A Brief Visit to the Very Large Array (VLA)
It may be that you’ve arrived here as a fan of the 1996 movie
‘Contact’ starring Jodie Foster, a dramatization of celebrity planetary
scientist Carl Sagan’s SETI novel. The movie had some scenes shot at the VLA
and it’s famous because of it, including that iconic shot of Jodie listening to
the signal on headphones with a VLA dish as a backdrop.
I suspect the VLA staff are a bit over Contact by now. As
they point out, the VLA is not suited to real-life SETI work, though in
contradiction it seems that it actually has been. They for sure never listen on
headphones, though (except maybe Spotify).
Still, the movie used the VLA as a backdrop because it’s an
atmospheric place and an interesting one to visit in its own right. Here I take
a quick look at how to find it and what you might see there. You’ll probably
just look at the pictures, though, ‘cos like I said it’s a most photogenic
spot.
History
Building of the VLA was started in 1972 and complete by 1980.
Most of its work has been in general astrophysics, with all kinds of studies on
quasars, masers, radio galaxies and black holes.
Despite their disavowal of Contact’s themes (see excerpt from
a visitor centre sign below), the VLA seems to be getting used for SETI after
all. Read this article by
Seth Shostak for more info’.
Getting There
Like so many observatories the VLA isn’t exactly somewhere
you’ll stumble across whilst heading somewhere else. It’s in central New
Mexico, in the middle of a vast and lonely desert valley that was a lake bed in
the Pleistocene.
The nearest town by road is Socorro 50 miles to the east on I-25
between Albuquerque and Las Cruces. After that it’s probably Grants on I-40
west a mere 112 miles away. The map will show you nearer names like Pie Town
but you’ll be lucky to find gas and food there (there is a pie shop, but it was
closed for me).
What to see
Layby off Highway 60
The array consists of twenty-eight 25-meter radio telescope
dishes that weigh 200 tons each and move on rail tracks. They’re spread in
three long (as in 13 miles each) arms across the plain.
When the walking tour is open you can walk up to one and there’s
another near to the visitor centre road. But the easy way if you’re in a hurry
is to just stop at a layby off Highway 60 where it crosses the north arm just west
of the signposted turn-off to the VC. You’ll get great photos there and can
walk reasonably close to a dish before meeting the no trespassing sign.
Tip: the dishes are usually a long way apart, so take a
telephoto lens if you want shots with more than just one dish and lots of
desert.
Gnomon for the radio sundial is great for selfies!
Visitor Centre
The visitor centre is a rather small and half-hearted effort,
it’s also a surprisingly long way (4 miles) off the highway. The most
interesting stuff is outside – the array itself, the maintenance hangar and a
walking tour to one of the main dishes.
There’s also a kind of radio telescope garden with an old
dish and silver spheres on graffitied columns. The latter turn out to be much
more interesting than just an odd way of taking a selfie – they comprise a sundial
that appropriately also has markers for a couple of the strongest and first-discovered
celestial radio sources (Cygnus and Cassiopea A)!
If you’re still not satisfied on the Jodie and SETI front,
there’s a pin-board about the filming inside and a notice that has this to say:
“Visitors to the VLA
often ask if we have made contact with the “Little green men”. Others see the
surplus military vehicles and wonder if we have a Department of Defence
mission.
As for aliens, NRAO is
funded by the U.S. Government, and our government does not believe in spending
money on looking for men from Mars. That work is best left to SETI Inc, a
privately funded group. SETI stands for the Search for Extra-Terrestrial
Intelligence. In fact, the VLA is ill-suited for SETI work because the “beam”
is too narrow; that is, both the VLA and VLBA can only listen to a very small
piece of the sky at one time. As well, neither the VLA or VLBA can search
rapidly over broad bands of radio frequencies, a feature desirable for SETI work.
Sorry, Jodie.
All that said, looking
for life-forming molecules and studying the formation an evolution of planets,
particularly habitable planets, is a high priority for U.S. science. Some of
the scientists who use the VLA and VLBA are studying these areas.
The VLA does not have a
defence mission either. Sometimes it may seem we are in the middle of a war
when the New Mexico Air National Guard is conducting aerial dog fights right
overhead, but our mission is purely scientific. We listen to cosmic sources
like stars and galaxies with an occasional project to listen to a space probe
like Voyager thrown in. Neither the VLA nor VLBA antennas include any
transmitting equipment.”
But what about those no trespassing signs in the exact same
font they stencil on cluster bombs? Too much X Files in that lonely desert
motel again last night.
Also, perplexingly, the VLA does in fact seem to be searching
for signals from extra-galactic civilisations on behalf of the SETI Institute,
sorry whoever wrote the sign – see above. Fate loves irony.
Summary
Like I said, look at the pics. Waffling on about aperture
synthesis interferometry doesn’t convey the slightly spooky atmosphere of this vast
science instrument built in the middle of nowhere. That said, the science and
history are intriguing too.
The VLA may not warrant a trip to New Mexico on its own, but
if you’re doing the tour at SpacePort America, or
maybe at White Sands spying on missile launches (I mean enjoying the
gypsum dunes at the national monument), it’s a fun detour... and not just
because of Jodie and Carl (and now Seth too).
Go for the X Files atmosphere but look beyond it at the
science! The fact that SETI research is apparently now happening here adds to
the ambience.
