Naked eyeNaked eye, also called bare eye or unaided eye, is the practice of engaging in visual perception unaided by a magnifying, light-collecting optical instrument, such as a telescope or microscope, or eye protection. Vision corrected to normal acuity using corrective lenses is still considered "naked". In astronomy, the naked eye may be used to observe celestial events and objects visible without equipment, such as conjunctions, passing comets, meteor showers, and the brightest asteroids, including 4 Vesta.
Solar eclipseA solar eclipse occurs when the Moon passes between Earth and the Sun, thereby obscuring the view of the Sun from a small part of the Earth, totally or partially. Such an alignment occurs approximately every six months, during the eclipse season in its new moon phase, when the Moon's orbital plane is closest to the plane of the Earth's orbit. In a total eclipse, the disk of the Sun is fully obscured by the Moon. In partial and annular eclipses, only part of the Sun is obscured.
Astronomical transitIn astronomy, a transit (or astronomical transit) is the passage of a celestial body directly between a larger body and the observer. As viewed from a particular vantage point, the transiting body appears to move across the face of the larger body, covering a small portion of it. The word "transit" refers to cases where the nearer object appears smaller than the more distant object. Cases where the nearer object appears larger and completely hides the more distant object are known as occultations.
Transit of VenusA transit of Venus across the Sun takes place when the planet Venus passes directly between the Sun and a superior planet, becoming visible against (and hence obscuring a small portion of) the solar disk. During a transit, Venus can be seen from Earth as a small black dot moving across the face of the Sun. The duration of such transits is usually several hours (the transit of 2012 lasted 6 hours and 40 minutes). A transit is similar to a solar eclipse by the Moon.
Lunar eclipseA lunar eclipse is an astronomical event that occurs when the Moon moves into the Earth's shadow, causing the Moon to be darkened. Such alignment occurs during an eclipse season, approximately every six months, during the full moon phase, when the Moon's orbital plane is closest to the plane of the Earth's orbit. This can occur only when the Sun, Earth, and Moon are exactly or very closely aligned (in syzygy) with Earth between the other two, which can happen only on the night of a full moon when the Moon is near either lunar node.
4 VestaVesta (minor-planet designation: 4 Vesta) is one of the largest objects in the asteroid belt, with a mean diameter of . It was discovered by the German astronomer Heinrich Wilhelm Matthias Olbers on 29 March 1807 and is named after Vesta, the virgin goddess of home and hearth from Roman mythology. Vesta is thought to be the second-largest asteroid, both by mass and by volume, after the dwarf planet Ceres, though in volume it overlaps with the uncertainty in the measurements of 2 Pallas.
Syzygy (astronomy)_Syzygy In astronomy, a syzygy (ˈsɪzədʒi ; ) is a roughly straight-line configuration of three or more celestial bodies in a gravitational system. When Earth is one of the bodies involved, the other objects appear to be close together (or overlapping) in the sky. The word is often used in reference to the Sun, Earth, and either the Moon or a planet, where the latter is in conjunction or opposition. Solar and lunar eclipses occur at times of syzygy, as do transits and occultations.
Vulcan (hypothetical planet)Vulcan 'vVlk@n was a theorized planet that some pre-20th century astronomers thought existed in an orbit between Mercury and the Sun. Speculation about, and even purported observations of, intermercurial bodies or planets date back to the beginning of the 17th century. The case for their probable existence was bolstered by the French mathematician Urbain Le Verrier who, by 1859, had confirmed unexplained peculiarities in Mercury's orbit and predicted they had to be the result of gravitational influences of another unknown nearby planet or series of asteroids.
Elongation (astronomy)In astronomy, a planet's elongation is the angular separation between the Sun and the planet, with Earth as the reference point. The greatest elongation of a given inferior planet occurs when this planet's position, in its orbital path around the Sun, is at tangent to the observer on Earth. Since an inferior planet is well within the area of Earth's orbit around the Sun, observation of its elongation should not pose that much a challenge (compared to deep-sky objects, for example).
Spherical astronomySpherical astronomy, or positional astronomy, is a branch of observational astronomy used to locate astronomical objects on the celestial sphere, as seen at a particular date, time, and location on Earth. It relies on the mathematical methods of spherical trigonometry and the measurements of astrometry. This is the oldest branch of astronomy and dates back to antiquity. Observations of celestial objects have been, and continue to be, important for religious and astrological purposes, as well as for timekeeping and navigation.
