December 21, 2015 - Swing Your Partner

Swing Your Partner The Hubble Space Telescope captured two spiral galaxies that are locked in an elegant but violent cosmic dance. The larger galaxy (top) is NGC 2207. The smaller galaxy is IC 2163. IC 2163 is swinging past NGC 2207 in a counter-clockwise direction, but it is not moving fast enough to escape NGC 2207’s grasp: IC 2163 will eventually circle around and swing past NGC 2207 again. This galactic square dance, with both partners locking their spiral arms together, will eventually cause repeated collisions and distortions of the two bodies. Billions of years from now, the two will merge into a single, more massive galaxy. Astronomers believe that many large galaxies (including our own Milky Way) are the result of similar galactic collisions. These galaxies are about 80 million light-years away.

Image credit: NASA / ESA / Hubble Heritage Team (STScI)

Weekly Calendar

December 21-27, 2015

Holidays - Sky Events - Space History

 

Monday 21

Moon at perigee
Mars 4° north of Spica
Solstice 11:48 PM ET

1968: Apollo 8 launched
1984: Vega 2 launched
1988: Cosmonauts Titov and Manarov return after spending one year aboard Mir space station
2011: Soyuz TMA-03M launched carrying ISS Expedition 30/31 crew

Tuesday 22

Ursid meteor shower

1966: Luna 13 launched
1966: First glide test of the HL-10 lifting body

Wednesday 23

Aldebaran 0.7° south of Moon
Ursid meteor shower

1672: Giovanni Cassini discovers Saturn’s moon Rhea

Thursday 24

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

Friday 25

Christmas Day

Full Moon 6:11 AM ET

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

Saturday 26

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

Uranus appears stationary

Sunday 27

1571: Johannes Kepler born
1984: Meteorite ALH 84001 discovered