About 2 of our solar nebula consisted of elements besides hydrogen and helium. However, the very first generation of star systems in the universe probably consisted only of hydrogen and helium.
Which of the following statements is most likely to have been true about these first-generation star systems? A) There were no comets or asteroids in these first-generation star systems.
B) Jovian planets in these first-generation star systems had clouds made of water and other hydrogen compounds.
C) These first-generation star systems typically had several terrestrial planets in addition to jovian planets.
D) Like the jovian planets in our solar system, the jovian planets in these first-generation systems were orbited by rings.
Question 2
What can we conclude about the structure of Earth's interior knowing that the average density of Earth is higher than the average density of the rock on the continents and seafloor?
A) That Earth's most dense material must be water
B) That Earth's most dense material must be the seafloor and the continents
C) That Earth's most dense material must be beneath the surface
D) That Earth's least dense material must be the seafloor and the continents
E) That Earth's least dense material must be beneath the surface
Measurements of solar cycle variation during the last 30 years
The reflection nebula NGC 1999 is brilliantly illuminated by V380 Orionis
This diagram shows a cross-section of a solar-type star.
Solar Granulation
Elements of an Experiment
Our planet absorbs solar radiation