Radio Waves

Model of one of the Deep Space Network antennas. This replica is in Barstow. The antenna is in nearby Goldstone.

April 21, 2018.

Sorry. No pics from our first radio antenna site. Antennas of the Deep Space Network are in a secure site near Barstow, CA, and the public is no longer allowed access to them. But there is a nice museum in Barstow with interactive displays about their use. Along with sister antennas in Madrid and Canberra they receive the faint radio transmissions of spacecraft from Voyager to those of numerous younger missions.

Our second site, the Very Large Array (VLA), gives guided tours every third Saturday. The VLA is part of an international group that studies black holes and gas clouds. They receive low frequency, very low energy waves. (We were told that the total energy of all the waves received since 1980 was the same as that of a snowflake hitting the ground.) So a really wide antenna base is needed. How wide? Well, a radius of about 13 miles seems to be working.

But where can you find such a wide flat space? Don’t forget that it must also be at a high altitude, close enough to civilization to allow for a support staff and visiting scientists, but shielded from local radio noise. As it turns out, there’s an ideal spot near Socorro, NM.

Site prep began around 30 million years ago. Volcanos started popping off around an area high in the Colorado Plateau. As the land around crumbled and shifted, this area remained relatively flat. Later a lake formed. After the lake was gone its flat bed remained. Now here, at 6970′, surrounded by mountains that block local radio interference, the VLA listens.

The array is a large “Y” configuration. The SW and SE arms each stretch out 13 miles from the center. The northern arm is stopped at 11 miles by a large ravine. Each arm is a railroad track with antennas positioned beside it. All antennas are wired to a central location, where an operator directs their slow ballet of changes in azimuth and altitude.

One of the studies we learned about involved dwarf galaxy Henize 2-10. The research implies that massive black holes may be linked to the births of galaxies. Of course Henize is pretty far off. The radio waves studied were sent around the time volcanos were erupting here.

Are there burning questions you have about space gas or black holes? Maybe you want to study the “brand new” black hole that appeared in Cygnus A, 800 million light years away. You can submit a proposal to get time on the VLA. Proposals are accepted based on merit. Or you could just use the “Ask an astronomer” page on the VLA website.

Click here for the Deep Space Network website, and here for the VLA website.

Right now, this very minute, we are still in Florida in Indiantown, but by the time you read this we should be at Greg’s folk’s house in North Carolina and then off to Cabbagetown the next day to start house sitting, doing odd jobs, and having fun with our friends in Atlanta! This post wraps up our travels out west this season, but we have high hopes of keeping up the blog this summer with updates about what we are doing, big plans for the fall, and more catching up on all the places we visited last year in Ballena Blanca.

* All pics are click to enlarge.

We found a campsite in the Cibola National Forest, fairly close to the VLA center. But elevation was 7,500′ and we got dusted with snow.
We’re parked at a pullout near the VLA visitor center, giving Bob a chance to check out one of the antennas.
This is one of the 28 antennas. The dish diameter is 82′. Antenna height is 90′, and the assembly weighs 230 tons. All dishes are wired to command central at the visitor center. The antennas send information about observations. They receive instructions telling them where to point. (Annual power bill for the facility is about $ 1M.)
The VLA partners with radio observatories around the world, and with the Hubble Telescope, to create images of galaxies far out in space.
The VLA can zoom in and out, but not automatically. And the process is slow. When we visited it was set to wide angle configuration A (which means A long way’s apart). After three months in A the dishes get moved closer, into the B formation. Three months more and they zoom in to C. And the last three months they are put into configuration D (Darn close together).
The VLA went online in 1980 with high tech (at the time) analog components that received radio frequencies from 1 to 5 GHz. From 2001 to 2012 internal components of the original dishes were upgraded while the system was still online. The new digital components transfer data much more quickly, and receive from 1 to 50 GHz.
Two custom-made red transporters are used to move the dishes along the RR tracks. One is pictured here. Their max speed is 5 MPH, and they don’t run if the wind blows over 20 MPH.
Each antenna location has tracks running perpendicular to the main track. When moving a dish the transporter stops at the intersection, lifts up, rotates 90 degrees, settles back down, and takes the dish to the concrete mounting pillars.
All the dishes were originally built in the barn to the right. One antenna is always swapped out of the rotation for maintenance. Work was just finished on this one. It’s out of the barn and ready to trade places with another.
Unlike visual light telescopes, radio telescopes run 24*7. Jesse, the day shift site manager, describes his responsibilities. He monitors the many planned projects, responds to extreme weather changes or power fluctuations, and may start unplanned observations if something unexpected pops up. We also heard him over the PA telling staff there was a short walkie talkie blackout while a hi frequency program was running. And he keeps the facility updated on cool wildlife sightings.
Visitors can use altitude and azimuth hand cranks to turn this small scope around. A voltmeter at the base shows the intensity of the radio waves received from the sun.
This is a Long Wavelength Array antenna. It has fours sides which constantly point in the same directions. There is also an array of these here at the VLA center.
Astronomer Bracewell designed this radio sundial. Like a regular sundial its shadow points to hour markers. In this case the markers are support pillars for old radio telescopes, autographed by famous astronomers. The small discs in the foreground can be used to locate three constellations that help radio astronomers check their bearings: Cassiopeia (11K light years away), Centaurus (9M light years off), and Cygnus (600M LY away).
Leaving the visitor center we saw these antelope. We were still in No Cellphone range, and refrained from reporting the sighting to Jesse.

4 thoughts on “Radio Waves

    1. Bob most definitely did not think the trip was a waste of time – he IS a rock hound, but the giant water dishes were a nice change of pace. I don’t think Bob really cares if there are aliens or UFOs – just as long as they don’t try to take his spot on the dash.

  1. I’m a bit behind on reading blog posts…so just came across this one. The title REALLY threw me for a loop though…I thought you wrote a blog post about US on S/V Radio Waves! LOL! Hope your summer is going well!

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