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Astéroïde 2024 PT5
is a near-Earth object roughly in diameter discovered by ATLAS South Africa, Sutherland on 7 August 2024, the day before approaching Earth at . Orbit The object orbits the Sun but makes slow close approaches to the Earth–Moon system. Between 29 September (19:54 UTC) and 25 November 2024 (16:43 UTC) (a period of ) it passed just outside Earth's Hill sphere (roughly ) at a low relative velocity (in the range – ) and became temporarily captured by Earth's gravity, with a geocentric orbital eccentricity of less than 1 and negative geocentric orbital energy. The most recent closest approach to Earth was 8 August 2024 at roughly when it had a relative velocity of . It also approached Earth on 9 January 2025 at roughly when it had a relative velocity of . On 18 August 2024 CNEOS removed from their Sentry Risk Table, having determined it poses no risk of a potential Earth impact. The object is expected to make another approach in 2055. This object will return to orbit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asteroid Terrestrial-impact Last Alert System
The Asteroid Terrestrial-impact Last Alert System (ATLAS) is a robotic astronomical survey and early warning system optimized for detecting smaller near-Earth objects a few weeks to days before they Impact event, impact Earth. Funded by NASA, and developed and operated by the University of Hawaii's Institute for Astronomy (Hawaii), Institute for Astronomy, the system currently has four 0.5-meter telescopes. Two are located apart in the Hawaiian islands, at Haleakala Observatory, Haleakala (ATLAS–HKO, observatory code IAU code#T05, T05) and Mauna Loa Observatory, Mauna Loa (ATLAS–MLO, observatory code IAU code#T08, T08) observatories, one is located at the South African Astronomical Observatory, Sutherland Observatory (ATLAS–SAAO, observatory code IAU code#M22, M22) in South Africa, one is at the El Sauce Observatory in Rio Hurtado (Chile) (ATLAS–CHL, observatory code IAU code#W68, W68). The newest at Teide Observatory (ATLAS-Teide) was commissioned in February 2025, bu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Period
The orbital period (also revolution period) is the amount of time a given astronomical object takes to complete one orbit around another object. In astronomy, it usually applies to planets or asteroids orbiting the Sun, moons orbiting planets, exoplanets orbiting other stars, or binary stars. It may also refer to the time it takes a satellite orbiting a planet or moon to complete one orbit. For celestial objects in general, the orbital period is determined by a 360° revolution of one body around its primary, ''e.g.'' Earth around the Sun. Periods in astronomy are expressed in units of time, usually hours, days, or years. Its reciprocal is the orbital frequency, a kind of revolution frequency, in units of hertz. Small body orbiting a central body According to Kepler's Third Law, the orbital period ''T'' of two point masses orbiting each other in a circular or elliptic orbit is: :T = 2\pi\sqrt where: * ''a'' is the orbit's semi-major axis * ''G'' is the gravitationa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Research Notes Of The AAS
The American Astronomical Society (AAS, sometimes spoken as "double-A-S") is an American society of professional astronomers and other interested individuals, headquartered in Washington, DC. The primary objective of the AAS is to promote the advancement of astronomy and closely related branches of science, while the secondary purpose includes enhancing astronomy education and providing a political voice for its members through lobbying and grassroots activities. Its current mission is to enhance and share humanity's scientific understanding of the universe as a diverse and inclusive astronomical community. History The society was founded in 1899 through the efforts of George Ellery Hale. The constitution of the group was written by Hale, George Comstock, Edward Morley, Simon Newcomb and Edward Charles Pickering. These men, plus four others, were the first Executive Council of the society; Newcomb was the first president. The initial membership was 114. The AAS name of the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jet Propulsion Laboratory
The Jet Propulsion Laboratory (JPL) is a Federally funded research and development centers, federally funded research and development center (FFRDC) in La Cañada Flintridge, California, Crescenta Valley, United States. Founded in 1936 by California Institute of Technology (Caltech) researchers, the laboratory is now owned and sponsored by NASA and administered and managed by Caltech. The primary function of the laboratory is the construction and operation of planetary robotic spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating the NASA Deep Space Network (DSN). Among the major active projects at the laboratory, some are the Mars 2020 mission, which includes the ''Perseverance (rover), Perseverance'' rover; the Mars Science Laboratory mission, including the ''Curiosity (rover), Curiosity'' rover; the ''Mars Reconnaissance Orbiter''; the ''Juno (spacecraft), Juno'' spacecraft orbiting Jupiter; the ''Soil Moisture Active P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Observation Arc
In observational astronomy, the observation arc (or arc length) of a Solar System body is the time period between its earliest and latest observations, used for tracing the body's path. It is usually given in days or years. The term is mostly used in the discovery and tracking of asteroids and comets. Arc length has the greatest influence on the accuracy of an orbital estimate. The number, spacing of intermediate observations, and timestamps have a lesser effect. Short arcs A very short arc leaves a high uncertainty parameter. The object might be in one of many different orbits, at many distances from Earth. In some cases, the initial arc was too short to determine if the object was in orbit around the Earth, or orbiting out in the asteroid belt. With a 1-day observation arc, was thought to be a trans-Neptunian dwarf planet, but is now known to be a 1 km main-belt asteroid. With an observation arc of 3 days, was thought to be a Mars-crossing asteroid that could be a thr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arjuna Asteroid
The Arjuna asteroids (also known as "Arjunas") are a dynamical group of asteroids in the Solar System. Arjunas are near-Earth objects (NEOs) whose orbits are very Earth-like in character, having low inclination, orbital periods close to one year, and low eccentricity. The group is named after Arjuna, a central hero in Hindu historic script Mahabharata. The definition is somewhat more relevant and overlaps the definition of the four well-established Apollo, Amor, Aten and Atira groups. They constitute a dynamically cold group of small NEOs that experience repeated trappings in the 1:1 mean-motion resonance with the Earth. Members Potential members of the Arjuna group with their Apollo (APO) or Aten Aten, also Aton, Atonu, or Itn (, reconstructed ) was the focus of Atenism, the religious system formally established in ancient Egypt by the late Eighteenth Dynasty pharaoh Akhenaten. Exact dating for the Eighteenth Dynasty is contested, thou ... (ATE) group classification in pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surveyor 2
Surveyor 2 was to be the second lunar lander in the uncrewed American Surveyor program to explore the Moon. After launch on September 20, 1966, a mid-course correction failure resulted in the spacecraft losing control. Contact was lost with the spacecraft at 9:35 UTC, September 22. Background On February 3, 1966, the Luna 9 spacecraft was the first spacecraft to achieve a lunar soft landing and to transmit photographic data to Earth. On May 30, Surveyor 1 launched, landing on Oceanus Procellarum on June 2. This craft also transmitted photographic data back to Earth. This spacecraft was the second of a series designed to achieve a soft landing on the Moon and to return lunar surface photography for determining characteristics of the lunar terrain for Apollo program lunar landing missions. Besides transmitting photos, Surveyor 2 was planned to perform a 'bounce', to photograph underneath its own landing site. It was also equipped to return data on radar reflectivity of the lunar s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centaur (rocket Stage)
The Centaur is a family of rocket propelled upper stages that has been in use since 1962. It is currently produced by U.S. launch service provider United Launch Alliance, with one main active version and one version under development. The diameter Common Centaur/Centaur III flies as the upper stage of the Atlas V launch vehicle, and the diameter Centaur V has been developed as the upper stage of ULA's new Vulcan rocket. Centaur was the first rocket stage to use liquid hydrogen (LH2) and liquid oxygen (LOX) propellants, a high-energy combination that is ideal for upper stages but has significant handling difficulties. Characteristics Common Centaur is built around stainless steel pressure stabilized balloon propellant tanks with thick walls. It can lift payloads of up to . The thin walls minimize the mass of the tanks, maximizing the stage's overall performance. A common bulkhead separates the LOX and LH2 tanks, further reducing the tank mass. It is made of two stainless ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2020 SO
2020 SO is a near-Earth object identified to be the Centaur upper stage used on 20 September 1966 to launch the Surveyor 2 spacecraft. The object was discovered by the Pan-STARRS 1 survey at the Haleakala Observatory on 17 September 2020. It was initially suspected to be an artificial object due to its low velocity relative to Earth and later on the noticeable effects of solar radiation pressure on its orbit. Spectroscopic observations by NASA's Infrared Telescope Facility in December 2020 found that the object's spectrum is similar to that of stainless steel, confirming the object's artificial nature. Following the object's confirmation as space debris, the object was removed from the Minor Planet Center's database on 19 February 2021. Overview As it approached Earth, the trajectory indicated the geocentric orbital eccentricity was less than 1 by 15 October 2020, and the object became temporarily captured on 8 November when it entered Earth's Hill sphere. It entered via the o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temporary Satellite
A temporary satellite is an object which has been captured by the gravitational field of a planet and thus has become the planet's natural satellite, but, unlike irregular moons of the larger outer planets of the Solar System, will eventually either leave its orbit around the planet or collide with the planet. The only observed examples are , a temporary satellite of Earth for twelve months from July 2006 to July 2007, and 2022 NX1. Some defunct space probes or rockets have also been observed on temporary satellite orbits. In astrophysics, a temporary satellite is any body that enters the Hill sphere of a planet at a sufficiently low velocity such that it becomes gravitationally bound to the planet for some period of time. Capture of asteroids The dynamics of the capture of asteroids by Earth was explored in simulations conducted on a supercomputer, with results published in 2012. Of 10 million virtual near-Earth asteroids, 18,000 have been temporarily captured. Earth has ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
469219 Kamoʻoalewa
469219 Kamooalewa (), provisionally designated , is a very small elongated asteroid, fast rotator and near-Earth object of the Apollo group, approximately in diameter. At present it is a quasi-satellite of Earth, and currently the second-smallest, closest, and most stable known such quasi-satellite (after ). The asteroid was discovered by Pan-STARRS at Haleakala Observatory on 27 April 2016. Numerous proposed missions have since targeted the object, including a NASA solar-sail mission,Heiligers, J., Fernandez, J. M., Stohlman, O. R., & Wilkie, W. K. (2019). Trajectory design for a solar-sail mission to asteroid 2016 HO3. Astrodynamics, 3(3), 231-246. https://doi.org/10.1007/s42064-019-0061-1 a University of Colorado flyby and impact experiment, and was selected as a target for the Chinese ZhengHe project, which has developed into the Tianwen-2 mission. The chondritic simulants QLS-1, 2, and 3 have been developed by the Qian Xuesen Laboratory of Space Technology to bett ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quasi-satellite
A quasi-satellite is an object in a specific type of co-orbital configuration (1:1 orbital resonance) with a planet (or dwarf planet) where the object stays close to that planet over many orbital periods. A quasi-satellite's orbit around the Sun takes the same time as the planet's, but has a different eccentricity (usually greater), as shown in the diagram. When viewed from the perspective of the planet by an observer facing the Sun, the quasi-satellite will appear to travel in an oblong retrograde loop around the planet. . In contrast to ''true'' satellites, quasi-satellite orbits lie outside the planet's Hill sphere, and are unstable. Over time they tend to evolve to other types of resonant motion, where they no longer remain in the planet's neighborhood, then possibly later move back to a quasi-satellite orbit, etc. Other types of orbit in a 1:1 resonance with the planet include horseshoe orbits and tadpole orbits around the Lagrangian points, but objects in these orbits do no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
