Breakthrough Listen will monitor the 1 million closest stars to Earth over a ten year period. Credit: Breakthrough Initiatives
In July of 2015, Breakthrough Initiatives – a non-profit dedicated to the search for extra-terrestrial intelligence, founded by Yuri Milner – announced the creation of Breakthrough Listen. A ten-year initiative costing $100 million, this program was aimed at using the latest in instrumentation and software to conduct the largest survey to date for extraterrestrial communications, encompassing the 1,000,000 closest stars and 100 closest galaxies.
On Thursday, April. 20th, at the Breakthrough Discuss conference, the organization shared their analysis of the first year of Listen data. Gathered by the Green Bank Radio Telescope, this data included an analysis of 692 stars, as well as 11 events that have been ranked for having the highest significance. The results have been published on the project’s website, and will soon be published in the Astrophysical Journal.
The Green Bank Telescope (GBT), a radio telescope located at the Green Bank Observatory in West Virginia. Credit: greenbankobservatory.org
While the results were not exactly definitive, this is just the first step in a program that will span a decade. As Dr. Andrew Siemion, the Director of the BSRC, explained in a BI press release:
“With the submission of this paper, the first scientific results from Breakthrough Listen are now available for the world to review. Although the search has not yet detected a convincing signal from extraterrestrial intelligence, these are early days. The work that has been completed so far provides a launch pad for deeper and more comprehensive analysis to come.”
The Green Bank Telescope searched for these signals using its “L-band” receiver, which gathers data in frequencies ranging from 1.1 to 1.9 GHz. At these frequencies, artificial signals can be distinguished from natural sources, which includes pulsars, quasars, radio galaxies and even the Cosmic Microwave Background (CMB). Within these parameters, the BSRC team examined 692 stars from its primary target list.
For each star, they conducting three five-minutes observation periods, while also conducting five-minute observations on a set of secondary targets. Combined with a Doppler drift search – a perceived difference in frequency caused by the motion of the source or receiver (i.e. the star and/or Earth) – the Listen science team identified channels where radio emission were seen for each target (aka. “hits”).
The Parkes radio telescope, one of the telescopes comprising CSIRO’s Australia Telescope National Facility. Credit: CSIRO/David McClenaghan
This led to a combined 400 hours and 8 petabytes worth of observational data. All together, the team found millions of hits from the sample data as a whole, and eleven events that rose above the threshold for significance. These events (which are listed here) took place around eleven distant stars and ranged from to 25.4 to 3376.9 SNR (Signal-to-Noise Ratio).
However, the vast majority of the overall hits were determined to be the result of radio frequency interference from local sources. What’s more, further analysis of the 11 events indicated that it was unlikely that any of the signals were artificial in nature. While these stars all exhibited their own unique radio “fingerprints”, this is not necessarily an indication that they are being broadcast by intelligent species.
But of course, finding localized and unusual radio signals is an excellent way to select targets for follow-up examination. And if there is evidence to be found out there of intelligent species using radio signals to communicate, Breakthrough Listen is likely to be the one that finds them. Of all the SETI programs mounted to date, Listen is by far the most sophisticated.
Not only do its radio surveys cover 10 times more sky than previous programs, but its instruments are 50 times more sensitive than telescopes that are currently engaged in the search for extra-terrestrial life. They also cover 5 times more of the radio spectrum, and at speeds that are 100 times as fast. Between now and when it concludes in the coming decade, the BSRC team plans to release updated Listen data once every six months.
Aerial view of the Automated Planet Finder at the Lick Observatory. Credit: Lick Observatory/Laurie Hatch
In the meantime, they are actively engaging with signal processing and machine learning experts to develop more sophisticated algorithms to analyze the data they collect. And while they continue to listen for extra-solar sources of life, Breakthrough Starshot continues to develop the first concept for a laser-driven lightsail, which they hope will make the first interstellar voyage in the coming years.
And of course, we here in the Solar System are looking forward to missions in the coming decade that will search for life right here, in our own backyard. These include missions to Europa, Enceladus, Titan, and other “ocean worlds” where life is believed to exist in some exotic form!
Breakthrough Listen‘s data analysis can be found here. Director Andrew Siemion also took to Facebook Live on Thursday, April 20th, to presents the results of Listen’s first year of study.And be sure to check out this video that marked the launch of Breakthrough Initiatives:
Artist's concept of Cassini diving between Saturn and its innermost ring. Credit: NASA/JPL-Caltech
One down, twenty-one to go! The Cassini spacecraft survived the first dive through the narrow gap between Saturn and its rings, and is now back communicating with Earth.
“No spacecraft has ever been this close to Saturn before. We could only rely on predictions, based on our experience with Saturn’s other rings, of what we thought this gap between the rings and Saturn would be like,” said Cassini Project Manager Earl Maize of NASA’s Jet Propulsion Laboratory in Pasadena, California. “I am delighted to report that Cassini shot through the gap just as we planned and has come out the other side in excellent shape.”
It was a long day for Cassini scientists and engineers at the Jet Propulsion Laboratory while the spacecraft was out of contact for 20 hours during this first dive, signaling the beginning of the end for the mission.
Cassini, running out of fuel, is heading toward its ultimate death by crashing into Saturn on September 15, 2017. But during the next few months, Cassini will make twenty-one more passes through the gap, and in doing so, further our understanding of how giant planets, and planetary systems everywhere, form and evolve.
A raw image of Saturn’s polar vortex, taken on April 26, 2017 by the Cassini spacecraft during the first close pass between Saturn and its rings. Credit: NASA/JPL-Caltech.
Project Scientist Linda Spilker said Cassini will be able to make close up measurements of Saturn and its rings to finally help us understand the mass and internal structure of Saturn. And the images should be absolutely stunning.
Contact was lost as the ring-plane crossing started at 2 a.m. PDT (5 a.m. EDT) on April 26. NASA’s Deep Space Network Goldstone Complex in California’s Mojave Desert acquired Cassini’s signal at 11:56 p.m. PDT on April 26, 2017 (2:56 a.m. EDT on April 27) and data began flowing at 12:01 a.m. PDT (3:01 a.m. EDT) on April 27.
Cassini was programmed to collect science data while close to the planet. As a protective measure, the spacecraft used its large, dish-shaped high-gain antenna (13 feet or 4 meters across) as a deflector shield, orienting it in the direction of oncoming ring particles. This orientation put the spacecraft out of contact with Earth.
“In the grandest tradition of exploration, NASA’s Cassini spacecraft has once again blazed a trail, showing us new wonders and demonstrating where our curiosity can take us if we dare,” said Jim Green, director of the Planetary Science Division at NASA Headquarters.
We did it! Cassini is in contact with Earth and sending back data after a successful dive through the gap between Saturn and its rings. pic.twitter.com/cej1yO7T6a
The gap between the rings and the top of Saturn’s atmosphere is about 1,500 miles (2,000 kilometers) wide, and Cassini came within about 1,000 miles (1,600 kilometers) of Saturn’s cloud tops.
The best models for the region suggested that if there were ring particles in the area where Cassini crossed the ring plane, they would be tiny, on the scale of smoke particles. However, the spacecraft was traveling at speeds of about 77,000 mph (124,000 kph) relative to the planet, so small particles hitting a sensitive area could potentially have disabled the spacecraft.
The spacecraft is being destroyed after a successful 13 year mission at Saturn, as NASA needs to follow the protocol of planetary protection, and not allow a spacecraft with possible microbes from Earth to crash into a potentially habitable moon such as Enceladus or Titan.
Cassini’s next dive through the gap is scheduled for May 2.
Multi-dome lunar base being constructed, based on the 3D printing concept. Once assembled, the inflated domes are covered with a layer of 3D-printed lunar regolith by robots to help protect the occupants against space radiation and micrometeoroids.
Credits: ESA/Foster + Partners
In recent years, multiple space agencies have shared their plans to return astronauts to the Moon, not to mention establishing an outpost there. Beyond NASA’s plan to revitalize lunar exploration, the European Space Agency (ESA), Rocosmos, and the Chinese and Indian federal space agencies have also announced plans for crewed missions to the Moon that could result in permanent settlements.
As with all things in this new age of space exploration, collaboration appears to be the key to making things happen. This certainly seems to be the case when it comes to the China National Space Administration (CNSA) and the ESA’s respective plans for lunar exploration. As spokespeople from both agencies announced this week, the CNSA and the ESA hope to work together to create a “Moon Village” by the 2020s.
The announcement first came from the Secretary General of the Chinese space agency (Tian Yulong). On earlier today (Wednesday, April 26th) it was confirmed by the head of media relations for the ESA (Pal A. Hvistendahl). As Hvistendahl was quoted as saying by the Associated Press:
“The Chinese have a very ambitious moon program already in place. Space has changed since the space race of the ’60s. We recognize that to explore space for peaceful purposes, we do international cooperation.”
Multi-dome lunar base being constructed, based on the 3D printing concept. Credits: ESA/Foster + Partners
Yulong and Hvistendahl indicated that this base would aid in the development of lunar mining, space tourism, and facilitate missions deeper into space – particularly to Mars. It would also build upon recent accomplishments by both agencies, which have successfully deployed robotic orbiters and landers to the Moon in the past few decades. These include the CNSA’s Chang’e missions, as well as the ESA’s SMART-1 mission.
As part of the Chang’e program, the Chinese landers explored the lunar surface in part to investigate the prospect of mining Helium-3, which could be used to power fusion reactors here on Earth. Similarly, the SMART-1 mission created detailed maps of the northern polar region of the Moon. By charting the geography and illumination of the lunar north pole, the probe helped to identify possible base sites where water ice could be harvested.
In addition, its is likely that the construction of this base will rely on additive manufacture (aka. 3-d printing) techniques specially developed for the lunar environment. In 2013, the ESA announced that they had teamed up with renowned architects Foster+Partners to test the feasibility of using lunar soil to print walls that would protect lunar domes from harmful radiation and micrometeorites.
Artist’s impression of a lunar base created with 3-d printing techniques. Credits: ESA/Foster + Partners
This agreement could signal a new era for the CNSA, which has enjoyed little in the way of cooperation with other federal space agencies in the past. Due to the agency’s strong military connections, the U.S. government passed legislation in 2011 that barred the CSNA from participating in the International Space Station. But an agreement between the ESA and China could open the way for a three-party collaboration involving NASA.
The ESA, NASA and Roscosmos also entered into talks back in 2012 about the possibility of creating a lunar base together. Assuming that all four nations can agree on a framework, any future Moon Village could involve astronauts from all the world’s largest space agencies. Such a outpost, where research could be conducted on the long-term effects of exposure to low-g and extra-terrestrial environments, would be invaluable to space exploration.
In the meantime, the CNSA hopes to launch a sample-return mission to the Moon by the end of 2017 – Chang’e 5 – and to send the Chang’e 4 mission (whose launch was delayed in 2015) to the far side of the Moon by 2018. For its part, the ESA hopes to conduct a mission analysis on samples brought back by Chang’e 5, and also wants to send a European astronaut to Tiangong-2 (which just conducted its first automated cargo delivery) at some future date.
As has been said countless times since the end of the Apollo Era – “We’re going back to the Moon. And this time, we intend to stay!”
You might think you’re reading an educational website, where I explain fascinating concepts in space and astronomy, but that’s not really what’s going on here.
What’s actually happening is that you’re tagging along as I learn more and more about new and cool things happening in the Universe. I dig into them like a badger hiding a cow carcass, and we all get to enjoy the cache of knowledge I uncover.
Okay, that analogy got a little weird. Anyway, my point is. Squirrel!
Fast radio bursts are the new cosmic whatzits confusing and baffling astronomers, and now we get to take a front seat and watch them move through all stages of process of discovery.
Stage 1: A strange new anomaly is discovered that doesn’t fit any current model of the cosmos. For example, strange Boyajian’s Star. You know, that star that probably doesn’t have an alien megastructure orbiting around it, but astronomers can’t rule that out just yet?
Stage 2: Astronomers struggle to find other examples of this thing. They pitch ideas for new missions and scientific instruments. No idea is too crazy, until it’s proven to be too crazy. Examples include dark matter, dark energy, and that idea that we’re living in a
Stage 3: Astronomers develop a model for the thing, find evidence that matches their predictions, and vast majority of the astronomical community comes to a consensus on what this thing is. Like quasars and gamma ray bursts. YouTuber’s make their videos. Textbooks are updated. Balance is restored.
Today we’re going to talk about Fast Radio Bursts. They just moved from Stage 1 to Stage 2. Let’s dig in.
Fast radio bursts, or FRBs, or “Furbys” were first detected in 2007 by the astronomer Duncan Lorimer from West Virginia University.
He was looking through an archive of pulsar observations. Pulsars, of course, are newly formed neutron stars, the remnants left over from supernova explosions. They spin rapidly, blasting out twin beams of radiation. Some can spin hundreds of times a second, so precisely you could set your watch to them.
Lorimer’s archive of pulsar observations was captured at the Parkes radio dish in Australia. Credit: CSIRO (CC BY 3.0)
In this data, Lorimer made a “that’s funny” observation, when he noticed one blast of radio waves that squealed for 5 milliseconds and then it was gone. It didn’t match any other observation or prediction of what should be out there, so astronomers set out to find more of them.
Over the last 10 years, astronomers have found about 25 more examples of Fast Radio Bursts. Each one only lasts a few milliseconds, and then fades away forever. A one time event that can appear anywhere in the sky and only last for a couple milliseconds and never repeats is not an astronomer’s favorite target of study.
Actually, one FRB has been found to repeat, maybe.
The question, of course, is “what are they?”. And the answer, right now is, “astronomers have no idea.”
In fact, until very recently, astronomers weren’t ever certain they were coming from space at all. We’re surrounded by radio signals all the time, so a terrestrial source of fast radio bursts seems totally logical.
About a week ago, astronomers from Australia announced that FRBs are definitely coming from outside the Earth. They used the Molonglo Observatory Synthesis Telescope (or MOST) in Canberra to gather data on a large patch of sky.
Then they sifted through 1,000 terabytes of data and found just 3 fast radio bursts. Three.
Since MOST is farsighted and can’t perceive any radio signals closer than 10,000 km away, the signals had to be coming outside planet Earth. They were “extraterrestrial” in origin.
Right now, fast radio bursts are infuriating to astronomers. They don’t seem to match up with any other events we can see. They’re not the afterglow of a supernova, or tied in some way to gamma ray bursts.
In order to really figure out what’s going on, astronomers need new tools, and there’s a perfect instrument coming. Astronomers are building a new telescope called the Canadian Hydrogen Intensity Mapping Experiment (or CHIME), which is under construction near the town of Penticton in my own British Columbia.
CHIME under construction in Penticton, British Columbia. Credit: Mateus A. Fandiño (CC BY-SA 4.0)
It looks like a bunch of snowboard halfpipes, and its job will be to search for hydrogen emission from distant galaxies. It’ll help us understand how the Universe was expanding between 7 and 11 billion years ago, and create a 3-dimensional map of the early cosmos.
In addition to this, it’s going to be able to detect hundreds of fast radio bursts, maybe even a dozen a day, finally giving astronomers vast pools of signals to study.
What are they? Astronomers have no idea. Seriously, if you’ve got a good suggestion, they’d be glad to hear it.
In these kinds of situations, astronomers generally assume they’re caused by exploding stars in some way. Young stars or old stars, or maybe stars colliding. But so far, none of the theoretical models match the observations.
This artist’s conception illustrates one of the most primitive supermassive black holes known (central black dot) at the core of a young, star-rich galaxy. Image credit: NASA/JPL-Caltech
Another idea is black holes, of course. Specifically, supermassive black holes at the hearts of distant galaxies. From time to time, a random star, planet, or blob of gas falls into the black hole. This matter piles upon the black hole’s event horizon, heats up, screams for a moment, and disappears without a trace. Not a full on quasar that shines for thousands of years, but a quick snack.
The next idea comes with the only repeating fast radio burst that’s ever been found. Astronomers looked through the data archive of the Arecibo Observatory in Puerto Rico and found a signal that had repeated at least 10 times in a year, sometimes less than a minute apart.
Since the quick blast of radiation is repeating, this rules out a one-time collision between exotic objects like neutron stars. Instead, there could be a new class of magnetars (which are already a new class of neutron stars), that can release these occasional shrieks of radio.
An artist’s impression of a magnetar. Credit: ESO/L. Calçada
Or maybe this repeating object is totally different from the single events that have been discovered so far.
Here’s my favorite idea. And honestly, the one that’s the least realistic. What I’m about to say is almost certainly not what’s going on. And yet, it can’t be ruled out, and that’s good enough for my fertile imagination.
Avi Loeb and Manasvi Lingam at Harvard University said the following about FRBs:
“Fast radio bursts are exceedingly bright given their short duration and origin at distances, and we haven’t identified a possible natural source with any confidence. An artificial origin is worth contemplating and checking.”
Artificial origin. So. Aliens. Nice.
Loeb and Lingam calculated how difficult it would be to send a signal that strong, that far across the Universe. They found that you’d need to build a solar array with twice the surface area of Earth to power the radio wave transmitter.
And what would you do with a transmission of radio or microwaves that strong? You’d use it to power a spacecraft, of course. What we’re seeing here on Earth is just the momentary flash as a propulsion beam sweeps past the Solar System like a lighthouse.
But in reality, this huge solar array would be firing out a constant beam of radiation that would propel a massive starship to tremendous speeds. Like the Breakthrough Starshot spacecraft, but for million tonne spaceships.
Credit: NASA/Pat Rawlings (SAIC)
In other words, we could be witnessing alien transportation systems, pushing spacecraft with beams of energy to other worlds.
And I know that’s probably not what’s happening. It’s not aliens. It’s never aliens. But in my mind, that’s what I’m imagining.
So, kick back and enjoy the ride. Join us as we watch astronomers struggle to understand what fast radio bursts are. As they invalidate theories, and slowly unlock one of the most thrilling mysteries in modern astronomy. And as soon as they figure it out, I’ll let you know all about it.
What do you think? Which explanation for fast radio bursts seems the most logical to you? I’d love to hear your thoughts and wild speculation in the comments.
An artist's impression of parallel universes. Credit: VisionGfx on deviantArt.com
Since the 1960s, astronomers have been aware of the electromagnetic background radiation that pervades the Universe. Known as the Cosmic Microwave Background, this radiation is the oldest light in the Universe and what is left over from the Big Bang. By 2004, astronomers also became aware that a large region within the CMB appeared to be colder than its surroundings.
Known as the “CMB Cold Spot”, scientists have puzzled over this anomaly for years, with explanations ranging from a data artifact to it being caused by a supervoid. According to a new study conducted by a team of scientists from Durham University, the presence of a supervoid has been ruled out. This conclusion once again opens the door to more exotic explanations – like the existence of a parallel Universe!
The Cold Spot is one of several anomalies that astronomers have been studying since the first maps of CMB were created using data from the Wilkinson Microwave Anisotropy Probe (WMAP). These anomalies are regions in the CMB that fall beneath the average background temperature of 2.73 degrees above absolute zero (-270.43 °C; -460.17 °F). In the case of the Cold Spot, the area is just 0.00015° colder than its surroundings.
Map of the cosmic microwave background (CMB) sky produced by the Planck satellite. The Cold Spot is shown in the inset, with coordinates and the temperature difference in the scale at the bottom. Credit: ESA/Durham University.
And yet, this temperature difference is enough that the Cold Spot has become something of a thorn in the hip of standard models of cosmology. Previously, the smart money appeared to be on it being caused by a supervoid – and area of space measuring billions of light years across which contained few galaxies. To test this theory, the Durham team conducted a survey of the galaxies in the region.
This technique, which measures the extent to which visible light coming from an object is shifted towards the red end of the spectrum, has been the standard method for determining the distance to other galaxies for over a century. For the sake of their study, the Durham team relied on data from the Anglo-Australian Telescope to conduct a survey where they measured the redshifts of 7,000 nearby galaxies.
Based on this high-fidelity dataset, the researchers found no evidence that the Cold Spot corresponded to a relative lack of galaxies. In other words, there was no indication that the region is a supervoid. The results of their study will be published in the Monthly Notices of the Royal Astronomical Society (MNRAS) under the title “Evidence Against a Supervoid Causing the CMB Cold Spot“.
As Ruari Mackenzie – a postdoctoral student in the Dept. of Physics at Durham University, a member of the Center for Extragalactic Astronomy, and the lead author on the paper – explained in an RAS press release:
“The voids we have detected cannot explain the Cold Spot under standard cosmology. There is the possibility that some non-standard model could be proposed to link the two in the future but our data place powerful constraints on any attempt to do that.”
The 3-D galaxy distribution in the foreground of the CMB Cold Spot, where each point is a galaxy. Credit: Durham University.
Specifically, the Durham team found that the Cold Spot region could be split into smaller voids, each of which were surrounded by clusters of galaxies. This distribution was consistent with a control field the survey chose for the study, both of which exhibited the same “soap bubble” structure. The question therefore arises: if the Cold Spot is not the result of a void or a relative lack of galaxies, what is causing it?
This is where the more exotic explanations come in, which emphasize that the Cold Spot may be due to something that exists outside the standard model of cosmology. As Tom Shanks, a Professor with the Dept.of Physics at Durham and a co-author of the study, explained:
“Perhaps the most exciting of these is that the Cold Spot was caused by a collision between our universe and another bubble Universe. If further, more detailed, analysis of CMB data proves this to be the case then the Cold Spot might be taken as the first evidence for the multiverse – and billions of other Universes may exist like our own.”
Multiverse Theory, which was first proposed by philosopher and psychologist William James, states that there may be multiple or an even infinite number of Universes that exist parallel to our own. Between these Universes exists the entirety of existence and all cosmological phenomena – i.e. space, time, matter, energy, and all of the physical laws that bind them.
Whereas it is often treated as a philosophical concept, the theory arose in part from the study of cosmological forces, like black holes and problems arising from the Big Bang Theory. In addition, variations on multiverse theory have been suggested as potential resolutions to theories that go beyond the Standard Model of particle physics – such as String Theory and M-theory.
Another variation – the Many-Worlds interpretation – has also been offered as a possible resolution for the wavefunction of subatomic particles. Essentially, it states that all possible outcomes in quantum mechanics exist in alternate universes, and there really is no such thing as “wavefunction collapse’. Could it therefore be argued that an alternate or parallel Universe is too close to our own, and thus responsible for the anomalies we see in the CMB?
As explanations go, it certainly is exciting, if perhaps a bit fantastic? And the Durham team is not prepared to rule out that the Cold Spot could be the result fluctuations that can be explained by the standard model of cosmology. Right now, the only thing that can be said definitively is that the Cold Spot cannot be explained by something as straightforward as a supervoid and the absence of galaxies.
And in the meantime, additional surveys and experiments need to be conducted. Otherwise, this mystery may become a real sticking point for cosmology!
For decades, we could only imagine what the view of Pluto’s surface might be. Now, we have the real thing.
The images and data from the New Horizons’ mission flyby of Pluto in July 2015 showed us an unexpectedly stunning and geologically active world. Scientists have used words like ‘magical,’ ‘breathtaking’ and ‘scientific wonderland’ to describe the long-awaited close-up views of distant Pluto.
Even though scientists are still analyzing the data from New Horizons, ideas are starting to formulate about sending another spacecraft to Pluto, but with a long-term orbiter mission instead of a quick flyby.
“The next appropriate mission to Pluto is an orbiter, maybe equipped with a lander if we had enough funding to do both,” New Horizons’ principal investigator Alan Stern told Universe Today in March.
This week, Stern has shared on social media that the New Horizons’ science team is meeting. But, separately, another group is starting to talk about a possible next mission to Pluto.
Getting a spacecraft to the outer regions of our solar system as fast as possible provides challenges, particularly in being able to slow down enough to enable going into orbit around Pluto. For the speedy and lightweight New Horizons, an orbital mission was impossible.
What propulsion system might make a Pluto orbiter and/or lander mission possible?
A few ideas are being tossed around.
Space Launch System
One concept takes advantage of NASA’s big, new Space Launch System (SLS), currently under development to enable human missions to Mars. NASA describes the SLS as “designed to be flexible and evolvable and will open new possibilities for payloads, included robotic scientific missions.” Even the first Block 1 version can launch 70 metric tons (later versions might be able to lift up to 130 metric tons.) Block 1 will be powered by twin five-segment solid rocket boosters and four liquid propellant engines, with a proposed 15% more thrust at launch than the Saturn V rockets that sent astronauts to the Moon.
An artist’s interpretation of NASA’s Space Launch System Block 1 configuration with an Orion vehicle. Image: NASA
But an orbiter mission to Pluto might not be the best use of the SLS alone.
It takes a lot of fuel to accelerate a vehicle to fast enough speed to get to Pluto in a reasonable amount of time. For example, New Horizons was the fastest spacecraft ever launched, using a souped-up Atlas V rocket with extra boosters, it performed a big burn when New Horizons departed Earth orbit. The lightweight spacecraft sped away from the Earth at 36,000 miles per hour (about 58,000 km/ hour), then used a gravity assist from Jupiter to boost New Horizons’ speed to 52,000 mph (83,600 km/h), traveling nearly a million miles (1.5 million km) a day in its 3 billion mile (4.8 billion km) journey to Pluto. The flight took nine and a half years.
“To enter Pluto orbit, a vehicle [like SLS] would have to boost up to that same speed, then turn around and decelerate for half the trip to arrive at Pluto with a net velocity of zero relative to the planet,” explained Stephen Fleming, an investor in several alt-space startups including XCOR Aerospace, Planetary Resources and NanoRacks. “Unfortunately, due to the tyranny of the rocket equation, you would have to carry all the fuel/propellant to decelerate with you at launch … which means accelerating the orbiter AND all that fuel in the initial phase. That requires logarithmically more fuel for the initial burn, and it turns out to be a LOT of fuel.”
Fleming told Universe Today that using the multi-billion dollar SLS to launch a Pluto orbiter, you would wind up launching an entire payload full of propellant just to accelerate and decelerate a tiny Pluto orbiter.
“That’s an extraordinarily expensive mission,” he said.
RTG-Ion Propulsion
A better option might be to use a propulsion system of combined technologies. Stern mentioned a NASA study that looked at using the SLS as the launch vehicle and to boost the spacecraft towards Pluto, but then using an RTG (Radioisotope Thermoelectric Generator) powered ion engine to later brake for an orbital arrival.
An RTG produces heat from the natural decay of non-weapons-grade plutonium-238, and the heat is converted into electricity. An RTG ion engine would be a more powerful ion propulsion system than the current solar electric ion engine on the Dawn spacecraft, now orbiting Ceres, in the asteroid belt, plus it would enable operation in the outer solar system, far from the Sun. This nuclear powered ion engine would enable a speeding spacecraft to slow down and go into orbit.
An artist’s illustration of NASA’s Dawn spacecraft with its ion propulsion system approaching Ceres. Image: NASA/JPL-Caltech.
“The SLS would boost you to fly out to Pluto,” Stern said, “and it would actually take two years to do the braking with ion propulsion.”
Stern said the flight time for such a mission to Pluto would be seven and a half years, two years faster than New Horizons.
The proposal uses a Direct Fusion Drive (DFD) engine that has propulsion and power in one integrated device. DFD provides high thrust to allow for a flight time of about 4 years to Pluto, plus being able to send substantial mass to orbit, perhaps between 1000 to 8000 kg.
A Direct Fusion Drive-powered spacecraft in orbit around Pluto, with the lander ready to deploy from the right-hand side. The large wing-like structures are the radiators and the optical communications lasers are on trusses extending from the center. Credits: Princeton Satellite Systems, NASA/JHUAPL/SwRI
DFD is based on the Princeton Field-Reversed Configuration (PFRC) fusion reactor that has been under development for 15 years at the Princeton Plasma Physics Laboratory.
If this propulsion system works as planned, it could launch a Pluto orbiter and a lander (or possibly a rover), and provide enough power to maintain an orbiter and all its instruments, as well as beam a lot of power to a lander. That would enable the surface vehicle to beam back video to the orbiter because it would have so much power, according to Stephanie Thomas from Princeton Satellite Systems, Inc., who is leading the NIAC study.
“Our concept is generally received as, ‘wow, that sounds really cool! When can I get one?’” Thomas told Universe Today. She said her and her team chose a prototype Pluto orbiter and lander mission in their proposal because it’s a great example of what can be done with a fusion rocket.
Their fusion system uses a small linear array of solenoid coils, and their fuel of choice is deuterium helium 3, which has very low neutron production.
Fusion-Enabled Pluto Orbiter and Lander. Credits: Stephanie Thomas.
“It fits on a spacecraft, it fits on a launch vehicle,” Thomas explained in a NIAC symposium talk (her talk starts about 17:30 in the linked video). “There’s no lithium, or other dangerous materials, it produces very few damaging particles. It’s about the size of a minivan or small truck. Our system is cheaper and faster to develop than other fusion proposals.”
The Princeton team has been able to produce 300 millisecond pulses with their plasma heating experiment, orders of magnitude better than any other system.
“The biggest hurdle is the fusion itself,” she said. “We need to build a bigger experiment to finish proving the new heating method, which will require an order of magnitude more resources than the project has been receiving from the Department of Energy so far,” Thomas said via email. “However, it’s still small in the grand scheme of advanced technology projects, about $50 million.”
Thomas said that DARPA has spent much more on many technology initiatives that ended up canceled. And it’s also much less than other fusion technologies require for the same stage of research, since our machine is so small and has a simple coil configuration.” (Thomas said have a look at the budget for ITER, the international nuclear fusion research and engineering megaproject, currently running over $20 billion).
“To put it simply, we know our method heats electrons really well and can extrapolate to heating ions, but we need to build it and prove it,” she said.
Thomas and her team are currently working on the “balance of plant” technology – the subsystems that will be required to operate the engine in space, assuming the heating method works as currently predicted.
In terms of the Pluto mission itself, Thomas said there aren’t any particular hurdles on the orbiter itself, but it would involve scaling up a few technologies to take advantage of the very large amount of power available, such as the optical communications.
“We could dedicate tens or more kW of power to the communication laser, not 10 watts, [like current missions]” she said. “Another unique feature of our concept is being able to beam a lot of power to a lander. This would enable new classes of planetary science instruments like powerful drills. The technology to do this exists but the specific instruments need to be designed and built. Additional technology that will be needed that is under development in various industries are lightweight space radiators, next-generation superconducting wires, and long-term cryogenic storage for the deuterium fuel.”
Thomas said their NIAC research is going well.
“We were selected for the NIAC Phase II study, and are in contract negotiations now,” she said. “We are busy working on higher fidelity models of the engine’s thrust, designing components of the trajectory, and sizing the various subsystems, including the superconducting coils,” she said. “Our current estimates are that a single 1 to 10 MW engine will produce between 5 and 50 N thrust, at about 10,000 sec specific impulse.”
Laser Zapping to Pluto
Another futuristic propulsion possibility is the laser-based systems proposed by Yuri Milner for his Breakthrough Starshot proposal, where small cubesats could be zapped by lasers on Earth, basically “bug zapping” spacecraft to reach incredible speeds (possibly millions of miles/km per hour) to visit the outer solar system or beyond.
“It’s not really in the cards for us to use this kind of technology, because we’d have to wait decades just for this to be developed,” Stern said. “But if you could send lightweight, inexpensive spacecraft at speeds like one-10th the speed of light based on lasers from Earth. We could send these small spacecraft to hundreds or thousands of objects in the Kuiper Belts, and you’d be out there in a matter of two-and-a-half days. You could send a spacecraft past Pluto every day. That would be really game changing.”
The Realistic Future
But even if everyone agrees a Pluto orbiter should be done, the earliest possible date for such a mission is sometime between the early 2020s and the early 2030s. But it all depends on the recommendations put forth by the scientific community’s next decadal survey, which will suggest the most top-priority missions for NASA’s Planetary Science Division.
These Decadal Surveys are 10-year “roadmaps” that set science priorities and provide guidance on where NASA should send spacecraft and what types of missions they should be. The last Decadal Survey was published in 2011, and that set planetary science priorities through 2022. The next one, for 2023-2034, will likely be published in 2022.
The New Horizons mission was the result of the suggestions from the 2003 planetary science Decadal Survey, where scientists said visiting the Pluto system and worlds beyond was a top-priority destination.
So, if you’re dreaming of a Pluto orbiter, keep talking about it.
New Horizon’s July 2015 flyby of Pluto taught us a lot about that planet. For one thing, Pluto is much more geophysically active than thought. Credit: NASA/JHUAPL/SwRI.
SpaceX conducts successful static hot fire test of Falcon 9 booster atop Launch Complex 39A at the Kennedy Space Center on 25 Apr. 2017 as seen from Merritt Island National Wildlife Refuge, Titusville, FL. The Falcon 9 is slated to launch the NROL-76 super secret spy satellite for the U.S. National Reconnaissance Office (NRO) on 30 April 2017. Credit: Ken Kremer/Kenkremer.com
SpaceX conducts successful static hot fire test of Falcon 9 booster atop Launch Complex 39A at the Kennedy Space Center on 25 Apr. 2017 as seen from Merritt Island National Wildlife Refuge, Titusville, FL. The Falcon 9 is slated to launch the NROL-76 super secret spy satellite for the U.S. National Reconnaissance Office (NRO) on 30 April 2017. Credit: Ken Kremer/Kenkremer.com
MERRITT ISLAND NATIONAL WILDLIFE REFUGE, FL – Elon Musk’s SpaceX is primed for another significant space first; the firms first launch of a spy satellite for the US governments super secret spy agency; the National Reconnaissance Office, or NRO – following today’s successful static hotfire test of the Falcon 9 launchers first stage booster.
Tuesday’s hotfire test to took place shortly after 3 p.m. this afternoon, April 25, at SpaceX’s seaside Launch Complex 39A at NASA’s Kennedy Space Center in Florida.
The successful test paves the path for launch of the NROL-76 classified payload for the NRO atop a SpaceX Falcon 9 rocket this Sunday morning, April 30 from pad 39A.
“Static fire test complete,” SpaceX confirmed via social media just minutes after finishing the brief test at 3:02 p.m. EDT (1902 GMT).
“Targeting Falcon 9 launch of NROL-76 on Sunday, April 30.”
The engine test is conducted using only the first two stages of the rocket – minus the expensive payload in case anything goes wrong as like occurred during the catastrophic AMOS-6 static fire disaster last September.
The test is routinely done so that SpaceX engineers can confirm the readiness of the rocket and all its systems to safely and successfully launch the specified payload to its intended orbit.
Furthermore this launch is also notable because it features the next land landing by a SpaceX Falcon 9 first booster back at the Cape for only the fourth time in history – which also makes for an extremely thrilling experience – and unforgettable space enthusiasts event.
So by all means try to witness this launch from the Florida Space Coast in person, if at all possible.
The breakfast time launch window on Sunday, April 30 opens at 7 a.m. EDT. It extends for two hours until 9.a.m. EDT.
The long range weather outlook currently looks favorable with lots of sun and little rain. But that can change on a moment’s notice in the sunshine state.
The brief engine test lasting approximately three seconds took place at 3:02 p.m. today, Tuesday, April 25, with the sudden eruption of smoke and ash rushing out the flame trench to the north and into the air over historic pad 39A on NASA’s Kennedy Space Center during a picture perfect sunny afternoon – as I witnessed from the Merritt Island National Wildlife Refuge in Titusville, FL.
SpaceX conducts successful static hot fire test of Falcon 9 booster atop Launch Complex 39A at the Kennedy Space Center on 25 Apr. 2017 as seen from Merritt Island National Wildlife Refuge, Titusville, FL. The Falcon 9 is slated to launch the NROL-76 super secret spy satellite for the U.S. National Reconnaissance Office (NRO) on 30 April 2017. Credit: Ken Kremer/Kenkremer.com
During today’s static fire test, the rocket’s first and second stages are fueled with densified liquid oxygen and RP-1 propellants like an actual launch, and a simulated countdown is carried out to the point of a brief engine ignition with the rocket firmly clamped down and held in place.
The hold down engine test with the erected rocket involved the ignition of all nine Merlin 1D first stage engines generating some 1.7 million pounds of thrust at pad 39A while the two stage rocket was restrained on the pad.
This is only the fourth Falcon 9 static fire test ever conducted on Pad 39A.
Pad 39A has been repurposed by SpaceX from its days as a NASA shuttle launch pad.
Watch this video of the April 25 static fire test from colleague Jeff Seibert:
Video Caption: Static fire test of the Falcon 9 core in preparation for NROL-76 launch scheduled for April 30, 2017. A Falcon 9 booster undergoes a captive static fire test as a step in the launch preparation for the first dedicated NRO launch by SpaceX. Credit: Jeff Seibert
Following the engine test, the propellants are drained and the rocket is rolled off the pad and back into the huge SpaceX processing hanger at the pad perimeter.
The NROL-76 classified surveillance satellite will be bolted on top. The rocket will be rolled back to pad 39A in advance of Sunday’s planned blastoff.
SpaceX conducts successful static hot fire test of Falcon 9 booster atop Launch Complex 39A at the Kennedy Space Center on 25 Apr. 2017 as seen from Merritt Island National Wildlife Refuge, Titusville, FL. The Falcon 9 is slated to launch the NROL-76 super secret spy satellite for the U.S. National Reconnaissance Office (NRO) on 30 April 2017. Credit: Ken Kremer/Kenkremer.com
Until now launch competitor United Launch Alliance (ULA) and its predecessors have held a virtual monoploy on the US military’s most critical satellite launches.
Worlds 1st ever reflown SpaceX Falcon 9 soars to orbit with SES-10 telecomsat from historic Launch Complex 39A at NASA’s Kennedy Space Center in Florida at 6:27 p.m. EDT on March 30, 2017. Credit: Ken Kremer/Kenkremer.com
The prototype greenhouse is being designed to provide astronauts with a continuous vegetarian diet. Image: University of Arizona.
NASA is all about solving challenges, and the goal of having a prolonged presence in space, or a colony on Mars or some other world, is full of challenges, including the necessity of growing food. Scientists at Kennedy Advanced Life Support Research are working on the Prototype Lunar/Mars Greenhouse Project to try and meet that challenge.
The Prototype Lunar/Mars Greenhouse Project (PLMGP) is all about growing vegetables for astronauts during extended stays on the Moon, on Mars, or anywhere they can’t be resupplied from Earth. Beyond growing food, the Project aims to understand how food-growing systems can also be a part of life-support systems.
“The approach uses plants to scrub carbon dioxide, while providing food and oxygen.” – Dr. Ray Wheeler
“We’re working with a team of scientists, engineers and small businesses at the University of Arizona to develop a closed-loop system. The approach uses plants to scrub carbon dioxide, while providing food and oxygen,” said Dr. Ray Wheeler, lead scientist in Kennedy Advanced Life Support Research.
The prototype itself is an inflatable, deployable system that researchers call a bioregenerative life support system. As crops are grown, the system recycles, water, recycles waste, and revitalizes the air.
The system is hydroponic, so no soil is needed. Water that is either brought along on missions or gathered in situ—on the Moon or at Mars for example—is enriched with nutrient salts, and flows continuously through plant root systems. Air in the system is recycled too. Astronauts exhale carbon dioxide, which plants absorb. Through photosynthesis, the plants produce oxygen for the astronauts.
This 18 foot long tube is a prototype of a bioregenerative life support system. The system grows crops, but also regenerates water and air. It’s at the University of Arizona’s Controlled Environment Agriculture Center. Image: University of Arizona
“We’re mimicking what the plants would have if they were on Earth and make use of these processes for life support,” said Dr. Gene Giacomelli, director of the Controlled Environment Agriculture Center at the University of Arizona. “The entire system of the lunar greenhouse does represent, in a small way, the biological systems that are here on Earth.”
“The entire system of the lunar greenhouse does represent, in a small way, the biological systems that are here on Earth.” – Dr. Gene Giacomelli
A key part of a system like this is knowing what astronauts will have to bring with them, and what resources they can find at their destination. This includes which type of plants and seeds will be needed, as well as how much water might be available once astronauts reach their destination. Methods of extracting water on Mars or the Moon are also being researched and developed.
Even if the necessary water can be found in situ on Mars and the Moon, that hardly means those are easy places to grow food. Astronauts have to be protected from radiation, and so will crops. These greenhouse chambers would have to buried underground, which means specialized lighting systems are also required.
“We’ve been successful in using electric LED (light emitting diode) lighting to grow plants,” Dr. Wheeler said. “We also have tested hybrids using both natural and artificial lighting.” Solar light could be captured with light concentrators that track the sun and then convey the light to the chamber using fiber optic bundles.
These systems are not NASA’s first experience at growing crops in space. Experiments aboard the International Space Station (ISS) have been an important part of the research into crop production in non-terrestrial environments. The Veggie Plant Growth System was NASA’s first attempt, and astronauts successfully harvested lettuce from that system.
NASA astronaut Shane Kimbrough harvesting lettuce from ‘VEGGIE’ on the International Space Station. Image: NASA
Earth has well-established systems for sustaining life, and this project is all about taking some of that to distant destinations in space.
“I think it’s interesting to consider that we’re taking our terrestrial companions with us,” Wheeler said. “While there may be ways to engineer around it in terms of stowage and resupply, it wouldn’t be as sustainable. The greenhouses provide a more autonomous approach to long-term exploration on the moon, Mars and beyond.”
A new study from the Center for Planetary Science claims that a comet may be responsible fr the famous Wow! Signal. Credit: NASA/JPL-Caltech
About 14,500 years ago, Earth began transitioning from its cold, glacial self to a warmer interglacial state. However, partway through this period, temperatures suddenly returned to near-glacial conditions. This abrupt change (known as the Younger Dryas period) is believed by some to be the reason why hunter-gatherers started forming sedentary communities, farming, and laying the groundwork for civilization as we know it – aka. the Neolithic Revolution.
For over a decade, there have been scientists who have argued that this period was the result of a comet hitting Earth. Known as the Younger Dryas Impact Hypothesis (aka. the Clovis Comet Hypothesis), the theory is largely based on ice core samples from Greenland that show a sudden global temperature change. But according to a new study by a research team from the University of Edinburgh, archaeological evidence may also prove this hypothesis correct.
The Younger Dryas period takes its name from a species of flower known as Dryas octopetala. This plant is known to grow in cold conditions, and became common in Europe during the period. Because of the way it began abruptly – roughly 12,500 years ago – and then ended just as abruptly 1200 years later, many scientists are convinced it was caused by an external event.
Göbekli Tepe, structures A-D of the site, located in southern Turkey. Credit: Wikipedia Commons/Teomancimit
For the sake of their study – which was recently published in the journal Mediterranean Archaeology and Archaeometry under the title “Decoding Göbekli Tepe With Archaeoastronomy: What Does the Fox Say?“- the team found an astronomical link to the stone pillars at Göbekli Tepe. Located in southern Turkey, this archaeological find is the oldest known temple site in the world (dated to ca. 10,950 BCE).
This site, it should be noted, is contemporary with the Greenland ice core samples, which are dated to around 10,890 BCE. Of the sites many features, none are more famous than the many standing pillars that dot the excavated grounds. This is because of the extensive pictograms and animal reliefs that decorate these pillars, which include various representations of mammal and avian species- particularly vultures.
Pillar 43, which is also known as the “vulture stone”, was of particular interest to archeologists, as it is suspected that its representations (associated with death) could have been intended to commemorate a devastating event. The other images, they ventured, were meant to depict the constellations, and that their placement relative to each other accorded to the positions of the then-known asterisms in the night sky.
This theory was based on images they took of the site, which they then examined using the planetarium program stellarium 0.15. In the end, they found that the images bore a resemblance to constellations that would have been visible in 10,950 BCE. As such, they concluded that the temple site may have been an observatory, and that the images were a catalog of celestial events – which include the Taurid meteor stream.
Wall pillars with three animal symbols in series. Part a) is pillar 2 from Enclosure A, while part b) is pillar 38, Enclosure D. Credit: Travel The Unknown
As they state in their study:
“We begin by noting the carving of a scorpion on pillar 43, a well -known zodiacal symbol for Scorpius. Based on this observation, we investigate to what extent other symbols on pillar 43 can be interpreted as zodiacal symbols or other familiar astronomical symbols… We suggest the vulture/eagle on pillar 43 can be interpreted as the ‘teapot’ asterism of our present-day notion of Sagittarius; the angle between the eagle/vulture’s head and wings, in particular, agrees well with the ‘handle’,‘lid’ and ‘spout’ of the teapot asterism. We also suggest the ‘bent-bird’ with downward wriggling snake or fish can be interpreted as the ‘13th sign of the zodiac’, i.e. of our present-day notion of Ophiuchus. Although its relative position is not very accurate, we suggest the artist(s) of pillar 43 were constrained by the shape of the pillar. These symbols are a reasonably good match with their corresponding asterisms, and they all appear to be in approximately the correct relative locations.
Similarly, they suggest that a carved circle at the center of pillar 43 could be interpreted as the Sun. They call this image the “date stamp” because it can be seen as communicating a specific date by indicating which part of the zodiac the Sun was in at the time of carving. By comparing the age of the site (based on carbon dating) to the apparent position of the Sun, they found that it was consistent with the Summer solstice of 10,950 BCE.
Of course, the team fully acknowledges that an astronomical interpretation is by no means the only possibility. In addition to the possibility of them being mythological references, they could also be representations of hunting or migration patterns. It’s also entirely possible they were not meant to convey any specific meaning, and were merely a description of the local environment, which would have been rich in flora and fauna at the time.
Pillar 43, Enclosure D, also known as the Vulture Stone of Göbekli Tepe. Credit: Martin B. Sweatman and Dimitrios Tsikritsis
In addition, the way vultures are commonly featured could be an indication that the site was a burial ground. This is consistent with iconography found at the archaeological sites of Çatalhöyük (in central, southern Turkey) and Jericho (in the West Bank). During the time period in question, Neolithic peoples were known to conduct sky burials, where the bodies of the deceased were left out in the open for carrion birds to pick over.
In such practices, the head was sometimes removed from the deceased and kept (for the sake of ancestor worship). This is consistent with one of the characters on Pillar 43, which appears to be a headless human. However, as the team go on to explain, they are confident that the connection between the site’s images and the Taurid meteor stream is a plausible one.
“[O]ur basic statistical analysis indicates our astronomical interpretation is very likely to be correct,” they write. “We are therefore content to limit ourselves to this hypothesis, and logically we are not required to pursue others.” And of course, they acknowledge that further research will be necessary before any conclusions can be made.
Despite the availability of other (and perhaps more plausible) explanations, one has to admit that the astronomical theory is appealing. Civilization as we know it being a response to a meteor impact, and ancient people cataloging it in their stone carvings. It’s got a real Deep Impact meets 2001: A Space Odyssey feel to it!
STEVE, as imaged by Dave Markel in the skies of northern Canada.. Copyright: https://instagram.com/davemarkelphoto
Nicknamed Steve, this unusual aurora feature is a 15.5-mile-wide (25 km) ribbon of hot gas flowing westward at about 13,300 mph, more than 600 times faster than the surrounding air. The photo was taken last fall. Copyright: Instagram.com/davemarkelphoto
This remarkable image was captured last fall by Dave Markel, a photographer based in Kamloops, British Columbia. Later, aurora researcher Eric Donovan of the University of Calgary, discovered Markel’s strange ribbon of light while looking through photos of the northern lights on social media. Knowing he’d found something unusual, Donovan worked sifted through data from the European Space Agency’s Swarm magnetic field mission to try and understand the nature of the phenomenon.
Swarm is ESA’s first constellation of Earth observation satellites designed to measure the magnetic signals from Earth’s core, mantle, crust, oceans, ionosphere and magnetosphere, providing data that will allow scientists to study the complexities of our protective magnetic field. Credit: ESA/AOES Medialab
Launched on 22 November 2013, three identical Swarm satellites orbit the Earth measuring the magnetic fields that stem from Earth’s core, mantle, crust and oceans, as well as from the ionosphere and magnetosphere. Speaking at the recent Swarm science meeting in Canada, Donovan explained how this new finding couldn’t have happened 20 years ago when he started to study the aurora.
A beautiful aurora featuring green arcs near the horizon and many parallel rays lights up the northern sky last October. A small meteor appears to the right of center. Credit: Bob King
While the shimmering, eerie, light display of auroras might be beautiful and captivating, they’re also a visual reminder that Earth is connected electrically and magnetically to the Sun. The more we know about the aurora, the greater our understanding of that connection and how it affects everything from satellites to power grids to electrically-induced corrosion of oil pipelines.
“In 1997 we had just one all-sky imager in North America to observe the aurora borealis from the ground,” said Prof. Donovan. “Back then we would be lucky if we got one photograph a night of the aurora taken from the ground that coincides with an observation from a satellite. Now we have many more all-sky imagers and satellite missions like Swarm so we get more than 100 a night.”
The Suomi NPP satellite photographed this view of the aurora on December 22, 2016, when the northern lights stretched across northern Canada. Credit: NASA Earth Observatory image by Jesse Allen / Suomi National Polar-orbiting Partnership. Colorized and labeled by the author
And that’s where sharing photos and observations on social media can play an important role. Sites like the Great Lakes Aurora Hunters and Aurorasaurus serve as clearinghouses for observers to report auroral displays. Aurorasaurus connects citizen scientists to scientists and searches Twitter feeds for instances of the word ‘aurora,’ so skywatchers and scientists alike know the real-time extent of the auroral oval.
At a recent talk, Prof. Donovan met members the popular Facebook group Alberta Aurora Chasers. Looking at their photos, he came across the purple streak Markel and others had photographed which they’d been referring to as a “proton arc.” But such a feature, caused by hydrogen emission in the upper atmosphere, is too faint to be seen with the naked eye. Donovan knew it was something else, but what?Someone suggested “Steve.” Hey, why not?
Aurora researchers now us a network of all-sky cameras and multiple satellites to keep track of the ever-shifting aurora. Click to see the video. Credit: University of Calgary
While the group kept watch for the Steve’s return, Donovan and colleagues looked through data from the Swarm mission and his network of all-sky cameras. Before long he was able to match a ground sighting of streak to an overpass of one of the three Swarm satellites.
“As the satellite flew straight though Steve, data from the electric field instrument showed very clear changes,” said Donovan.
“The temperature 186 miles (300 km) above Earth’s surface jumped by 3000°C and the data revealed a 15.5-mile-wide (25 km) ribbon of gas flowing westwards at about 6 km/second compared to a speed of about 10 meters/second either side of the ribbon. A friend of mine compared it to a fluorescent light without the glass.
Little did I know I’d met Steve back on May 18, 1990 in this remarkable, narrow arc that stretched from the northwestern horizon to the southeastern. To the eye, a “wind” of vague forms pulsed through the arc. The Big Dipper stands vertically at right. Credit: Bob King
It turns out that these high-speed “rivers” of glowing auroral gas are much more common than we’d thought, and that in no small measure because of the efforts of an army of skywatchers and aurora photographers who keep watch for that telltale green glow in the northern sky.
I spoke to Steve’s keeper, Dave Markel, via e-mail yesterday and he described what the arc looked like to his eyes:
“It’s similar to the image just not as intense. It looks like a massive contrail moving rapidly across the sky. This one lasted almost an hour and ran in an arc almost perfectly east to west. I was directly below it but often there are green pickets (parallel streaks of aurora) rising above the streak.”
This is the same May 18, 1990 streak as above but the eastern half. The bright star Arcturus is visible at upper right. Wish I’d had a fisheye! Credit: Bob King
I know whereof Dave speaks because thanks to his photo and Prof. Donovan’s research, I realize I’ve seen and photographed Steve, too! In decades of aurora watching I’ve only seen this rare streak a handful of times. On most of those occasions, there was either no other aurora visible or minor activity in the northern sky. The narrow arc, which lasted for an hour or so, pulsed and flowed with light and occasionally, Markel’s “pickets” were visible. Back in May 1990 I had a camera on hand to get a picture.
Goes to show, you never know what you might see when you poke your head out for a look. Keep a lookout when aurora’s expected and maybe you’ll get to meet Steve, too.
