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December 23, 2019 - A Rare Ring in the Sky

A Rare Ring in the Sky  Because the Moon is about 400 times smaller than the Sun and also about 400 times closer to Earth, the Moon and Sun appear nearly the same size. Orbital variations make the Moon appear slightly larger or smaller than the Sun at times. About once every 18 months, the Moon appears directly in line with the Sun, resulting in a solar eclipse. When it appears larger than the Sun, it covers the Sun entirely (a total eclipse), but when it is appears slightly smaller than the Sun, it covers all but a ring, or annulus, of the Sun (annular eclipse). An annular solar eclipse will occur this week for observers in the Middle East and southeast Asia. This image shows the annular eclipse of May 21, 2012. If you view an annular eclipse, use approved solar filters at all times to avoid permanent eye damage.

Image credit: uemura (CC BY 2.0)

Weekly Calendar

December 23 - 29, 2019

Holidays - Sky Events - Space History


Moon phase Monday 23

Ursid meteor shower

1672: Giovanni Cassini discovers Saturn’s moon Rhea

Moon phase Tuesday 24

1968: Apollo 8 enters lunar orbit
1978: Venera 11 lands on Venus
1979: European Space Agency launches first Ariane rocket

Moon phase Wednesday 25

Christmas Day

1642: Isaac Newton born
2003: Mars Express and Beagle 2 arrive at Mars
2004: Huygens probe separates from Cassini spacecraft

Moon phase Thursday 26

Boxing Day (Canada, U.K., Australia)
First Day of Kwanzaa

New Moon 12:13 AM ET
Annular Solar Eclipse (Middle East, N Africa, Asia)

1780: Mary Somerville born

Moon phase Friday 27

Saturn 1.2° N of Moon
Pluto 0.6° N of Moon
Jupiter in conjunction with Sun

1571: Johannes Kepler born
1984: Meteorite ALH 84001 discovered

Moon phase Saturday 28

Venus 1° north of Moon

1882: Arthur Eddington born

Moon phase Sunday 29

1980: STS-1 leaves Vehicle Assembly Building and rolls out to launch pad

Suggestions for new history dates or better links? Corrections for errors on this page? Please e-mail me.