Rough Notes:


Asteroids Ceres and Vesta
 
 
 
 

Dawn Approaches the Asteroid Belt
Nov 09, 2009

A new mission to explore the largest asteroids in the Solar System.

On September 27, 2007, NASA launched the Dawn spacecraft on a mission that will take it into the asteroid belt, where it will study two of the largest planetesimals in orbit between Mars and Jupiter, Ceres and Vesta. Dawn is so named because it will be observing objects thought to have existed since the dawn of the Solar System. 

"Asteroid" was first coined by William Herschel and means "star-like." Ceres was the first asteroid discovered in 1801 by Guiseppe Piazzi and the largest known, with a diameter of approximately 950 kilometers. Since no spacecraft has visited Ceres, its size estimate is determined by combining data from various telescope observations. Ceres compares in size to Saturn's moons Tethys and Dione and might look similar to Dione, with craters and ridges, although Ceres is about 15% smaller.

Ceres has recently been added to the roster of "dwarf planets" along with Pluto—Ceres being the only one within the asteroid belt. Vesta, the first one of the Dawn mission's targets, could also be added, something that data from the space probe will help to determine.

Vesta is the second largest asteroid, with a diameter of approximately 530 kilometers. It was found in 1807 by Heinrich Wilhelm Olbers. Using Saturn's moons for scale again, Vesta compares to Enceladus or Mimas in size.

There are indications that Vesta has experienced some powerful collisions in the past, since more than one large crater marks its surface. One of the craters near Vesta's south pole is 460 kilometers in diameter, more than 80% of the asteroid's size. The crater is close to 13 kilometers below the mean elevation of the terrain, with a rim about 6 kilometers above. There is an 18 kilometer high central peak, as well. Why did an impact that removed more than 1% of the asteroid's mass not blast it into pieces?

The "rubble pile" theory of asteroid composition was created to help explain the mass anomalies that have been seen in asteroid crater studies. Other asteroids, as well as small moons, exhibit craters that should have exploded them into fragments when they were hit. The only suitable explanation, according to gravity-based models, is that they are loosely compacted. It is presumed that they act like big sand piles and absorb the impacts without shattering. They have no hard crust to begin with so they haven't fractured despite repeated pounding.

The Electric Universe theory of asteroid formation does not require that one object smash into another one for there to be craters. Electric arcs can gouge surfaces and scoop out material, accelerating it into space, leaving clean, deep pits. Comets also exhibit surface features that are the same as those observed on asteroids, so the conclusion is that the two are really one thing and not "dirty snowballs" versus rocky bodies.

Plasma arcs do not disturb the surrounding surfaces when they are used in industrial applications. Based on laboratory analysis, that is what has occurred on Vesta and on all the asteroids, moons, and planets of the solar system: plasma discharge erosion. Planetary scientists ignore electrical explanations, which rectify the anomalies in other theories, because they know almost nothing about plasma and electric currents in space. Electricity can create the very things they are sending out probes to study

Stephen Smith

Dynamic Asteroids

  
Asteroid 21 Lutetia from the Rosetta Cometary Probe. Credit: NASA/JPL

Asteroid 21 Lutetia from the Rosetta Cometary Probe. Credit: NASA/JPL

 

Jan 15, 2015

Electrically active objects dominate the Solar System

Small planetoids, called Near Earth Objects (NEO), are a concern for space scientists because it is thought that large rocks might strike our planet with devastating force. It is a commonly held belief that such an object caused the extinction of the dinosaurs. The Earth has supposedly been struck many times by asteroids and comets, so astronomers have been tracking as many objects as they can find to see if any of them cross the plane of Earth’s orbit.

Most asteroids are presumed to be loosely compacted “rubble piles”. The idea came about in order to help explain various mass anomalies that have been seen in asteroid crater studies, along with experiments like Deep Impact, and observations of what appears to be “regolith migration” on asteroids Itokawa and Eros. Since gravitational acceleration on asteroids is minute, banding, landslides, and layering is thought to be due to micro-meteor impacts shaking the asteroids. Over long periods of time, the shaking sorts the materials by size and density in the same way that a jar of sand and pebbles will sort itself when it is shaken.

Some asteroids, such as Vesta, have craters that should have shattered them into fragments when they were hit. Vesta is only 520 kilometers wide, but possesses a crater 460 kilometers in diameter The only suitable explanation, according to gravity-based models of asteroid behavior, is that they are like big sand piles, absorbing impacts without shattering.

The electric model of asteroid formation does not require that one body crash into another one for there to be craters. Electric arcs have the ability to cut surfaces, scoop out material and then accelerate it into space, leaving clean cuts, deep pits and chaotic topography. The effect is commonly called electric discharge machining (EDM). Comets also exhibit surface features that are the same as what has been seen on asteroids, leading Electric Universe theorists to speculate that the two are really one thing and not “dirty snowballs” vs. rocky bodies.

Recently, NASA scientists have become more interested in the environment around asteroids because they are speculating about a manned-mission to one of the larger ones. According to a recent press release, they are planning studies of various bodies to see if their electrical activity will be a problem for astronauts.

Conventional viewpoints consider solar wind ions to be the method by which asteroids accumulate electric charge. It is the magnetic fields accompanying the charged particles from the Sun that “… warp, twist, and snap as they slam into the magnetic fields around other objects…” Those fields impart acceleration that slam particles into asteroids, blasting electrons from their surfaces, increasing the positive charge in sunlit regions.

Shadowed areas accumulate negative charge, since electrons “fly ahead” of heavier positive ions and accumulate in those regions where positive charge has increased.

A theory of electrical interaction might provide a more reasonable hypothesis than sunlight and angular momentum, although the sunlight theory has the advantage of acceding to the billion-year timescale that dominates science today. Everything takes so much time that the numbers no longer have meaning and is relegated to a past so remote that it is unimaginable.

As Wal Thornhill wrote: “The flaw in the conventional approach is that only gas-phase chemical reactions and reactions induced by solar radiation (photolysis) are considered. The far more energetic molecular and atomic reactions due to plasma discharge sputtering of an electrically charged comet nucleus are not even contemplated…”

This leads to the conclusion that comet-like behavior could also take place on an asteroid. As mentioned in a previous Picture of the Day, there are several “Centaur objects” orbiting near the asteroid belt that demonstrate an indeterminate state between comet and asteroid. 2060 Chiron is classified as both comet and asteroid. Chiron manifests a coma whenever it reaches its closest approach to the Sun, although it does not grow a tail. 174P Echeclus displayed a coma in 2005, so it too is now classified as a cometary asteroid. At least ten Centaurs are known to have cometary activity at great heliocentric distance.

According to a press release from December 2010, asteroid 596 Scheila became much brighter than previously observed, forming a large C-shaped coma. The Swift space-based observatory did not find water vapor thought to be “normally” associated with comets. Instead, two dusty plume-like tails trailed behind the asteroid, subsequently fading over the next several months. The primary reason for thinking that 596 Scheila is an asteroid and not a comet is because there is no water vapor in its vicinity.

Proponents of mainstream viewpoints are slowly beginning to realize that asteroids and comets exist in a continuum: neither are strictly identical nor completely different from the other. It is electric effects that are seen. Discharges and arcs form the comet phenomena, so exposing an asteroid to an intense electric field over time will most likely turn it into a comet.

Stephen Smith