Tag Archives: Radio Astronomy

Hurricane Damages Arecibo Radio Telescope

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.

Five reasons why FRBs aren’t being broadcast by ET

Many thanks to SWLing Post contributor, Ed, who shares an update to his previous post regarding Fast Radio Bursts. Ed writes:

Here’s a followup article explaining, “Five Reasons Why The Signals From Stephen Hawking’s Breakthrough Initiative Aren’t Aliens”.

It compares the power of these Fast Radio Bursts (FRB’s) with that of the mediumwave array in Roumoules, France (the most powerful radio broadcast facility in the world) which is reportedly nineteen orders of magnitude *weaker* than these FRB signals. Wow!

https://www.forbes.com/sites/startswithabang/2017/09/04/five-reasons-why-the-signals-from-stephen-hawkings-breakthrough-initiative-arent-aliens/#7544e2c017a7

It also mentions the novel Canadian CHIME radio telescope under construction [above], which will have the most gain of any in the world.

http://chime.phas.ubc.ca/

Thanks, Ed! Yeah, while I would certainly love to hear that the SETI program has identified broadcasts from other intelligent beings, the likelihood is that any candidate signal(s) are explainable in many other ways. Still, what’s so great about the SETI program is they doggedly pursue the search, pour over the data, scrutinize the results, draw conclusions then continue the search.

SDRs processing Fast Radio Bursts from distant universe

The Green Bank Telescope (Source: NRAO)

Many thanks to SWLing Post contributor, Ed, who shares a link to the following article at Breakthrough Initiatives:

Green Bank Telescope observations of a dwarf galaxy three billion light years away reveal 15 bursts of radio emission. This is the first time bursts from this source have been seen at these frequencies.

San Francisco – August 29, 2017 – Breakthrough Listen – the initiative to find signs of intelligent life in the universe – has detected 15 fast radio bursts emanating from the mysterious “repeater” FRB 121102. Fast radio bursts, or FRBs, are brief, bright pulses of radio emission from distant galaxies. First detected with the Parkes Telescope in Australia, FRBs have now been seen by several radio telescopes around the world. FRB 121102 was discovered in 2012, on November 2nd (hence its name). In 2015, it was the first FRB seen to repeat, ruling out theories of the bursts’ origins that involved the catastrophic destruction of the progenitor (at least in this particular instance). And in 2016, the repeater was the first FRB to have its location pinpointed with sufficient precision to allow its host galaxy to be identified. It resides in a dwarf galaxy about 3 billion light years away from Earth.

Attempts to understand the mechanism that generates FRBs have made this galaxy a target of ongoing monitoring campaigns by instruments across the globe. Possible explanations for FRBs range from outbursts from rotating neutron stars with extremely strong magnetic fields, to more speculative ideas that they are directed energy sources used by extraterrestrial civilizations to power spacecraft.

Breakthrough Listen is a global astronomical initiative launched in 2015 by Internet investor and philanthropist Yuri Milner and cosmologist Stephen Hawking. As part of their program to observe nearby stars and galaxies for signatures of extraterrestrial technology, the Listen science team at UC Berkeley added FRB 121102 to their list of targets. In the early hours of Saturday, August 26, UC Berkeley Postdoctoral Researcher Dr. Vishal Gajjar observed the location of FRB 121102 using the Breakthrough Listen backend instrument at the Green Bank Telescope in West Virginia. The instrument accumulated 400 TB of data on the object over a five hour observation, observing the entire 4 to 8 GHz frequency band.[…]

Analysis by Dr. Gajjar and the Listen team revealed 15 new pulses from FRB 121102. As well as confirming that the source is in a newly active state, the high resolution of the data obtained by the Listen instrument will allow measurement of the properties of these mysterious bursts at a higher precision than ever possible before.

The observations also show for the first time that FRBs emit at higher frequencies (with the brightest emission occurring at around 7 GHz) than previously observed. The extraordinary capabilities of the Listen backend, which is able to record several gigahertz of bandwidth at a time, split into billions of individual channels, enable a new view of the frequency spectrum of FRBs, and should shed additional light on the processes giving rise to FRB emission.
When the recently-detected pulses left their host galaxy our entire Solar System was just 2 billion years old. […]

The new results are reported as an Astronomer’s Telegram at www.astronomerstelegram.org/?read=10675 and will be described in further detail in an upcoming scientific journal article.

Breakthrough Listen is a scientific program in search for evidence of technological life in the Universe. It aims to survey one million nearby stars, the entire galactic plane and 100 nearby galaxies at a wide range of radio and optical bands.[…]

The linked animation shows 14 of the 15 detected bursts in succession, illustrating their dispersed spectrum and extreme variability. Capturing this diverse set of bursts was made possible by the broad bandwidth that can be processed by the Breakthrough Listen backend at the Green Bank Telescope:

https://storage.googleapis.com/frb121102/FRB121102_Cband_GB.gif

Click here to read the full article at Breakthrough Initiatives.

Image shows the extent of human radio broadcasts

Click to enlarge (Image credit: Adam Grossman of The Dark Sky Company)

(Source: Popular Mechanics)

Carl Sagan’s famous line from his 1990 speech about the Pale Blue Dot image—”Our planet is a lonely speck in the great enveloping cosmic dark”—is an understatement. We might consider our Milky Way, with its estimated 100 to 400 billion stars, a significant fixture in the cosmos. But there are some 100 billion galaxies just like it in the observable universe. It’s a daunting reality to consider when we’re thinking about the possibility of making contact with any intelligence that might be out there.

This map designed by Adam Grossman of The Dark Sky Company puts into perspective the enormity of these scales. The Milky Way stretches between 100,000 and 180,000 light-years across, depending on where you measure, which means a signal broadcast from one side of the galaxy would take 100,000 years or more to reach the other side. Now consider that our species started broadcasting radio signals into space only about a century ago. That’s represented by a small blue bubble measuring 200 light-years in diameter surrounding the position of the Earth. For any alien civilizations to have heard us, they must be within the bubble.[…]

Continue reading at Popular Mechanics online…

Solar Eclipse 2017: In the path of totality

A portion of the PARI campus

Tomorrow, we will be experiencing a total solar eclipse here in the mountains of western North Carolina.

Instead of enjoying the eclipse at home, I will be volunteering as a docent at the Pisgah Astronomical Research Institute in Rosman, North Carolina. Post readers might recall PARI as it was the location of our 2015 PARI DXpedition.

One of PARI’s 26 meter radio telescopes.

PARI is expecting at least 1,000 visitors tomorrow, from a number of countries. Many are scientists, astronomers, and guests who want to be in the path of totality.

On the PARI campus, we will be in totality for about 1 minutes, 47 seconds.

What makes the event truly special for PARI is that this is the first time in history a world-class radio astronomy observatory has been in the path of totality. To say the PARI astronomers are excited is simply an understatement. All four of PARI’s telescopes will be trained on our local star and gathering copious amounts of data.

If you don’t live in the path of the Eclipse, I invite you to check out PARI’s YouTube channel where they will host a live stream:

Click here to watch on YouTube.

Gathering spectrum

I will also be gathering data of my own during the event.

I will remotely record the entire mediumwave (AM broadcast) band several hours before, during and after the eclipse. I will also set up a separate SDR to record either the 31/30 meter bands and my buddy, Vlado (N3CZ) is kindly using his SDRplay RSP1 to record from 6 MHz – 8 MHz.

What do I expect to see/hear in the spectrum recordings? Certainly a drop in noise. If I’m lucky, I also hope to hear some DX anomalies–hopefully a signal or two that I wouldn’t normally here in the middle of a summer day.

I don’t expect any dramatic results (though I would love to be proven otherwise!) since the ionosphere takes time to change states. My buddy Mike (K8RAT) likens it to an oven: it takes time for it to heat up to the desired temperature, and it takes time for it to cool down as well. I’m not so sure the shadow of the moon, which moves at a good clip, will be persistent enough to change the state of the ionosphere in any meaningful way.

If it does, I’ll be there to record it!

There are many other radio related experiments happening during the solar eclipse. A notable one that you can even help with is the 2017 Ham Radio Eclipse Experiment.

SWLing Post contributor, Dan Srebnick also suggests a few stations you might try catching on the AM broadcast band. Dan notes:

Something to do during the solar eclipse on Monday. There are 13 clear channel AM stations along the path of totality. Give a listen for them:
[LIST OF AM CLEAR CHANNEL STATIONS]
kHz CALL Location Eclipse UTC
—— ——- —————- ————–
650 WSM Nashville, TN 18:28
670 KBOI Boise, ID 17:27
750 WSB Atlanta, GA 18:36
840 WHAS Louisville, KY 18:27
880 KRVN Lexington, NE 17:57
1030 KTWO Casper, WY 17:43
1040 WHO DesMoines, IA 18:08
1110 KFAB Omaha, NE 18:04
1110 WBT Charlotte, NC 18:41
1120 KPNW Eugene, OR 17:17
1120 KMOX St. Louis, MO 18:18
1190 KEX Portland, OR 17:19
1510 WLAC Nashville, TN 18:28

Kudos to Bob WB4APR (of APRS fame) for producing this list.

Post readers: Will you be in the path of totality or do you plan to enjoy a partial eclipse? Have you ever experienced a total solar eclipse?  What are your plans if any? Please comment!