Stellarium – See the Analemma

See the Analemma

Stellarium can help you see sky patterns and practice Physical Astronomy.

By following this article you will be able to see the analemma moving – a figure 8 shaped path that the Sun follows yearly.

Here is a composite image that shows the position of the Sun in the morning sky each week. The pictures show every Sun position frozen in the sky each week at the same time of day: early in the morning. The June weeks are at the top left, December weeks at the bottom right and April and September weeks are in the middle at the crossing of the figure 8.

The analemma is easier to see when it is animated. In this visualization we will be using the Time Control features of Stellarium.  Continue reading “Stellarium – See the Analemma”

Walk to Mintaka

Physical Astronomy by Daniel Cummings
Mistakable rises toward the zenith as you walk toward the equator
As you walk toward the equator, Mintaka appears to rise higher in the sky.

In this post we will learn how to use one bright star of Orion’s belt to visualize the Earth’s equator.

Mintaka is a Star in Orion’s Belt

When you look up at the winter sky in the northern hemisphere, Orion and his famous belt are impossible to miss. The belt is made up of three stars of equal brightness.

One of these stars is called Mintaka and it is a guidepost for finding the Earth’s equator in space. Continue reading “Walk to Mintaka”

Tilt Head to Tilt Earth

Physical Astronomy by Daniel CummingsTilt your head to tilt the earth and experi nice the seasons

Seasons are caused by a titled Earth

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.

The Moon is Upside Down

The Moon is Upside Down

The moon is upside down (as seen from the Southern Hemisphere)
The moon as seen from the Southern Hemisphere. source: Wikipedia.

When you are in the southern hemisphere, the moon looks upside down.

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.”

 

Arms around the ecliptic

Learn to see the ecliptic

Physical Astronomy by Daniel Cummings

Ecliptic Arms

The sun follows the same path through the sky every day.

Sun up. Noon. Sun down.

The sun starts the day in the east in the morning, rises high in the sky at noon, and settles down again in the west for a nap at night.

See the ecliptic

Here is an exercise to discover that path – the ecliptic.

Continue reading “Arms around the ecliptic”

Train your Brain – See the shape of the solar system

Physical Astronomy by Daniel Cummings.

Train your Brain - See the solar system disk

See the solar system from Earth

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.

Continue reading “Train your Brain – See the shape of the solar system”

Night is…

“‘Night’ is not what time it is… it is where you are.” – Daniel Cummings

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””