Plutoids and other Dwarf Planets D.10.1

Objects that fail the criterion – those that have not cleared other similar-sized bodies from their orbit – are considered dwarf planets.

Pluto falls into this category, as do many other objects in the Kuiper Belt, a vast area beyond Neptune.

Pluto is very far away; on average it is about forty times farther away from the Sun than Earth is. The planet is exceptionally cold, and the sun is very dim from that distance. Even our best telescopes cannot see it very clearly.

The official definition of a planet D.9.29

The official definition of a planet, from the International Astronomical Union, states that a planet must fit all three of the following criteria:

1. It is in orbit around its star – in our case, the Sun – and is not in orbit around another object. An object that fails this criterion is considered a satellite (a moon) rather than a planet.
2. It has sufficient mass to “assume hydrostatic equilibrium,” which means that it has a nearly round shape. Objects that fail this criterion are typically fairly small, and include most asteroids.
3. It has “cleared the neighbourhood” around its orbit. This means that there are no objects of similar size, other than perhaps the moons of the planet. This criterion excludes objects like Pluto, which has many other similar-sized planetoids in its orbit.

This definition is not without its critics, but it is generally accepted at this time.

Venus and Earth D.9.28

Planet Earth is what we call in the Goldilocks position. It is not too hot, not too cold but just right.

Out there in the system are many planets which if the elements and position were right could also support life but that is not so.

So what is it that Venus, the planet of love has in common with Earth? Well Venus is nearly identical in size to Earth.

Solar Wind D.9.27

Solar Wind is made up of charged particles flowing outward from the Sun.

Feature of Planet Mars D.9.26

The planets in our solar system carry vary features and besides their position this attribute is what makes them special.

The feature of Planet Mars is it has ice caps made up of carbon dioxide and water.

Planet Mercury D.9.25

Of the eight planets have you ever wondered which is the smallest?

It is true of the planet Mercury – It is the smallest of the eight planets.

Venus D.9.24

So that the Sun rises in the west and sets in the east do you know which planet rotates in the opposite direction of Earth?

It is the planet Venus – the planet of love.

Center of Mass D.9.23

The point around which the star and its extrasolar planet orbit is called the center of mass.

Star Transit D.9.22

The constant movement of the planetary bodies are being observed and documented.

It is observed that during transits and eclipses, a star appears to become slightly dimmer as a planet passes in front of it.

Extrasolar Planet D.9.21

An exoplanet or extrasolar planet is a planet that orbits a star other than the Sun.

Extrasolar planets are difficult to detect because their host stars are far away and are a billion times brighter than their planets’ reflected light. And yet, while exoplanets may be largely invisible, they are not undetectable.