The first Earth satellite, Sputnik 1, was launched on October 4, 1957 by the Soviet Union. **

The frequency at which a satellite orbits the Earth depends on its altitude and purpose. Most satellites in low Earth orbit (LEO) complete an orbit roughly every 90 minutes, traveling at speeds of around 28,000 kilometers per hour. Satellites in higher orbits, such as geostationary orbit, take longer to complete an orbit, typically around 24 hours. Overall, satellites orbit the Earth continuously, providing various services such as communication, weather monitoring, and navigation. **

The boundary between Earth and outer space is defined by the Kármán line, which is located at an altitude of 100 kilometers (62 miles) above sea level. At this point, the Earth's atmosphere becomes so thin that it is no longer able to support human flight without the use of specialized equipment, and the effects of aerodynamic lift are negligible. Beyond the Kármán line, the atmosphere gradually transitions into the vacuum of space, where there is no air or atmospheric pressure. This boundary is recognized internationally as the demarcation between Earth's atmosphere and outer space. **

The Earth is often shown from space because it provides a unique and comprehensive perspective of our planet. From space, we can see the Earth as a whole, showcasing its beauty, complexity, and interconnectedness. This view helps us understand the Earth's geography, weather patterns, and environmental changes in a way that is not possible from the ground. Additionally, images of the Earth from space can inspire awe and appreciation for our planet's fragility and the need to protect it. **

We cannot see outer space from Earth during the day because the sunlight is scattered by the Earth's atmosphere, making the sky appear blue. At night, we cannot see outer space because the Earth's atmosphere absorbs and scatters light from distant stars and galaxies, creating a dark sky. Additionally, light pollution from artificial sources on Earth can also hinder our ability to see outer space clearly. **

The Earth moves through space at an average velocity of about 67,000 miles per hour (107,000 kilometers per hour) as it orbits around the Sun. Additionally, the Earth rotates on its axis at a speed of about 1,000 miles per hour (1,600 kilometers per hour) at the equator. **

Babies born in space would likely face significant challenges if they were to return to Earth. The effects of microgravity and radiation exposure in space could potentially impact their development and health. Additionally, the lack of gravity in space could affect their bone and muscle development, making it difficult for them to adapt to Earth's gravity. Furthermore, the long-term effects of space travel on a developing fetus are not fully understood, so it is uncertain how their bodies would cope with the transition from space to Earth. Therefore, it is currently unknown whether babies born in space would be able to survive and thrive on Earth. **

It is highly unlikely that a single Space Marine could conquer our Earth. While Space Marines are incredibly powerful and skilled warriors, Earth is home to billions of people, advanced military technology, and diverse geographical challenges. Additionally, Earth's governments and military forces would likely mobilize to defend against such an invasion. The Space Marine would face overwhelming odds and would likely be unable to conquer the entire planet on their own. **