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This is the Daily Space for today, Tuesday, November 10, 2020. I am your host, Dr. Pamela Gay.
I am your host, Beth Johnson.
And we are here to put science in your brain.
Today’s science is largely radioed in from observatories around the world and starts with what appears to be the first identification of an object emitting a fast radio burst (FRB).
First discovered in 2006, these fraction-of-a-second events bundle together the energy of three days’ worth of sunlight. They come in various styles, ranging from the random, single detection to recurring systems that exhibit periods of bursts and periods of quiet. It has been speculated that some kind of a compact object – a neutron star or black hole – could be the source of the bursts, but because they had always been detected in distant galaxies, these theories hadn’t been grounded in a lot of observations.
At least not until now.
On April 27, the Neil Gehrels Swift Observatory detected a storm of X-ray bursts associated with the SGR 1935+2154. This spinning neutron star is known to have a powerful magnetic field that releases X-ray and gamma-ray light in association with changes in its structure. Starquakes and other events that occur as this young neutron star settles into equilibrium can create storms that last for hours and even days.
The April 27 storm lasted for hours, with X-ray bursts that lasted less than a second being detected by Swift, Fermi, and NICER, but thirteen hours after it quieted, and while all these orbiting observatories were on the wrong side of the planet, SGR 1935+2154 let off a half-second long burst of incredible brightness that was caught by ESA’s INTEGRAL, Russia’s Konus, and China’s Huiyan missions. As the spacecraft detected this final massive X-ray burst, ground-based radio systems CHIME and STARE2 caught a single radio burst that, like an FRB, lasted just a thousandth of a second.
These results appear in a pair of papers in the journal Nature, and co-author Paul Scholz explains: The radio burst was far brighter than anything we had seen before, so we immediately knew it was an exciting event. We’ve studied magnetars in our galaxy for decades, while FRBs are an extragalactic phenomenon whose origins have been a mystery. This event shows that the two phenomena are likely connected.
The energy of SGR 1935+2154 is consistent with how weaker FRBs in other galaxies appear, and it is only because it is located not too far away in our galaxy that we were able to see so many details of its activity. If this was a local FRB, then we can expect that other FRBs also have associated X-ray activity that is simply waiting to be discovered. We now just need more magnetars in our galaxy and nearby galaxies to do their thing, and let us catch all their flickering and flaring across the electromagnetic spectrum.
Not everything this week is brought to you courtesy of radio telescopes. Space science can involve fieldwork, too.
High in the Atacama Desert in Chile, scientists continue to study the extremely arid region as an analog of Mars. And last week, researchers at Cornell and Spain’s Centro de Astrobiología published a paper in Nature Scientific Reports where they have given us a potential primer in how to look for microbial markers in the soil of Mars.
The soils in the Atacama are clay-rich, and at shallow depths, they contain a diverse population of microbes. It involves a layer of wet clay about a foot down from the surface. As corresponding author Alberto G. Fairén explains: The clays are inhabited by microorganisms. Our discovery suggests that something similar may have occurred billions of years ago – or it still may be occurring – on Mars.
If there were microbes on Mars in the past, there should still be evidence, or markers, of those microbes in the soil. Several rover missions are scheduled to land in the coming years, including NASA’s Perseverance, which is specifically designed to look for those markers. This research gives those rover teams a guide for where to search and what to look for in the Martian clays.
Per the press release: The researchers’ Atacama discovery reinforces the notion that early Mars may have had a similar subsurface with protected habitable niches, particularly during the first billion years of its history.
Life really does find a way, y’all. Here’s hoping we find evidence of it on the red planet.
While not all today’s news comes to you from radio telescopes, most of it comes from radio telescopes. These giant dishes can conveniently work day or night, and thanks to our ability to easily combine multiple telescopes of data into a sprawling virtual telescope, they allow the highest resolution images of our universe.
We take advantage of radio dishes to do everything from imaging distance supermassive black holes to watching aurorae flicker in the atmosphere of Jupiter. While we’ve known for some time that giant planets and small stars can warmly emit radio waves, discovering these kinds of objects has generally be left to the infrared observatories, with radio telescopes stepping in to do the followup work.
As you may have noticed, we’re currently short on infrared observatories, with Spitzer retired and JWST not yet launched. And while infrared and even optical telescopes can spot warm brown dwarfs and planets, cold ones will generally be too faint to be seen – and cold lone objects might be some of the more interesting objects out there.
In a new radio survey, the LOFAR radio array was used to search for objects too cold and faint to be found in existing infrared surveys. Objects found in this survey could then be observed with large scopes like Gemini or IRTF and identified.
One such pinprick of radio light came from an object designated BDR J1750+3809 but dubbed Elegast by the LOFAR team. This is the first non-extragalactic object to be discovered in the radio, and it was determined to be a brown dwarf star. The way they did this is actually kind of cool.
Light from an individual star or planet will have a specific polarization – this is a fancy way of saying the light waves are oriented in a measurable way. Galaxies, which are made of many different objects with light oriented in many different ways, don’t have the same kind of polarization. To separate the distant galaxies radio scopes are so good at detecting from nearby tiny objects they aren’t generally used to detect, the research team looked for objects with polarized light.
According to team member Joe Callingham: With LOFAR, we want to go down the mass-ladder all the way to Jupiter-like planets that are too faint to have been found in existing infrared surveys, so we decided to search for these objects directly in our radio images.
This work appears in the Astrophysical Journal. In looking at the object with multiple scopes, they determined it is consistent in makeup with our system’s gas giant, Jupiter. According to co-author Harish Vedantham: The Gemini observations told us that the object was cold enough for methane to form in its atmosphere — showing us that the object is a close cousin of Solar System planets like Jupiter.
This is a new technique being used to do new and awesome things, and I, for one, look forward to seeing what can be discovered in this long wavelength of light.
Oh, hey look! A Bennu story. Unless you have been living under a rock – and frankly the way this year has gone, who could blame you? – you know that OSIRIS-REx snagged a sample of Bennu’s surface last month. Well, that sample is not the only work being done in regards to Bennu and its history.
Using all of those images and the resulting rock maps you helped with, scientists at Southwest Research Institute have taken detailed measurements of centimeter- to meter-sized craters in some of those bigger boulders we saw. The goal was to understand more about the age of Bennu.
A reminder for those new to our show: Bennu is a rubble pile asteroid. It’s held together by gravity (barely) and could be the remnant of a larger asteroid that was hit by a bigger object. It actually has a lot of impact craters, albeit smallish ones, scattered across the surface, and these are most easily seen in those boulders I mentioned earlier. They are not easy to see, however, as our citizen scientists found out the hard way.
So the team at the University of Arizona developed a mathematical method to calculate how much of an impact a boulder of a given size and strength could handle without being broken apart. The result? The teams “brought together an understanding of the number of craters, the strength of the materials impacted, and the numbers of impactors to help constrain the chronology of Bennu’s existence in the inner Solar System at 1.75 million years.”
Bennu hasn’t been in the inner solar system long at all. Of course, we’ll have to wait for that sample return to arrive in 2023 to gain any further understanding of Bennu’s age and composition. I suspect we’ll keep hearing about our favorite asteroid to hate as institutes attempt to keep the OSIRIS-REx mission in the public eye now that the sampling portion of the mission is done.
Sometimes science gives, and sometimes reality takes.
In our next story, once again radio-related, we have bad news from Arecibo National Observatory. This massive dish, built in Puerto Rico, had another support cable fail.
As we reported in an earlier episode on August 13, an auxiliary cable failed, and in the process damaged an instrument and several panels in the dish. While the damage was minimal, repairs have been slowed by COVID and other issues such as hurricane season. Since those repairs remain incomplete, the other cables in the system have carried a larger load than normal, and one of the main cables simply failed on Friday. Ironically, repairs on this initial damage were scheduled to start this week.
According to observatory director Francisco Cordova: We have been thoughtful in our evaluation and prioritized safety in planning for repairs that were supposed to begin Tuesday. Now this. There is much uncertainty until we can stabilize the structure. It has our full attention. We are evaluating the situation with our experts and hope to have more to share soon.
Arecibo is managed by the University of Central Florida (UCF), who said in a released statement that: The team hopes to be able to reduce the tension in the existing cables at the tower and install steel reinforcements to temporarily alleviate some of the additional load that is being distributed among the remaining cables. Experts are being mobilized to do the work as quickly as possible. The team will attempt to expedite the arrival of two new cables that were already on order.
Repairs aren’t cheap, and their current funding doesn’t cover these needs. UCF has already requested funding from the National Science Foundation (NSF) for their initial repairs, and I anticipate that request being increased to deal with this new reality. After watching this facility face numerous cuts across the decades, and hearing NSF threaten to cut its funding more than once, I truly hope these accidents aren’t a death knell for this historic and still powerful facility that can both do radar imaging of asteroids and detect faint radio signals from objects near and far.
Well, that sucked. Everyone take a deep breath and look at the beauty of Europa. It glows. No, literally, it glows. You see, Jupiter is constantly zapping Europa’s surface night and day with high-energy radiation such as electrons and other particles. And those high-energy particles are making the surface of Europa glow in the dark.
This new research from NASA’s Jet Propulsion Laboratory details what this glow would look like. Per the press release: It could reveal…the composition of ice on Europa’s surface. Different salty compounds react differently to the radiation and emit their own unique glimmer. To the naked eye, this glow would look sometimes slightly green, sometimes slightly blue or white and with varying degrees of brightness, depending on what material it is.
Usually, scientists take spectra of an object to determine its composition. Of course, you need sunlight to use a spectrometer, which means taking the measurements on Europa’s dayside if we want to know what the ice is made of. Now we can talk about how Europa looks in the dark.
JPL’s Murthy Gudipati, lead author of the new paper published just yesterday in Nature Astronomy, explains: We were able to predict that this nightside ice glow could provide additional information on Europa’s surface composition. How that composition varies could give us clues about whether Europa harbors conditions suitable for life.
In case you weren’t aware, Europa is a strong candidate for finding life elsewhere in our solar system because it has a massive interior ocean of liquid water. And scientists are primed to understand that subsurface ocean as much as possible.
Per the press release: Scientists have inferred from prior observations that Europa’s surface could be made of a mix of ice and commonly known salts on Earth, such as magnesium sulfate (Epsom salt) and sodium chloride (table salt). The new research shows that incorporating those salts into water ice under Europa-like conditions and blasting it with radiation produces a glow.
To be honest, that part of the story isn’t a surprise. Where this research broke a little new ground is best explained by co-author Bryana Henderson: When we tried new ice compositions, the glow looked different. And we all just stared at it for a while and then said, ‘This is new, right? This is definitely a different glow?’ So we pointed a spectrometer at it, and each type of ice had a different spectrum.
And here is where a fantastic NASA acronym comes in. The team used a new instrument called Ice Chamber for Europa’s High-Energy Electron and Radiation Environment Testing (ICE-HEART) and did experiments with high-energy electron beams. As co-author Fred Bateman pointed out: Seeing the sodium chloride brine with a significantly lower level of glow was the ‘aha’ moment that changed the course of the research.
So while our Moon glows from sunlight, Europa glows from sunlight AND the radiation of Jupiter. It’s possible that the upcoming Europa Clipper mission could detect this glow, and the instrument team is determining that possibility. If that’s the case, the spacecraft could match its data with the measurements in this research to identify salty components on the moon’s surface and narrow down what they might be.
It will be a bit of a wait, but I think it will be worth it.
And to give you one final bit of cheer, we are pleased to share that iconic Parkes Observatory in Australia has gone on a telescope naming spree. Working in collaboration with the aboriginal peoples of the local area, the Wiradjuri people, they have chosen traditional names for the scopes that allow them to connect the historic instruments with cultures of one of the oldest societies in the world. This was done as part of Australia’s Reconciliation Action Plans, which looks to recognize the knowledge and traditions of the Aboriginal and Torres Strait Islander people.
The new names for the scopes are as follows: The 64-meter Parkes radio telescope has been named Murriyang. In the Wiradjuri Dreaming, Biyaami (Baiame) is a prominent creator spirit and is represented in the sky by the stars which also portray the Orion constellation. Murriyang represents the ‘Skyworld’ where Biyaami lives.
Giyalung Miil is the new name for the 12-meter Australian Square Kilometre Array Pathfinder (ASKAP) testing antenna. Meaning ‘Smart Eye’, this telescope was commissioned in 2008 as a testbed for a special new type of receiver technology.
In addition, the 18-meter decommissioned antenna has been named Giyalung Guluman. This means ‘Smart Dish’. This antenna had the ability to move along a railway track while observing, and when linked to the main 64-meter antenna became pivotal in early work that determined the size and brightness of radio sources in the sky.
These names are amazing, and today you are going to probably hear a myriad of different pronunciations. I would like to make a request on behalf of journalists everywhere: please include recordings of native speakers of these different languages saying the names of these scopes and other objects when you give them indigenous names. We are so pleased to see these names bestowed, and we just want to honor them the way they deserve.
Isn’t it nice to end a show this year with some heartwarming news? This has been the Daily Space.
Learn More
NASA Missions Help Pinpoint the Source of a Unique X-Ray, Radio Burst
- NASA press release
- “A Bright Millisecond-Duration Radio Burst from a Galactic Magnetar,” CHIME/FRB Collaboration, 2020 Nov. 4, Nature
- “A Fast Radio Burst Associated with a Galactic Magnetar,” C. D. Bochenek et al., 2020 Nov. 4, Nature
Clay Subsoil at Earth’s Driest Place May Signal Life on Mars
- Cornell University press release
- “Inhabited Subsurface Wet Smectites in the Hyperarid Core of the Atacama Desert as an Analog for the Search for Life on Mars,” Armando Azua-Bustos, 2020 Nov. 5, Nature Scientific Reports
Maunakea Telescopes Confirm Radio Discovery of Brown Dwarf
- NOIRLab press release
- ASTRON press release
- The University of Hawaii at Manoa press release
- “Direct Radio Discovery of a Cold Brown Dwarf,” H. K. Vedantham et al., 2020 Nov. 9, Astrophysical Journal Letters (preprint on arxiv.org)
Craters on Bennu’s Boulders Indicate Asteroid’s Age
- Southwest Research Institute press release
- “Bennu’s Near-Earth Lifetime of 1.75 Million Years Inferred from Craters on Its Boulders,” R.-L. Ballouz et al., 2020 Oct. 26, Nature
Second Cable Fails at NSF’s Arecibo Observatory in Puerto Rico
Radiation Does a Bright Number on Jupiter’s Moon Europa
- NASA JPL press release
- “Laboratory Predictions for the Night-Side Surface Ice Glow of Europa,” Murthy S. Gudipati, Bryana L. Henderson & Fred B. Bateman, 2020 Nov. 9, Nature Astronomy
Iconic Parkes Radio Telescope Given Indigenous Name
Credits
Written by Pamela Gay and Beth Johnson
Hosted by Pamela Gay and Beth Johnson
Audio and Video Editing by Ally Pelphrey
Content Editing by Beth Johnson
Intro and Outro music by Kevin MacLeod, https://incompetech.com/music/
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