Answer:
c) The planetoid is being attracted toward another massive object.
Explanation:
We can rule out a, the planetoid is travelling through space, friction is effectively nonexistent. B can be ruled out as well, as there is nothing in space that could naturally repel a planetoid. D is also implausible, as the question says the planetoid slows down for a certain period in its orbit, suggesting this behavior is repeated. Option c is incredibly likely, as the planetoid is far from the sun, a large mass, possibly far smaller than the sun but also far closer to the planetoid, could have the effect described in the question.
Answer: Scientists know that the Colorado River carved Grand Canyon. ... The age of the river falls between the rocks determined to be older than the river and those determined to be younger. Through this method, scientists have estimated an age for the river, and thus the canyon through which it flows, of 5-6 million years.
Explanation: