Your hands and arms help you see the orbits of Mercury and Venus and the shape of solar system
Question: If you could see the orbit of Venus would it fill the whole sky?
The answer might surprise you!
You can use your hands and arms to see the size of the orbits of the solar system’s inner planets: Mercury and Venus.
Imagine (as pictured below) if the orbit of Mercury were visible as a red oval and the orbit of Venus were visible in green.
Physical Astronomy – see Mercury and Venus orbits
Caution! Do not look directly at the Sun without proper solar safety glasses on.
Turn toward the Sun, hold your arms out straight, hands up in the air with fingers spread wide and thumbs touching. Your pinky fingers now span the width of the orbit of Mercury and your elbows span the width of the orbit of Venus.
Both of the entire orbits of Mercury and Venus orbits would be visible in the sky all at once – if they could be made visible during the day.
Ptolemaeus, Alphonsus, and Arzachel… the names of three massive, interlocking craters on the Moon. These three craters tell the story of the ancient Moon’s creation and evolution. It’s a story of violent bombardments and oceans of lava. We can use light and shadows to reveal the shapes and deep history of these features.
Most people think of astronomy a science of light. But, light creates shadows when it hits things. Those features that lie in the shadows, the dark parts and seemingly just-in-the-way-of-the-light parts, are just as important as those that shine brightly. These dark shadows form most of the mass of all galaxies, house stellar nurseries, reveal old lava rivers on the Moon, and create curious plays of light and dark. These can play tricks on our eyes and make patterns appear.
Use this technique to understand how seasons happen on the Earth. The Earth is tilted. When the northern part (your forehead and eyes) tilts away from the Sun the season is winter. When the northern part tilts toward the Sun the season is summer.
The Earth is tilted as it spins daily – it is not straight up and down like a top, but more like the Leaning Tower of Pisa (if the tower could spin!). As it goes through its yearly orbit, the Sun hits the northern and then the southern parts of the Earth.
Tilt your head to tilt the Earth
In this model, when the northern part (your forehead and eyes) tilts away from the Sun the season is winter. When the northern part tilts toward the Sun the season is summer.
Did you like this season model? Any questions? Type in the comments to send me a message.
When I came back to the US from living in Australia for 4 years, I published a poster with a picture of the moon on in and I placed it “upside down” – someone pointed it out and I looked at the moon and said “the moon is upside down.” This was true – in the Northern Hemisphere – but to people living in the Southern Hemisphere the moon appears “upside down.”
I was shocked, but the claim was true – in the Northern Hemisphere! But to Australians and other people living in places in the Southern Hemisphere the moon appears “upside down.”
Most people, when they look up at the night sky can easily see stars and identify some familiar groups of stars (asterisms and constellations). Some people can even find and name some planets – Venus, Jupiter, and Mars are all bright and easy to see.
But, there are many invisible wonders in the sky – and some of them can be seen without a telescope. In fact they are so big that a telescope is not the right tool to use; we have to use something even more powerful… imagination!
Using visualization and imagination, I am going to show you how to find and “see” a very large structure in our sky: the solar system disk itself.