Astronomy-Interesting Facts

[PeiWen]

Four small planets lie quite close to the Sun. All of them have about the same density as the Earth and so they are called "Terrestrial". Besides the Earth, they are Mercury, Venus, and Mars. The most distant of these planets from the Sun is Mars, a little over 1.5 A.U. from the Sun. Want to walk about 350 million miles? Then head for the next nearest planet: Jupiter.
As you cross the road on your way to Jupiter, watch out for vehicle traffic! If you were crossing between the orbits of Mars and Jupiter in the actual Solar System, you would have to watch out for asteroids. They are found in great numbers in this region of the Solar System (they appear on the Solar System Map of the Inner Planets as Ida and Gaspra) near the giant planet Jupiter. It's the largest planet in our Solar System and its strong gravitational tug probably broke up a small planet that came too close.

As you walk along the path from the model of Neptune to the model of Pluto, you are following the orbital path of Neptune as it circles the Sun - but in the opposite direction to the real motion of the planet. It would take Neptune about 20.5 years to make the trip you will complete in about 3.5 minutes!

Pluto is about 1600 feet, in a direct line, from the corner of Albertus Hall - where our solar walk began. The real Pluto is nearly 4 billion miles from the Sun! Our walk from the Sun to Pluto took about 15 minutes: light from the Sun, traveling at 186,000 miles per second, would take about 5.5 hours to reach Pluto.

[PeiWen]

Four small planets lie quite close to the Sun. All of them have about the same density as the Earth and so they are called "Terrestrial". Besides the Earth, they are Mercury, Venus, and Mars. The most distant of these planets from the Sun is Mars, a little over 1.5 A.U. from the Sun. Want to walk about 350 million miles? Then head for the next nearest planet: Jupiter.
As you cross the road on your way to Jupiter, watch out for vehicle traffic! If you were crossing between the orbits of Mars and Jupiter in the actual Solar System, you would have to watch out for asteroids. They are found in great numbers in this region of the Solar System (they appear on the Solar System Map of the Inner Planets as Ida and Gaspra) near the giant planet Jupiter. It's the largest planet in our Solar System and its strong gravitational tug probably broke up a small planet that came too close.

As you walk along the path from the model of Neptune to the model of Pluto, you are following the orbital path of Neptune as it circles the Sun - but in the opposite direction to the real motion of the planet. It would take Neptune about 20.5 years to make the trip you will complete in about 3.5 minutes!

Pluto is about 1600 feet, in a direct line, from the corner of Albertus Hall - where our solar walk began. The real Pluto is nearly 4 billion miles from the Sun! Our walk from the Sun to Pluto took about 15 minutes: light from the Sun, traveling at 186,000 miles per second, would take about 5.5 hours to reach Pluto.

[PeiWen]

Please try out this link, it's a simulator that can show you whichever planet you wish to view from whichever location...have fun!

http://space.jpl.nasa.gov/

[PeiWen]

Please try out this link, it's a simulator that can show you whichever planet you wish to view from whichever location...have fun!

http://space.jpl.nasa.gov/

[jo_n]

say. what's the difference between astrology and astronomy? just asking?

[__earth]

Astronomy is the study of celestial bodies. It is science. Astronomy has nothing to do with astrology.

Astrology is about predicting one's fortune. Astrology is a pseudoscience and pretends to use astronomy in its practice.

It is simply an unfortunate decision to have astrology and astronomy in one sig.

[Zeroth]

Astrology is metascience, Astronomy is science, haha!

Similarity is, they both involve the stars.. haha!

[tezuka87]

If the sun blots out it would take 8 minutes for us to find out..this is cos it takes 8 minutes for the sun's light to reach earth. This also means that the sun we see is actually the sun as it was 8 minutes ago.

Similarly, the moon we see is the moon as it was 1 minute ago.

[youngyew]

Originally Posted by tezuka87

If the sun blots out it would take 8 minutes for us to find out..this is cos it takes 8 minutes for the sun's light to reach earth. This also means that the sun we see is actually the sun as it was 8 minutes ago.

Similarly, the moon we see is the moon as it was 1 minute ago.

The light from moon should be about 1.2 to 1.3 seconds ago, as the moon's distance from earth is 360,000 km to 400,000 km while the speed of light is about 300,000 km/s.

Anyway, it's interesting to think about the speed of light in terms of interstellar distances. There's an interesting paragraph in Bill Bryson's book "A Short History of Nearly Everything" about Drake equation:

"... Unfortunately, space being spacious, the average distance between any two of these civilizations is reckoned to be at least two hundred light years, which is a great deal more than merely saying it makes it sound. It means, for a start, that even if these beings know we are here and are somehow able to see us in their telescopes, they're watching light that left Earth two hundred years ago. So they're not seeing you and me. They're watching the French Revolution and Thomas Jefferson and people in silk stockings and powdered wigs - people who don't know what an atom is, or a gene, and who make their electricity by rubbing a rod of amber with a piece of fur and think that's quite a trick. Any message we receive from these observers is likely to begin 'Dear Sire', and congratulate us on the handsomeness of our horses and our mastery of whale oil. Two hundred light years is a distance so far beyond us as to be, well, just beyond us."

[tezuka87]

Originally Posted by youngyew

The light from moon should be about 1.2 to 1.3 seconds ago, as the moon's distance from earth is 360,000 km to 400,000 km while the speed of light is about 300,000 km/s.

I stand corrected! Yeah...should do calculations b4 claiming something.

Hey, true! If it's possible to see such things...hehehehe...nothing is secret anymore! You can murder someone, and then it is possible to find out!!! Brings a whole new meaning to the Chinese idiom "tian wang hui hui, shu er bu lou". I think its "The wheels of God grind slowly, but they grind exceeding small." in English...Criminals, beware! I (Mr Alien) know wat you did last summer...kakakka