|
|
 |
|
Education: Learn About Mars |
| Mars has long held the fascination of scientists and the general public since the invention of the telescope. It wasn't until the late 1800s that Mars began to attract the attention of a number of astronomers. The wealthy astronomer Percival Lowell had an observatory built in Flagstaff, Arizona, for the sole purpose of observing and gathering as much information as possible about the Red Planet. After careful observations and much reading about other astronomers' findings, Lowell came to the startling conclusion that Mars was inhabited by advanced life forms. He based his rather incredible theory on what he observed to be canals crisscrossing the surface of Mars. These canals, Lowell believed, were the work of intelligent life forms desperately trying to bring water from melting ice caps at the poles to the warmer regions at the equator. Lowell even wrote a book about his findings, titled Mars as the Abode of Life. Lowell had unknowingly set the world on edge with his remarkable ideas. Various artists shared their visions of what the planet must look like if it were visited by an Earthly being. In H.G. Wells' famous science fiction story The War of the Worlds, Martians leave their dying planet for the Earth's vast resources. Ruthless and uncaring, they destroy everything in their path. The alien invaders eventually die as a result of a common germ to which they have no immunity. |
Percival Lowell sits at the eyepiece of his 24-inch telescope.
Lowell Obervatory Archives |
This drawing shows the canals that Percival Lowell believed to exist on Mars.
NASA
|
After much debate, advances in telescope making, and better observations it was decided that Mars was not likely populated with life as we know it. Still, speculation remained that vegetation growing in the Martian soil was responsible for what many observers identified as dark spots when looking at the planet.
By 1964, the United States began in earnest to explore Mars. A space probe named Mariner 4 sent back several close-up photographs. Based on the data sent back, scientists were fairly certain that Mars was devoid of any kind of life. In fact, it was compared to the Moon – geologically dead. Interest in the Red Planet began to wane. It wasn't until another space probe, Mariner 9, that scientists took a renewed interest in the planet. Mariner 9 was the first spacecraft to orbit Mars and sent back more than 7,000 images of the planet's surface. Scientists were surprised to find a canyon |
| long enough to stretch from Washington, D.C., to Las Vegas, Nevada! The dark patches thought to be vegetation were in fact patches of windblown dust. Many more space probes followed the Mariner missions. In addition to the United States, other countries have sent space probes to inspect the planet. Together, the data collected has helped scientists to map the planet's surface. Scientists have also been able to date many of Mars' geological features. By 1976, the United States was landing space probes on the surface of the planet. We now have two large rovers searching the planet for signs that water once existed in abundance on its surface. |
Mariner 9 paved the way for Mars landers such as this one – the Viking Lander, 1976.
NASA |
Mars continues to hold a great deal of interest to scientists. NASA now has four main goals for the exploration of Mars:
- Determine whether life ever arose on Mars
- Characterize the climate of Mars
- Characterize the geology of Mars
- Prepare for human exploration
|
| If only Percival Lowell could be alive today to witness the frenzy of activity taking place around the exploration of his favorite planet. Although he wouldn't be able to say, "I told you so," he could at least appreciate his pioneering efforts in our hope to someday send humans to the planet. Who knows, maybe you or your children will watch as the first humans set out on their maiden voyage to Mars. What will lie in store for them? What discoveries will be made? How will our view and understanding of Earth be changed? |
| Many instruments have accompanied the spacecraft that have orbited and landed on Mars. Each one was designed to carry out a very specific task, such as study the Mars atmosphere or map the planet's surface. The Compact Reconnaissance Imaging Spectrometer for Mars (better known as CRISM) is an instrument built by the Johns Hopkins University Applied Physics Laboratory (APL). It is due to fly aboard the Mars Reconnaissance Orbiter in 2005. This advanced instrument will use super-cooled detectors to search the planet for signs of past water. CRISM will measure 560 colors reflected back |
NASA's Mars Exploration Rover seeks out answers to our questions about the planet Mars.
NASA |
to the instruments' two spectrometers, looking for these signs of past water. Such evidence would greatly help future missions to Mars. Data collected by CRISM also will help scientists to determine where to land the next Mars rover.
If this is your introduction to Mars, take some time to read over the facts put together for you. Although Mars shares some features in common with Earth, it is also very different. It has several volcanoes like those on Earth. However, they are quite enormous and would dwarf even the largest ones here on Earth. Mars also has valleys and channels. Some scientists believe that these are the result of past water and geological activity.
|
|
Radius: 3,390 kilometers (0.53 of Earth)
Density: 3.93 grams per cubic centimeter (71% of Earth)
Gravity: 0.38 of Earth
Mass: 0.1 of Earth
Two small moons: Phobos (Fear) and Deimos (Panic) |
NASA |
This true-color view of Mars is centered on the Valles Marineris chasma system. The Tharsis plateau, topped with three immense volcanoes, is at left. |
|
Elliptical Orbit 1.38 to 1.67 AU
(1 AU = Earth-Sun distance)
Mars Year: 687 days
Rotates: 24 hours, 37 minutes
Axis Inclined 25˚, has seasons |
|
|
Surface Temperature: –129˚ C to 37˚ C (–199˚ F to 99˚ F)
Atmosphere 1% of Earth, primarily carbon dioxide; polar caps of water, ice and carbon dioxide ice; strong winds, driven by seasonal heating and cooling; great dust storms – near perihelion (southern summer) |
|
This false-color image of Mars shows its topography. Areas of blue indicate a low region. Red and white indicate elevated areas of the planet.
|
Build your own CRISM! Download a cut-out model and create a miniature, 3-D paper version of the instrument that will lead the search for past water on Mars. [Adobe Acrobat required]
|
|
|
|
Put yourself in the role of planetary geologist on our online spectroscopy laboratory! Learn how scientists recognize different types of rocks that may initially look or feel the same, or which are too far away to be touched at all, based on subtle differences in the light they reflect.
Enter the Lab! |
|
|
