Eclipse
Sun, Earth and Moon stand in one line, and one body casts its shadow on the other. Eclipses only happen when New Moon or Full Moon falls close to a lunar node.
How an eclipse comes about
In a solar eclipse the New Moon moves in front of the Sun, and its shadow falls on the Earth. In a lunar eclipse the Full Moon stands in the shadow of the Earth. In both cases Sun, Earth and Moon stand in one line.
There is a New Moon and a Full Moon every month, but eclipses only a few times a year. The Moon’s orbit is tilted by just over 5 degrees against the ecliptic, and mostly the Moon passes above or below the line. Only when the phase falls close to a lunar node does the shadow hit. This is why eclipses come in pairs: a solar eclipse and a lunar eclipse are often only two weeks apart.
The kinds
| Kind | What happens |
|---|---|
| Total solar eclipse | The Moon covers the Sun completely. In the narrow strip of totality it grows dark for a few minutes. |
| Annular solar eclipse | The Moon stands close to apogee and appears too small to cover the Sun completely. A bright ring remains. |
| Partial solar eclipse | The Moon covers only part of the Sun. |
| Total lunar eclipse | The Full Moon stands wholly in the Earth’s umbra and glows copper red. |
| Partial lunar eclipse | Part of the Moon dips into the umbra. |
| Penumbral lunar eclipse | The Moon only grazes the Earth’s penumbra and grows barely noticeably darker. |
Eclipses in the biodynamic calendar
Dyyna records every eclipse as an unfavourable window for its whole duration, from the first to the last contact anywhere on Earth. For lunar eclipses the penumbra counts too. During this time biodynamic practice does not sow or plant.
The window applies everywhere alike, even where the eclipse cannot be seen.
The saros cycle
Eclipses repeat after 18 years and a good 11 days. Then Sun, Moon and node stand in almost the same position to one another again. This span is called the saros cycle. The total solar eclipse of 2 August 2027 thus returns on 12 August 2045, then over North America. More on the orbital periods behind it under lunar month.
Eclipses 2027
| Date | Kind | Maximum | Unfavourable |
|---|---|---|---|
| 6 Feb | Annular solar eclipse | 16:59 | 13:57 – 20:01 |
| 21 Feb | Penumbral lunar eclipse | 0:12 | 22:09 (20 Feb) – 2:15 |
| 18 Jul | Penumbral lunar eclipse | 18:02 | 17:38 – 18:27 |
| 2 Aug | Total solar eclipse | 12:06 | 9:30 – 14:43 |
| 17 Aug | Penumbral lunar eclipse | 9:13 | 7:20 – 11:06 |
Times for Central Europe (CET, CEST in summer). The “Unfavourable” column shows when the eclipse is under way somewhere on Earth.
The total solar eclipse on 2 August 2027 crosses southern Spain, North Africa and Egypt. In Central Europe it can be seen as a partial eclipse.
Sources
- Solar eclipse, Lunar eclipse, Wikipedia
- Saros (astronomy), Wikipedia
Frequently asked questions about eclipses
When is the next solar eclipse?
There are two in 2027: an annular one on 6 February and a total one on 2 August.
Why is there not an eclipse every month?
The Moon’s orbit is tilted against the ecliptic. Only when New Moon or Full Moon falls close to a lunar node do Sun, Earth and Moon stand in one line.
What is a penumbral lunar eclipse?
The Full Moon only grazes the Earth’s penumbra. It grows barely noticeably darker. There are three of them in 2027.
How long does an eclipse count as unfavourable in the planting calendar?
For its whole duration, from the first to the last contact anywhere on Earth. For the total solar eclipse on 2 August 2027 that is a good five hours.