Space

The Universe: nceopticsu/powersof10/index.html nceopticsu/powersof10/index.html

*What is…. Dark matter? Anitmatter?

The Solar System

Solar System Facts 1. The Solar System only has 8 planets Pluto orbits sun, has enough mass to be spherical but not enough to “clear the orbital path” 2. But the Solar System has 4 dwarf planets Ceres, Pluto, Eris and Makemake. Dwarf planets are objects that orbit the Sun and have enough mass to form a sphere, but they share their orbit with other objects. 3. The influence of the Solar System extends out for almost 2 light-years The theoretical size of the Solar System goes out as far as the Sun's gravity overpowers anything else in the region; and this is almost 2 light-years away, nearly halfway to the nearest star. 4. Most of the mass of the Solar System is the Sun In fact, the Sun contains 99.86% of the mass in the Solar System. 5. The Solar System is 4.6 billion years old Scientists have sampled meteorites and learned that they're all 4.6 billion years old. 6. Everything orbits in the same direction All the objects in the Solar System orbit the Sun in a counter-clockwise direction. 7. The Sun is just one star in 200 billion in the Milky Way Doesn't that give you perspective? 8. But they're really far apart There are only a few stars within 10 light-years of the Sun. The closest system is the Alpha Centauri system, 4.4 light-years away. Barnard's Star is 5.9 light-years away. 9. Astronomers used to think the Earth was the centre Astronomers used to think that the Earth was the center of the entire Universe. It wasn't until the 17th century, when Nicolas Copernicus first presented the concept, and showed how it accurately predicts the positions of the planets. 10. Humans have sent spacecraft almost everywhere Spacecraft from Earth have visited or orbited every planet in the Solar System, and more are on their way to visit some of the dwarf planets. Some of the oldest spacecraft still active – NASA's Voyager spacecraft – have almost reached the Sun's heliosphere the point where the solar wind slows down as it bumps against the interstellar wind.

Sun Facts Yes it is a star! Nearest star to earth: 150,000,000km Takes 8min for light to reach Earth Diameter: 1,392,000 km Volume: could hold 1.3 million Earths Mass: 99.86% of mass of solar system Mass: 1,989,100,000,000,000,000,000,000,000,000 kg Made mostly of: hydrogen (74%), helium (24%) It loses approximately 4 million tons every second Surface temperature: 5,510°C Core temperature: 15,000,000°C Age: 4.5 billion years Escape velocity: 618 km/s More:

When is a planet not a planet? Requirements: Must have enough gravity to clear orbital path of other celestial bodies Enough gravity to pull itself into a sphere Orbits a star Pluto = FAIL on first two

The Ecliptic

To Scale…

How big does the sun look from space?

Spacecraft escaping the Solar System

Apparent Retrograde Motion

Asteroids Animation of asteroid 433 Eros in rotation. Ceres, discovered 1801 is the largest asteroid or is it a dwarf planet? 950km across

Comets Comet Hale-BoppComet Hale-Bopp, as seen in Pazin, Croatia 1997.PazinCroatia Halley's Comet on 8 March 1986 Halley's Comet approach

Eclipses

Lunar Eclipse

2007 Lunar Eclipse - Dunedin Clouds part for eclipse STAR-GAZERS grabbed glimpses last night, through partly cloudy skies, of the first total lunar eclipse to be visible from Dunedin in seven years. A lunar eclipse occurs when the Earth passes between the sun and the moon, blocking the sun’s light from reaching the moon’s surface. The moon was fully eclipsed from 9.52pm to 11.23pm. The next lunar eclipse visible from Otago is not expected until December The moon as seen from Dunedin at (top) 8pm and (bottom) 10.30pm. PHOTOS: STEPHEN JAQUIERY

Solar Eclipse

8 Feb 2008 – Solar Eclipse Dark side of the moon BIG bite out of the sun... At the peak of yesterday’s partial eclipse, the moon blocks about half the sun, viewed from Dunedin about 5.30pm through a telescope covered with a protective filter at the city’s Beverly Begg Observatory. About 50 members of the public were at the observatory to watch the eclipse, which lasted from about 4.22pm to 6.30pm.

2008 Total Solar Eclipse Northern China 008/TSE2008galleryA.html

Looking Back at an Eclipsed Earth Credit: Mir 27 Crew;

Future Eclipses See: RASNZ website - Map showing paths of total and annular eclipses across New Zealand, 2028 to 2037.

Lunar Libration