Space Weather

Tuesday 16th October, 2018

Our speaker was Dr Ian Whittaker from Nottingham Trent University who had come to talk to us about "Spaceweather". He began his talk by saying that the Earth actually sits within the Sun's atmosphere and so our planet is affected daily by whatever the Sun sends our way. The gas and particles that the Sun emits are known collectively as the solar wind and because this electrically charged wind can be travelling at speeds of over 300-500 kilometres per second (up to a million miles per hour) it can do great damage to our technology both on the ground and in space.

He then mentioned that on the first two days of September in 1859 a huge solar storm impacted Earth. It was given the name the Carrington Event as the British astronomer Richard Carrington observed a flash of white light on the 1st September and then just over 17 hours later the effects were seen and felt as erupted material from the Sun met the Earth. Fortunately, the technology of the day was relatively primitive and mostly survived the onslaught, although telegraph systems all over Europe and North America failed with sparks leaping from the wires and operators receiving nasty electric shocks. There were even reports of vividly bright auroras in the sky that reached down to equatorial regions with people being able to read their newspapers at night.

Dr Whittaker then added that should such an event occur today our society would not be able to escape so lightly due to our reliance on computer technology and orbiting satellites. We are protected somewhat from the solar wind by Earth's magnetic field which deflects the solar wind around our planet. However, sometimes the solar wind can break through this natural barrier and disrupt our power grids, GPS and worldwide communications. This type of event occurred as recently as 1989 in the province of Quebec in Canada when a solar eruption penetrated the Earth's magnetic shielding and induced electrical currents in the ground in Canada and North America. This led to a power outage known as the Quebec Blackout causing disruption in North American power grids and even the Discovery Space Shuttle suffered various system anomalies.

He then continued by saying that just as we try to predict terrestrial weather patterns, the scientific and military communities are using computer models and satellite data to observe space weather from the Sun, as well as observing the Sun from the ground using large solar telescopes. There are already a number of dedicated solar telescopes in space such as the Solar and Heliospheric Observatory (SOHO), Solar Dynamics Observatory (SDO), plus the Stereo A and Stereo B spacecraft.

One of the latest missions sent to study the Sun is NASA's Parker Solar Probe, which launched on August 12th this year. It will be orbiting the Sun in a series of long ellipses where for short periods it will pass closer to the Sun than any previous spacecraft, before retreating to a point out beyond the orbit of Venus. During its close passes it will need to withstand temperatures of about 1,400°C. It will accomplish this by keeping its carbon solar shield facing the Sun and, as it will be out of contact with NASA as it rounds the far side of the Sun, it will have to perform this autonomously.