Related papers: The discovery and characterization of Earth-crossi…
On 27 December 2024, near-Earth object (NEO) 2024 YR$_4$ was discovered by the ATLAS survey and identified as a virtual impactor. A few weeks later, it eventually reached level 3 on the Torino Scale and was the first and only asteroid to be…
Recently discovered asteroid 2024 YR$_4$ has an orbital period of almost exactly 4 years, a descending node located almost exactly 1 au from the Sun, with a perihelion slightly less than that. Its combination of semi-major axis and…
Near-Earth asteroid 2024 YR4 was discovered on 2024-12-27 and its probability of Earth impact in December 2032 peaked at about 3% on 2025-02-18. Additional observations ruled out Earth impact by 2025-02-23. However, the probability of lunar…
2024 YR4 is a 40-100 meter-diameter asteroid and former Torino Scale 3 object which currently has a roughly 4% chance of impacting the Moon on 2032 December 22, an event which recent studies suggest could pose a hazard on Earth due to…
On 4 March 2021 at 9 UTC a 30-m in diameter near-Earth asteroid 2021 DW1 passed the Earth at a distance of 570000 km, reaching the maximum brightness of V=14.6 mag. We observed it photometrically from 2 March, when it was visible at V=16.5…
The near-Earth asteroid 2024 YR4 -- a $\sim$60 m rocky object that was once considered a potential Earth impactor -- has since been ruled out for Earth but retained a $\sim$4.3% probability of striking the Moon in 2032. Such an impact, with…
Imminent impactors may be detected only a few hours before their impact with Earth, providing a brief opportunity to characterize them before impact. We describe the characterization of imminent impactor 2024 RW$_1$, which was discovered by…
We present comprehensive photometric characterisation of 2025 FA$_{22}$, a Potentially Hazardous Asteroid (PHA) discovered on 29 March 2025 and observed during the seventh International Asteroid Warning Network (IAWN) coordinated campaign.…
Near-Earth asteroid 2012 DA14 made its closest approach on February 15, 2013, when it passed at a distance of 27,700 km from the Earth's surface. It was the first time an asteroid of moderate size was predicted to approach that close to the…
2024 PT$_5$ is a tiny ($D\leq10$ m) near-Earth asteroid (NEA) discovered in August 2024. 2024 PT$_5$ was gravitationally bound to the Earth-Moon system from September to November 2024 and classified as a minimoon. Several quick response…
At the end of its discovery apparition, the $\sim$60 m near-Earth object 2024 YR4 was associated with a non-zero probability of lunar impact during its 2032 December 22 close approach. While posing no threat to Earth, a lunar impact of this…
Near-Earth Asteroids can be hazardous to the Earth, due to their orbital characteristics and proximity to inner Solar System planets. Using three sets of CCD images collected in June and July 2011, the orbital elements of asteroid 1994 PC1…
The discovery of 2024 YR4 presented the planetary defense community with the most significant impact threat in almost two decades, reaching level 3 on the Torino scale. The community, now mature and well-organized, responded with a global…
We observed near-Earth asteroid (162421) 2000 ET70 using the Arecibo and Goldstone radar systems over a period of 12 days during its close approach to the Earth in February 2012. We obtained continuous wave spectra and range-Doppler images…
The asteroid 2014 JO25, considered to be "potentially hazardous" by the Minor Planet Center, was spectroscopically followed during its close-Earth encounter on 19th and 20th of April 2017. The spectra of the asteroid were taken with the low…
The near-Earth asteroid (308635) 2005 YU55 is a potentially hazardous asteroid which was discovered in 2005 and passed Earth on November 8th 2011 at 0.85 lunar distances. This was the closest known approach by an asteroid of several hundred…
Minimoons are asteroids that become temporarily captured by the Earth-Moon system. We present the discovery of 2024 PT$_5$, a minimoon discovered by the Asteroid Terrestrial-impact Last Alert System (ATLAS) Sutherland telescope on 2024…
Near-Earth asteroids (NEAs) that may evolve into impactors deserve detailed threat assessment studies. Early physical characterization of a would-be impactor may help in optimizing impact mitigation plans. We first detected NEA…
We present visible spectroscopic observations of a near-earth object (NEO) 2012 DA14. The asteroid 2012 DA14 came close to the surface of the Earth on February 15, 2013 at a distance of 27,700 km. Its estimated diameter is around 45 m. The…
We report new observations of the active asteroid P/2010 A2 taken when it made its closest approach to the Earth (1.06 au in 2017 January) after its first discovery in 2010. Despite a crucial role of the rotational period in clarifying its…