1
Answer:
The moon's surface exhibits active volcanic activity.
Explanation:
According to observations made from outside earth's surface, the moon has got active volcanic activity going on there.
Other than the moon, the other ones are:
- Earth.
- Venus.
- Saturn's moon Enchiladas.
- Neptune's moon Triton.
This volcanic activity causes mass movement of land masses from their original position to a new position.
2
Answer:
B. When a star explodes as a supernova
Explanation:
Elements are spread thought the universe in many different ways.
Elements that are heavier than hydrogen are formed in the massive stars and spread in the universe when the massive stars end in supernova explosions.
After this explosions, this elements that there before are held in the massive stars are released into the universe.
3
Answer:
B. Its size
Explanation:
By accessing the speed at which the objects around the black hole move, we can determine its mass which is its size.
Since a black hole cannot be seen, we identify its mass and location through observing and analyzing the movement of objects like stars around it, if they appear to be moving at a very high speed, then that infers that there is a large black hole that is making the stars spin.
4
Answer:
D. It must follow a closed orbit around a star.
Explanation:
In order for an object to qualify to be a planet it must follow a closed orbit around a star.
A good example is the planet earth, it follows a closed orbit around a star with the star being the sun.
Other qualifications are:
It must have enough gravitational pull that leads it to be in a spheroidal shape.
