Tag Archives: space

The Ultimate Sunset

April 15, 2014 03:49am

April 15, 2014 03:49am

I took the telescope out during April’s lunar eclipse…

20140415_022302

April 15, 2014 02:23am

… and had a really amazing time. At first it was just the mosquitoes, the clouds, a cool drink, and myself, but after a while people started pouring out of their apartments to see the show.

April 15, 2014 01:18am  Staying homed in with the laser finder, waiting for the clouds to leave.

April 15, 2014 01:18am
Staying homed in with the laser finder, waiting for the clouds to leave.

So of course I invited them all over to watch through the telescope. By the end about 10 strangers were standing around watching the bloodmoon and discussing human history, space, science, etc.

April 15, 2014 12:54am

April 15, 2014 12:54am

Imagine what it would be like not knowing anything about the true nature of eclipses and, one seemingly random and unpredicted night, the full moon started disappearing- and then turned blood red. What a sign!

Luckily, we live in a time where humans have walked on the moon, so we do know a bit about it. So, why does the moon turn red?

Well, what color is the sky? (class shouts blue!) If the sky was blue, then how come images of the Earth from space aren’t of a blue ball? Or we don’t normally see a blue moon and blue stars? The sky appears blue because our atmosphere scatters blue wavelengths of light more than other wavelengths of light. When the sun is low in the sky, like during a sunset, the light reaching your eyes has passed through much more atmosphere than when the sun is high in the sky, causing most of the blue light to be scattered out already (for people who are experiencing noon elsewhere). So all that’s left in the light when it reaches your eyes during a sunset are the yellows and reds.

During a lunar eclipse the moon is behind the Earth, with the sun on the other side. The light reaching the moon has passed through the edges of the Earth’s atmosphere, causing a projection of what we see in a sunset to fall on the face of the moon. It’s the ultimate sunset!

 

Open question: Alright, after reading some Wikipedia articles on diffuse sky radiation and the like… I have a question. If our atmosphere scatters blue light, and images of the Earth from space are possible because sunlight is being reflected off of the Earth’s surface and into a camera, how come the Earth doesn’t appear reddish? You know, since the sunlight has passed through the atmosphere twice (down to Earth and back up to space?)

 

p.s. here’s a paper from 1868 “On the blue colour of the sky, and the polarization of light

Advertisements

Our message to the cosmos.

In 1977 we flung an atomic powered robot into space. Voyager 1’s primary mission was to beam data back to Earth as it cruised through the outer solar system. One of the most famous bits of data sent back is this image of Earth captured as Voyager looked back towards its home planet in 1990 (Awesome commentary on this image and our planet/species by Carl Sagan here)

Pale_Blue_Dot

The Pale Blue Dot image taken 6 billion km from Earth in 1990.

 

Voyager, continuing with the momentum gained from its primary mission, has recently left our solar system and started its secondary mission of being a message in a bottle from our species to the cosmos. The message is stored on an easy-to-read golden record, and contains greetings in different languages, sounds from Earth, brainwaves of a human, and images from around the planet.

The_Sounds_of_Earth_Record_Cover_-_GPN-2000-001978

The Golden Record.

The cover of the record contains an easy to read explanation on how to retrieve the data– defining time units in the universal constant of the fundamental transition of the hydrogen atom. The location of our solar system is also printed on the cover, in relation to 14 pulsars with unique periods.

Check out President Jimmy Carter’s message to who/whatever finds Voyager- “This is a present from a small distant world, a token of our sounds, our science, our images, our music, our thoughts, and our feelings. We are attempting to survive our time so we may live into yours. We hope someday, having solved the problems we face, to join a community of galactic civilizations. This record represents our hope and our determination, and our good will in a vast and awesome universe.”

It’s awesome to know that there is a time capsule of our species and planet floating through interstellar space- likely to last billions of years in the cold reaches between the stars. I’d like the think that one day something pics it up and gets to hear Johnny B. Goode by Chuck Berry.