Which planets can sustain life?

哪些行星可以维持生命的存在？

Does life exist on other planets?

其他行星上有生命吗？

Is there intelligent life on other planets?

在其他星球上存在具有智力的生命吗？

The theory supposes the existence of life on other planets.

这个理论假定其他行星存在生命。

The picture shows six of the nine planets in the solar system.

这张图片展示太阳系9个行星中的6个行星。

All the planets orbit the Sun in roughly the same plane, around its equator.

所有行星基本在同一个平面上围绕太阳赤道运转。

The Sun, Moon, and the planets formed from a huge spinning gas cloud that collapsed into a gyrating disc.

太阳、月亮和这些星球形成于倒塌进一个旋转盘状物的一团巨大旋转汽云。

They shunned the belief that there is a link between the alignment of the planets and events on the Earth.

他们回避了在行星的排列和地球上发生的事件之间有联系的看法。

Science fiction writers have long dreamed that humans might one day quit the earth to colonize other planets.

科幻小说作家们长期以来一直梦想着人类有一天可以离开地球移居到其它星球上。

They are aliens on other planets.

它们是其他星球上的外星人。

The planets revolve around the sun.

行星绕着太阳运转。

Is it the distance of the planets from the Sun?

它是行星到太阳的距离吗？

Hence, the Jovian planets are often called giants.

因此，木星行星通常被称为巨行星。

There is a more violent theory about how planets form.

关于行星是如何形成的，还有一种更为激烈的理论。

It is the gravitational interaction with planets, right?

这是引力与行星的相互作用，对吧？

One of the outer planets, Saturn, has a density of only 0.

土星是外行星之一，它的密度只有0。

If they were shadows of the planets, they would be circular, right?

如果它们是行星的影子，它们就会是圆形的，对吧？

In 1997, they saw evidence of planets near other stars like the sun.

1997年，他们发现了太阳等其他恒星附近有行星存在的证据。

Of all the inner planets, only Mercury and Earth boast such a field.

在所有的内行星中，只有水星和地球拥有这样一个领域。

If those planets are out there, we should be finding them pretty soon.

如果那里真有那些行星，我们应该很快就会找到它们。

By comparison, the terrestrial planets have meager atmospheres at best.

相比之下，类地行星最多只有稀薄的大气层。

When astronomers have found the star, they look at the planets around it.

当天文学家发现了这颗恒星，他们就会观察它周围的行星。

In recent years, astronomers have found nearly 400 new planets with stars.

近年来，天文学家已经发现了近400颗新的有行星的恒星。

The most popular one is that they may contain visitors from other planets.

最常见的一种说法是它们可能包含来自其他行星的访客。

It would have been warm enough on these planets for liquid water to exist.

这些行星上的温度足够高，足以让液态水存在。

Most known extrasolar planets reside in highly elongated, not circular, orbits.

大多数已知的太阳系外行星都居住在高度拉长而非圆形的轨道上。

Mercury is known to have a high density in comparison with other rocky planets.

众所周知，与其他岩石行星相比，水星的密度很高。

"Regions of outward migration allow planets and planetoids to survive, " Mac Low said.

麦克·劳说：“向外迁移的地区使行星和小行星得以生存。”

The most obvious difference between the terrestrial and the Jovian planets is their size.

类地行星和类木行星之间最明显的区别是它们的大小。

American scientists have been using instruments for years to look for earth-like planets.

美国科学家多年来一直在使用仪器寻找类地行星。