As we learned in the movie "Alien," in space, no one can hear you scream. Of course, we can't hear anything because there is no atmosphere out there. But scientists can still use sound to understand the solar system a little better by turning masses of data collected by NASA satellites into sound and music. Robert Alexander is a sonification specialist with the Solar Heliospheric Research Group at the University of Michigan. Welcome.

ROBERT ALEXANDER: Hi. Thanks for having me.

LYDEN: Well, we're delighted to have you, and we're all wondering what a sonification specialist is.

ALEXANDER: So what I do is I take data, and I translate it into sound. I myself work mostly with solar wind data and data from satellites and explore these sounds in a new way.

LYDEN: And how do you convert that data into sound without getting into a blizzard of technical details?


ALEXANDER: Sure. To sonify data is essentially to take any given data parameter - so it could be, let's say, the speed of the solar wind - and I can then map that and create a sound, a whooshing sound like (makes whooshing sound) that represents the solar wind in some kind of way.

LYDEN: OK. Let's hear an example of what you do, Robert, and this is the heartbeat of the sun.


LYDEN: So that's pretty cool, kind of reminds me of listening to a heat ventilation shaft, but of course, it's the sun. What are we actually hearing right now?

ALEXANDER: So that's actually 40 years' worth of solar data - it's several hundred thousands of lines' worth of data. And what we're listening to - I've filtered out a lot of the high frequency content, so we're listening to this low hum. And that's created by the rotation of the sun, actually.


ALEXANDER: When you have something that's rotating like the sun every 27 days, over the course of 40 years, we end up with this underlying hum, essentially.

LYDEN: Hmm. Is there something about the sun that lends itself to sonification as opposed to any other planetary body or the moon?

ALEXANDER: The sun, it's a window into getting to know many other stars much more deeply. And we have so many satellites up. They're all streaming down masses of information. And, you know, we have so much of this solar data, and we're trying to find ways to quickly and effectively navigate it all. And sonification offers us a way to, you know, possibly begin to do that.

LYDEN: Now, it is, after all, a sound experiment, and you're getting scientific inquiries from it, but I understand you've also taken it a step further, just for yourself, and you've actually composed some music from these sounds. Let's just listen for a moment.


LYDEN: Well, Robert Alexander, what you've done is incredibly beautiful. I hope you can take this music maybe to, you know, a hall, and people can hear it somewhere.

ALEXANDER: Sonification does really lend itself to education and public outreach, because I think a lot of people, they see a glass, and they just kind of turn off. And I think sonification has the potential to really engage the curiosity of the listener and to relate to it on a human level, more of a visceral level.

LYDEN: Well, thanks for the fascinating conversation.

ALEXANDER: Thank you so much.

LYDEN: Robert Alexander is a sonification specialist with the Solar Heliospheric Research Group at the University of Michigan. He turns solar data into sound and music.


LYDEN: It's NPR News.

Copyright © 2013 NPR. All rights reserved. Visit our website terms of use and permissions pages at www.npr.org for further information.

NPR transcripts are created on a rush deadline by a contractor for NPR, and accuracy and availability may vary. This text may not be in its final form and may be updated or revised in the future. Please be aware that the authoritative record of NPR’s programming is the audio.



Please keep your community civil. All comments must follow the NPR.org Community rules and terms of use, and will be moderated prior to posting. NPR reserves the right to use the comments we receive, in whole or in part, and to use the commenter's name and location, in any medium. See also the Terms of Use, Privacy Policy and Community FAQ.