Sun and Seasons

Page
3

The eruption of a huge bubble of hot gas from the Sun

This series of images of coronal mass ejections taken with LASCO C3 (May 1-31, 1997) at

Slide 19

CME’s effects on Earth

Can damage satellites

Very dangerous to astronauts

Power problems

Animation of a CME leaving the Sun, slamming into our magnetosphere.

Slide 20

Activities

Let’s go observe the Sun

Sunspot graphing

Slide 21

Influences on Earth

Gravity

Light (Radiation)

Solar Wind (already discussed)

Slide 22

Gravity

Orbits

The Sun’s powerful gravity keeps the planets in orbit

Slide 23

Radiation

Our Sun (and all active stars) emits radiation

Radio, infrared, visible, ultraviolet, x-ray and even some gamma rays

Most of the sunlight is yellow-green visible light or close to it

The Sun at X-ray wavelengths

Image and info at http://imagine.gsfc.nasa.gov/docs/teachers/gammaraybursts/imagine/page18.html and

http://starchild.gsfc.nasa.gov/docs/StarChild/solar_system_level2/sun.html

.

Slide 24

Activities on Sunlight

UV Man (or woman, or dog, bug, etc.)

Observations of infrared light using filters and cell phones

Slide 25

Sun’s Radiation at Earth

The Earth’s atmosphere filters out some frequencies

Ozone layer protects us from some ultra-violet, and most x-rays and gamma rays

Water and oxygen absorb some radio waves

Water vapor, carbon dioxide, and ozone absorbs some infrared

Electromagnetic spectrum

.

Slide 26

Sunlight is absorbed by Earth

Let’s test what happens to the light.

Activity Time!!

Slide 27

Sunlight is absorbed by Earth

The Sun does NOT send “heat rays” into space. Some of its light is infrared, but that is not the same thing as heat.

The Sun’s light is absorbed by Earth (clouds, plants, oceans, rock…)

By absorbing the light, we are transforming it into heat energy

Slide 28

Sun as a Source of Energy

Light from the Sun is absorbed by the Earth, unevenly to: