- Satellites 101
- GAME: Cruise to Mars
- INTERACT: Exploring orbits
- Mariner 4
- Mariner 9
- Viking mission
- Mars global surveyor
- Dry ice experiment
- Mars odyssey
- Mars express
- Martian methane
- Spirit & Opportunity
- Mars reconnaissance orbiter
- Modern discoveries
- INTERACT: Features of Mars
Engineers designed Mariner 9 to provide the most complete view of Mars ever obtained. Launched on May 30, 1971, it became the first spacecraft to orbit another planet.
Scientists designed Mariner 9 to return more data on atmospheric structure, composition, density, and pressure, but equally important, mission goals included mapping over 70% of the Martian surface. Using infrared radiometry, the spacecraft could also look for signs of volcanic activity as inferred by any heat anomalies found on the surface. Engineers also designed Mariner 9 to study Mars’ two moons, Phobos and Deimos. As an orbiter, Mariner 9 could refine the findings of previous missions and take away the veil of uncertainty which had so far concealed most of the Martian surface. Ironically, when Mariner 9 arrived, a global dust storm obscured the surface from view for about a month. With the dust clearing, Mariner 9 revealed a planet much more interesting than previously expected from the limited views provided by prior flyby missions....
Here is the striking image of Olympus Mons, a giant volcano 22 kilometers high and 600 km wide - about the size of the state of Arizona. One reason volcanos are important is that they can contribute to the development and evolution of a rocky planet’s atmosphere.
Ice & Clouds
Water on Mars exists as ice in the polar caps, as ice or possibly in liquid form beneath the surface, or as scant water vapor in the atmosphere. Here is an image of the north polar cap, which Mariner 9 scientists determined is comprised of water ice and frozen carbon dioxide thanks to spectroscopy. Gray swirls represent frost-free areas. A huge field of dark dunes surrounds the cap. Images like this one indicate a dynamic climate on Mars.
Moisture in the atmosphere condenses when it is lifted high up into the atmosphere. Here we can see clouds forming around volcanos in the Tharsis region. By analyzing the spectral lines, Mariner 9 scientists determined that the clouds are comprised of mostly water crystals.
Past evidence of running water
Mariner 9 gave us an entirely new perspective about the history of Mars. Its images showed ancient river beds and many other flow features indicating free-flowing water on its surface in the ancient past. Mariner 9 provided clear evidence of channels, which looked like they’d been cut by running water through similar processes as we see on Earth.
Valles Marineris is 4000 km (2500 mi) long and reaches depths of up to 7 km (4 mi)! For comparison, the Grand Canyon in Arizona is about 800 km (500 mi) long and 1.6 km (1 mi) deep. If on Earth, this canyon system would stretch from San Francisco to New York.
Below is Mariner 9's view of the "labyrinth" at the western end of Vallis Marineris. Grooves, and crater chains dominate this region, along with a number of flat-topped mesas. The image is roughly 400 km across.
Evidence provided by the channel-like features suggests Mars once had a much thicker atmosphere, warmer conditions, and a lot more water on the surface than we see today. Mariner 9 atmospheric experiments showed current atmospheric pressures ranging from 2.8 to 10.3 mbar (water would rapidly evaporate at this temperature). With evidence of flow features, and therefore the possibility of a time when water was in liquid form on the surface of Mars, scientific interest in the question of the existence of past or present life on Mars intensified.
This image shows upclose, visual evidence of a thin atmosphere. It was thought to be comprised mainly of carbon dioxide crystals:
Another exciting thing we discovered by being in a long-term orbit around the planet: things were changing before our eyes. We saw high winds (up to 200 mph), and seasonal changes due to weather that corrected the assumption of early observers that these variations could have been due to vegetation. The image below shows dust storms which can carry micron-size particles high into Mars' atmosphere. The low-density atmosphere requires high wind speeds for the movement of particles on Mars.
Mapping of Mars
After 349 days in orbit, Mariner 9 had transmitted 7,329 images, covering 100% of Mars' surface. These images were manually combined to form a full map:
The results of the Mariner 9 mission paved the way for the Viking program, a set of two orbiters and the first two landers. Mariner 9 confirmation of atmospheric pressure allowed engineers to design the Viking landers for a safe descent, and the fantastic images and data retrieved fueled the fire for further Mars exploration.
Want to join the conversation?
- does mars have frozen surfaces like antarctica? and how did they found water running if it was frozen?(7 votes)
- Initially, mars did have running water and an atmosphere, but due to the planet's lack of a magnetic field, solar wind literally ripped the atmosphere away from the planet, blasting it into space. Thus, the temperature and pressure dropped, and all water evaporated away (Since the pressure was very low, mars's atmosphere is less than 1% on Earth's, the low temperature didn't matter and individual water molecules escaped into space). The ice at the poles is frozen carbon dioxide.(1 vote)
- how come mariner 9 took black and white photos and not color photos?(7 votes)
- In order for the spacecraft to map the entire surface of Mars, it had to send a lot of photos back to Earth. It is not easy to send a lot of color photos, because color photos take longer to transmit back to Earth. Black and white photos however have a small file size, so more of them can be taken and transmitted.(5 votes)
- Is Mars's lack of water due to it's wildly shifting axis?(5 votes)
- No, the "ice" at the poles is actually a mix of carbon dioxide and water(1 vote)
- If you take a jar 1/6 filled with soil,some water,a plant and an insect and you put a some kind of shield from UV rays and extreme temperatures, will that plant grow and insect live if that jar is kept on Mars?(6 votes)
- If the shield from radiation and extreme temperature works correctly, you would still need to protect the jar from the difference in air pressure in the jar and the Martian atmosphere. Without strengthening the jar to maintain high pressure in the jar and low pressure outside, the jar would explode, killing everything in the jar. However if the jar is reinforced to prevent this from happening, the jar could sustain the life of the bug and the plant for a little while, before their food or water is used up, but to keep them alive indefinitely you would need someone regularly feeding the bug and watering the plant.(6 votes)
- If mars is a dust planet and we have not found enough water on mars for a large storm that we see in the third picture so obviously there is more water on mars then we thought(4 votes)
- They aren't storms, they're thin clouds roughly similar in size and composition to cirrus clouds on Earth. Those are the very thin high up wispy ones you can see on most days.(8 votes)
- why does the video not exist?(3 votes)
- This link also has the video. https://www.facebook.com/MarsInitiative/videos/712519755516089/(4 votes)
- What changed that would make water that used to flow on the planets surface vanish in to space? did something catastrophic happen? Or was this a slower process?(3 votes)
- Mars does not have a magnetosphere that can protect its atmosphere, and solar winds have been stripping it away.(2 votes)
- waht if we cant get to mars :((1 vote)
- We are planning to put humans on Mars by 2023. SpaceX, a company privately owned by Elon Musk, and NASA are working to get us there. Its likely scientists will be taking two-three years missions there.
Another ''company'', Mars One, is trying to put permanent colonists on Mars as a reality TV show.(2 votes)
- Which is the last mission NASA had spent on Mars?(1 vote)
- How did they find a giant pile of photos and turn them into a globe, It is not like they can assemble it as a giant puzzle?(1 vote)
- yes they can fit it in a giant globe because they took pictures of 100% of mars(2 votes)