It is not known if acne, a common skin condition characterized by the appearance of pimples, was present in prehistoric times. There is no direct evidence one way or the other, and it is difficult to say for certain what the prevalence of acne might have been among ancient peoples.
Acne is thought to be caused by a variety of factors, including hormones, genetics, and certain aspects of lifestyle and environment. It is possible that some of these factors, such as hormones and genetics, have been present in human populations for a long time. However, it is also likely that other factors, such as diet, pollution, and stress, are more closely related to modern lifestyles and environments. It is difficult to say for certain how these factors may have affected the prevalence of acne in ancient times.

It is not known for certain whether the asteroid impact that is believed to have led to the extinction of the dinosaurs affected the Earth's orbit. Some scientists have suggested that the impact may have caused a temporary change in the Earth's orbit, but the evidence for this is not conclusive.
It is generally accepted that the asteroid impact, which is thought to have occurred around 66 million years ago, was a catastrophic event that had a major impact on the Earth's climate and environment. The impact is believed to have caused widespread wildfires, tsunamis, and other disasters that likely had a profound effect on the Earth's ecosystems. However, the precise effects of the impact on the Earth's orbit are not well understood and remain a topic of ongoing research.

Yes, astronauts who spend long periods in orbit can be prophylactically treated with medications for osteoporosis and other conditions that can arise as a result of prolonged exposure to microgravity. It is well known that microgravity can cause a range of negative health effects, including loss of bone density and muscle atrophy. To help combat these effects, astronauts on long-duration missions are typically given a variety of medications and supplements to help maintain their health. This may include medications to prevent osteoporosis, as well as other treatments to help maintain muscle mass and strength. Additionally, astronauts are also required to perform regular exercise and other physical activities while in orbit to help combat the negative effects of microgravity on their bodies.