Grote Reber, 1911–2002

December 30, 2002 | Grote Reber, a radio engineer credited with the first survey of the radio sky, died on December 23rd at the age of 90. In 1937, five years after learning about Karl Jansky's discovery of natural radio emission from cosmic sources, Reber used his own money to build a 31-foot-wide dish in his Illinois backyard. His first all-sky radio map followed in 1941, effectively launching the discipline of radio astronomy. "Reber was the first to systematically study the sky by observing something other than visible light," notes Fred K. Y. Lo, director of the National Radio Astronomy Observatory. "This gave astronomers a whole new view of the universe." Although not a professional researcher, Reber published his findings in prestigious journals and received numerous scientific honors.

An NRAO press release with details about Reber's life and work is at

Jupiter's 40th Satellite

December 30, 2002 | Last Halloween, while making follow-up observations of known Jovian satellites with a 2.2-meter telescope atop Mauna Kea, Scott S. Sheppard (University of Hawaii) found yet another small member of the planet's extended family. According to IAU Circular 8035, which announced the discovery on December 23rd, S/2002 J1 has an estimated diameter of only 3 or 4 kilometers and a 748-day retrograde orbit inclined 163° to Jupiter's equator. This new find marks the 23rd Jovian satellite discovered by Sheppard and the planet's 40th overall.

Sheppard has posted details and the discovery images at
See also's guide to planetary satellites.


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