If you’re seen the movie Contact, you’ve at least, virtually, been to the Very Large Array (VLA). The facility, run by the National Radio Astronomy Observatory (NRAO) is about three hours from Santa Fe. It’s a long day-trip, but, but if outer space or inter-planetary communication interests you, or you like to visit movie locations, it’s worth the trip.
What is the VLA? It’s an installation of steel and aluminum parabolic dish antennas that comprise the world’s most powerful radio telescope. It sits off US 60 in the middle of nowhere about an hour west of Socorro, NM. As you approach the site, you’ll see the large antennae also known as dishes that comprise this vast scientific instrument.
The tour starts at the Visitor Center. Take time to watch the 24-minite film Beyond the Visible; the Story of the Very Large Array, narrated by Jodie Foster one of stars of Contact’s. Informative and fascinating, it gives you an idea of the significance of what you’ll be looking at when you walk the site as well as how the telescope works.
Beyond the Visible
The following is a bit of what we learned from the film. The 27 dishes or antennae are each 94 feet tall and 82 feet in diameter. Working together they form a single telescope which, according to Foster, is “larger than New York City.” The movable antennae are set on over 40 miles of tracks. They can extend as far as 13 miles in each direction depending on their configuration. There are four configurations: A, B, C, and D. The A formation is the most wide-spread and the D the most clustered. These antennae monitor the cosmos 24 hours a day observing light across the entire electromagnetic spectrum. This light, says Foster “reveals the birth of stars, the secrets of ancient galaxies and the presence of black holes.” The VLA allows scientists to explore the early stages of galaxy evolution, gaining insight into the first massive black holes in space. Astronomer Amy Reines, who’s interviewed in the film, says that the kind of work they’re doing wouldn’t be possible with any other instrument on earth. With these radio telescopes they can see tens of millions of light-years away. Foster calls the VLA the “foremost astronomical instrument of its kind.” Are you hooked yet? Watch the video on the VLA website, or better yet, visit the VLA in person.
Some VLA facts
The official name of the site is the Karl Jansky Very Large Array. Jansky was an American physicist who made the 1932 discovery that objects in space emit radio waves.
All the data collected at the VLA is transmitted to the Domenici Science Operations Center in Socorro for interpretation. The NRAO also operates three other radio telescope sites: Atacama Large Millimeter Array (ALMA) located in Peru’s Atacama Desert, Robert C. Byrd Green Bank Telescope (GBT) in Green Bank, West Virginia, and Very Long Baseline Array (VLBA) which, while in Hawaii, is operated out of the Socorro location.
The VLA was completed in 1980. As time passed, the electronics were becoming obsolete. In 2003, the NRAO began rebuilding and replacing the telescope’s infratructiur antennae by antenna. The work took a decade to complete. As the work was done antenna by antenna the telescope was up and running the entire time it was being updated.
The VLA is able to receive weak signals that go as far back in time as the Big Bang. That piece of information was boggling. We were in the presence of an instrument reaches out to the beginning of time.
Why was this site chosen for the VLA? This ancient lake bed in this remote high desert location was chosen for its elevation (almost 7,000 feet above sea level), its flatness of the land, its mostly clear skies and its southwest exposure.
About every four months the antennas moved into a new configuration (either the A, B, C, or D positions.
Take the self-guided VLA tour
As we toured the site we stopped to read the educational signs posted throughout. At the time of our visit, the telescope was in the A formation.
The first thing we passed was the Bracewell Radio Sundial, named for Ronald Bracewell, a pioneer in radio astronomy, it the only sundial of its kind in the world. Check out the concrete piers holding the silver-colored balls. They are a piece of science history. Over 200 prominent astronomers, including two Nobel Prize recipients “signed” the concrete pillars with a chisel when they visited the now-defunct observatory at Stanford. An informational sign tells visitors that the sundial uses radio shadows to tell time. See if you can tell what time it is by the shadows cast.
The antennae (dishes) that make up the VLA’s vast telescope are parabola-shaped, allowing radio waves to bounce off a single spot called the “focus.” A second reflector then transmits the waves to a receiver that turns them into signals. These are transmitted to the Correlator, a supercomputer that receives and combines the signals from all the antennae. According to the posted information the VLA gathers image from all over the sky to “map the radio universe.”
To help visitors better understand how the antennae work, there installed two parabolic dishes (Whisper Dishes) so visitors can better understand the VLA’s ability to amplify the signals which bounce off the focus on the telescope’s antennae. These dishes are set about 30 feet apart. We each stood at one of the dishes and whispered into the focus. Our words were transmitted with crystal clarity. It was as if we were standing right next to each other.
Another sign at the site explains that the signals collected by the telescope are less than a billionth (yes that’s billionth) of the strength of the signals our cell phones pick up. To keep them from interfering with these weak signals coming from outer space, visitors are asked to shut off electronic devices while at the VLA. These weak radio waves the antennae collect are processed into data that becomes what the sign calls “gorgeous views of the once-invisible universe.”
The last thing we pass on our walk through the VLA is a three armed stainless steel sculpture titled Shiva Shiwana created by artist Jon Barlow Hudson. The 1980 work, funded by the NM Arts Council, represents the Y shape of the VLA’s tracks and the floating 3-demensional nature of the objects the giant telescope studies.
We headed back to the Visitor Center for a bit before getting back on the road. We would have gone a bit further west and visited Pie Town, a small town sitting on the Continental Divide. It’s on our New Mexico to-visit list. Our quest: the Pie-o-Neer Café, home of Kathy Knapp, the Pie Lady of Pie Town. It was closed the day of our visit so we headed east to Socorro and then north towards home.
If you go:
Admission to the VLA is $6 for adults, $5 for seniors (65+). Ages 17 and under are admitted free.
The VLA site and Visitor Center are open daily from 8:30am until sunset. Tours are self-guided unless you come on days that guided tours are offered. On Sundays and Mondays free guided tours are offered at 1pm. They also hold them on the first Saturday of the month, at 11am, 1pm and 3pm. In the summer, tours are every Saturday at 11am and 1pm. (Check before you go to make sure the schedule is up-to-date.) Tours are approximately 45 minutes long. The VLA also semi-annual open houses in April and October.
If it’s snowing, call or check their website for current information before you go. The VLA may be closed to visitors during snowy conditions. Their phone number is 575-835-7410 for current information.
If you’re a pie lover, before or after touring the VLA head to the Pie-O-Neer Café in Pie Town for a pie fix. The cafe is open from Thursday through Sunday from 11am “until the pie runs out” from April through early January. Call ahead to make sure they’re open and to reserve a slice of your favorite pie.