The sun and the moon

Questions 1. What is a moon? What planets don’t have moons? 2. How did the moon form? 3. What causes moon phases? What’s waxing and waning? 4. What is a sun? How does it create energy? 5. What are the layers of the sun? 6. What are sunspots? 7. What’s solar min and solar max? What happens in both?

Definition Moon: A rocky object that orbits around a planet All planets in our solar system have at least 1 moon EXCEPT Mercury and Venus Jupiter has 67 moons!

Earth’s moon The Earth’s moon It has no real name—we just call it “the Moon” No atmosphere and no wind – Preserves all asteroid craters LOTS of impact craters The moon is roughly the same age as the earth About 4.5 billion years old

Some data on the moon Moon Facts: 30 Earth lengths away from the Earth 238,857 miles Very similar to the Earth’s inner layers of rock 4 times smaller than the Earth

How the moon was formed Creation of moon: 1. Impact: – A boiling hot, semi-liquid Earth hits a Mars-sized object 2. Ejection: Rocks from Earth were thrown into space, and started to orbit around Earth 3. Formation: – The chunks came together in space to form the moon

Background The moon looks different at different times of the month These are called moon phases

Phases of the moon Phases of the moon are caused by the amount of sunlight the moon is getting from the Sun as viewed from Earth It takes 28 days to get from full moon back to a full moon Waxing- The moon appears to be getting larger Waning- the moon appears to be getting smaller The moon isn’t actually growing or shrinking-- always stays the same size. We just see more or less of it based on how much light from the sun is on it

Moon Myths Full moons were traditionally linked with insomnia and insanity Luna, which means moon, is where we got the terms lunacy, loony and lunatic The full moon was also thought to cause werewolves! There have been LOTS of studies on whether the full moon causes people’s behavior to change The results? No significant evidence that full moons OR new moons cause increases in arrests, suicides, or emergency room visits

The Sun  The sun—A star that is the center of our solar system  Made of helium  Has different layers like an onion  Produces energy by converting hydrogen into helium through fusion  Our Sun is 93 million miles away, and light takes 8 minutes to reach us (traveling at million mph)

Layers of the sun Core- The center of the sun where energy is produced Radiative zone- Atoms in this layer are packed so dense it can take light millions of years to pass through Convective zone- Hot gases move in convection currents, bringing the sun’s energy to the surface Photosphere- the layer of the sun we consider the visible surface Chromosphere - A thin red layer only visible during an eclipse Corona- The very thin outer layer where the gases can go times farther than the diameter of the sun

Sunspots Sunspots: Cooler, darker areas on the sun Caused by intense magnetic activity Slows down convection in the Convective Zone layer of the sun Areas of the sun cool down and aren’t replaced by warmer gas Sunspots allow us to study the sun We can’t get close (too hot), so scientists use sunspots Allows us to see how fast the sun is rotating

Sunspot Cycle Happen in regular, measurable cycles Cycles last around 11 years High point of activity: Solar maximum (solar max) Low points of activity : Solar minimum (solar min) Goes from lots of sunspots, to only a few sunspots

Solar Minimum and Max During Solar Max Huge sunspots and intense solar flares happen daily Northern Lights appear in Florida. Radiation storms knock out satellites. The last Solar Max took place in the years around During Solar Min: The opposite occurs! Solar flares are extremely rare Whole weeks go by without a single sunspot

What’s going on now? The sun has been pretty quiet these past few years In , there were barely any sunspots—75% of the time, the sun was clear! We had 4 years of a solar min! We’re currently in a solar max—we’ve had 110 sunspots this year so far Solar Minimums are normal part of the solar cycle In the early 20th century there were periods of quiet lasting almost twice as long as the current spell. The longest minimum on record, the Maunder Minimum of , lasted 70 years! So, everything is normal!

How the sun will die Our sun will start to run out of fuel (hydrogen) in about 5 billion years The outer layers of the sun will swell, eating up Mercury, Venus, and maybe Earth After time, the sun will shrink into a cold ball of coal smaller than the moon It will no longer give off light