1995 Ad

Science News, Jan 14, 1995 by Ron Cowen

Several of the craft's detectors will explore the processes that generate and heat the sun's outer atmosphere, or corona, and create the stream of charged particles known as the solar wind. Other instruments will attempt to peek inside the sun by studying its sound waves, much as geologists use seismic waves to "see" inside Earth.

A group of SOHO instruments will measure changes in gas motion at the sun's surface, as well as fluctuations in temperature and radiation that provide vital clues to the density and composition of gases in the sun's interior.

november

* Two small platforms, known collectively as the Cosmic Dust Experiment, ride a manned Russian craft to MIR, the Russian space station. Mounted by cosmonauts, the U.S. experiment will use special gels and foams to collect cosmic dust particles over a period of 10 months. A U.S. shuttle crew will return the experiment to Earth so scientists can analyze the composition of the dust.

* ESA launches its Infrared Space Observatory (ISO), only the second satellite devoted entirely to infrared studies. ISO will study the solar system, the birth and death of stars in the Milky Way, and quasars billions of light-years beyond our galaxy. During its 18-month survey, the observatory's helium-cooled instruments will study selected sources over a wide range of infrared wavelengths, from 2.5 to 200 micrometers.

* An ESA-NASA joint venture focuses on planet Earth. Launched by an ESA Ariane 5 rocket, four identical spacecraft collectively known as Cluster will fly in formation to study the ionized gas, or plasma, within Earth's magnetosphere. This is the region surrounding our planet dominated by Earth's magnetic field.

Ground controllers will adjust the distance between the Cluster spacecraft, depending on the size of the plasma structure under study; comparison of measurements from all four craft should yield a three-dimensional picture of the plasma. This mission is expected to last for at least 2 years.

december

* Complementing the July launch of FAST and last year's Wind mission, NASA in December sends aloft the Polar satellite, which carries 11 instruments to study the solar wind's interaction with Earth's magnetic field. In particular, the craft will monitor the flow of the solar wind over Earth's magnetic poles. Polar will also photograph the northern aurora, observing the energy exchange between the ionosphere, the region just above Earth's upper atmosphere, and its magnetosphere.

* On the seventh day of December, the Galileo probe released in July will reach its final destination, parachuting deep into Jupiter. The detector-laden probe will beam data to its mother craft for about 75 minutes before meeting its demise, crushed by the pressures deep in the planet's thick atmosphere. Because Galileo's main communications antenna remains stuck, the data will be stored on the craft's tape recorder for transmission to Earth several months later.

* Just as its free-flying probe reaches Jupiter, Galileo will embark on a 2-year grand tour of the giant planet and its moons. Despite Galileo's antenna problem, which will prevent the craft from radioing to Earth as much data as intended, NASA scientists expect Galileo to accomplish about 70 percent of its original mission.