See Mercury and Venus orbits during the day

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.

Use your hands and elbows to see Mercury and Venus orbits any time of day or night. The orbits of Mercury and Venus can be seen.
Two hand spans show Mercury’s orbit, elbows show Venus’s orbit.

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.

Continue reading “See Mercury and Venus orbits during the day”

Stars like ours – 9 bright “Life Stars”

Life Stars – Visible Exoplanets

Physical Astronomy by Daniel Cummings

Life Star in the night skyA “Life Star” is a visible star that could host life. This is a name I came up with in February 2017 (around the time of the TRAPPIST announcement) to describe visible stars with confirmed planets orbiting in the habitable zone. “Life Star” is easier to say and explain. I hope it catches on! Continue reading “Stars like ours – 9 bright “Life Stars””

The Moon Moves Toward the Dawn – a Mnemonic

The moon moves toward the dawn

Memorize this mnemonic: The moon moves toward the dawn. This phrase describes the day-by-day movement of the moon. With this simple phrase, you can understand the phases of the moon. You will actually begin to see the moon’s beautiful orbit traced out in the sky.

Repeat. The moon moves toward the dawn. The moon moves toward the dawn. 

The moon moves toward the dawn.
It rises higher in the dusky sky after each day. It sweeps over the hills.
It circles and rolls. It transits. It leaves the Sun, then chases the Sun.
The moon moves toward the dawn.
Look East! That’s where the moon wants to go.
Once arrived, it crosses the face of the Sun and once again moves toward the dawn.
The moon moves toward the dawn.