An impact crater is an approximately circular depression in the surface of a planet, moon, or other solid body in the Solar System or elsewhere, formed by the hypervelocity impact of a smaller body. In contrast to volcanic craters, which result from explosion or internal collapse, impact craters typically have raised rims and floors that are lower in elevation than the surrounding terrain. Impact craters range from small, simple, bowl-shaped depressions to large, complex, multi-ringed impact basins. Meteor Crater is a well-known example of a small impact crater on Earth.
The Lunar Roving Vehicle (LRV) is a battery-powered four-wheeled rover used on the Moon in the last three missions of the American Apollo program during 1971 and 1972. They are popularly known as "Moon buggies", a play on the words "dune buggy".
In celestial mechanics, the Lagrange points are orbital points near two large co-orbiting bodies. At the Lagrange points the gravitational forces of the two large bodies cancel out in such a way that a small object placed in orbit there is in equilibrium relative to the center of mass of the large bodies.
A mass driver or electromagnetic catapult is a proposed method of non-rocket spacelaunch which would use a linear motor to accelerate and catapult payloads up to high speeds. All existing and contemplated mass drivers use coils of wire energized by electricity to make electromagnets. Sequential firing of a row of electromagnets accelerates the payload along a path. After leaving the path, the payload continues to move due to momentum.
Atmospheric entry is the movement of an object from outer space into and through the gases of an atmosphere of a planet, dwarf planet, or natural satellite. There are two main types of atmospheric entry: uncontrolled entry, such as the entry of astronomical objects, space debris, or bolides; and controlled entry of a spacecraft capable of being navigated or following a predetermined course. Technologies and procedures allowing the controlled atmospheric entry, descent, and landing of spacecraft are collectively termed as EDL.
The giant-impact hypothesis, sometimes called the Big Splash, or the Theia Impact, suggests that the Moon formed from the ejecta of a collision between the proto-Earth and a Mars-sized planetesimal, approximately 4.5 billion years ago, in the Hadean eon. The colliding body is sometimes called Theia, from the name of the mythical Greek Titan who was the mother of Selene, the goddess of the Moon. Analysis of lunar rocks, published in a 2016 report, suggests that the impact may have been a direct hit, causing a thorough mixing of both parent bodies.
A space habitat is more than a bare-bones space station, in that it is intended as a permanent settlement or green habitat rather than as a simple way-station or other specialized facility. No space habitat has been constructed yet, but many design concepts, with varying degrees of realism, have come both from engineers and from science-fiction authors.
The Stanford torus is a proposed NASA design for a space habitat capable of housing 10,000 to 140,000 permanent residents.
A micrometeoroid is a tiny meteoroid: a small particle of rock in space, usually weighing less than a gram. A micrometeorite is such a particle that survives passage through the Earth's atmosphere and reaches the Earth's surface.
The Interplanetary Transport Network (ITN) is a collection of gravitationally determined pathways through the Solar System that require very little energy for an object to follow. The ITN makes particular use of Lagrange points as locations where trajectories through space can be redirected using little or no energy. These points have the peculiar property of allowing objects to orbit around them, despite lacking an object to orbit. While it would use little energy, transport along the network would take a long time.
Colonization of the Moon is the proposed establishment of a permanent human community or robotic industries on the Moon, the closest astronomical body to Earth.
A Moon landing is the arrival of a spacecraft on the surface of the Moon. This includes both crewed and robotic missions. The first human-made object to touch the Moon was the Soviet Union's Luna 2, on 13 September 1959.
Lunar craters are impact craters on Earth's Moon. The Moon's surface has many craters, all of which were formed by impacts.
In-Space Manufacturing(ISM) involves a comprehensive set of processes aimed at the production of manufactured goods in the space environment. ISM is also often used interchangeably with the term in-orbit manufacturing given that current production capabilities are limited to low Earth orbit.
The geology of the Moon is quite different from that of Earth. The Moon lacks a true atmosphere, which eliminates erosion due to weather; it does not have any known form of plate tectonics, it has a lower gravity, and because of its small size, it cooled more rapidly. The complex geomorphology of the lunar surface has been formed by a combination of processes, especially impact cratering and volcanism. The Moon is a differentiated body, with a crust, mantle, and core.
The Kessler syndrome, proposed by NASA scientist Donald J. Kessler in 1978, is a theoretical scenario in which the density of objects in low Earth orbit (LEO) due to space pollution is high enough that collisions between objects could cause a cascade in which each collision generates space debris that increases the likelihood of further collisions. One implication is that the distribution of debris in orbit could render space activities and the use of satellites in specific orbital ranges difficult for many generations.
Space-based solar power (SBSP) is the concept of collecting solar power in outer space and distributing it to Earth. Potential advantages of collecting solar energy in space include a higher collection rate and a longer collection period due to the lack of a diffusing atmosphere, and the possibility of placing a solar collector in an orbiting location where there is no night. A considerable fraction of incoming solar energy (55–60%) is lost on its way through the Earth's atmosphere by the effects of reflection and absorption. Space-based solar power systems convert sunlight to microwaves outside the atmosphere, avoiding these losses and the downtime due to the Earth's rotation, but at great cost due to the expense of launching material into orbit. SBSP is considered a form of sustainable or green energy, renewable energy, and is occasionally considered among climate engineering proposals. It is attractive to those seeking large-scale solutions to anthropogenic climate change or fossil fuel depletion.
The Moon Impact Probe (MIP) developed by the Indian Space Research Organisation (ISRO), India's national space agency, was a lunar probe that was released by ISRO's Chandrayaan-1 lunar remote sensing orbiter which in turn was launched, on 22 October 2008, aboard a modified version of ISRO's Polar Satellite Launch Vehicle. It discovered the presence of water on the Moon.
Asteroid capture is the entering by an asteroid into an orbit around a larger planetary body. The larger body is said to have "captured" the asteroid, which thereafter is its natural satellite. Typically, asteroids that approach close to a planet are either thrown out into space or else hit the planet. However, occasionally the asteroid is captured in an orbit around the planet. This is possible with any planetary body given the right conditions.
Beresheet was a demonstrator of a small robotic lunar lander and lunar probe operated by Israel Aerospace Industries. Its aims included promoting careers in science, technology, engineering, and mathematics (STEM), and landing its magnetometer, digital time capsule, and laser retroreflector on the Moon. The lander's gyroscopes failed on 11 April 2019 causing the main engine to shut off, which caused the lander to crash on the Moon. Its final resting position is 32.5956°N, 19.3496°E.
