Radio Astronomy Archives

July 19, 2023July 19, 2023 by Matt Williams

Star Birth and Death Seen Near the Beginning of Time

An artist's illustration of the Universe's first stars, called Population 3 stars. Pop 3 stars would have been much more massive than most stars today, and would have burned hot and blue. Their lifetimes would've been much shorter than stars like our Sun. Credit: Wikimedia Commons

Until recently, astronomers could not observe the first stars and galaxies that formed in the Universe. This occurred during what is known as the “Cosmic Dark Ages,” a period that took place between 380,000 and 1 billion years after the Big Bang. Thanks to next-generation instruments like the James Webb Space Telescope (JWST), improved methods and software, and updates to existing observatories, astronomers are finally piercing the veil of this era and getting a look at how the Universe as we know it began.

This includes new observations from the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, which obtained images of a stellar nursery inside a galaxy roughly 13.2 billion light-years away in the constellation Eridanus. This galaxy has a redshift value of more than 8.3, corresponding to when the Universe was less than 1 billion years old. The images discerned the sites of star formation and possible star death inside a nebula (MACS0416_Y1) located within this galaxy. This represents a major milestone for astronomy as this is the farthest distance such structures have been observed in our Universe.

May 19, 2023May 21, 2023 by Matt Williams

An Astronomical First! A Radiation Belt Seen Outside the Solar System

Artist’s impression of an aurora and the surrounding radiation belt of the ultracool dwarf LSR J1835+3259. Credit: Chuck Carter/Melodie Kao/Heising-Simons Foundation)

In 1958, the first satellites launched by the United States (Explorer 1 and 3) detected a massive radiation belt around planet Earth. This confirmed something that many scientists suspected before the Space Age began: that energetic particles emanating from the Sun (solar wind) were captured and held around the planet by Earth’s magnetosphere. This region was named the Van Allen Belt in honor of University of Iowa professor James Van Allen who led the research effort. As robotic missions explored more of the Solar System, scientists discovered similar radiation belts around Jupiter, Saturn, Uranus, and Neptune.

Given the boom in extrasolar planet research, scientists have eagerly awaited the day when a Van Allen Belt would be discovered around an exoplanet. Thanks to a team of astronomers led by the University of California, Santa Cruz (UCSC) and the National Radio Astronomy Observatory (NRAO), that day may have arrived! Using the global High Sensitivity Array (HSA), the team obtained images of persistent, intense radio emissions from an ultracool dwarf star. These revealed the presence of a cloud of high-energy particles forming a massive radiation belt similar to what scientists have observed around Jupiter.

May 19, 2023May 19, 2023 by Brian Koberlein

Astronomers Want to Build the Next Generation Arecibo Telescope

The Arecibo Radio Telescope. Though it's decommissioned now, Arecibo Data may explain 1977's mysterious Wow! Signal. Image Credit: UCF

The Arecibo Telescope was an amazing tool for astronomers. Built in the early 1960s, it had a 1,000-foot-wide dish and was capable of both receiving and transmitting radio signals. It did radar mapping of near-Earth asteroids, Venus, and the Moon, discovered water at the polar regions of Mercury, searched for alien civilizations, and even send a radio message from Earth to a globular cluster 25,000 light years away. So when it collapsed in 2020, many astronomers wondered if it could be rebuilt.

May 9, 2023May 9, 2023 by Laurence Tognetti

NASA Uses Powerful Transmitters to Talk to Deep Space Spacecraft. Will Other Civilizations Receive Those Signals?

Artist rendition of Voyager 1 entering interstellar space. (Credit: NASA/JPL-Caltech)

In a recent study submitted to the Publications of the Astronomical Society of the Pacific, a pair of researchers from the University of California, Los Angeles (UCLA) and the University of California, Berkeley (UC Berkeley) examine the likelihood of extraterrestrial intelligent civilizations intercepting outward transmissions from NASA’s Deep Space Network (DSN) that are aimed at five deep space spacecraft: Voyager 1, Voyager 2, Pioneer 10, Pioneer 11, and New Horizons. Members of the public are free to track such transmissions at DSN Now, which displays real-time data of outgoing and incoming transmissions to all spacecraft at various times.

May 1, 2023May 1, 2023 by Brian Koberlein

Aliens Could Map Earth From its Mobile Phone Towers

A mobile cell tower on a clear day. Credit: Ervins Strauhmanis, via Flickr

Mobile phones are so ubiquitous that we typically don’t think about how they work. They just do, much to our benefit, and sometimes annoyance. But the key to their function is a vast array of radio transmission towers. These cell towers span a large percentage of Earth’s land surface, particularly in heavily populated areas, and they transmit microwave signals all the time. With all those cell towers emitting all those radio signals, a fun question to ask is whether those signals could be detected by an alien civilization.

April 18, 2023April 18, 2023 by Nancy Atkinson

Three Fast Radio Bursts Punched Right Through a Nearby Galaxy

Three new Fast Radio Bursts discovered by the Westerbork telescope were shown to have pierced the halo of our neighbouring Triangulum Galaxy. Invisible electrons in that galaxy deform the FRBs. From sharp, new, live images, astronomers could estimate the maximum number of invisible atoms in the Triangulum Galaxy for the first time. (Credit: ASTRON/Futselaar/van Leeuwen)

Fast Radio Bursts (FRBs) are cosmic mysteries that are slowly but surely revealing their secrets. These bright flashes of light are visible in the radio wave part of the spectrum and usually last only a few milliseconds before fading away forever. They come from random locations across the Universe and are so powerful that we can see them emanating from billions of light-years away.

Astronomers have used a newly upgraded radio telescope array to find five new FRBs and discovered that multiple bursts pierced right through the Triangulum Galaxy (M33). These brief flashes lit up the gas inside M33, allowing astronomers to calculate the maximum number of otherwise invisible atoms.

March 21, 2023March 21, 2023 by Andy Tomaswick

Machine Learning Finds 140,000 Future Star Forming Regions in the Milky Way

Our galaxy is still actively making stars. We’ve known that for a while, but sometimes it’s hard to understand the true scale in astronomical terms. A team from Japan is trying to help with that by using a novel machine-learning technique to identify soon-to-be star-forming regions spread throughout the Milky Way. They found 140,000 of them.

February 28, 2023February 28, 2023 by Andy Tomaswick

Humanity has Never Seen the sky in the Longest Wavelengths. That Could Change With a new Space Telescope

Technological revolutions can bring about dramatic changes in various fields, some of which are only tangentially related to the field being disrupted. Occasionally, a few technological revolutions happen simultaneously, enabling concepts that would have been impossible without any of them. Such revolutions are currently happening in the space industry. With rockets more massive than ever coming online, and mega-constellations of satellites roaming our skies, there is plenty of disruption going on. Now a team from MIT hopes to use those technologies to look at an area of astronomy that has never been seen before – low-frequency radio astronomy.

February 21, 2023February 21, 2023 by Nancy Atkinson

A 500-Meter-Long Asteroid Flew Past Earth, and Astronomers Were Watching

This collage shows six planetary radar observations of 2011 AG5 a day after the asteroid made its close approach to Earth on Feb. 3. With dimensions comparable to the Empire State Building, 2011 AG5 is one of the most elongated asteroids to be observed by planetary radar to date. Credit: NASA/JPL-Caltech

An asteroid the size of the Empire State Building flew past Earth in early February, coming within 1.8 million km (1.1 million miles) of our planet. Not only is it approximately the same size as the building, but astronomers found the asteroid – named 2011 AG5 — has an unusual shape, with about the same dimensions as the famous landmark in New York City.

“Of the 1,040 near-Earth objects observed by planetary radar to date, this is one of the most elongated we’ve seen,” said Lance Benner, principal scientist at JPL who helped lead the observations, in a JPL press release.

This extremely elongated asteroid has a length-to-width ratio of 10:3.

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.