There hasn’t been any other planet other than Earth that has been studied as much as Mars. Humans have sent more spacecraft to Mars than any of the other planets and we are finding out more about it every day. As the fourth planet from the sun in our solar system it has been the single planet that has brought the most curiosity.
Mars has been observed in the celestial skies for thousands of years. Its odd red color can be seen with the naked eye and many civilizations associated the color with blood and therefore battle and war. It’s because of this that it was named after the mythological god of war.
During early history there were many stories made up about Mars and the belief that there was a civilization of Martians that lived on the planet. Science fiction books, movies, television shows and even games have been made up about creatures both good and bad that lived on the Red Planet.
Thanks to the orbiters, landers, and rovers sent to Mars, we now know an incredible amount of detail about Mars and part of its past.
NASA has established the Mars Exploration Program for continued research of the Red Planet. The list their mission statement as:
“The goal of the Mars Exploration Program is to explore Mars and to provide a continuous flow of scientific information and discovery through a carefully selected series of robotic orbiters, landers and mobile laboratories interconnected by a high-bandwidth Mars/Earth communications network.
Mars is over 142 million miles from our sun and in size it’s about one-sixth the size of Earth. The reddish color of the soil is due to oxidization (rust) from the iron-rich soil. Mars has two small moons named Phobos and Deimos and they are named after the sons of the mythological god of war. Phobos translates to “fear,” and Deimos translates to “flight.”
We know that Mars is a small rocky planet that may have once been similar to Earth. It joins the other terrestrial planets of Mercury, Venus, and Earth, and we have seen that it has a surface that has been altered due to volcanism, crust movements, impacts from other objects, and atmospheric conditions such as dust storms.
Mars has a type of seasonal change and the polar ice caps grow and get smaller as each season changes. The layers of soil that are located near each of the poles also indicate that the planet has experienced changes in climate on more than one occasion and possibly as part of its regular change due to alterations in the orbit of the planet.
On Earth, we have tectonic movement involving plates that grind, crash into, and slide up and over each other. Some of the biggest of these are spread out on the floors of our oceans. Mars tectonism differs from ours in that they seem to be more vertical. The changes on the crust of the planet seemed to have shoved hot lava upwards to the surface but they didn’t spread out.
The planet has periodic dust storms that are so huge that they surround the whole planet. The effects of the storms are incredible, creating giant dunes, wind-carved features, and wind streaks.
The average temperature on Mars is incredibly cold at -80 degrees F. The surface is covered with a lot of features that would be familiar on Earth including: dry lake beds, volcanoes, canyons, and craters. All of the features are covered in red dust that blows from the huge storms. Like Earth, Mars also has clouds as well as wind, and it even has tornados that are so big that we can see them on Earth.
The gravity on Mars is about one-third that of the Earth. This means that if you dropped a rock on Mars it would fall slower than on Earth. A person that weights 100 lbs on Earth would only weigh 37 lbs on Mars.
Mars does have an atmosphere but it’s much thinner than our atmosphere on Earth. It contains about 95% carbon dioxide and around 1% of oxygen.
Mars Lessons Learned by NASA:
The first orbiter that NASA flew to Mars was the Mariner 4 in 1965. Mariner 4 took close-up images of the Red Planet and sent them back to Earth. The Viking 1 and Viking 2 landers were the second successful spacecraft and they arrived in 1976. Both landers collected science data from Mars’ surface and took images.
Since that time there have been quite a few successful spacecraft that have orbited, landed, and even roamed around the planet. Scientists have been focusing on the search for water on Mars. Water is one of the key ingredients for life to begin and thrive, so finding evidence of liquid water on any planet would mean that life might exist or have existed at one point.
The NASA rovers Spirit and Opportunity both found evidence that at one time in the history of Mars, water flowed. They found flood-paths on the surface that had not been covered by the massive dust storms, which also means that there was some form of liquid flowing and flooding surface areas more recently. The rovers also located minerals that can only form in water.
NASA sent the Mars Global Surveyor to orbit around Mars for nine years. During that time it mapped the surface of Mars in such detail that they could create a geological map. The orbiter also found that at one time, Mars had a magnetic field that was similar to Earth’s and that it shielded it from the deadly cosmic rays.
NASA has quite a few spacecraft that continue to orbit Mars and they use various scientific tools to collect data including information about the topography, climate, and the types of minerals found on Mars. Scientists are studying the results of the scientific experiments done by the rovers on the soil and rock as well as all of the images returned to Earth.
The Mars Exploration Program is a long term project involving spacecraft and technologies to continue researching Mars and preparing for the possible human expedition to the planet. By investigating the results sent back by all of the previous spacecraft and rovers, scientists have learned that Mars is home to volcanoes that are from 10-100 times larger than those on Earth.
They have studied the geology to recognize that the crust on Mars doesn’t move like the tectonic plates on Earth and the lava from the volcanos on Mars just reaches the surface and piles up on top of previous layers. The largest volcano in the solar system is found on Mars.
Olympus Mons is in the northern Tharsis region and is so big that it has actually had an effect on the roundness of the planet by causing a deformity, creating an enormous equatorial rift valley of Valles Marineris. The canyon that has been made stretches out the distance from Los Angeles, California to New York, New York. The Grand Canyon in Arizona would fit on one side of the chasm of this canyon.
The atmosphere on Mars is a lot thinner than the atmosphere on Earth. It’s mainly made up of 96% carbon dioxide, and smaller percentages of other gases such as nitrogen and argon. Although the atmosphere is thin, the atmospheric pressure on Mars’ surface is around 0.6 percent of that at sea level on Earth.
Data sent from the MAVEN mission spacecraft has shown that at one time, the atmosphere on Mars was a lot thicker and that Mars lost most of its atmosphere through time. Scientists believe that the reason for the atmospheric loss is due to solar wind.
The Presence of Water?
Mars has many areas that show that the planet probably had water around 3.5 billion years ago. The evidence indicates that Mars might have had some of the largest floods of any planet in the solar system. The current temperatures on Mars are too cold and, combined with the thin atmosphere, liquid water can’t exist on the surface for very long. There is water that is close to the surface and frozen at the polar ice caps, however, the sheer volume of water that is required to carve out the huge channels and flood plains isn’t on the surface today.
NASA’s Mars Global Surveyor has sent back images that suggest that there may be reservoirs of water underground and that they break the surface at intervals. If this is true, liquid water underground might also be harboring life.
Figuring out if there is liquid water on Mars is one of the most important factors to understanding everything about Mars as well as unlocking some of the secrets of the evolution of other planets, including Earth. Before any humans visit and stay on Mars we need to know everything that we can about the environment, especially if there is a resource such as water available.
This is a rather new field of study and brings together scientists from a lot of areas including: astronomy, biology, physics, geology, etc. They all work together to try to understand the history of a planet and whether there is the potential for life to exist outside of our Earth.
With the discovery of possible fossil life in the Mars meteorite, ALH84001, the interest in Mars increased so that NASA formed their Astrobiology Program and the Astrobiology Institute. During this same time, the NASA Mars Exploration Program focused on the data being sent by the various rover missions. The information that was being studied included the search for potential water on Mars as well as the mineral ingredients held within the rocks to see if they ever hosted life.
NASA has shifted their science them so that they are seeking for signs of life on Mars. The details are held in the rocks at incredibly small levels. Compounds that are called biosignatures that are molecular fossils can indicate if organisms created them. The difficulty with the rocks on Mars is that they are subject to destruction and transformation over hundreds of millions of years and the signatures may not be recognizable.
One of the plans for future missions is to locate places on the surface where the wind-blown erosion has exposed more ancient material. The plan will include the ExoMars rover which will drill and take samples from a depth of around two meters for analysis.
- Mars landmass is 10% of the Earth and it has only 15% the volume of Earth.
- Of the 39 missions sent to Mars, only 16 have been successful.
- Chunks of Mars have been found on Earth. When meteorites crashed into Mars it ejected pieces of Mars that eventually found their way and made it through our atmosphere.
- For many years, people thought that Mars had intelligent life. This was due to what Italian astronomer Giovanni Schiaparelli called “canals” that he thought he saw on the surface from his telescope. As we explored Mars we found out that the canals were just an optical illusion.
- The huge dust storms on Mars is due to the elliptical shape of the orbit path of the planet around the sun.
- When you are standing on Mars, the sun looks about half the size that it does when you are looking at it from the surface of Earth.
- So far, other than Earth, Mars has been the planet that has been found to be most hospitable to life.
- It takes 687 Earth days for Mars to complete its orbit around the sun.
- Other than Earth, Mars is the only planet to have polar ice caps.
- Mars experiences seasons like Earth, except that they last twice as long.