January 25, 2016 - Mutual Attraction on a Galactic Scale
Mutual Attraction on a Galactic Scale These two galaxies really have a hold on each other—gravitationally speaking, that is. The neighboring galaxies NGC 3166 (top) and NGC 3169 (bottom) are close enough to have a gravitational pull on each other that’s stretching and shredding their star and dust lanes apart. The galaxies are steadily moving closer together and will eventually merge entirely. These galactic partners are located comparatively nearby—a mere 70 million light-years away within the southern constellation Sextans. A relatively “new” constellation, Sextans was named in 1687 by the Polish astronomer Johannes Hevelius, who was born 405 years ago this week. Hevelius discovered four comets, identified the Moon’s libration (sideways wobble), and spent years charting the lunar surface.
Image credit: ESO / Igor Chekalin
Weekly Calendar
January 25 - January 31, 2016
Holidays - Sky Events - Space History
Monday 25
Mercury appears stationary
1736: Joseph Lagrange born
1962: NASA authorizes Saturn V rocket
1983: IRAS launched
1994: Clementine spacecraft launched
2004: Mars Exploration Rover Opportunity lands
Tuesday 26
Wednesday 27
Jupiter 1.4° north of Moon
1829: Isaac Roberts born, pioneer astrophotographer
1967: Apollo 1 astronauts Grissom, White, and Chaffee die in cockpit fire on launch pad during test
Thursday 28
1611: Johannes Hevelius born
1986: Space Shuttle Challenger explodes, 7 astronauts die
Friday 29
1964: SA-5 launched, first Saturn I Block 2 rocket
1989: Phobos 2 enters orbit around Mars
Saturday 30
Moon at apogee
1964: Ranger 6 launched
Sunday 31
Last Qtr Moon 10:28 PM ET
1958: Explorer 1 launched
1961: Mercury Redstone 2 suborbital flight with chimpanzee Ham
1966: Luna 9 launched
1971: Apollo 14 launched
1985: ESA approves the Columbus program