ch 6-4 planetary alignment

what is planetary alignment?

• astronomical phenomenon (known as conjunction) when the planets appear close together in the sky as seen from the earth

• means that from Earth can see many planets in sky

why do planetary alignment happen?

• planets in same orbital plane

• different speeds, different distances

• sometimes position of planets make them look relatively close together from Earth

Jupiter takes 12 Earth years to orbit the sun and Mars takes 2 years

• distant in orbital period means that every so often Jupiter and Mars are positioned in a way that they appear next to each other in our sky → temporary alignment

what do planetary alignments mean for astronomers?

conjunctions serve as

• calibrate instruments

• gravitational assist

how did voyager take advantage of rare 4 alignment in 1970-1980?

• allow mission to explore outer regions of the solar system

when planets do align in 3D space…

• fly by or needed gravitational will adjust their leverage

historical impacts of planetary alignments

• significant for many civilizations

  • mayans

  • babylonians

  • renaissance europe

how did the Mayan track planetary movements?

• eclipses and alignments were deemed powerful enough to influence terrestrial events

• keen astronomers

what was the detailed astronomical observations of the Babylonians?

• detailed “massing of planets” in 185 BCE - on March 25 that year, Mercury, Venus, Mars, Jupiter, and Saturn aligned

• documented conjunctions

how did the Renaissance Europe view planetary alignment?

• both scientific curiosity and divine interpretation

  • Tyche Bache and Keiper study this phenomenon and tracked planets position to better understand their motion

  • appearance of multiple planets was often seen through a dual lens

when was the most recent planetary alignment?

• February 28, 2026

  • rare 6-planet alignment

what planets were present in the 6-planet alignment?

• Mercury, Venus, Saturn, Jupiter, Uranus, and Neptune (same side of sky)

  • Saturn, Venus, and Mercury clustered in southern sky

  • Jupiter was near the moon

  • Uranus and Neptune required binoculars or telescope (not visible to naked eye)

when will the planets align again?

• June 12, 2026

what planets will be in planetary alignment on June 12, 2026?

• Mercury, Venus, and Jupiter will be seen from the Norther Hemisphere

  • planets will be visible with the naked eye after sunset