Waiting for the Leonids

While some Earthlings are being wow'd in the movie theaters by the threat of a comet or two hitting the Earth (and likely wondering if such a threat actually exists) , another group of Earthlings have met in a conference to decide how best to minimize damage to  their orbiting property from a much smaller sized, but real cosmic threat.  They called this meeting the Leonid  Meteoroid Storm and Satellite Threat Conference, and it is a threat which could possibly cause major monetary damage to the owners and cause disruption in communications and other areas to business and the general public. The storm will either hit November 17 of this year, or November 18 of 1999.

There are at least 500 satellites operating in orbit around the Earth. They represent billions of dollars floating around transferring and gathering information. Satellites are critical in weather forecasting, gathering scientific data, relaying radio and television signals, telephone communications, as well as the many uses of the military. We have come to depend on these high-tech satellites and the jobs they do. Now it seems that many of them may be threatened by pieces of space debris no larger than a grain of sand.

The Leonid meteor shower takes place around November 18 of every year. It is not one of the more spectacular of the dozen or so meteor showers which take place every year, but the Leonids peak every 33 years. When the shower peaks, it can literally become a storm of tiny debris which the Earth in its orbit will pass through. None of the particles are large enough to cause any threat to Earth. They are tiny particles which will burn up if they enter the Earth?s atmosphere. The problem is the havoc they will wreak to the satellites orbiting the Earth.

Thirty-three years ago when the Leonids peaked last, there were only about 100 satellites around the Earth. Today there are over 500 and we have become dependent on them. At first thought it might be hard to imagine how a piece of debris the size of a grain of sand could cause damage to a satellite weighing a thousand pounds (some weigh far more, some far less) but that's before you consider that that grain of sand will be traveling so fast they will have the destructive power of a .22 caliber bullet. This is more than enough to put holes in solar panels, chip mirrors, short out electrical components and even reprogram computers. This could easily be enough damage to render a satellite useless.

The purpose of the conference was for aerospace engineers, scientists and satellite owners to discuss the hazard and try to come up with ideas to protect their satellites. One of NASA's many concerns is the Hubble Space Telescope. In 1993 the Space Telescope suffered minor surface damage from the annual Leonid shower. But storms produce far more micrometeorites, this year's storm could yield anywhere from 2000 to 100,000 micrometeorites per hour! NASA plans to move Hubble and turn it away from the stream of particles in an effort to protect it. Many other satellite owners will likely opt for the same solution, but that is not possible with every satellite.

A lot of satellites are in geostationary orbits, meaning they are "parked" over the equator at various longitudes and travel at the same speed with which the earth rotates. This means that the satellites are always "over" the same spot on Earth. Weather satellites and many communication satellites are in geostationary orbits. It is not possible to move these satellites and still have them operable. To move communications satellites would mean a break in public service.

Additionally there is concern about Mir, the aging soviet space station. The station is already crippled, damage from the Leonids could cause life threatening conditions.

For many satellite owners, it will be a game of chance. They will simply have to wait and hope for the best, but the outlook is poor. One main conclusion from the conference was that most satellites will suffer minor to major damage.

Whether the storm occurs this year or next is in question, but that it will occur is imminent. It is also a problem we will have to deal with in the future as well. The storm will likely not be very visible from Earth, you may only be aware of it if suddenly your cable tv signal disappears to be replaced by static!

Constellations

The Solar System