It’s a story about us

When you look up at the stars at night, you are reading the story of the cosmos.

Light travels at 300,000 km/s (186,000 mps) in the vacuum of space. The distance light travels in one year is called a light year, which is 9,500,000,000,000,000 km. That means that it takes a ray of light a whole year to travel that far.

Think about the implications. Proxima Centauri, the closest star to our sun, is 4.2 light years away. So, if Proxima Centauri were to suddenly explode, we would not know for 4.2 years, since nothing travels faster than light, and we need the light to know that it happened!

But that’s just the closest star. The closest galaxy, Andromeda, is 2,530,000 light years away. So it would take 2,530,000 years for us to know that something happened to Andromeda.

But that’s only the closest galaxy! There are something like 100,000,000,000 galaxies in the universe, and all of them are farther away than that, and so it takes light that much longer to reach us!

So when you see the Andromeda galaxy in the sky, you are seeing it the way it looked 2,530,000 million years ago. You are looking at the history of the cosmos. But it’s not just the history of the cosmos. We came from the cosmos. Every atom in your body was cooked in the center of a star that eventually exploded. The story of the cosmos is the story of us.

The night sky is the story of us.

Peering deep into the heart of the Milky Way, this image shows a region of the sky in the constellation of Sagittarius. The two knots of stars you see are the globular clusters NGC 6522 (upper right) and NGC 6528 (lower left). There are over 200,000 stars in this image alone which covers a patch of sky just two-thirds as wide as the full moon.

The vastness of the cosmos is staggering.

Photo by Adam Block/Mount Lemmon SkyCenter/University of Arizona
Info Credit: Phil Plait, Bad Astronomy


For myself, I like a universe that, includes much that is unknown and, at the same time, much that is knowable. A universe in which everything is known would be static and dull, as boring as the heaven of some weak-minded theologians. A universe that is unknowable is no fit place for a thinking being. The ideal universe for us is one very much like the universe we inhabit. And I would guess that this is not really much of a coincidence.
Carl Sagan  - Can We know the Universe?’ in M. Gardner (ed.), T


Galactic Center of Our Milky Way

The Hubble Space Telescope, the Spitzer Space Telescope, and the Chandra X-ray Observatory – collaborated to produce an unprecedented image of the central region of our Milky Way galaxy.

Observations using infrared light and X-ray light see through the obscuring dust and reveal the intense activity near the galactic core. The center of the galaxy is located within the bright white region in the upper portion of the image. The entire image covers about one-half a degree, about the same angular width as the full moon.

Each telescope’s contribution is presented in a different color:

  • Yellow represents the near-infrared observations of Hubble. They outline the energetic regions where stars are being born as well as reveal hundreds of thousands of stars.
  • Red represents the infrared observations of Spitzer. The radiation and winds from stars create glowing dust clouds that exhibit complex structures from compact, spherical globules to long, stringy filaments.
  • Blue and violet represents the X-ray observations of Chandra. X-rays are emitted by gas heated to millions of degrees by stellar explosions and by outflows from the supermassive black hole in the galaxy’s center. The bright blue blob toward the bottom of the full field image is emission from a double star system containing either a neutron star or a black hole.

Astronomers at the European Southern Observatory’s Paranal Observatory in Chile have released a breathtaking new photograph showing the central area of our Milky Way galaxy. The photograph shows a whopping 84 million stars in an image measuring 108500×81500, which contains nearly 9 billion pixels.

Crops of the zoomable version.


“We inhabit a universe where atoms are made in the centers of stars; where each second a thousand suns are born; where life is sparked by sunlight and lightning in the airs and waters of youthful planets; where the raw material for biological evolution is sometimes made by the explosion of a star halfway across the Milky Way; where a thing as beautiful as a galaxy is formed a hundred billion times - a Cosmos of quasars and quarks, snowflakes and fireflies, where there may be black holes and other universe and extraterrestrial civilizations whose radio messages are at this moment reaching the Earth.”

                                                                    Carl Sagan, Cosmos

The Milky Way over Crater Lake National Park is just mesmerizing. Tiffany Nguyen took this amazing photo a few weeks ago while visiting the park. Of the experience, she says, “I must’ve gotten over a dozen mosquito bites and hardly any sleep, but it’s nights like this I’ll never forget.” Photo courtesy of Tiffany Nguyen.


“For as long as there been humans we have searched for our place in the cosmos. Where are we? Who are we? We find that we live on an insignificant planet of a hum-drum star lost in a galaxy tucked away in some forgotten corner of a universe in which there are far more galaxies than people. This perspective is a courageous continuation of our penchant for constructing and testing mental models of the skies; the Sun as a red-hot stone, the stars as a celestial flame, the Galaxy as the backbone of night.” – CARL SAGAN 

(Photography credit: Michael Goh)


Stars above, stars below. Watch them dance and glow!

Stars light up the sky as bioluminescent phytoplankton glow like stars; in the Maldives, South Asia.

Image sources [1] [2] [3] [4]