Search for line in the sky

Press, Volume CXII, Issue 32861, 9 March 1972, Page 16

Search for line in the sky

A thin blue line about 12,000 miles above New Zealand is being sought by scientists and amateur astronomers. The purpose is to check on an experiment by American scientists who, from College, Alaska, have or are planning to fire a rocket which on a given signal will blow out coloured barium which, it is hoped, will travel along one of the earth’s magnetic field lines.

Mr R. S. Unwin, head of the geophysical division of the Department of Scientific and Industrial Research in

Christchurch, said yesterday the barium was expected to travel into the Southern Hemisphere to a point slightly east of New Zealand.

It should come down between 300 and 400 miles south of Campbell Island, he said. According to information received from the United States the rocket was to have been launched between

Saturday and today and in anticipation the department’s auroral station at Lauder had a range of optical instruments and radar looking out for what is expected to be a thin blue line.

Very low frequency radio observations are also expected to be made. It is understood that the University of Canterbury will be making observations from the tracking station at Mount John. The purpose of the coloured barium is to render a line in the earth’s magnetic field visible. By spacing the points of observation it is possible to find out where it lies in relation to the earth.

Mr Unwin said a similar experiment was undertaken last October when a magnetic field line about 7000 kilometres long, above a part of the Pacific Ocean was “painted." This was successful and led to the more ambitious present experiment. It is unlikely the blue line will be visible to the naked eye.