Continuing the legacy of the 50th anniversary of the International Geophysical year in 1958, the International Heliophysical year or IHY-(2007-2009 and continued) seeks to advance our understanding of the heliophysical processes that govern the Sun, Earth and the heliosphere IHY is designed to demonstrate the beauty, relevance and significance of space and Earth science to the world.
The goals of IHY are to develop the basic science of helio-physics and to determine the Sun-heliosphere relationship. In short, scientists would like to know how the Sun influences the electromagnetic environment of the Earth and other planets. A major thrust is setting up magnetometers and other monitoring instruments.
Though the Sun is 150 million kilometers away from us, it is continuously pouring out charged particles into space, called the solar wind. When surges in the solar wind warp Earth’s magnetosphere, geomagnetic storms occur sending charged particles into the upper atmosphere. The fiercest storms occur when the Sun’s eleven-year activity cycle is at its peak. It is marked by coronal mass ejections (CMEs) that are great bubbles of plasma. They contain billions of tons of charged particles that the Sun sporadically spews into space. CMEs can disrupt power grids and damage satellites. Astronauts will also be in danger.
The ionized upper part of the atmosphere—called the ionosphere—which acts as a radio mirror in the sky—can suffer what is termed “bubbles”, near the equator and disrupt TV transmission. A US satellite is designed to look for such bubbles. Meanwhile, China has announced its plans to build and orbit three satellites called Kua Fu, to watch the Sun. Canada and Europe will also participate in defining the scientific objectives. One of the satellites will be at Lagrangian point (L-1) and would send images of solar flares and CMEs and given unto three days of warning L-1 is at 1.5 million km from the Earth towards the Sun, where the gravitational forces of the Earth and the Sun balance each other.
Prediction of CMEs is now a major goal of solar physicists. Kodaikanal, situated near the Earth’s magnetic equator, is specially suited for studying the impact of solar activity on the Earth’s magnetic field. The Kodaikanal observatory has a magnetograph, which can accurately map the magnetic field on the solar surface.
Severe magnetic storms on the Sun can cause havoc on Earth, resulting in widespread power cuts, disrupted radio communications and damage to satellites. On January 20, 2005, the Earth was bombarded by a barrage of energetic protons from the Sun that resulted in the most intense ground level radiation in half a century. By 2011, when the solar activity is supposed to peak, India will have as many as eleven satellites in the geosynchronous orbit. Their components are designed to at least withstand one major solar flare. The possibility of risky space weather during the 15-year lifetime of the satellites has to be borne in mind. One of the INSAT satellites was in fact affected by the space weather in 2007 and it took about 30 minutes to fix the problem. The satellites are so integrated with the daily broadcasts of TV, radio and data, any lengthy interruption would result in a huge loss.
It has been reported that the International Space Station loses 146 km of altitude each year during the solar maximum. The Station has to be boosted every few months, as otherwise it would burn up in the atmosphere of the Earth.