We have been observing Mars long since before the time of Galileo. Being the first person to bother pointing a telescope up at the sky (instead of across the oceans looking for pirates), Galileo could add more details to the knowledge of Mars, such as the fact that it occasionally appears to go backwards across the sky. This is called retrograde motion, and it happens because being in an inner orbit Earth overtakes Mars every so often. He also observed Mars’ motion over time and concluded that Mars was orbiting something that was clearly not Earth.
In Star Trek’s time Mars will be not only well explored, but colonized with permanent settlements and major Federation installations such as the Daystrom Institute of Technology and the Utopia Planitia Fleet Yards, where the USS Enterprise NCC-1701-D, the USS Defiant, and the USS Voyager will be built.
Figure 1: Utopia Planitia Fleet Yards (from Memory Alpha).
Today, Mars has many mysteries yet to be revealed. Since the 1970s we’ve been sending robots to explore the surface of Mars both from orbit as well as on the ground. The twoViking explorers launched in 1975 were active until 1980 and 1982, respectively. Their tasks were to obtain images, record as much detail as possible about the surface and the atmosphere, and search for signs of life, past or present. The first two tasks were achieved; the result of the third was negative.
Figure 2: Valles Marineris as seen by Viking 1 (from NASA).
Some of the most striking features shown in the Viking images are what looks like dry river beds and flood plains, in addition to one very large canyon. Subsequent missions, such as the various generations of rovers, as well as other orbital craft such as the Mars Global Surveyor, have added images and data making it clear that these features are not there by accident. The presence of sedimentary formations, gullies running down crater walls, river valleys, and gray hematite deposits can mean only one thing. There once was liquid water on Mars.
Figure 3: A flood plain (left) and gullies (right) on Mars (from NASA).
In order to have liquid water, the temperature on the surface must be between the freezing and boiling points of water. Looking at Mars today, even a nice summer day has temperatures well below the freezing point of water. Furthermore, to have liquid water on the surface the atmosphere would have to be far more substantial in order to provide the pressure necessary to maintain this liquid. Mars’ atmosphere today is very thin, only about 1/150 of what we enjoy here on Earth. This is not enough atmosphere to allow the presence of liquid water.
Therefore, if there once was liquid water on Mars, the surface conditions to support it must have existed. Obviously, they do not exist anymore today. So what happened to the climate on Mars?
In order to answer this question, a new mission was launched to Mars on November 18, 2013, in the early afternoon hours (EST) from Cape Canaveral. The Mars Atmosphere and Volatile EvolutioN (MAVEN) mission is part of NASA's Mars Scout program, funded by NASA Headquarters. The travel time to Mars will be about 10 months, after which the space craft will collect data from Mars’ atmosphere in order to ascertain the role that the loss of atmosphere might have played in the climate change and the history of liquid water on the surface. If Mars once had habitable conditions, we’d like to know what happened to change that.
Figure 4: MAVEN launch from Cape Canaveral (left) and MAVEN at Mars (right, artist concept). (both images from NASA).
If we can find out what happened to Mars’ climate, maybe we can determine where all the water went that made these surface features. And maybe we can find out if the water was around long enough to allow life to develop just as it did on the young Earth. But that’s something for another mission, hopefully in the not too distant future.
Here are a few links for you if you’d like to know more about this topic.
The MAVEN Mission:
The Viking Landers:
The Mars Global Surveyor:
The Mars Rovers: