science/space/facts-about-mars/

THINGS WE DON’T KNOW:

Why Does Mars Have Two Faces?

Scientists have been puzzling over the differences between the two sides of Mars for decades. The northern hemisphere of the planet is smooth and low — it is among the flattest, smoothest places in the solar system, potentially created by water that once flowed across the Martian surface.
Meanwhile, the southern half of the Martian surface is rough and heavily cratered, and about 2.5 miles to 5 miles (4 km to 8 km) higher in elevation than the northern basin. Recent evidence suggests the vast disparity seen between the northern and southern halves of the planet was caused by a giant space rock smacking into Mars long ago. –https://www.space.com/13681-mars-biggest-mysteries-water-life.html

A Mars Methane Mystery

Methane — the simplest organic molecule — was first discovered in the Martian atmosphere by the European Space Agency’s Mars Express spacecraft in 2003. On Earth, much of the atmospheric methane is produced by life, such as cattle digesting food. Methane is suspected to be stable in the Martian atmosphere for only about 300 years, so whatever is generating this gas did so recently.

Still, there are ways to produce methane without life, such as volcanic activity. ESA’s ExoMars spacecraft planned for launch in 2016 will study the chemical composition of Mars’ atmosphere to learn more about this methane. –https://www.space.com/13681-mars-biggest-mysteries-water-life.html

Does Water Flow?

Although large amounts of evidence suggest that liquid water once ran on the surface of Mars, it remains an open question as to whether or not it occasionally flows on the face of the Red Planet now. The planet’s atmospheric pressure is too low, at about 1/100th of Earth’s, for liquid water to last on the surface. However, dark, narrow lines seen on Martian slopes hint that saltwater could be running down them every spring. –https://www.space.com/13681-mars-biggest-mysteries-water-life.html

Did Mars Have Oceans?

Numerous missions to Mars have revealed a host of features on the Red Planet that suggest it was once warm enough for liquid water to run across its surface. These features include what appear to be vast oceans, valley networks, river deltas and minerals that required water to form.

However, current models of early Mars’ climate cannot explain how such warm temperatures could have existed, as the sun was much weaker back then, leading some to ask whether these features might have been created by winds or other mechanisms. Still, there is evidence suggesting that ancient Mars was warm enough to support liquid water in at least one site on its surface. Other findings hint that ancient Mars was once cold and wet, not cold and dry nor warm and wet, as is often argued. –https://www.space.com/13681-mars-biggest-mysteries-water-life.html

Is There Life on Mars?

The first spacecraft to successfully land on Mars, NASA’s Viking 1, began a mystery that remains tantalizingly unsolved: Is there evidence of life on Mars? Viking represented the first and so far only attempt to search for life on Mars, and its findings are hotly debated today. Viking had detected organic molecules such as methyl chloride and dichloromethane. However, these compounds were dismissed as terrestrial contamination — namely, cleaning fluids used to prepare the spacecraft when it was still on Earth.

The surface of Mars is very hostile to life as we know it, in terms of cold, radiation, hyper-aridity and other factors. Still, there are numerous examples of life surviving in extreme environments on Earth, such as the cold, dry soils of the Antarctic Dry Valleys and the hyper-arid Atacama Desert in Chile.

There is life virtually wherever there is liquid water on Earth, and the possibility that there were once oceans on Mars leads many to wonder if life ever evolved on Mars and, if so, whether it might be extant. Answering these questions might help shed light on how common life may or may not be in the rest of the universe. –https://www.space.com/13681-mars-biggest-mysteries-water-life.html

Is Earth’s Life from Mars?

Meteorites discovered in Antarctica that came from Mars — blasted off the Red Planet by cosmic impacts — have structures that resemble ones made by microbes on Earth. Although much research since then suggests chemical rather than biological explanations for these structures, the debate continues. These findings do raise the tantalizing possibility that life on Earth actually originated on Mars long ago, carried here on meteorites. –https://www.space.com/13681-mars-biggest-mysteries-water-life.html

Can Humans Live on Mars?

To answer whether or not life did or does exist on Mars, people might actually have to go there and find out.

NASA’s plan as of 1969 was to have a human Mars mission by 1981 and a permanent Mars base in 1988. However, interplanetary human voyages pose definite scientific and technological challenges. One would have to deal with the rigors of travel — issues of food, water and oxygen, the deleterious effects of microgravity, potential hazards such as fire and radiation and the fact that any such astronauts would be millions of miles away from help and confined together for years at a time. Landing, working, living on another planet and returning from it would offer a host of challenges as well.

Nevertheless, astronauts seem eager to find out. For example, this year six volunteers lived in a pretend spacecraft for nearly a year and a half in the so-called Mars500 project, the longest spaceflight simulation ever conducted, aimed at replicating a manned mission to Mars from beginning to end. There are even numerous volunteers for a one-way trip to the Red Planet. Tiny rock-eating microbes could mine precious extraterrestrial resources from Mars and pave the way for the first human colonists, and farmers could grow crops on its surface. The mystery as to whether or not humans will ever go to Mars may rest largely on whether or not the powers-that-be can be convinced to go there. –https://www.space.com/13681-mars-biggest-mysteries-water-life.html

THEORETICAL SCIENCE OF ORIGIN:

THE meteorite THEORY

Evidence is building that Earth life originated on Mars and was brought to this planet aboard a meteorite, said biochemist Steven Benner of The Westheimer Institute for Science and Technology in Florida. –https://www.space.com/22577-earth-life-from-mars-theory.html

Journal

Unexplained Mars