Topic: Solar System/Moon
The Artemis program is a U.S. government-funded international human spaceflight program that has the goal of landing "the first woman and the next man" on the Moon, specifically at the lunar south pole region, by 2024. The program is carried out predominantly by NASA, U.S. commercial spaceflight companies contracted by NASA, and international partners including the European Space Agency (ESA), the Japan Aerospace Exploration Agency (JAXA), Canadian Space Agency (CSA), the Italian Space Agency (ASI) the Australian Space Agency (ASA), the UK Space Agency (UKSA), the United Arab Emirates Space Agency (UAESA) the State Space Agency of Ukraine, and the Brazilian Space Agency (AEB). NASA is leading the program, but expects international partnerships to play a key role in advancing Artemis as the next step towards the long-term goal of establishing a sustainable presence on the Moon, laying the foundation for private companies to build a lunar economy, and eventually sending humans to Mars.
In December 2017, President Donald Trump signed Space Policy Directive 1, authorizing the lunar campaign. Artemis draws upon ongoing spacecraft programs including Orion, the Gateway, and Commercial Lunar Payload Services, and adds an undeveloped crewed lander. The Space Launch System will serve as the primary launch vehicle for Orion, while commercial launch vehicles are planned for use to launch various other elements of the campaign. NASA requested US$1.6 billion in additional funding for Artemis for fiscal year 2020, while the Senate Appropriations Committee requested from NASA a five-year budget profile which is needed for evaluation and approval by Congress.
Project A119, also known as A Study of Lunar Research Flights, was a top-secret plan developed in 1958 by the United States Air Force. The aim of the project was to detonate a nuclear bomb on the Moon, which would help in answering some of the mysteries in planetary astronomy and astrogeology. If the explosive device detonated on the surface, not in a lunar crater, the flash of explosive light would have been faintly visible to people on Earth with their naked eye, a show of force resulting in a possible boosting of domestic morale in the capabilities of the United States, a boost that was needed after the Soviet Union took an early lead in the Space Race and was also working on a similar project.
The project was never carried out, being cancelled primarily out of a fear of a negative public reaction, with the potential militarization of space that it would also have signified, and because a Moon landing would undoubtedly be a more popular achievement in the eyes of the American and international public alike. A similar project by the Soviet Union also never came to fruition.
The existence of the US project was revealed in 2000 by a former executive at the National Aeronautics and Space Administration (NASA), Leonard Reiffel, who led the project in 1958. A young Carl Sagan was part of the team responsible for predicting the effects of a nuclear explosion in vacuum and low gravity and in evaluating the scientific value of the project. The project documents remained secret for nearly 45 years, and despite Reiffel's revelations, the United States government has never officially recognized its involvement in the study.
Lunar lava tubes are lava tubes on the Moon formed during the eruption of basaltic lava flows. When the surface of a lava flow cools, it hardens and the lava can channel beneath the surface in a tube-shaped passage. Once the flow of lava diminishes, the tube may drain, forming a hollow void. Lunar lava tubes are formed on sloped surfaces that range in angle from 0.4° to 6.5°. These tubes may be as wide as 500 metres (1,600 ft) before they become unstable against gravitational collapse. However, stable tubes may still be disrupted by seismic events or meteoroid bombardment.
The existence of a lava tube is sometimes revealed by the presence of a "skylight", a place in which the roof of the tube has collapsed, leaving a circular hole that can be observed by lunar orbiters.
- "Lunar Lava Tube" | 2021-11-01 | 59 Upvotes 22 Comments
The Moon illusion is an optical illusion which causes the Moon to appear larger near the horizon than it does higher up in the sky. It has been known since ancient times and recorded by various cultures. The explanation of this illusion is still debated.
- "Moon Illusion" | 2022-06-12 | 129 Upvotes 71 Comments