Core Viewpoint - The European Space Agency (ESA) has confirmed a 4% probability of the near-Earth asteroid 2024 YR4 impacting the Moon in December 2032, while it poses no direct threat to Earth [1]. Group 1: Asteroid Observation - 2024 YR4 is an approximately 80-meter diameter asteroid discovered at the end of 2024 [1]. - Early monitoring raised concerns about potential Earth impact due to data uncertainty, but ESA has ruled out this risk, indicating the probability of an Earth impact is nearly zero [1]. Group 2: Potential Impact Effects - If 2024 YR4 were to collide with the Moon, it could create a crater about 1 kilometer in diameter and eject debris into the lunar space, which may pose some risk to orbiting spacecraft and satellites [1]. Group 3: Future Monitoring - ESA stated that no intervention measures are currently necessary and will continue to collaborate with international agencies to track the asteroid's orbital changes, with the next critical observation opportunity expected in 2028 [1].

Core Points - The asteroid Apophis, also known as "destroyer star," will make a close approach to Earth on April 13, 2029, with a distance of 32,000 kilometers, closer than geostationary satellites [1][2] - Initial predictions in 2004 indicated a 2.7% chance of collision, but subsequent observations have confirmed that the risk is negligible [2] - The event has garnered attention from multiple space agencies, including NASA, ESA, and JAXA, which plan to send probes for research [1][2] Group 1: Observational Opportunities - The close approach of Apophis presents a unique opportunity for scientific observation, with the potential for visibility to the naked eye in Europe and Africa [2] - The United Nations has designated 2029 as the "International Asteroid Awareness and Planetary Defense Year" to emphasize the significance of this event [2] - Ground-based radar and other observational methods will be employed to measure Apophis's size, shape, and trajectory [2] Group 2: NASA's OSIRIS-APEX Mission - NASA's OSIRIS-APEX spacecraft is en route to Apophis, building on the previous OSIRIS-REx mission that collected samples from the asteroid Bennu [3][4] - The spacecraft will begin distant observations on April 2, 2029, and will closely monitor the gravitational effects of Earth on Apophis during its closest approach [4] - Following the close approach, the spacecraft will enter orbit around Apophis for an 18-month exploration mission [4] Group 3: European and Japanese Missions - ESA's "Rapid Apophis Mission for Space Safety" (RAMSES) is proposed to monitor changes in Apophis's rotation and potential seismic activity due to Earth's tidal forces [5][6] - JAXA's DESTINY+ mission aims to study the active asteroid "Didymos" but will also make a brief visit to Apophis in early 2029 [6] - A proposed experiment, the Apophis Crater Experiment (ACE), aims to observe the effects of a collision with Apophis to understand its internal structure and mechanical properties [6]