SDO solar image - 131 angstroms - Courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.
radio propagation
Today's Space Weather
Monday 25 July
last updated 24/2331 UT
Solar activity was moderate during 24 July because active region 2567 produced two M-class flares: M2.0 peaking at 0620 UT and M1.9 peaking at 1743 UT. No Earth-directed CMEs were observed in the SOHO LASCO imagery. Low to moderate solar flare activity is expected on 25 July due to a chance that active region 2567 may produce M-class flares. Moderate solar wind. Geomagnetic conditions at quiet to unsettled levels with possible active periods. Conditions for high-frequency radio communications are expected to be normal to mildly depressed. Short-wave radio fadeouts are possible.
What is Space Weather ?

Space weather refers to changes in the space environment, particularly the region between the Earth and Sun. The "solar wind" from the Sun stream past the Earth and is mostly deflected by the Earth's magnetic field, but variations in the solar wind cause changes in the Earth's magnetic field.

solar prominence

Occasionally, a huge release of magnetic energy, called a solar flare, occurs on the Sun. Flares can produce large quantities of x-rays which affect the Earth's atmosphere. They can also accelerate atomic particles (mostly protons) to very high speeds (a substantial fraction of the speed of light!). These high energy particles are dangerous to man and can reach the stratosphere where jetliners fly.

Most aspects of space weather affect us to some extent. The more our society becomes dependent on technology and the more we utilise space, the more we are affected by space weather. Some aspects of space weather are benevolent, and allow activities not otherwise possible such as long range radio communications. Some aspects are benign but fascinating such as the Aurora, and some are malevolent. Like terrestrial weather, it sometimes depends on the situation and the event.

The image below is an artists impression of the solar wind interacting with the Earth's magnetic field.

Solar wind
Aurora Australis as seen from the International Space Station, with the port wing of space shuttle Atlantis, and segment of a boom sensor system attached to the shuttle's robotic arm.
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