August Night Sky

In keeping with the smorgasbord of celestial events that the month of August has had to offer I would like to introduce you to something new.  A protoplanet.

A protoplanet (Word of the Day) is basically a dwarf or normal planet in the making.  The difference is that it lacks the spherical shape of the heavenly bodies we understand to be planets as a consequence of insufficient gravity relative to their smaller mass.

I bring this subject-up because I posted a sky map a few days ago pertaining to Saturn's opposition.  The map included an object visible to the naked eye named Vesta.  Vesta is the last known protoplanet in our solar system. 

Vesta is the second most massive body in the asteroid belt surpassed only by Ceres which happens to be classified as a dwarf planet.  One of the brightest objects in the sky Vesta is visible to a determined observer from time to time.  It also happens to be the first of the four largest asteroids - Ceres, Vesta, Pallas and Hygiea) to have been explored by unmanned spacecraft.  The Dawn mission orbited Vesta in 2012 and discovered new insights into this big rock.

Discovered by the German astronomer Heinrich Wilhelm Matthias Olbers in 1807 it is named for Vesta - the virgin goddess of hearth and home in Roman mythology.

This image of the asteroid was taken by NASA's Dawn spacecraft and the numerous impact craters are evidence of a violent life.

Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Unlike its asteroid neighbors the interior of Vesta is different.  As with other terrestrial planets it has a crust of cooled lava covering a rocky mantle and a nickle and iron core.  It is for these reasons it is classified as a protoplanet instead of an asteroid.

In any event, I shared that this object is sometimes viewed by means of the naked eye.  In the early morning hours of August 22 Vesta will be in opposition and its 326 mile-wide reflective surface may be highly visible under a waning crescent moon.  These are good viewing conditions.

If you get-up to pee in the wee hours take moment to look for this Roman virgin in the southern night sky.  If you require reading material you can learn more about Vesta via Space.com.

Locator map...

Stellarium