Tag Archives: Radio Astronomy

Ruby Payne-Scott: a pioneer in radio astronomy

(Source: New York Times via Howard Bailen)

Since 1851, obituaries in The New York Times have been dominated by white men. With Overlooked, we’re adding the stories of remarkable people whose deaths went unreported in The Times.

By Rebecca Halleck
Every so often our sun emits an invisible burst of energy.

This energy ripples through space as electromagnetic waves and then crashes into planets and meteors and space debris and one another, causing a great cacophony above and around us.

A cacophony that was inaudible, until Ruby Payne-Scott entered a laboratory.

In the 1940s, Payne-Scott helped lay the foundation for a new field of science called radio astronomy. Her work led to the discovery of deep-space phenomena like black holes and pulsars and later helped astronauts understand how solar storms disrupt weather in space and electrical grids on Earth.

Yet as a married woman she was denied equal employment status and compensation. She challenged the scientific establishment in her native Australia and fought for the rights of women in the workplace, but ultimately left science to raise her children full time.

World War II opened the door to Payne-Scott’s scientific career. The Australian armed forces needed physicists, and men were joining the military to fight instead.[…]

Continue reading the full article at the NY Times.

Spread the love

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:

 

Spread the love

A history of listening to Mars

(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.

Spread the love

ADMX: A Dark Matter receiver

(Image source: NASA)

(Source: Futurity)

Radio receiver ‘listens’ for dark matter particles

Researchers have developed a way to “listen” for the signs of dark matter axions, the particles that may make up dark matter.

Forty years ago, scientists theorized a new kind of low-mass particle that could solve one of the enduring mysteries of nature: what dark matter is made of. Now a new chapter in the search for that particle has begun.

The Axion Dark Matter Experiment (ADMX) is the world’s first and only experiment to have achieved the necessary sensitivity to “hear” the telltale signs of dark matter axions.[…]

Click here to view on YouTube.

Click here to read this full story at Futurity.

Spread the love

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

(Image: NASA – Hubble Space Telescope)

(Source: ABC Science via William Lee)

Astronomers detect signal from the dawn of the universe, using simple antenna in WA outback

They have picked up a radio signature produced just 180 million years after the Big Bang using a simple antenna in the West Australian outback.

The ground breaking discovery, reported today in the journal Nature, sheds light on a period of time known as the “cosmic dawn”, when radiation from the first stars started to alter the primordial gas soup surrounding them.

[…]The signal they’ve been looking for is a miniscule fraction — between 0.1 and 0.01 per cent — of the radio noise from the sky.

“It’s like trying to hear a whisper from the other side of a roaring football stadium,” Professor Bowman said.

The signal is also within the lower range of FM radio, so finding a place on Earth that is free of human radio interference was essential.

That’s why Professor Bowman and colleagues decided to base their experiment at CSIRO’s Murchison Radio-astronomy Observatory, 300 kilometres north-east of Geraldton.

“Going to Western Australia and working at the Murchison Radio-astronomy Observatory was an absolutely critical first step for us,” he said.

There they built a small table-sized radio spectrometer with a radio receiver attached to two metal panels that act as an antenna. Akin to a set-up from the 60s or 70s, the EDGES instrument is much simpler in design than bigger array telescopes around the world.[…]

Click here to read the full article at ABC Science.

Spread the love