• Space-Junk: Non-functioning hardware and bits of debris floating around in Earth’s orbit are “Space Junk”. Inoperative satellites, rockets, fragments of spacecraft, satellites are main sources of Space Junk. Space exploration or any operational mission in orbit like working satellites, space stations, pace telescopes, spacecraft are at risk of colliding with this debris- Space Junk. The most polluted orbits in general are considered to be those between 200-2000 km above Earth (Lower Earth Orbits or LEO), and the 36,000 km orbit (Geosynchronous). – Weforum.org
  • Space hazard: While the chances of a major collision of a massive asteroid hitting earth are low in the near term, there is a certainty that one will happen eventually unless defensive measures are taken. In 2016, a NASA scientist warned that the Earth is unprepared for such an event. In April 2018, the B612 Foundation reported “It’s 100 percent certain we’ll be hit [by a devastating asteroid], but we’re not 100 percent sure when. Also in 2018, physicist Stephen Hawking, in his final book Brief Answers to the Big Questions, considered an asteroid collision to be the biggest threat to the planet.(Source Wikipedia). As of 2020 no proven and standard technology exist to intercept and tackle Near-Earth-Objects (NEO) that could hit earth.
  • Earth alternative: As of 2020, no space colonies have been established or developed for an alternative settlement for mankind in the event of a planetary disaster (such as asteroid hitting earth).

  • Space-Junk: Any human-made object in orbit that does not serve a useful purpose is considered debris. Debris from space missions, debris from satellite tests, fragmentation of debris and accidental collisions of satellites. A hundreds of thousands of man-made objects are orbiting around earth-from dead satellites to errant nuts and bolts, putting our working satellites at risk. There is no universal government bodies that foster and enforce global standards in space junk waste mitigation. Biggest issues are financing and international cooperation. The question of who pays for these ‘garbage collection’ missions is a tricky one. Challenge is negotiating the international diplomatic space and persuading a country to de-orbit old satellite derbies (Weforum.org).
  • Space Hazard: Dangerous asteroids have struck the Earth in the past and will do so again in future. Asteroids are rocky, revolving around the sun. There are millions of asteroids, ranging in size from hundreds of miles to several feet across. According to Space.com asteroids are leftovers from the formation of our solar system about 4.6 billion years ago. Early on, the birth of Jupiter prevented any planetary bodies from forming in the gap between Mars and Jupiter, causing the small objects that were there to collide with each other and fragment into the asteroids seen today.
  • Earth alternative: Space colonization is permanent human habitation off the earth. As of 2020 no space colonies have been built. Currently, the building of a space colony would present a set of huge technological and economic challenges. Building self-sustained space colony for mankind survival require invention in construction, material, a massive amount of money and resources.

  • Space-Junk: Accumulation of space debris poses a risk to inhabitants on Earth and also to astronauts and scientists who engage in space exploration work for future possibilities of mankind. Collisions with debris have become a hazard to spacecraft; the smallest objects cause damage akin to sandblasting, especially to solar panels and optics like telescopes or star trackers that cannot easily be protected by a ballistic shield. – Wikipedia
  • Space Hazard: Dangerous asteroids have struck the Earth in the past and will do so again in future. According to abundant geological evidence, an asteroid roughly 10 km (6 miles) across hit Earth about 65 million years ago. This impact made a huge explosion and a crater about 180 km (roughly 110 miles) across. Debris from the explosion was thrown into the atmosphere, severely altering the climate, and leading to the extinction of roughly 3/4 of species that existed at that time, including the dinosaurs. Many asteroids of this type are now known; their orbits pass through the inner solar system and cross Earth’s orbit. Some of these could potentially hit Earth in the future. Most, but not all are smaller than the one that hit us 65 million years ago. – psi.edu
  • Earth alternative: The primary argument calling for space colonization is the long-term survival of human civilization. By developing alternative locations off Earth, the planet’s species, including humans, could live on in the event of natural or man-made disasters on our own planet. There is no immediate impact to earth without having space colony. In a theoretical study from 2019, a group of researchers have pondered the long-term trajectory of human civilization. It is argued that due to Earth’s finitude as well as the limited duration of our solar system, mankind’s survival into the far future will very likely require extensive space colonization. – Wikipedia

  • Space-Junk: we need to start removing the most volatile and biggest pieces from the most congested orbits. De-orbit derbies and burn. The UN guidelines on space debris mitigation are among the key international efforts to get different actors to follow proper rules of the road, but they are voluntary. Need international governing body to develop, enforce and sustain solutions for space-junk.
  • Space Hazard: Although NASA and other advanced countries’d agencies formally embraced the goal of finding and cataloging all near-Earth objects (NEOs) with diameters of 1 km or larger that could represent a collision risk to Earth, technological development on essential techniques and instruments needed for guidance, navigation and control (GNC) in close vicinity of asteroids and comets. This will, for example, allow hitting such bodies with a high-velocity kinetic impactor spacecraft and observing them before, during and after a mitigation attempt, e.g., for orbit determination and monitoring.
  • Earth alternative: Building colonies in space would require access to water, food, space, people, construction materials, energy, transportation, communications, life support, simulated gravity, radiation protection and capital investment. It is likely the colonies would be located near the necessary physical resources. The practice of space architecture seeks to transform spaceflight from a heroic test of human endurance to a normality within the bounds of comfortable experience. As is true of other frontier-opening endeavors, the capital investment necessary for space colonization would probably come from governments,[42] an argument made by John Hickman[43] and Neil deGrasse Tyson. – Wikipedia