Astronomy in the new Millenium Volker Crede Grigory Rogachev

Formation of the Solar System Nebular contraction: Cloud of gas and dust contracts due to gravity; conservation of angular momentum means it spins faster and faster as it contracts

Conservation of angular momentum Angular momentum – the tendency of a body to keep spinning.

Formation of the Solar System Condensation theory: Interstellar dust grains help cool cloud, and act as condensation nuclei

Lets name them (in correct order). Mercury. (0.38 AU from the Sun) Venus. (0.72 AU) Earth. (1.0 AU ≈ 100,000,000 miles) Mars. (1.52 AU) Jupiter. (5.2 AU) Saturn. (9.52 AU) Uranus. (20 AU) Neptune (30 AU)

Planets

Venus

Venus’s surface

“Cool” Venus features. (HOT actually) Venus is the hottest planet in the Solar system! (900 oF – twice as hot as your oven can do). Venus’s atmosphere is 90 time thicker then Earth’s atmosphere! HOT, Crashing and Orange/Red… And, eh, it is also very sloooooooooow. One Venus’s day = 243 Earth’s days and it rotates the wrong way!

Any pictures? A photograph of the surface, from the Venera lander, which did not survive for long though…

Mars We learned SO much about Mars during the last decade! Mars rovers, Spirit and Opportunity, and Mars orbiter Odyssey are diamonds in our scientific portfolio.

Mars

Mars

Mars’s “cool” facts. (wet actually) A long, long time ago… In a galaxy far, far away…

Mars’s “cool” facts. (wet actually) 1 or 2 billion years ago Mars was covered with liquid WATER!

“Cool” facts. (cont.) Mars is home of the largest mountain in the Solar system – Olympus mons. 25 km high! Mars has the largest and the deepest canyon in the Solar system – Valles Marineris. It is as big as the entire USA and 7 km deep.

Gas Giants Gas Giants are … Well, gas giant. They consist almost exclusively of gas, hydrogen and helium. Lots of gas! 

Jupiter

“Cool” fact about Jupiter Jupiter is the Largest and the most massive planet in the Solar system. If it would be just 80 time heavier it would become a star! Jupiter has storm which is at least 300 years old! (Great Red Spot). It looks like a zebra. 

Jupiter moons

Saturn

Origin of Saturn rings

Saturn rings

Uranus Neptune

What else is out there?

Asteroids

Asteroids Impact of a large asteroid can be VERY unpleasant.

Giant impact 65 millions years ago asteroid impact caused the Cretaceous extinction

Meteoroid Small rocky object in space. If burn in the atmosphere – meteor. If survived the atmosphere and hits the ground – meteorite.

Grand design

The Sun

The Heart of the Sun Nuclear fusion requires that like-charged nuclei get close enough to each other to fuse. This can happen only if the temperature is extremely high – over 10 million K.

The Sun

The Sun

The Sun