The Aten asteroids are a dynamical group of asteroids whose orbits bring them into proximity with Earth. By definition, Atens are Earth-crossing asteroids (a < 1.0 AU and Q > 0.983 AU). The group is named after 2062 Aten, the first of its kind, discovered on 7 January 1976 by American astronomer Eleanor Helin at Palomar Observatory. As of November 2023, 2,646 Atens have been discovered, of which 256 are numbered, 14 are named, and 102 are classified as potentially hazardous asteroids.
The Amor asteroids are a group of near-Earth asteroids named after the archetype object 1221 Amor. The orbital perihelion of these objects is close to, but greater than, the orbital aphelion of Earth, with most Amors crossing the orbit of Mars. The Amor asteroid 433 Eros was the first asteroid to be orbited and landed upon by a robotic space probe.
Eleanor Francis "Glo" Helin was an American astronomer. She was principal investigator of the Near-Earth Asteroid Tracking (NEAT) program of NASA's Jet Propulsion Laboratory.
The Spacewatch Project is an astronomical survey that specializes in the study of minor planets, including various types of asteroids and comets at University of Arizona telescopes on Kitt Peak near Tucson, Arizona, in the United States. The Spacewatch Project has been active longer than any other similar currently active programs.
(99907) 1989 VA is a very eccentric, stony asteroid and near-Earth object, approximately 1 kilometer in diameter. It was discovered on 2 November 1989, by American astronomer couple Carolyn and Eugene Shoemaker and Canadian astronomer David Levy at the Palomar Observatory on Mount Palomar, California.
Many works of fiction have featured UFOs. In most cases, as the fictional story progresses, the Earth is being invaded by hostile alien forces from outer space, usually from Mars, as depicted in early science fiction, or the people are being destroyed by alien forces, as depicted in the film Independence Day. Some fictional UFO encounters may be based on real UFO reports, such as Night Skies. Night Skies is based on the 1997 Phoenix UFO Incident.
19982 Barbaradoore is an eccentric, stony Phocaea asteroid and a recent Mars-crosser from the inner regions of the asteroid belt, approximately 5 kilometers in diameter. It was discovered on 22 January 1990, by American astronomer Eleanor Helin at the Palomar Observatory in California, United States. The asteroid was named after Barbara Doore, a cousin of the discoverer.
4451 Grieve, provisional designation 1988 JJ, is a stony asteroid and large Mars-crosser on an eccentric orbit from the central asteroid belt, approximately 12 kilometers in diameter. It was discovered on 9 May 1988, by American astronomer Carolyn Shoemaker at the Palomar Observatory in California. The S-type asteroid is likely elongated and has a rotation period of 6.9 hours. It was named for Canadian geologist Richard Grieve.
A minor planet is "lost" when today's observers cannot find it, because its location is too uncertain to target observations. This happens if the orbital elements of a minor planet are not known accurately enough, typically because the observation arc for the object is too short, or too few observations were made before the object became unobservable.
(4953) 1990 MU is a large Earth-crossing asteroid (ECA) belonging to the Apollo group of near-Earth objects which also cross the orbits of Mars and Venus. At approximately 3 km in diameter, it is one of the largest known ECAs. It has been assigned a permanent number from the Minor Planet Center (4953) indicating that its orbit has been very well determined. With an observation arc of 45 years, the asteroid's trajectory and uncertainty regions are well known through to the year 2186.
(7025) 1993 QA is a sub-kilometer asteroid classified as near-Earth object of the Apollo and Amor group, respectively. It was discovered on 16 August 1993, by astronomers of the Spacewatch program at the Kitt Peak National Observatory near Tucson, Arizona, United States. The asteroid measures approximately half a kilometer in diameter and has a short rotation period of 2.5057 hours.
In observational astronomy, the observation arc 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 orbit. The number, spacing of intermediate observations, and timestamps have a lesser effect.
Mouloudia Club d'Alger, referred to as MC Alger or MCA for short, is an Algerian handball team that was founded on 1964, it is also considered as the most titled handball club in Africa(90 titles), as a division of MC Alger. They play their home games in Hacène Harcha Arena, which has a capacity of 8,000 people.
In planetary science, the term unusual minor planet, or unusual object, is used for a minor planet that possesses an unusual physical or orbital characteristic. For the Minor Planet Center (MPC), which operates under the auspices of the International Astronomical Union, any non-classical main-belt asteroid, which account for the vast majority of all minor planets, is an unusual minor planet. These include the near-Earth objects and Trojans as well as the distant minor planets such as centaurs and trans-Neptunian objects. In a narrower sense, the term is used for a group of bodies – including main-belt asteroids, Mars-crossers, centaurs and otherwise non-classifiable minor planets – that show a high orbital eccentricity, typically above 0.5 and/or a perihelion of less than 6 AU. Similarly, an unusual asteroid (UA) is an inner Solar System object with a high eccentricity and/or inclination but with a perihelion larger than 1.3 AU, which does exclude the near-Earth objects.
