VIEWING VESTA AT ITS BRIGHTEST:
The asteroid Vesta, the brightest of the asteroids, will be visible to the naked eye at an apparent magnitude of 5.4. The human eye can see down to about 6th magnitude so it is possible to view Vesta in ideal viewing conditions without the use of binoculars or a telescope. The asteroid will fade to magnitude 6.0 by July 1st and to 6.7 by August 1st. The location of Vesta can be found from the above two charts. If you are facing southeast you should be able to find the planet Jupiter. Vesta will be a bit to the north and west of this planet through the next few months. Vesta is now at its brightest in 18 years. The brightness is due to a number of factors. The asteroid reached opposition on May 31st. This combined with the fact that its perigee(closest point to Earth) is only a few weeks distant and a particularly favourable tilt make this one of the best times to view Vesta.
Vesta, with a diameter of about 530 km, is the second largest asteroid after Ceres (now classified as a "dwarf planet" along with Pluto. Because of its uniquely bright surface it is actually the one more easily seen without optical aids. Ceres is visible to the naked eye only in exceptional circumstances. Vesta is about 4 times as bright as Ceres.
Vesta was discovered by the German astronomer Heinrich Wilhelm Olbers on March 29th, 1807. Vesta was the fourth asteroid to be found and hence it is sometimes referred to as 4 Vesta . No further asteroids were found after Vesta for 38 years. The German mathematician Carl Friedrich Gauss named the asteroid after Vesta, the Roman goddess of the hearth , home and family. Vesta was somewhat equivalent to the Greek goddess Hestia, but her worship predated Greek influence on Roman mythology. Vesta was a rather shadowy figure, never depicted and never mentioned in other myth cycles. Each Roman city had a public hearth sacred to Vesta with a fire that was never allowed to go out. When a new colony was to be established coals from the mother city's hearth were sent with the colonists to kindle the new city's public hearth. Rome's fire burned until 391 when it was extinguished by Emperor Theodosius I when he forbade public pagan worship.
Romans traditionally both began and ended their meals with a prayer to Vesta. The sacred flame of Vesta was tended in Rome by the Vestales, better known as the vestal virgins. in imitation of the goddess they took 30 year vows of chastity and lived together in a house near the Forum. If any of these priestesses broke her vow of chastity she was buried alive in the Campus Sceleris (Field of Wickedness). Vesta's feast, called the Vestalia, was held from June 7th to June 15th each year.
While Vesta is about the same diameter as another asteroid Pallas it is considerably more massive. While the general shape of Vesta is that of gravitationally formed spheroid it is not classified as a dwarf planet like Ceres because of an enormous crater near the south pole with a width 80% of that of the entire asteroid. The rim of the crater and a central protrusion are additional arguments against the reclassification of Vesta. This whole matter, however, is still under debate. This huge southern crater is the likely site of the HED meteorites which have been shown to come from Vesta. This asteroid is one of only 4 extraterrestrial bodies (the others are the Moon, Mars and Comet Wild2) from which we have physical samples.
The next few weeks are an unique opportunity to actually view an asteroid. Good luck and happy searching.
