Solar Cycles

Why in news?

• Scientists from NASA and the National Oceanic and Atmospheric Administration (NOAA) announced their predictions about the new solar cycle, called Solar Cycle 25, which they believe has begun.
• Solar cycles have implications for life and technology on Earth as well as astronauts in space.

What is a solar cycle?

• Since the Sun’s surface is a very active space, electrically charged gases on its surface generate areas of powerful magnetic forces, which are called magnetic fields.
• Since the gases on the Sun’s surface are constantly moving, these magnetic fields can get stretched, twisted and tangled creating motion on the surface, which is referred to as solar activity.
• Scientists track a solar cycle by using sunspots.
• Solar activity varies with the stages of the solar cycle, which lasts on average for a period of 11 years.
• The beginning of a solar cycle is typically characterised by only a few sunspots and is therefore referred to as a solar minimum and for Solar Cycle 25 it occurred in December 2019.

What are sunspots?

• A Sunspot is an area on the Sun that appears dark on the surface and is relatively cooler than the surrounding parts.
• These spots, some as large as 50,000 km in diameter, are the visible markers of the Sun’s magnetic field, which forms a blanket that protects the solar system from harmful cosmic radiation.
• When a Sunspot reaches up to 50,000 km in diameter, it may release a huge amount of energy that can lead to solar flares which occur in active regions around sunspots.
                                                                

PRELIMS QUESTION

Consider the following statements:
1.Sunspot is an area on the Sun that appears exceptionally brighter than surroundings.
2.Presence of Sunspots may indicate the presence or development of a Solar Flare.
Which of the statements given above is/are correct?
(a)1 only
(b)2 only
(c)Both 1 and 2
(d)Neither 1 nor 2

Answer to prelims question