October 19, 2009 - Cosmic Push and Pull

Cosmic Push and Pull Astronomers using the European Southern Observatory’s Very Large Telescope have measured the distribution and motions of thousands of galaxies in the distant Universe. Expansion from the Big Bang explosion pushes galaxies away from each other, while the gravitational attraction of galactic matter (both visible and “dark”) pulls them together. This computer simulation of an area 100 million light-years across shows the motions of galaxies flowing towards the highest mass concentration in the center (shown in red). Like compass needles, the yellow lines show the intensity and direction of the galaxies’ velocities, and measure the central structure’s rate of growth, which depends on the subtle relationship between dark matter, dark energy, and the expansion of the Universe.

Image credit: European Southern Observatory / Klaus Dolag and the VVDS team

Weekly Calendar

October 19-25, 2009

Holidays - Sky Events - Space History

Moon phase Monday 19

1910: Subramanyan Chandrasekhar born
1967: Mariner 5 flies past Venus
2005: Final Titan IV rocket launched

Moon phase Tuesday 20

1970: Zond 8 launched
1995: STS-73 Columbia launched

Moon phase Wednesday 21

Antares 1° south of Moon
Orionid meteor shower

1923: First public planetarium show, Deutsches Museum in Munich
1998: Hubble Heritage Project website launched
2008: Chandrayaan-1 lunar probe launched

Moon phase Thursday 22

Orionid meteor shower

2136 BC: First record of solar eclipse
1905: Karl Jansky born
1966: Luna 12 launched
1975: Venera 9 orbits Venus
1992: STS-52 Columbia launched

Moon phase Friday 23

1968: First powered flight of the HL-10 lifting body
2007: STS-120 Discovery launched

Moon phase Saturday 24

United Nations Day

1851: William Lassell discovers Uranus moons Umbriel & Ariel
1968: 199th and final X-15 flight
1998: Deep Space 1 launched
2001: Mars Odyssey arrives at Mars
2007: Chang'e-1 lunar spacecraft launched

Moon phase Sunday 25

First Quarter Moon 8:42 pm
Moon at apogee

1671: Giovanni Cassini discovers Iapetus, moon of Saturn
1877: Henry Norris Russell born
1975: Venera 10 lands on Venus
2006: STEREO spacecraft launched

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