The Earth and our Moon from Voyager 1

"There is a tide in the affairs of men, 

Which taken at the flood, leads on to fortune. 

Omitted, all the voyage of their life is bound in shallows and in miseries. 

On such a full sea are we now afloat. 

And we must take the current when it serves, or lose our ventures." 

-William Shakespeare

This picture of the Earth and Moon were taken by the Voyager 1 spacecraft from a distance of 7.25 million miles (~11.66 million km). Taken on 18 September 1977 (when I was -6 years old!), this picture as the very first ever taken that showed the Earth and the Moon in one single frame.

Voyager 1 is the most distant piece of human engineering and human exploration. It's fanciful to sit and think sometimes about how far away it really is now. As of the exact time of this writing, Voyager 1 is 20,661,735,297 km from the Earth and still going. The Voyagers and their mission were a hallmark of early space exploration. Now is truly the time for us to work together to take this current of humanity's evolution as a spacefaring species, and find our ventures among the other realms in the cosmic ocean.


(Note: in the picture above, the Moon appears very close to the Earth. However, the Moon is really about as far away from us as 30 times the diameter of the Earth! The picture certainly wasn't taken from equal distances to both Earth and Moon)

"Voyagers" by Santiago Menghini

Voyager 1, traversing the heavens (NASA/JPL)

The Voyager spacecraft were launched in 1977, at a time when the alignments of the outer planets would allow for a "Grand Tour" of the Solar System. 

Voyager 1 traveled past Jupiter and Saturn, discovering volcanoes on Io and the thick atmosphere of Titan, before it was turned around to take pictures of the planets as it traveled beyond their orbits. The famous Pale Blue Dot picture was taken by Voyager 1 when it was over 40 times further from the Sun than Earth. Since that time, Voyager 1 has passed beyond the region of space where the solar wind from our star dominates over other stars; Voyager 1 is now an interstellar traveler.

Voyager 2, while not garnering as much fame as its twin, is the only spacecraft to ever flyby Uranus and Neptune. All of our best detailed information regarding those worlds and their moons comes from Voyager 2, which passed by Uranus in 1986 and Neptune in 1989. For instance, the odd surface of Neptune's moon Triton was revealed by Voyager 2, giving us the first hints that cryovolcanism is a process which occurs on the icy worlds of our solar system.

Recently, filmmaker Santiago Menghini has put together a short film highlighting the journeys of the Voyager spacecraft. Including photographs from the missions as well as sounds from the plasma frequencies of the planets, the film is a tribute to the successes of the Voyager mission. I highly recommend checking out the movie (below, or at Vimeo). Turn up your speakers' volume and full screen this one, you won't regret it.

Voyagers from Santiago Menghini on Vimeo.

Voyaging, for Almost Four Decades

This beautiful image was produced by NASA to commemorate the anniversary of the Voyager spacecraft, which were launched in August and September of 1977. 

We'll soon be closing on 40 years since the launch of Voyagers 1 and 2. These missions have done so much for planetary science and are still alive, continuing to send data back to us about the space environment along their travels. They may last as much as another 5 or 10 years before they run so low on power that all of their instruments shut down. 

Even after the Voyagers have shut down their instruments and died, they will still travel; out there amongst the stars, the furthest reach of humanity, they will continue on.

There is no sound in space (or is there?)

(You can pickup some threads with this picture here)

In space, no one can hear you scream! That's what the tagline from the film Alien taught a generation of folks. Well, at least it taught some part of a generation. Well, maybe it only slightly hinted at an idea for a minimal fraction of some part of a generation. Or something like that. 

Too many times we've gone to the movies to see yet another sci-fi adventure with spaceships blasting each other with phasers and lasers and things that go "boom", all making lots of noises that some sound technicians likely spent hours in a studio putting together. And, most of the time it seems, these films get space completely wrong. 

Humans cannot hear in the vacuum of space. We can't. Since sound waves need a medium through which to travel and space generally offers nothing of the sort, there will be no propagation of sound from space battles, Star Destroyers traveling past you, or your fellow astronaut screaming from inside their space suit as they drift away from the ship after forgetting to attach their tether (unless, of course, they're screaming into their radio communication system).

Check out this vid from Coma Niddy at Sci Code on Space Myths

Star Trek, Star Wars, Battlestar Galactica, and more: the sounds of the spaceships and space battles and other spacey stuff in most of our television and films seem to show an utter lack of understanding on the part of the populace general. Even if filmmakers know that there shouldn't be sounds in space, it seems like most of them pander to the ignorance of the people by adding sounds to space. There are some who get it right, though. The cult sensation Firefly was well-known for presenting the lack of sound waves in space. 2001: A Space Odyssey, Gravity, and a few others also present the silence of space to the audience.

But hold on now, you might be thinking. Slow your roll, Cosmo Boy. Perhaps you've heard that NASA has recordings of some sounds from space. So what's up with that?

Just because sound waves don't generally propagate through space doesn't mean there's nothing for us to hear out there. For instance, several spacecraft (including the Voyager, Injun, and Hawkeye spacecraft) have had instruments capable of detecting the interactions of various particles with the ionospheres and magnetospheres of planets as well as the solar wind. The electromagnetic interactions spread over a large range of vibrations, but a lot of them are in the 20-20,000 Hz range in which we humans hear. NASA has released lots of these sound data sets online, including files primed for ringtones and notification sounds. Here's a video compilation of some of these sounds from our solar system (definitely awesome!):



Pretty cool, huh?!

Well, guess what? There's more.

As if listening to the interactions of the planets with the space environment weren't awesome enough, we can also take data from many our observations of the universe and convert those data into sound files. This is done through a process called sonification. For instance, we can take the Kepler light curves of stars and convert those light curves into sounds, allowing us to listen to the data. We can listen to the variations in the stars and we can even listen to the dips in the light curves as exoplanets transit in front of the stars. 

Sounds that are produced in this way aren't anything you would naturally hear, but they're still pretty awesome. For instance, this video presents a chorus of sounds produced through the sonification of light curves:



That's some eerie stuff. We can use sonification to convert all kinds of data into sounds, but listening to the processes occurring so far away in some way seems haunting and yet inspiring. Pod Academy recorded an episode called The Sounds of Space back in 2012 which can give you a fuller description of some of the cool stuff that what we can listen to from our observations of space. It's definitely worth a listen.

So even though no one can hear you scream in space, and even though all those spaceships going "pew pew pew" with their lasers and phasers and such in science fiction movies is a bunch of silliness (even if it does sound cool), there are some awesome things that we can really hear from our observations of space, either actual interactions of matter that cause vibrations in our hearing range or from data that we've converted to sounds. 

If you'd like to hear some more, I have another post to accompany this one that includes several embedded videos with the sounds from some of the worlds of our solar system.

(Image from PRX)