Ice and StoneTopicWeek 40

In an earlier “Special Topics” presentation I described how meteorites are classified based upon their respective compositions. As I indicated in that presentation, the majority of known meteorites are the “stony” meteorites composed primarily of various silicates, and of these, most contain small, roughly spherical particles called “chondrules” that are primarily made up of silicates …

HistoryIce and StoneWeek 39

SEPTEMBER 21, 2012: Two amateur astronomers, Vitali Nevski of Belarus and Artyom Novichonok of Russia, discover Comet ISON C/2012 S1 with a telescope of the International Scientific Optical Network located at Kislovodsk, Russia. Comet ISON was expected to become a brilliant object when near the sun and Earth in late 2013 but instead disintegrated as …

CometIce and StoneWeek 39

Perihelion: 1914 October 26.77, q = 1.104 AU  After the spectacular appearances of the Daylight Comet of 1910 and of Comet 1P/Halley later that same year – both of these objects having been discussed in previous “Ice and Stone 2020” presentations – the next few years brought some additional bright comets to Earth’s nighttime skies. …

Ice and StoneTopicWeek 39

Of all the phenomena associated with comets, the one that more than any other gives them their beauty and their mystique is their tails. As recounted in a previous “Special Topics” presentation, the first recorded scientific observation of a comet concerned its tail: when observing the bright comet that appeared during the second half of …

Asteroids

The official go-ahead has been given by NASA to a mission to launch a pair of small spacecraft to capture the first-ever closeup look at a mysterious class of solar system objects: binary asteroids. These bodies are pairs of asteroids that orbit around each other in space, much like the Earth and Moon. In a project …

HistoryIce and StoneWeek 38

SEPTEMBER 13, 1959: The then-Soviet Union’s Luna 2 spacecraft impacts the lunar surface slightly to the east of the Mare Imbrium. This was the first human spacecraft to reach the moon and the first spacecraft to impact another object in the solar system.  SEPTEMBER 13, 1985: The U.S. Defense Department’s P78-1 satellite is deliberately destroyed …