Tag Archives: Radio Astronomy

Wired: The ngVLA and “Rebirth of Radio Astronomy”

The NRAO’s Very Large Array (VLA) in New Mexico is 40 years old.

(Source: WIRED)

IN THE EARLY 1930s, Bell Labs was experimenting with making wireless transatlantic calls. The communications goliath wanted to understand the static that might crackle across the ocean, so it asked an engineer named Karl Jansky to investigate its sources. He found three: nearby thunderstorms, distant thunderstorms, and a steady hiss, coming from … somewhere.

Jansky studied the hiss for a year, using a rudimentary antenna that looked like toppled scaffolding, before announcing its origin: The static was coming from the the galaxy itself. “Radio waves heard from remote space,” announced The New York Times in May 1933. “Sound like steam from a radiator after traveling 30,000 light-years.” Janksy had unwittingly spawned the field of radio astronomy.

Today, a replica of Jansky’s scope sits on the lawn in front of Green Bank Observatory, one of the four world-class public radio telescopes in the US. Along with the Very Large Array, Arecibo Observatory, and the Very Long Baseline Array (VLBA), it is the legacy of a boom time in federal investment in the field that began in earnest after World War II.

In the past several years, though, the National Science Foundation has backed away from three of those instruments. In 2012 the NSF published a review recommending that the foundation ramp down funding to Green Bank—just 11 years after it was finished—as well as the VLBA, which can resolve a penny from about 960 miles away. Three years later, the foundation asked Arecibo for management proposals that “involve a substantially reduced funding commitment from NSF.”

[S]upport for pure science in the US is always complicated, since it relies on the good graces of federal agencies and annual budgets. As funders balance building and operating new scopes with the old, while giving grants to the astronomers who actually use those instruments, something’s gotta give. And no matter what it is, the science will not be the same.

[…]THERE IS A new facility potentially on the horizon: The Next-Generation VLA (the VLA itself, while upgraded, is 40 years old). As currently envisioned, the ngVLA’s many antennas will together have 10 times the sensitivity and resolution as the VLA, at a wider range of frequencies. The primary array will have 214 18-meter antennas, spiraled across New Mexico, Texas, Arizona, and Mexico. Nineteen smaller ones will sit close to the center, and 30 18-meterers will constellate the continent.[…]

Read the full article at WIRED magazine.

Check out this video for more info about the ngVLA:

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A history of listening to Mars

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(Source: Atlas Obscura via William McFadden)

When the red planet comes close to Earth, some people have tried to tune in to see if it has anything to say.

ON RECENT EVENINGS, AS JULY has melted into August, Earth’s rocky red companion has dropped by for a visit. Earth and Mars, when they’re on opposite sides of the Sun, can be as many as 250 million miles apart. This week, however, Mars has been just shy of 36 million miles from Earth, the snuggest our planets have been since 2003. Looming bright and orange in the night sky, it has been easily visible to the naked eye. The close-up comes courtesy of opposition—the point at which Mars, Earth, and the Sun align, with us sandwiched in the middle.

When the planets approached a similarly cozy distance 94 years ago, in August 1924, some people, including Curtis D. Wilbur, the Secretary of the U.S. Navy, thought it might be possible to actually hear messages from our neighbor. If Martians were ever going to drop us a line, they suspected, that’d be the time.

From an office in Washington, D.C., Wilbur’s department sent orders to every naval station clear across the country. An outpost in Seattle received a telegram asking operators to keep their ears tuned to anything unusual or, maybe, otherworldly.

“Navy desires [sic] cooperate [sic] astronomers who believe [sic] possible that Mars may attempt communication by radio waves with this planet while they are near together,” it read. “All shore radio stations will especially note and report any electrical phenomenon [sic] unusual character …” The orders asked for operators to keep the lines open and carefully manned between August 21 and August 24, just in case.

NATIONAL ARCHIVES/596070

This request didn’t come out of nowhere. There was a long buildup to the idea that Mars might be trying to tell us something, with technologies that were then new to us.[…]

Click here to read this article at Atlas Obscura.

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ADMX: A Dark Matter receiver

78 Megahertz: Australian astronomers detect signal from the dawn of the universe

Tom explores the depths of radio astronomy

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26 meter telescope at the Pisgah Astronomical Research Institute.

Many thanks to SWLing Post contributor, Tom L, who writes:

I have been curiously surveying uses of radio in different areas of industry and Astronomy came up as a hot topic the last couple of years according to recent Google searches. Radio was a giant popular commercial success in the 1930’s and 1940’s. But Radio Astronomy was still in its infancy with military radar. A Bell Labs engineer (Karl Jansky) accidentally discovered signals coming from an unknown source. He and his mentor figured out that it was coming from the center of the Milky Way.

https://en.wikipedia.org/wiki/Radio_astronomy

Fast forward to today and it looks nothing like the early days. Computer control and very large arrays have made it possible to boost the wide-field resolution massively. We are now able to see molecules in space outside our solar system and filaments connecting star nurseries. Here are just a few recent articles that hint at major news coming from this field of study. If you have a science student interested and has the talent for Astronomy, Radio Astronomy promises to be on a variety of cutting edges of discoveries over the next few decades from local Space Weather, biological search, and how stars form.

Snatching at the cradle of life

Cosmic filament probes our galaxy’s giant black hole

Astronomers make real-time, 3-D movies of plasma tubes …

Radio telescopes are essential to discovering “Galaxy Ecosystems”: Click here to download PDF.

Enjoy!

Thanks, Tom! I’ve been fascinated with radio astronomy since my undergraduate years in the early 1990s. I’m now a volunteer at the Pisgah Astronomical Research Institute (PARI) and have learned so much through their research. If you ever have the time, I would encourage you to visit PARI or one of the NROA sites like Green Bank or the Very Large Array. Well worth the detour! Thanks for sharing those articles!

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Listening to Oumuamua via the Green Bank Telescope

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Many thanks to SWLing Post contributor, Ferruccio Manfieri, who writes:

I bother you to mention this uncommon radio listening project i’ve just found via The Guardian:

Green Bank telescope in West Virginia will listen for radio signals from ‘Oumuamua, an object from another solar system

Astronomers are to use one of the world’s largest telescopes to check a mysterious object that is speeding through the solar system for signs of alien technology.

The Green Bank telescope in West Virginia will listen for radio signals being broadcast from a cigar-shaped body which was first spotted in the solar system in October. The body arrived from interstellar space and reached a peak speed of 196,000 mph as it swept past the sun.

Scientists on the Breakthrough Listen project, which searches for evidence of alien civilisations, said the Green Bank telescope would monitor the object, named ‘Oumuamua, from Wednesday. The first phase of observations is expected to last 10 hours and will tune in to four different radio transmission bands.

“Most likely it is of natural origin, but because it is so peculiar, we would like to check if it has any sign of artificial origin, such as radio emissions,” said Avi Loeb, professor of astronomy at Harvard University and an adviser to the Breakthrough Listen project. “If we do detect a signal that appears artificial in origin, we’ll know immediately.”

The linked article says that “(…)Scientists on the Breakthrough Listen project, which searches for evidence of alien civilisations, said the Green Bank telescope would monitor the object, named ‘Oumuamua, from Wednesday. The first phase of observations is expected to last 10 hours and will tune in to four different radio transmission bands.”

From the website of the project (http://breakthroughinitiatives.org/initiative/1):

Breakthrough Listen is the largest ever scientific research program aimed at finding evidence of civilizations beyond Earth. The scope and power of the search are on an unprecedented scale:

The program includes a survey of the 1,000,000 closest stars to Earth. It scans the center of our galaxy and the entire galactic plane. Beyond the Milky Way, it listens for messages from the 100 closest galaxies to ours.

The instruments used are among the world’s most powerful. They are 50 times more sensitive than existing telescopes dedicated to the search for intelligence.
The radio surveys cover 10 times more of the sky than previous programs. They also cover at least 5 times more of the radio spectrum – and do it 100 times faster. They are sensitive enough to hear a common aircraft radar transmitting to us from any of the 1000 nearest stars.

In particular:

“Listen’s observation campaign will begin on Wednesday, December 13 at 3:00 pm ET. Using the Robert C. Byrd Green Bank Telescope, it will continue to observe ‘Oumuamua across four radio bands, from 1 to 12 GHz. Its first phase of observations will last a total of 10 hours, divided into four “epochs” based on the object’s period of rotation.”

I know it’s out of our common shortwave range and scope of interest, but as a radio listening enthusiast I’m fascinated by this visionary scientific enterprise.

Thank you, Ferruccio, for sharing this. Being a fan of radio astronomy, SETI, and weak signal DXing, of course I find this fascinating! Thanks for sharing!

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Hurricane Damages Arecibo Radio Telescope

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Arecibo Observatory

(Source: National Geographic via Eric WD8RIF)

Hurricane Damages Giant Radio Telescope—Why It Matters” at National Geographic, written by the daughter of Frank Drake, pioneer SETI investigator:

Scientists and ham radio operators have confirmed that the Arecibo Observatory in Puerto Rico—arguably the world’s most iconic radio telescope, which has a dish stretching a thousand feet across—has come through Hurricane Maria mostly intact, but with some significant damage.

More importantly, the observatory’s staff sheltering on-site are safe, and the facility is in good enough condition to potentially serve as a local center for the U.S. Federal Emergency Management Agency, or FEMA, reports Arecibo deputy director Joan Schmelz.

Because of its deep water well and generator, the observatory has been a place for those in nearby towns to gather, shower, and cook after past hurricanes. It also has an on-site helicopter landing pad, so making sure the facility is safe in general is not just of scientific importance, but is also relevant for local relief efforts.

News about the facility has been primarily coming from Arecibo telescope operator Ángel Vazquez, who managed to get to the site and start communicating via short-wave radio in the early evening of September 21.

According to initial reports, the hurricane damaged a smaller, 12-meter dish and it caused substantial damage to the main dish, including about 20 surface tiles that were knocked loose.

Also because of the storm, a 96-foot line feed antenna—which helps focus, receive, and transmit radio waves—broke in half and fell about 500 feet into the huge dish below, puncturing it in several places, says Pennsylvania State University’s Jim Breakall, who talked with Vazquez.[…]

Click here to read the full article.

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