GOOD MORNING SPACE EXPLORERS!

-is located within the Milky Way Galaxy

-is located about 25,000 light-years to the galactic center and 25,000 light-years away from the rim. -revolves around the galactic center once in about 240 million years

-4.6 billion years old

Large Scale Features of the Solar System

1. Much of the mass (99.85%) of the Solar System is concentrated at the center (Sun) while angular momentum is held by the outer planets.

Large Scale Features of the Solar System

2. Orbits of the planets are on the same plane and elliptical

3. All planets revolve around the sun.

Large Scale Features of the Solar System

4. The periods of revolution of the planets increase with increasing distance from the Sun.

Large Scale Features of the Solar System

5. All planets are located at regular intervals from the Sun.

Small Scale Features of the Solar System

1. Most planets rotate prograde.

Mercury 0° Venus 177° Earth 23° Mars 25°

Jupiter 3° Saturn 27° Uranus 98° Neptune 30°

Small Scale Features of the Solar System

2. Terrestrial planets have:high densities thin or no atmospheres rotate slowly rocky materials such as silicates, iron , and

nickel of high melting pointspoor in ices(H2O, NH3, CH4) and lower

contents of H, He, and noble gases

Small Scale Features of the Solar System

3. Jovian Worlds have:low densities thick atmospheres rotate rapidly many natural satellitesfluid interiors, rich in ices, H/He

4. Most of outer Solar System objects are ice-rich.

ACTIVITY

PLANETS OF THE SOLAR SYSTEM

ORIGIN OF THEORIGIN OF THE

HYPOTHESISHYPOTHESIS

NEBULAR HYPOTHESIS-proposed by Emanuel Swedenborg, Immanuel Kant, and Pierre-Simon Laplace in 1700s

“A rotating cloud of gas and dust that cools and contracts in the middle to form the sun and the rest into a disc that become the planets.”

NEBULAR HYPOTHESIS

b. Condensation of primordial dust. Forms disk-shaped nubular cloud rotating counter-clockwise.

a. Supernova and formation of primordial dust cloud.

c. Proto sun and planets begin to form.

d. Accretion of planetesimals and differentiation of planets and moons.

e. Existing solar system takes shape.

Evidence to support the nebular hypotheses:

1. Planets and moons revolve in a counterclockwise direction.

2. Almost all planets and moons rotate on their axis in a counterclockwise direction.

3. Planetary orbits are aligned along the sun’s equatorial plane.

ENCOUNTER HYPOTHESIS-proposed by Chamberlin and Moulton

“The planets formed from debris torn off the Sun by a close encounter with another star.”

“That our planets, moons, and sun all spun off from a collision between stars.”

PROTOPLANET HYPOTHESIS-developed by Carl von Weizsacker and Gerard Kuiper

“The Solar System begins to form, as a rotating cloud, or nebula collapses. But instabilities develop in the nebula causing dust particles to pull together. Then the dust particles merge into billions of planetesimals then collide and form protoplanets. At the center of the nebular disk the protosun increases in mass and becomes a star by the process of hydrogen fusion. 

RECENT ADVANCEMENT ON THE SOLAR SYSTEM

Exploration of MarsRecently, NASA presented evidence of seasonal flow liquid water (in the form of brine water) on the surface of Mars.

RECENT ADVANCEMENT ON THE SOLAR SYSTEM

Rosetta's Comet-67P/Churyumov–Gerasimenko (67P or 67P/C-G) is a Jupiter-family comet and composed of two lobes, resembling a pair of snowballs stuck together. -Rosetta's lander, Philae, touched down on its surface on 12 November 2014, becoming the first spacecraft to land on a comet nucleus.

RECENT ADVANCEMENT ON THE SOLAR SYSTEM

Pluto Flyby

-On 14 July 2015, NASA's New Horizon spacecraft provided mankind the first close-up view of the dwarf planet Pluto.

-revealed a complex terrain - ice mountains and vast crater free plains. The presence of crater free plains suggests recent (last 100 millions of years) of geologic activity.

LONG QUIZ TOMORROW!

Review :Universe and Solar System