Features:

  1. Vesta was the 4th asteroid discovered: hence it's full name 4 Vesta.

  2. Vesta was discovered 1807 Mar29 by Heinrich Wilhelm Matthias Olbers (1758--1840)---a man whose life spanned the French Revolution and the Napoleonic Wars---stirring times.

  3. Olbers is the eponym of Olbers' paradox---though he was NOT first at all to think of it.

  4. Vesta has mean diameter 525.4(2) km and is the 2nd largest asteroid (see Wikipedia: List of exceptional asteroids: Largest by diameter).

  5. Vesta facts:
    1. Astronomical symbol: ⚶.
    2. Mean orbital radius: 2.36179 AU.
    3. Eccentricity: 0.08874.
    4. Orbital period: 1325.75 days = 3.62971 Julian year.
    5. Sidereal rotation period: 0.2226 days = 5.342 hours prograde (i.e., eastward as seen on the sky and rightward in the film version of this image: see file 004_vesta_rotating.html). The rotation axis is the short axis??? and it is tilted by 29° from the ecliptic axis.
    6. Mean radius: 262.7 ± 0.1 km.
    7. Dimensions: 572.6 x 557.2 x 446.4 km. It is NOT very round as you can see. Self-gravity has NOT won a complete victory in spherizing Vesta over the centrifugal force and the rigid chemical bonds of solids.
    8. Oblateness f = (a-b)/a = 0.2204, where a is equatorial radius and b is polar radius.
    9. Mass: 2.59076(1)*10**20 kg = 4.33791*10**(-5) Earth masses = 3.529*10**(-3) Moon masses = 0.2758 Ceres masses.

  6. The north polar region is roughly at the top and the south polar region is roughly at the bottom. The film version of this image (see file 004_vesta_rotating.html) changes orientation as is goes along, but the north polar region is roughy at the top and the south polar region is roughly at the bottom is still true.

  7. Vesta is often considered a true protoplanet left over from Solar System formation since it had chemical differentiation by primordial-radiogenic heat geology (see also Wikipedia: Earth's internal heat budget: Radiogenic heat: Primordial heat) in its early days. The primordial-radiogenic heat geology turned off of order 10 Myr after formation (Wikipedia: 4 Vesta: Geology).

    The turn-off was due to the exhaustion of its initial formation heat energy and probably aluminum-26 (half-life 0.717 Myr) which was probably a main source of heat energy (see Wikipedia: Aluminium-26: Occurrence in the interstellar medium; Wikipedia: 4 Vesta: Geology).

    Vesta is sufficiently small that it loses heat energy too quickly from the radioactive decay of long-lived radioactive isotopes (e.g., uranium-238 (half-life 4.468 Gyr)) for those radioactive isotopes to power primordial-radiogenic heat geology. See radiogenic_heat.html for long-lived radioactive isotopes.

  8. The relatively short-lived radioactive isotopes (like aluminum-26) would have to have been produced by a supernova that went off shortly before Solar System formation and that seeded the primordial nebula with its debris enriched in metallicity and radioactive isotopes.

  9. The primordial-radiogenic heat geology powered volcanism on Vesta and this gave Vesta some basaltic rock.

  10. Perhaps many asteroids larger than 100 km underwent some chemical differentiation and volcanism in their first few million years due to heat energy from formation and relatively short-lived radioactive isotopes.

  11. Vesta like most airless rocky-bodies. has many impact craters mostly probably left from the heavy bombardment in the early Solar System (4.6--3.8 Gyr ago).

    Since then meteoritic weathering and diurnal temperature cycle weathering have ground the surface down to mostly regolith which gives the surface a soft powdery look which is also typical of airless rocky-bodies.

  12. A prominent feature of Vesta is Crater Rheasilvia that is roughly centered on the south pole. It is NOT clearly shown in the film version of this image (see file 004_vesta_rotating.html).

    Crater Rheasilvia has a diameter of 525 km and a central peak rising 22 km about the base---which makes it the highest mountain in the Solar System by some standard (see Wikipedia: List of tallest mountains in the Solar System).