star定位到原文倒数第二句:When this happened, the contraction stopped and a true star(the Sun) was born.句首this与前文构成指代关系,所以要往前文找答案,即Eventually, after perhaps 100 million years had passed since the solar nebula first began to contract, the central temperature of the proto...
a consensus has arisen about the most likely series of events that led to the present-day system of the sun and planets. a key piece of evidence about the origin of the solar system is that all the planets orbit the sun in the same direction and in nearly the same ...
Which of the following can be inferred from paragraph 6 about the formation of the solar system? A. The Sun was already billions of years old when the planets were formed. B. The planets closest to the Sun formed first. C. Meteorites entered the solar system sometime after the planets we...
You know, larger objects attract smaller ones and sort of gobble them up. And eventually you get a full-sized planet in its own orbit. Ok, that's how the inner rocky planets probably formed by accretion. But what about those gas planets in the outer solar system, in the outer accretion...
Several mechanisms have been proposed for theMoon formationbillions years ago, some 30–50 million years after the origin of the Solar System. Recent research presented by Rick Carlson indicates a slightly lower age of between 4.40 and 4.45 billion years. These mechanisms included the fission of ...
1.The four innermost planets of our solar system-Mercury, Venus, Earth, and Mars-are terrestrial, or rocky. planets. The beginning of their creation process occurred when the cloud of leftover material from the formation of the Sun settled into disc around the young star. Most of the materi...
collapse of the gas cloud that became the Sun and solar system.(在太阳形成之前,一颗超新星出现在成为太阳的云附近;甚至有可能是这次爆炸产生的爆炸波触发了形成太阳和太阳系的气体云的坍塌。)通过验证各种各样的同位素,也证实了这样一个观点,所以也就表明铁-60和铝-26最初都是起源于同一个大恒星的。
NARRATOR: Listen to part of a lecture in an astronomy class. MALE PROFESSOR: Last week we discussed the formation of Earth and the other rocky planets—the planets in the inner solar system.Uh, s-so, what about the gas giants?Jupiter, Saturn, Uranus, and Neptune. ...
We believe our solar system began as a huge spinning cloud of dust and gas, which flattened and eventually collapsed in on itself. The matter at the center condensed into a ball of hot gas and dust, eventually becoming our Sun. And … what happened to the remaining cloud, to the disk ...