If you’re looking for an unpopulated spot to vacation in this winter, Mars isn’t it. In interplanetary terms, the Mars neighborhood is going to be rather crowded, as spacecraft from Europe and the United States descend on it in a kind of Martian land rush.
It’s not a coincidence: the orbital mechanics involved have produced the closest approach of the two planets to each other in 70,000 years.
The first probe to arrive will be Mars Express, the first interplanetary mission launched by the European Space Agency. It lifted off successfully Monday from the Baikonur Cosmodrome in Kazakhstan, riding a Soyuz rocket. Riding along with it is a tiny hitchhiker called Beagle 2.
Beagle 2 is a British-made lander that is designed to search for life. When Mars Express swings into orbit, Beagle 2 will be released, to touch down on Christmas Eve at Isidis Planitia.
The site was carefully chosen. Beagle 2 has no maneuvering ability. That means it needs a large flat area to land in–ideally a flat ellipse 120 kilometres long and 60 kilometres wide. The site is also one where scientists think water could be lurking, and Isidis Planitia is pockmarked with volcanic cones that resemble ones formed on Earth when hot magma explosively meets water. It’s also close to the equator, so the sunlight is strong enough to charge the lander’s solar batteries, shouldn’t be too windy.
Beagle 2 will first use the atmosphere to slow itself down, then open a parachute, and finally inflate huge gas-filled landing bags to cushion its impact with the ground. Once the bouncing and rolling has ended, the bags will be deflated..
Next, Beagle 2’s solar panels will open up and it will start to take pictures with its stereo cameras. Once it has enough power, it will send a signal back to Earth–a song specially recorded and composed by the pop group Blur. (Beagle 2 also includes a tiny painting by U.K. artist Damien Hirst, which it will use to calibrate its instruments.)
Beagle 2 can’t move around. Instead, it will use a robotic arm to reach out and, as one scientist put it, “scratch and sniff” the surface of Mars. Its instruments are marvels of miniaturization. The lander’s diameter is about the same as that of a bicycle wheel it masses just 34 kilograms, of which 11 kilograms are scientific equipment. It carries a mass spectrometer, a microscope, an X-ray spectrometer, a corer, a grinder, a torch and a mirror, all as tiny as they can possibly be made.
The goal of all of this equipment is to look for the chemical signatures of water and life in the rocks and soil. Beagle 2 will also sniff the atmosphere for traces of methane, another sign of living organisms.
Meanwhile, Mars Express will be mapping the planet, and also searching for water with a high-powered radar that will allow it to probe beneath the surface. It will also measure water concentrations in the thin Martian atmosphere.
Beagle 2 is expected to remain active for at least six months, while Mars Express will orbit for at least one year, sending back data from both Beagle 2 and its own instruments daily.
On January 4 and 25, 2004, NASA’s probes, the Mars Exploration Rovers, are scheduled to join Beagle 2 on the surface. They, too, will descend by means of parachutes and landing bags. Their landing sites are Meridiani Planum, thought to be rich in hematite, possibly a byproduct of ancient hot springs, and Gusev crater, considered a possible ancient lakebed. Again, the focus is on discovering if Mars once had, or still has, large quantities of water.
The rovers are far more complex than Beagle 2. Each is the size of a small golf cart, and will roll around the Martian surface for at least 90 Mars days (92 Earth days). Their tools include a camera and an infrared spectrometer, for scanning the landscape for interesting rocks and soils, and a microscopic imager and two other spectrometers which can be placed right up against rocks for a more detailed examination of them. There’s also the Rock Abrasion Tool, or RAT, which can scrape away the outer layers of a rock.
Japan’s Nozomi orbiter should arrive at about the same time as all of these other spacecraft. (It was originally supposed to arrive in 1999, but a navigation error pushed back its arrival. It’s also encountered a vicious blast of solar radiation that knocked out communications. It’s unknown whether it will be able to provide data or not.)
This Christmas and New Year’s, keep your eyes on Mars. It’s the happening place for 2004.
