Partial Eclipseof the

Sun

9:32 am

Partial Eclipse of the SunWhat is it?

• It’s where the Moon passes in front of the disc of the Sun

• The Sun is 400 times bigger than the Moon but it is also approximately 400 times further away. This means that sometimes they appear the same size.

• The eclipse that we see is the shadow of the Moon.

• A total eclipse is when we view from the umbra

• A partial eclipse is when we view from the penumbra

Partial Eclipse of the Sun

You can see the shadow formed on the Earth

Partial Eclipse of the Sun• Observers in the

umbra see a total eclipse. The Sun is blocked out.

• Observers in the penumbra see a partial eclipse.

• The path of totality is 16,000 kilometres long.

• The diameter of the umbra is only 260 km.

Partial Eclipse of the Sun• There are 3 types of

solar eclipse.• A total eclipse is where

the Sun is blocked out.• A partial eclipse is

where part of the Sun is blocked out.

• An annular eclipse is when the Moon is a little further from the Earth and it doesn’t cover the Sun completely. The orbit of the Moon is not circular.

This animation shows the eclipse as it travels across the Earth

NEVER LOOK DIRECTLY AT THE SUN….

YOU WILL BE BLINDED

This is what a total solar eclipse looks like

NEVER LOOK AT THE SUN DIRECTLY

This is what a partial solar eclipse looks like

NEVER LOOK AT THE SUN DIRECTLY

Things that you may notice…

Eclipse projections from trees

Things that you may notice…

The Moon in front of the Sun and it going quite dark

Things that you may notice…

The temperature may drop by a few degrees

Things that you may notice…

The birds may stop singing and dogs will bark

How to view safely…• You can only view the

sun indirectly during a partial eclipse.

• Sunglasses do not protect your eyes.

• If you do look at the Sun directly then you will be blinded (permanently)

How to view safely…Pinhole card method (simple)

Instructions on the next slides…

How to view safely…The competition

• Your task is to build a safe eclipse viewer.

• There are prizes for the best ones.

• Your tutor will show you ways of building them.

• You can find instructions on the net.

• You can work on them in tutor time and at home.

How to view safely…Pinhole card method (simple)You will need:

2 pieces cardAluminium foilPin or needleSellotapeScissors

How to view safely…Pinhole card method (simple)Cut a rectangle in the centre of one of the pieces of card.

How to view safely…Pinhole card method (simple)Sellotape a square of aluminium foil over the hole.

How to view safely…Pinhole card method (simple)

Pierce a small hole in the centre of the foil.

How to view safely…Pinhole card method (simple)Secure the uncut card to somewhere. Hold the pinhole card at a distance with your back to the Sun

How to view safely…Camera obscura method (harder) The box

makes the image brighter because it blocks out other light

How to view safely…Other methods