Eclipses of the Sun and Moon

Curriculum links

Quoted word for word from the official documents.

Step by step

The caption is what the class reads on screen; the talking points are in your notes drawer (N) when you present. Steps marked Presenter only appear only when you present. Steps marked Pupils only appear only in the pupil lesson.

1. 01

   Lining up

   Presenter only

   Caption

   In a solar eclipse the Moon gets in the way of the Sun's light. Seen from near Earth, it covers the Sun. This view is not to scale.

   Talking points

   • NASA Space Place: a solar eclipse happens when the Moon gets in the way of the Sun's light and casts its shadow on Earth.
   • In a lunar eclipse it is the other way round. NASA Space Place: Earth gets in the way of the Sun's light hitting the Moon.
   • Here the Moon has been moved between Earth and the Sun to show the line-up, seen from near Earth. The Moon's shadow on Earth is in the next step, which shows a real eclipse at true scale.

   Sources 1Present from this step →

2. 02

   A total solar eclipse

   Presented and for pupils

   Caption

   This is the total solar eclipse of 2 August 2027, at true scale. The dark spot on Earth is the Moon's shadow.

   Talking points

   • NASA: greatest eclipse at 10:07:49 TD (Terrestrial Dynamical Time), which NASA's path table gives as 10:06:38 UT. The longest totality, 6 minutes 23 seconds, is on the central line in Egypt (26° 49' N, 31° 08' E).
   • NASA lists totality over Morocco, Spain, Algeria, Libya, Egypt, Saudi Arabia, Yemen and Somalia, and a partial eclipse over Africa, Europe, the Middle East and western and southern Asia.
   • NASA Space Place: the Moon's shadow on Earth is not very big, so only a small portion of places on Earth see a total eclipse. You have to be on the sunny side of Earth and in the path of the shadow.
   • The clock runs at a minute a second, so the shadow can be seen moving.

   Sources 1 3 4Present from this step →

3. 03

   A total lunar eclipse

   Presented and for pupils

   Caption

   In a total lunar eclipse Earth's shadow covers the whole Moon, and the Moon can look red. This one is on 31 December 2028.

   Talking points

   • NASA: greatest eclipse at 16:53:15 TD, umbral magnitude 1.246, with totality lasting 1 hour 11 minutes. It can be seen from Europe, Africa, Asia, Australia and the Pacific.
   • NASA Space Place: the Moon can look reddish because Earth's atmosphere absorbs the other colours while it bends some sunlight towards the Moon. During a total lunar eclipse the Moon is lit by all the sunrises and sunsets on Earth.
   • NASA Space Place: lots of people get to see each lunar eclipse. Anyone on the night-time half of Earth when it happens can see it.
   • The clock runs at five minutes a second.

   Ask the class

   A lunar eclipse can only happen at one phase of the Moon. Which one?

   1. ANew Moon
   2. BFirst quarter
   3. CFull MoonRight answer
   4. DLast quarter

   WhyEarth's shadow points away from the Sun. The Moon is on that side of Earth at full Moon, so that is when Earth's shadow can cover it.

   Sources 1 5Present from this step →

4. 04

   Why not every month?

   Presented and for pupils

   Caption

   The Moon's orbit is tilted by about 5 degrees. At most new Moons it passes above or below the Sun, and there is no eclipse.

   Talking points

   • NASA Moon Fact Sheet: the Moon's orbit is inclined 5.145 degrees to the ecliptic, the plane of Earth's orbit.
   • NASA: because of the tilt, at new Moon the Moon does not usually pass directly between Earth and the Sun. It only passes near the Sun as seen from Earth.
   • The same tilt explains why there is not a lunar eclipse at every full Moon. NASA Space Place: the Moon's path around Earth is tilted compared with Earth's orbit around the Sun, so the Moon can be behind Earth and still be lit by the Sun.
   • This new Moon, on 8 March 2027 at 09:29 UTC (USNO), brings no eclipse. NASA lists the solar eclipses of 2027 on 6 February and 2 August only.
   • This view is not to scale.

   Ask the class

   Why is there not a solar eclipse at every new Moon?

   1. AThe Moon's orbit is tilted, so the Moon usually passes above or below the SunRight answer
   2. BThe Moon stops moving for part of the year
   3. CThe Sun is too bright for the Moon to block

   WhyThe Moon's orbit is tilted about 5 degrees to Earth's, so most months the Moon passes above or below the Sun and its shadow misses Earth.

   Sources 1 3 6 7 8Present from this step →

5. 05

   Find a new Moon

   Pupils only

   Caption

   Your turn. A solar eclipse can only happen at new Moon. Run the clock to the next new Moon and pause it.

   Talking points

   • The scene opens at last quarter on 28 February 2027 (USNO). The next new Moon is on 8 March 2027, and NASA lists no solar eclipse then.
   • The check passes within 12 degrees of new Moon, about a day either side.

   Pupil task

   Play the clock. Pause it at new Moon, when the Moon is between Earth and the Sun.

   HintNew Moon comes about a week after last quarter. Watch the Moon swing round towards the Sun.

   The viewer checks the task as the pupil works and says when it is done.

   Sources 3 6 7 8Open this step as a pupil →

6. 06

   Check what you saw

   Pupils only

   Caption

   Look at the Moon's shadow on Earth again, then answer.

   Talking points

   • Facts from NASA's table of solar eclipses for 2021 to 2030 and its path table for this eclipse, which gives the longest totality as 6 minutes 23 seconds.

   Pupil question

   Which of these are true about the eclipse of 2 August 2027? Choose all that are.

   More than one answer is right.

   1. ATotality lasts up to 6 minutes 23 secondsRight answer
   2. BIt is an eclipse of the Moon
   3. CThe path of totality crosses Spain and EgyptRight answer
   4. DEveryone on Earth will see the Sun completely covered

   WhyIt is a total eclipse of the Sun lasting up to 6 minutes 23 seconds, with totality over Spain, Egypt and other countries. Only people inside the Moon's small dark shadow see totality.

   Sources 1 3 4Open this step as a pupil →

7. 07

   Watching safely

   Presented and for pupils

   Caption

   Never look straight at the Sun without proper eclipse glasses or a solar viewer. Sunglasses are not safe, however dark they are.

   Talking points

   • NASA: "Except during the brief total phase of a total solar eclipse, when the Moon completely blocks the Sun’s bright face, it is not safe to look directly at the Sun without specialized eye protection for solar viewing."
   • NASA: eclipse glasses are not regular sunglasses. Regular sunglasses, no matter how dark, are not safe for viewing the Sun. Safe solar viewers should comply with the ISO 12312-2 international standard. Inspect them before use, throw away any that are torn or scratched, and always supervise children using them.
   • NASA: as soon as even a little of the bright Sun reappears after totality, put eclipse glasses back on or use a handheld solar viewer.
   • NASA: viewing any part of the bright Sun through a camera lens, binoculars or a telescope without a special-purpose solar filter secured over the front of the optics will instantly cause severe eye injury. Do not look through them while wearing eclipse glasses either: the concentrated solar rays will burn through the filter.
   • Without glasses, use a pinhole projector: a small hole in a card projects an image of the Sun onto a surface, with the Sun behind you. Never look at the Sun through the pinhole.

   Ask the class

   Is it safe to look at a partly eclipsed Sun through very dark sunglasses?

   1. AYes, if they are dark enough
   2. BNo, only proper eclipse glasses or a solar viewer are safeRight answer
   3. CYes, for a few seconds

   WhyNASA: regular sunglasses, no matter how dark, are not safe for viewing the Sun.

   Sources 2Present from this step →

Sources

Every fact in this lesson comes from these sources, and each step lists the ones it uses.

1. Lunar Eclipses and Solar Eclipses, NASA Space Place
2. Eclipse Viewing Safety, NASA Science
3. Solar Eclipses: 2021 to 2030, NASA Eclipse Web Site (Fred Espenak)
4. Total Solar Eclipse of 2027 August 02: path of the eclipse, NASA Eclipse Web Site (Fred Espenak)
5. Lunar Eclipses: 2021 to 2030, NASA Eclipse Web Site (Fred Espenak)
6. Moon Fact Sheet, NASA NSSDCA
7. Moon Phases, NASA Science
8. Phases of the Moon from 1 January 2027, US Naval Observatory