The landing procedure

As the lander approaches Mars about 10 minutes before touchdown, the two Deep Space 2 microprobes are released. Once released, the projectiles will collect atmospheric data before they crash at about 200 m/s and bury themselves beneath the Martian surface. The microprobes will test the ability of very small spacecraft to deploy future instruments for soil sampling, meteorology and seismic monitoring. A key instrument will draw a tiny soil sample into a chamber, heat it and use a miniature laser to look for signs of vaporized water ice.

About 60 kilometers from the microprobe impact sites, Mars Polar Lander will dig into the top of the terrain using a 2-meter-long robotic arm. A camera mounted on the robotic arm will image the walls of the trench, viewing the texture of the surface material and looking for fine-scale layering. The robotic arm will also deliver soil samples to a thermal and evolved gas analyzer, an instrument that will heat the samples to detect water and carbon dioxide. An onboard weather station will take daily readings of wind temperature and pressure, and seek traces of water vapor. A stereo imager perched atop a 1.5-meter mast will photograph the landscape surrounding the spacecraft. All of these instruments are part of an integrated science payload called the Mars Volatiles and Climate Surveyor (MVACS).

When will we learn the news?

During a longer communication session 4:08...6:40 UTC on the morning of Dec. 4 the mission team will attempt to achieve the highest possible data rate with the lander. At a low rate, data sent to Earth during this session could include black-and-white images from the lander camera. At higher data rates, this session could include some color images as well as some images from the descent camera. Data from the Deep Space 2 microprobes are expected to be received (via the MGS) at the same time and could be reported as soon as the news briefing at 07:30 UTC that morning. Results of the probes' soil experiments would come later.

The communication session with the lander on the morning of December 5 (4:50...6:50 UTC) under best possible conditions could include remaining pictures from the descent camera, a stereo image mosaic of the soil near the robot arm and data from MVACS. The first sound from the surface of Mars via microphone could be released no earlier than Dec. 5 under a best-case scenario. Under a best-case scenario, the lander's robot arm could perform its first dig no earlier than the morning of Dec. 8: The first dig will probably occupy two mornings, with analysis of the soil sample performed on the second morning. All of these events and data releases could move later into the mission due to telecommunications factors or other conditions.

The six new planets increase by about 25 percent the number of known "extrasolar" planets, giving astronomers a substantial amount of additional information about planetary systems. The new planets orbit stars that are similar in size, age, and brightness to the Sun and are at distances ranging from 65 to 192 light-years from Earth. The planets themselves range in mass from 0.8 to 6.5 times the mass of Jupiter and they are probably also similar to Jupiter in their compositions - basically giant balls of hydrogen and helium gas.

In addition to the discovery of six new planets, the researchers gathered new data on four previously known planets. Two of them, around the stars HD 217107 and HD 187123, showed long-term trends in their orbits indicating the presence of an additional companion. These companions, which may be planets or larger objects (e.g., brown dwarfs), appear to be orbiting their host stars in a long period, taking at least two to three years to complete an orbit, Vogt said. These findings are significant because previously only one other system of multiple planets, around the star Upsilon Andromedae, had been identified.