摘要

描述S2007 S 4 PIA08369.gif	Animated GIF of discovery images of Saturnian moon S/2007 S 4
日期	2007年5月30日
来源	http://photojournal.jpl.nasa.gov/catalog/PIA08369 本图像或视频收录于美国国家航空航天局 （NASA）喷气推进实验室（Jet Propulsion Laboratory），其照片编号是： PIA08369 此标签不表示文件的著作权状态。任何文件在附有此标签的同時还需要一个有效的著作权标签。请参阅许可协议说明页面以了解更多信息。 其他语言： العربية ∙ беларуская (тарашкевіца) ∙ български ∙ català ∙ čeština ∙ dansk ∙ Deutsch ∙ English ∙ español ∙ فارسی ∙ français ∙ galego ∙ magyar ∙ հայերեն ∙ Bahasa Indonesia ∙ italiano ∙ 日本語 ∙ македонски ∙ മലയാളം ∙ Nederlands ∙ polski ∙ português ∙ русский ∙ sicilianu ∙ slovenščina ∙ Türkçe ∙ українська ∙ 简体中文 ∙ 繁體中文 ∙ +/−
作者	NASA/JPL/Space Science Institute
其他版本	still image

Original Caption Released with Image:

The 60th moon of Saturn reveals itself in a sequence of images. The discovery suggests that the new moon, along with its neighbors Methone and Pallene (discovered by the Cassini imaging team in 2004), may form part of a larger group of moons in this region. The movie spans six hours.

Initial calculations show the moon to have a width of approximately 2 kilometers (1.2 miles), with an orbit that lies between those of the moons Methone and Pallene. The moon's orbit is in resonance with another moon, Mimas, also seen in this sequence as a very bright, moving object. The new moon's location is indicated by a red box.

The (narrow) ring visible in the images is the G ring, and the G ring arc passes through the field of view during the course of the movie. Calypso, a Trojan moon of Tethys, is also visible in the sequence. Trojan moons are found near gravitationally stable points ahead or behind a larger moon.

This view looks toward the non-illuminated side of the rings from about 3 degrees above the ringplane.

The series of images was taken in visible light with the Cassini spacecraft wide-angle camera on May 30, 2007, at a distance of approximately 1.76 million kilometers (1.09 million miles) from Saturn. Image scale is about 105 kilometers (65 miles) per pixel. The ghostly shape that stretches across the scene results from scattered light within the camera optics.

许可协议

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