In Frankie and the Gift of Fantasy, Frankie travels across the galaxy to a planet called Urth, where he has an amazing adventure.
Urth orbits a sun much like our own. But we can’t see it from Earth, even up high in the mountains on a very dark night. The bright central bulge of our galaxy blocks the view.
Out in the spiral arms, where we live, stars are spread out, like golf balls thousands of miles apart. There’s lots of empty space between them. The nearest star to us, Alpha Centauri, is 4.2 light years away. That’s 24 trillion miles! If stars were people, they’d be very lonely.
But in the central bulge, the stars are much more tightly packed. They’re still not touching. Not even close. Light might take a week to get from one to the other, a distance of 111 billion miles. Still, that’s very cozy for stars, and the bulge is very bright.
Have you ever seen the central bulge our galaxy? If you’re lucky enough to live in or visit a place that has very dark skies, it’s clearly visible.
This is what it looks like to the naked eye. You’ll find it in the constellation Sagittarius, which has the shape of a teapot. The central bulge appears to be steam coming out of the pot! (Photo credit: Stellarium: http://www.stellarium.org/)
How many stars are in the Milky Way galaxy? About 100 billion! That’s a big number, but just how gigantic is it? Well, if you started counting out loud right now (“1, 2, 3, 4, 5…”), it would take you 3,200 years to count to 100 billion – probably not a good use of 40 successive lifetimes!
The sheer size of the galaxy is mind-blowing as well. The distance between Earth and Urth is 64,000 light years. That means that it takes light 64,000 years to travel from one planet to the other!
Light travels so fast that it can whiz around Earth three times in a single second. Wow, that’s speedy! Yet it takes it 64,000 YEARS to cross the galaxy.
So how does Frankie get to Urth? You’ll have to read the book to find out… but I can give you a hint: It doesn’t take him 64,000 years!
If you have access to a cell phone, upload an app like:
Google Sky Map (android phones)
Sky View (iphones)
These apps allow you to point your phone in any direction (including below your feet) to find the location of constellations, stars, planets, and deep-sky objects like galaxies and nebulae. You can use the apps any time of day of day or night, and from anywhere in the world.
You can do it right now!
Sweep your phone around until you find the constellation Sagittarius. That’s where the central bulge of our galaxy is located.
Where is it with respect to you?
Try again in a few hours. Has it shifted? If so, why do you think that is? (Hint: You’re the one in motion!)