Sunday, February 1st, 2004
Mars is a busy place these days. The U.S. rover (mobile robot) Spirit landed on the Red Planet Jan. 3. Then, a couple of weeks ago, a European spacecraft ? the Mars Express ? flew a mere 300 kilometres overhead and buzzed the Spirit. Then another NASA rover, called Opportunity, landed on the planet's surface Jan. 25. But these are not the first machines to visit Mars. The planet is littered with the remains of spacecraft sent from Earth. Many have sent back amazing pictures and information. Some didn't do so well. One spacecraft that didn't do so well is the Beagle 2. The probe was launched in 2003 and was attached to Mars Express. The two separated Dec. 19. Express kept orbiting the planet and Beagle 2 was supposed to land. But something went wrong and there have been no signals from the probe. People first launched spacecraft to Mars in the early 1960s. The former Soviet Union launched five probes then, but none made it. In 1965, the U.S. Mariner 4 spacecraft flew by Mars and sent back the first close-up pictures. In 1969, two more Mariner spacecraft flew by. In 1971, the first spacecrafts actually landed on the planet's surface. They were the Mars 2 and Mars 3, sent by the Soviet Union. Unfortunately, Mars 2 crashed, and Mars 3 relayed just 20 seconds worth of information. Amazingly, over the years the Soviet Union sent 17 spacecraft to Mars, but they all failed. In 1972, the first spacecraft from the U.S. spun into orbit around Mars, the Mariner 9. In the mid-1970s, the Viking 1 and 2 spacecrafts landed on the planet's surface and sent back 52,000 images. In 1997, the U.S. Mars Pathfinder lander and Sojourner rover successfully landed and sent back information for several months. They are still there decorating the landscape. In 1999, the Mars Polar Lander got to the planet, but immediately conked out. In 1998, Japan got in on the act and sent the Nozomi spacecraft. It never quite got to the planet. Oops. More spacecraft will be sent to Mars. Right now the U.S., the French Space Agency and the Italian Space Agency are all making plans. Mars, why bother? Starship asked University of Toronto astronomer John Percy this question. "Mars is one of the closest planets to us, and is the most Earth-like ? compared to places like Venus and the Moon," Percy said. It has an atmosphere (thin by our standards), and friendly enough for us to explore. It has features, like large canyons and extinct volcanoes that look interesting. One big question is whether Mars ever had life on it. Life started on Earth billions of years ago, maybe it started on Mars back then, too. If there are signs primitive life started on Mars, it means humans may not be alone in the universe. There might be life in other solar systems. There is water (ice) on Mars, and signs it once flowed in rivers. Scientists wonder whether there might be remains of ancient bacteria there. Rover Opportunity sent back pictures showing rocks with layers in them. Those layers could have been created over time by sediments carried by water, wind or falling volcanic ash. Each layer will tell scientists something of the history of the planet. Mars Express sent information confirming there is frozen water buried under ice made of carbon dioxide at the planet's south cap. Water vapour was detected in the atmosphere, too. These are signs Mars may have once supported life.