NASA scientists using the Kepler space telescope also announced the discovery of six planets orbiting a star called Kepler-11.

VOA: special.2011.02.09

Look, take the argument of the planets, the Morning Star and the Evening Star example.

拿行星的论证,晨星和昏星的那个例子来说

耶鲁公开课 - 死亡课程节选

By putting the two together, out comes the elliptical motion of the planets.

将这两个式子联立,就得到了行星作椭圆运动的方程

耶鲁公开课 - 基础物理课程节选

So when spacecraft are sent to other planets, scientists will look for layers of gypsum in hopes of finding similar fossils.

VOA: special.2010.05.25

In fact, there's a property of gravitational fields anywhere, even in outer space, but there is some residual field between all the planets and all the stars in the universe, that the force on a body is proportional to the mass of the body.

实际上,这是任何地方的引力场都具备的属性,甚至是在外太空,在所有的行星和恒星之间,存在着某种剩余场,在这个场里作用在物体上的力,和物体的质量之间存在比例关系

耶鲁公开课 - 基础物理课程节选

Experts credit the Greek astronomer Archimedes with developing the earliest known device to show the daily movement of the planets.

VOA: special.2010.09.29

A planetarium is a theater with a rounded ceiling onto which images of the stars and planets are projected.

VOA: special.2010.09.29

These mechanical devices that show the relative placement and movement of the planets and moons are sometimes called orreries.

VOA: special.2010.09.29

We will also tell about a historic record of rainy seasons in Asia, and the search for life on other planets.

VOA: special.2010.05.25

The Kepler space telescope looks for planets by measuring tiny decreases in the brightness of stars when planets cross in front of them.

VOA: special.2011.02.09

Some scientists have called Jupiter the protector of the inner planets and our own Earth -- from objects from the outer solar system.

VOA: special.2009.08.25

Or Venus? Or on any of the other planets either inside or outside our solar system?

VOA: special.2010.05.25

But the Kepler mission's chief scientist, William Borucki,says eighty percent of the possible planets will probably be confirmed in the coming months and years.

VOA: special.2011.02.09

Scientists say extensive observations from earth-based telescopes are needed to confirm the existence of the planets.

VOA: special.2011.02.09

Still another is the crash of large asteroids, minor planets that fall to earth.

VOA: special.2009.03.17

"Kepler 11 is a surprising flat and compact system of six transiting planets.

VOA: special.2011.02.09