surface features of the sun

solar dynamics observatory

The video above was taken from the SDO, the most advanced spacecraft ever designed to study the Sun. During its five-year mission, SDO will examine the Suns magnetic field and also provide a better understanding of the role the Sun plays in Earths atmospheric chemistry and climate. Since just after its launch on February 11, 2010, SDO is providing images with clarity 10 times better than high-definition television and will return more comprehensive science data faster than any other solar-observing spacecraft. The Solar Dynamics Observatory is a NASA spacecraft launched in early 2010 is obtaining IMAX-like images of the Sun every second of the day, generating more data than any NASA mission in history. The data will allow researchers to learn about solar storms and other phenomena that can cause blackouts and harm astronauts. Click image to the left or use the URL below. URL:


The most noticeable surface features of the Sun are cooler, darker areas known as sunspots (Figure 1.1). Sunspots are located where loops of the Suns magnetic field break through the surface and disrupt the smooth transfer of heat from lower layers of the Sun, making them cooler, darker, and marked by intense magnetic activity. Sunspots usually occur in pairs. When a loop of the Suns magnetic field breaks through the surface, a sunspot is created where the loop comes out and where it goes back in again. Sunspots usually occur in 11-year cycles, increasing from a minimum number to a maximum number and then gradually decreasing to a minimum number again.

surface features

The Suns surface features are quite visible, but only with special equipment. For example, sunspots are only visible with special light-filtering lenses.

solar prominences

Another highly visible feature on the Sun are solar prominences. If plasma flows along a loop of the Suns magnetic field from sunspot to sunspot, it forms a glowing arch that reaches thousands of kilometers into the Suns atmosphere. Prominences can last lengths of time ranging from a day to several months. Prominences are also visible during a total solar eclipse. Most of the imagery comes from SDOs AIA instrument; different colors represent different temperatures, a common technique for observing solar features. SDO sees the entire disk of the Sun in extremely high spatial and temporal resolution, allowing scientists to zoom in on notable events such as flares, waves, and sunspots.


solar flares

There are other types of interruptions of the Suns magnetic energy. If a loop of the Suns magnetic field snaps and breaks, it creates solar flares, which are violent explosions that release huge amounts of energy (Figure 1.2). A strong solar flare can turn into a coronal mass ejection. A solar flare or coronal mass ejection releases streams of highly energetic particles that make up the solar wind. The solar wind can be dangerous to spacecraft and astronauts because it sends out large amounts of radiation that can harm the human body. Solar flares have knocked out entire power grids and disturbed radio, satellite, and cell phone communications. (a) Sunspots. (b) A close-up of a sunspot taken in ultraviolet light.



instructional diagrams

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sunspots are __.

a) warmer areas on the sun

-->  b) cooler, darker areas of the sun

c) landforms on the sun

d) explosions on the sun

which of the following is true about sunspots?

a) they are where loops of the suns magnetic field disrupt the transfer of heat.

b) because they are loops, they usually occur in pairs.

c) they have a minimum-maximum cycle that lasts 11 years.

-->  d) all of these.

violent explosions that release huge amounts of energy on the sun are called ___.

a) sunspots

b) solar winds

-->  c) solar flares

d) solar spots

a coronal mass ejection

-->  a) is the source of the solar wind.

b) can turn into a solar flare.

c) releases streams of slow moving particles.

d) all of these.

sunspots occur in _____.

-->  a) 1 year cycles

b) 5 year cycles

c) 11 year cycles

d) 20 year cycles

solar prominences are ___.

a) cooler, darker areas

b) interruptions of magnetic energy

-->  c) plasma loops that connect two sunspots

d) all of the above

prominences can last lengths of time ranging from days to months.

-->  a) true

b) false

nasas solar dynamics observatory is studying

a) nuclear fusion in the sun.

-->  b) the effect of the sun on earths chemistry and climate.

c) changes of state between the four states of matter on the sun.

d) all of these.

earth is too far away to be affected by solar flares.

a) true

-->  b) false

spacecraft and astronauts can be harmed by radiation in space.

-->  a) true

b) false

diagram questions

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