Green Bank Telescope Archives

June 13, 2024June 13, 2024 by Mark Thompson

The Inner and Outer Milky Way Aren’t the Same Thickness, and that’s Surprising

Illustration depicting the Smith Cloud on its journey to the Milky Way Creator: NRAO/AUI/NSF Credit: B. Saxton, NRAO/AUI/NSF

At first glance, the universe and night sky seem largely unchanging. The reality is very different, even now, a gas cloud is charging toward the Milky Way Galaxy and is expected to crash into us in 27 million years. A team of astronomers hoping to locate the exact position of the expected impact site have been unsuccessful but have accidentally measured the thickness of the Milky Way! Analysing radio data, they have been able to deduce the thickness of the inner and outer regions and discovered a dramatic difference between the two.

June 3, 2024June 12, 2024 by Nancy Atkinson

Part 2: The History and Future of Planetary Radar

The Green Bank Observatory in summer. Credit: NSF/GBO/Jill Malusky

To reach the U.S. National Science Foundation’s Green Bank Observatory, you take the road less traveled, winding through scenic and remote regions of the Allegheny Mountains and the Monongahela National Forest of West Virginia. About an hour away, you’ll start to lose cell phone service. The Green Bank Observatory – a collection of radio telescopes that search the heavens for faint radio signals from black holes, pulsars, neutron stars or gravitational waves — sits near the heart of the United States National Radio Quiet Zone, a unique area the encompasses an area of approximately 13,000 square miles, spanning the border between Virginia and West Virginia.

Here in the NRQZ, human-generated radio transmissions are limited to shield the radio telescopes from Earth-based radio signals called RFI (Radio Frequency Interference), which are high-frequency electromagnetic waves that emanate from electronic devices such as computers, cell phones, microwave ovens, and even digital cameras. Even the weakest RFI signals can drown out the faint radio waves coming from the cosmos.

May 30, 2024June 12, 2024 by Nancy Atkinson

Next-Generation Radar Will Map Threatening Asteroids

The Robert C. Byrd Green Bank Telescope. Credit: Jay Young.

When the Arecibo Observatory dish in Puerto Rico collapsed in 2020, astronomers lost a powerful radio telescope and a unique radar instrument to map the surfaces of asteroids and other planetary bodies. Fortunately, a new, next-generation radar system called ngRADAR is under development, to eventually be installed at the the U.S. National Science Foundation’s 100-meter (328 ft.) Green Bank Telescope (GBT) in West Virginia. It will be able to track and map asteroids, with the ability to observe 85% of the celestial sphere. It will also be able to study comets, moons and planets in our Solar System.

“Right now, there is only one facility that can conduct high-power planetary radar, the 70-meter (230-foot) Goldstone antenna that is part of NASA’s Deep Space network,” said Patrick Taylor, the project director for ngRADAR and the radar division head for the National Radio Astronomy Observatory. “We had begun this process of developing a next generation radar system several years ago, but with the loss of Arecibo, this becomes even more important.”

May 22, 2023May 22, 2023 by Alan Boyle

SETI Researchers Are Simulating Alien Contact — and You Can Help

Radio telescopes monitor the sky at the Allen Telescope Array in California. Finding a signal from a distant civilization is one way we could experience first contact with ET. (SETI Institute Photo)

Is it a multimedia art project? Or a rehearsal for alien contact? Let’s call it both: Researchers specializing in the search for extraterrestrial intelligence, or SETI, are working with a media artist to stage the receipt of an interstellar message — and a global effort to decode the message.

The project, titled “A Sign in Space,” is orchestrated by media artist Daniela de Paulis in collaboration with the SETI Institute, the European Space Agency, the Green Bank Observatory and the Italian National Institute for Astrophysics (also known as INAF).

The metaphorical curtain rises on May 24, when ESA’s ExoMars Trace Gas Orbiter transmits an encoded radio message from Martian orbit to Earth at 19:00 UTC / noon PDT.

February 11, 2023February 11, 2023 by Laurence Tognetti

A Green Bank Telescope Prototype Radar System Can Image the Moon in High-Resolution and Detect Asteroids

Prototype radar image zoom-in of Tycho Crater floor in 5-meter resolution detail. (Credit: Raytheon Technologies)

Everyone loves taking pictures of the Moon. Whether it’s with their phones or through the wonders of astrophotography, photographing the Moon reminds us about the wonders and awesomeness of the universe. But while we can take awesome images of the whole Moon from the Earth, it’s extremely difficult to get close-up images of its surface given the enormous distance we are from our nearest celestial neighbor at 384,400 km (238,855 mi). This is because the closer we try to zoom in on its surface, the blurrier, or more pixelated, the images become. Essentially, the resolution of the images becomes worse and worse. But what if we could take high-resolution images of the Moon’s surface from Earth instead of relying on satellites presently in lunar orbit to take them for us?

February 10, 2023March 6, 2023 by Matt Williams

More Data and Machine Learning has Kicked SETI Into High Gear

Artist’s impression of Green Bank Telescope connected to a machine learning network. Credit: Breakthrough Listen/Danielle Futselaar.

For over sixty years, astronomers and astrophysicists have been engaged in the Search for Extraterrestrial Intelligence (SETI). This consists of listening to other star systems for signs of technological activity (or “technosignatures), such as radio transmissions. This first attempt was in 1960, known as Project Ozma, where famed SETI researcher Dr. Frank Drake (father of the Drake Equation) and his colleagues used the radio telescope at the Green Bank Observatory in West Virginia to conduct a radio survey of Tau Ceti and Epsilon Eridani.

Since then, the vast majority of SETI surveys have similarly looked for narrowband radio signals since they are very good at propagating through interstellar space. However, the biggest challenge has always been how to filter out radio transmissions on Earth – aka. radio frequency interference (RFI). In a recent study, an international team led by the Dunlap Institute for Astronomy and Astrophysics (DIAA) applied a new deep-learning algorithm to data collected by the Green Bank Telescope (GBT), which revealed eight promising signals that will be of interest to SETI initiatives like Breakthrough Listen.

December 12, 2022December 12, 2022 by Evan Gough

A Black Hole has been Burping for 100 Million Years

Artist view of an active supermassive black hole. Credit: ESO/L. Calçada

Black holes are gluttonous behemoths that lurk in the center of galaxies. Almost everybody knows that nothing can escape them, not even light. So when anything made of simple matter gets too close, whether a planet, a star or a gas cloud, it’s doomed.

But the black hole doesn’t eat it at once. It plays with its food like a fussy kid. Sometimes, it spews out light.

When the black hole is not only at the center of a galaxy but the center of a cluster of galaxies, these burps and jets carve massive cavities out of the hot gas at the center of the cluster called radio bubbles.

April 7, 2022April 7, 2022 by Matt Williams

Canada's CHIME is Getting More Observatories to Search for Fast Radio Bursts

CHIME consists of four metal "half-pipes", each one 100 meters long. Image Credit: CHIME/Andre Renard, Dunlap Institute.

In 2017, the Canadian Hydrogen Intensity Mapping Experiment (CHIME) began to gather light from the Universe to address some of the biggest questions and astrophysics and cosmology. Located at the Dominion Radio Astrophysical Observatory (DRAO) in British Columbia, this interferometric radio telescope has been a game-changer for studying Fast Radio Bursts (FRBs), which remain one of the most mysterious cosmic mysteries facing astronomers today.

In the near future, CHIME will be getting an expansion that will help it more accurately identify where FRBs are coming from. This will consist of a new radio telescope outrigger located at the SETI Institute’s Hat Creek Radio Observatory (HCRO), new outriggers near Princeton, British Columbia, and at the Green Bank Observatory in West Virginia. These will work with the main CHIME telescope to localize CHIME-detected FRBs precisely in the night sky.

January 23, 2022April 13, 2022 by Matt Williams

Astronomers Might Have Detected the Background Gravitational Waves of the Universe

Artistic impression of the Double Pulsar system, where two active pulsars orbit each other in just 147 min. The orbital motion of these extremely dense neutrons star causes a number of relativistic effects, including the creation of ripples in spacetime known as gravitational waves. The gravitational waves carry away energy from the systems which shrinks by about 7mm per days as a result. The corresponding measurement agrees with the prediction of general relativity within 0.013%. The picture at high resolution and two alternative versions (1b, 1c) are accessible in the left column. [less] © Michael Kramer/MPIfR

In February 2016, Gravitational Waves (GWs) were detected for the first time in history. This discovery confirmed a prediction made by Albert Einstein over a century ago and triggered a revolution in astronomy. Since then, dozens of GW events have been detected from various sources, ranging from black hole mergers, neutron star mergers, or a combination thereof. As the instruments used for GW astronomy become more sophisticated, the ability to detect more events (and learn more from them) will only increase.

For instance, an international team of astronomers recently detected a series of low-frequency gravitational waves using the International Pulsar Timing Array (IPTA). These waves, they determined, could be the early signs of a background gravitational wave signal (BGWS) caused by pairs of supermassive black holes. The existence of this background is something that astrophysicists have theorized since GWs were first detected, making this a potentially ground-breaking discovery!

February 5, 2021February 5, 2021 by Andy Tomaswick

A New Radar Instrument Will Try To Fill the Void Left By Arecibo

Observational astronomy is dependent on its data, and therefore also dependent on the instruments that collect that data. So when one of those instruments fails it is a blow to the profession as a whole. The collapse of the Arecibo Telescope last year after it was damaged by Hurricane Maria in 2017 permanently deprived the radio astronomy world of one of its primary observational tools. Now a team at the National Radio Astronomy Observatory (NRAO) hopes to upgrade an existing telescope at the Green Bank Observatory in West Virginia to replace the failed Puerto Rican one and provide even more precise images of near Earth objects in the radio spectrum.