June 7, 2010 - Radio Rings

Radio Rings In 2005, the Saturn-orbiting Cassini spacecraft sent a series of radio signals through Saturn’s rings toward Earth. Ring particles of different sizes distorted the signals in distinct ways, allowing a high-resolution profile to be created of the distribution of matter within the rings. Italian astronomer Giovanni Cassini, born 385 years ago this week, was the first person to spot a division within Saturn’s rings. In this image, taken by the spacecraft that bears his name, the Cassini Division is the largest single “gap” in the rings, about two-thirds of the way from the innermost ring to the outer edge. Although it appears to be empty space when seen from Earth, the “gap” quickly resolves into a region filled with an astonishing number of ringlets when viewed from the proper angle by visiting spacecraft.

Image credit: NASA / JPL

Weekly Calendar

June 7-13, 2010

Holidays - Sky Events - Space History

Moon phase Monday 7

1992: Extreme Ultraviolet Explorer launched

Moon phase Tuesday 8

1625: Giovanni Cassini born
1959: First X-15 unpowered glide test
1975: Venera 9 launched
2007: STS-117 Atlantis launched

Moon phase Wednesday 9

Venus 5° south of Pollux

1812: Johann Gottfried Galle born

Moon phase Thursday 10

Mercury 5° south of Moon

1985: Vega 1 deploys lander and balloon on Venus
2003: Mars rover Spirit launched

Moon phase Friday 11

2008: Fermi Gamma-Ray Telescope launched

Moon phase Saturday 12

New Moon 7:15 AM ET

1967: Venera 4 launched

Moon phase Sunday 13

1831: James Clerk Maxwell born
1974: National Space Society founded
1983: Pioneer 10 leaves solar system, begins traveling in interstellar space
2010: Hayabusa spacecraft returns first asteroid samples to Earth

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