This week’s Carnival of Space is hosted by Allen Versfeld at his Urban Astronomer blog.
Click here to read Carnival of Space #569.
Continue reading “Carnival of Space #569”
Carnival of Space #569
A Partial Solar Eclipse Down Under
Eclipse season in nigh… though most of us won’t notice the start this week. The second eclipse season for 2018 commences with the arrival of New Moon and Brown Lunation number 1182 at 3:01 Universal Time on (triskaidekaphobics take note) Friday July 13th, 2018. This eclipse is a shallow partial, just skimming the southern hemisphere of the Earth between the Australian and Antarctic continents.
The Eclipse
We doubt many eclipse chasers will make the pilgrimage to Tasmania to see such a slim partial, though we know of at least one, veteran eclipse chaser Jay Pasachoff who has expressed intent on the Yahoo! Solar Eclipse Message List (SEML) message board to head southward this week.
Tasmania gets the best view, with a maximum 9.5% obscuration of Sol as seen from the capital Hobart around 3:25 UT. The upper limit of the eclipse path just skims the southern coast of Australia across the Great Australian Bight and the southern Indian Ocean, and nicks the very southern tip of the south island of New Zealand and Steward Island at 3:48 UT with a barely discernible 1% eclipse before the lunar penumbra departs the Earth. If skies are clear, the very best view just might come along the coast of Antarctica, as the 33% eclipsed Sun rolls along the northern horizon.
Perhaps a few lone penguins will notice, if they bother to look at the Sun filtered through the murk of the atmosphere along the horizon. France does have one permanently occupied research station in Antarctica named Dumont D’urville along the coast that will see a 30% eclipsed Sun on the horizon right around 3:00-3:15 UT.
We say that this heralds the start of eclipse season, as the ascending node where the Moon’s orbit intersects the ecliptic plane is very near the current position of the Sun. In fact, node crossing occurs at 18:50 UT on July 13th, just 24 hours after New Moon. Eclipses always occur in at least pairs, and the Full Moon two weeks later is close enough to the descending node for a nearly central total lunar eclipse on July 27th (more on that in a bit). This season, however, is special, with a third eclipse ending the cycle on August 11th, 2018, this time gracing the Arctic pole of the Earth along with Scandinavia and Russia.
We’re already seeing some hype surrounding this event as a “Supermoon eclipse,” as the Moon reaches perigee 5 hours 27 minutes past maximum eclipse. Note that this also sets us up for a Minimoon total lunar eclipse two weeks later, as the Moon is near apogee on July 27th.
The Moon’s orbit is tilted 5.145 degrees relative to the plane of the ecliptic, and the nodes make one full revolution around the Earth relative to the equinoctial points once every 18.6 years in what’s known as the precession of the line of apsides.
Viewing a Partial
A partial solar eclipse means that all safety precautions must be taken throughout all phases of the eclipse. This means using approved solar filters that fit snugly over the aperture of a telescope, and solar glasses with the approved ISO 12312-2 rating for solar viewing. We built a safe binocular filter out of a set of spare eclipse safety glasses for the August 21st, 2017 total solar eclipse last year.
Unfortunately as of writing this, the disk of Sol is blank in terms of Earthward facing sunspots, and may be so on eclipse day. We’re currently headed towards a profound solar minimum and the Sun has already been spotless for more than half of 2018 thus far.
Don’t own a solar filter, safety glasses or a telescope? You can always use our tried and true method of projecting the eclipse using a spaghetti strainer.
It’s all in the gamma. This eclipse is partial only, because the dark inner shadow or umbra misses the Earth by 35.4% of the radius of the planet or about 1,400 miles. The gamma for an eclipse states how many Earth radii an eclipse deviates from central (where the Moon’s umbra is aimed straight at the center of the Earth) and Friday’s eclipse has a gamma value of 1.3541.
Tales of the Saros
Friday’s eclipse is part of an older saros series, member 69 of 71 eclipses for saros series 117. This saros started waaaaaay back on June 24th, 792 AD, and produced its last total solar eclipse on May 9th, 1910. This was also the last total solar eclipse for Tasmania until June 25th, 2131. This series only has two more eclipses to go, with its last event occurring briefly over the Antarctic on August 3rd, 2054. Perhaps, Friday’s event will be the very last one witnessed by human eyes for saros 117.
This also sets us up for the best of the three eclipses this season, the total lunar eclipse at the end of the month on July 27th. This eclipse will be widely visible across Africa, Europe, Asia and Australia—only the Americas miss out.
A Possible Views… “From Spaaaaaaace…”
The International Space Station also threads its way through the outer shadow of the Moon towards the end of the event Friday at ~3:50 UT. ESA’s solar observing Proba-2 spacecraft might just get a very brief view as well from its vantage point in low Earth orbit, around 3:09 UT.
And although most of us miss out on Friday’s eclipse, you can still try and spot the slender crescent Moon on the evening of Friday, July 13th. The U.S. East Coast is particularly well placed to try and spy the slim Moon low to the west, only 22 hours after New. After that, the Moon tours all of the naked eye planets, passing Mercury and Venus this weekend and passing Jupiter, Saturn and Mars en route to the July 27th total lunar eclipse.
Will anyone webcast the eclipse live? So far, no webcasts (not even from the venerable Slooh site) have surfaced… if anyone else is planning on featuring the July 13th partial solar eclipse, let us know!
It’s the biggest question when it comes to solar eclipses. When’s the next total? Well, just under a year from now, the next total solar eclipse crosses Chile and Argentina on July 2nd, 2019. Note that this event crosses over several major astronomical observatories at La Silla. How many newly minted eclipse chasers fresh off last year’s Great American Eclipse experience can’t wait until totality next visits the United States on April 8th , 2024 and plan to head to South America next summer?
A partial eclipse may not inspire many eclipse chasers to hop on a plane, but we can still marvel at the celestial ticks of a clockwork Universe carry on, right on schedule.
-Got the eclipse chasing bug? Read all about eclipse chasing, observing and photography in our new book, the Universe Today Guide to Viewing the Cosmos: Everything You Need to know to Become and Amateur Astronomer out on October 23rd.
NASA is Looking for New Ways to Deal With Trash on Deep Space Missions
Life aboard the International Space Station is characterized by careful work and efficiency measures. Not only do astronauts rely on an average of 12 metric tons of supplies a year – which is shipped to the station from Earth – they also produce a few metric tons of garbage. This garbage must be carefully stored so that it doesn’t accumulate, and is then sent back to the surface on commercial supply vehicles.
This system works well for a station in orbit. But what about spacecraft that are conducted long-duration missions? These ships will not have the luxury of meeting with a regular cadence of commercial ships that will drop off supplies and haul away their garbage. To address this, NASA is investigating possible solutions for how to handle space trash for deep space missions.
For this purpose, NASA is turning to its partners in the commercial sector to develop concepts for Trash Compaction and Processing Systems (TCPS). In a solicitation issued through the Next Space Technologies for Exploration Partnerships (NextSTEP), NASA recently issued a Board Agency Announcement that called for the creation of prototypes and eventually flight demonstrations that would fly to the ISS.
The details of the proposal were outlined in Appendix F of the Board Agency Announcement, titled “Logistics Reduction in Space by Trash Compaction and Processing System“. As they state in this section:
“NASA’s ultimate goal is to develop capabilities to enable missions that are not reliant on resupply from Earth thus making them more sustainable and affordable. NASA is implementing this by employing a capability-driven approach to its human spaceflight strategy. The approach is based on developing a suite of evolving capabilities that provide specific functions to solve exploration challenges. These investments in initial capabilities can continuously be leveraged and reused, enabling more complex operations over time and exploration of more distant solar system destinations.”
When it comes right down to it, storing trash inside a spacecraft is serious challenge. Not only does it consume precious volume, it can also create physical and biological hazards for the crew. Storing garbage also means that leftover resources can not be repurposed or recycled. All told, the BAA solicitation is looking for solutions that will compact trash, remove biological and physical hazards, and recover resources for future use.
To this end, they are looking for ideas and technologies for a TCPS that could operate on future generations of spaceships. As part of the Advanced Exploration Systems (AES) Habitat’s Logistics Reduction (LR), the TCPS is part of NASA’s larger goal of identifying and developing technologies that reduce logistical mass, volume, and the amount of time the crew dedicates to logistics management.
The objectives of the TCPS , as is stated in the Appendix, are fourfold:
“(1) trash compaction to a suitable form for efficient long-endurance storage; (2) safe processing of trash to eliminate and/or reduce the risk of biological activity; (3) stabilize the trash physically, geometrically, and biologically; and (4) manage gaseous, aqueous, and particulate effluents. The TCPS will be the first step toward development and testing of a fully-integrated unit for further Exploration Missions and future space vehicles.”
The development will occur in two phases. In Phase A, selected companies will create a concept TCPS system, conduct design reviews with NASA, and validate them through prototype ground demonstrations. In Phase B, a system will be prepared for transport to the ISS so that a demonstration cant take place aboard the station as early as 2022.
The various companies that submit proposals will not be working in the dark, as NASA has been developing waste management systems since the 1980s. These include recent developments like the Heat Melt Compactor (HMC) experiment, a device that will recover residual water from astronaut’s garbage and compact trash to provide volume reduction (or perhaps an ionizing radiation shield).
Other examples include the “trash to gas” technologies, which are currently being pursued under the Logistics Reduction and Repurposing project (LRR). Using the HMC, this process involves creating methane gas from trash to make rocket propellant. Together, these technologies would not only allow astronauts on long-duration spaceflights to conserve room, but also extract useful resources from their garbage.
NASA plans to host an industry day on July 24th in order to let potential industry partners know exactly what they are looking for, describe available NASA facilities, and answer questions from potential respondents. Official proposals from aspiring partners are due no later than August 22nd, 2018, and whichever proposals make the cut will be tested on the ISS in the coming decade!
New Insights Into What Might Have Smashed Uranus Over Onto its Side
The gas/ice giant Uranus has long been a source of mystery to astronomers. In addition to presenting some thermal anomalies and a magnetic field that is off-center, the planet is also unique in that it is the only one in the Solar System to rotate on its side. With an axial tilt of 98°, the planet experiences radical seasons and a day-night cycle at the poles where a single day and night last 42 years each.
Thanks to a new study led by researchers from Durham University, the reason for these mysteries may finally have been found. With the help of NASA researchers and multiple scientific organizations, the team conducted simulations that indicated how Uranus may have suffered a massive impact in its past. Not only would this account for the planet’s extreme tilt and magnetic field, it would also explain why the planet’s outer atmosphere is so cold.
Continue reading “New Insights Into What Might Have Smashed Uranus Over Onto its Side”Instead of Building Single Monster Scopes like James Webb, What About Swarms of Space Telescopes Working Together?
In the coming decade, a number of next-generation instruments will take to space and begin observing the Universe. These will include the James Webb Space Telescope (JWST), which is likely to be followed by concepts like the Large Ultraviolet/Optical/Infrared Surveyor (LUVOIR), the Origins Space Telescope (OST), the Habitable Exoplanet Imager (HabEx) and the Lynx X-ray Surveyor.
These missions will look farther into the cosmos than ever before and help astronomers address questions like how the Universe evolved and if there is life in other star systems. Unfortunately, all these missions have two things in common: in addition to being very large and complex, they are also very expensive. Hence why some scientists are proposing that we rely on more cost-effective ideas like swarm telescopes.
Two such scientists are Jayce Dowell and Gregory B. Taylor, a research assistant professor and professor (respectively) with the Department of Physics and Astronomy at the University of New Mexico. Together, the pair outlined their idea in a study titled “The Swarm Telescope Concept“, which recently appeared online and was accepted for publication by the Journal of Astronomical Instrumentation.
As they state in their study, traditional astronomy has focused on the construction, maintenance and operation of single telescopes. The one exception to this is radio astronomy, where facilities have been spread over an extensive geographic area in order to obtain high angular resolution. Examples of this include the Very Long Baseline Array (VLBA), and the proposed Square Kilometer Array (SKA).
In addition, there’s also the problem of how telescopes are becoming increasingly reliant on computing and digital signal processing. As they explain in their study, telescopes commonly carry out multiple simultaneous observation campaigns, which increases the operational complexity of the facility due to conflicting configuration requirements and scheduling considerations.
A possible solution, according to Dowell and Taylor, is to rethink telescopes. Instead of a single instrument, the telescope would consist of a distributed array where many autonomous elements come together through a data transport system to function as a single facility. This approach, they claim, would be especially useful when it comes to the Next Generation Very Large Array (NGVLA) – a future interferometer that will build on the legacy of the Karl G. ansky Very Large Array and Atacama Large Millimeter/submillimeter Array (ALMA). As they state in their study:
“At the core of the swarm telescope is a shift away from thinking about an observatory as a monolithic entity. Rather, an observatory is viewed as many independent parts that work together to accomplish scientific observations. This shift requires moving part of the decision making about the facility away from the human schedulers and operators and transitioning it to “software defined operators” that run on each part of the facility. These software agents then communicate with each other and build dynamic arrays to accomplish the goals of multiple observers, while also adjusting for varying observing conditions and array element states across the facility.”
This idea for a distributed telescope is inspired by the concept of swarm intelligence, where large swarms of robots are programmed to interact with each other and their environment to perform complex tasks. As they explain, the facility comes down to three major components: autonomous element control, a method of inter-element communication, and data transport management.
Of these components, the most critical is the autonomous element control which governs the actions of each element of the facility. While similar to traditional monitoring and control systems used to control individual robotic telescopes, this system would be different in that it would be responsible for far more. Overall, the element control would be responsible for ensuring the safety of the telescope and maximizing the utilization of the element.
“The first, safety of the element, requires multiple monitoring points and preventative actions in order to identify and prevent problems,” they explain. “The second direction requires methods of relating the goals of an observation to the performance of an element in order to maximize the quantity and quality of the observations, and automated methods of recovering from problems when they occur.”
The second component, inter-element communication, is what allows the individual elements to come together to form the interferometer. This can take the form of a leaderless system (where there is no single point of control), or an organizer system, where all of the communication between the elements and with the observation queue is done through a single point of control (i.e. the organizer).
Lastly, their is the issue of data transport management, which can take one of two forms based on existing telescopes. These include fully 0ff-line systems, where correlation is done post-observation – used by the Very Long Baseline Array (VLBA) – to fully-connected systems, where correlation is done in real-time (as with the VLA). For the sake of their array, the team emphasized how connectivity and correlation are a must.
After considering all these components and how they are used by existing arrays, Dowell and Taylor conclude that the swarm concept is a natural extension of the advances being made in robotic and thinking telescopes, as well as interferometry. The advantages of this are spelled out in their conclusions:
“It allows for more efficient operations of facilities by moving much of the daily operational work done by humans to autonomous control systems. This, in turn, frees up personnel to focus on the scientific output of the telescope. The swarm concept can also combine the unused resources of the different elements together to form an ad hoc array.”
In addition, swarm telescopes will offer new opportunities and funding since they will consist of small elements that can be owned and operated by different entities. In this way, different organizations would be able to conduct science with their own elements while also being able to benefit from large-scale interferometric observations.
Credit: D. Savransky
This concept is similar to the Modular Active Self-Assembling Space Telescope Swarms, which calls for a swarm of robots that would assemble in space to form a 30 meter (~100 ft) telescope. The concept was proposed by a team of American astronomers led by Dmitri Savransky, an assistant professor of mechanical and aerospace engineering at Cornell University.
This proposals was part of the 2020 Decadal Survey for Astrophysics and was recently selected for Phase I development as part of the 2018 NASA Innovative Advanced Concepts (NIAC) program. So while many large-scale telescopes will be entering service in the near future, the next-next-generation of telescopes could include a few arrays made up of swarms of robots directed by artificial intelligence.
Such arrays would be capable of achieving high-resolution astronomy and interferometry at lower costs, and could free up large, complex arrays for other observations.
Further Reading: arXiv
What Would a Camera on a Breakthrough Starshot Spacecraft See if it’s Going at High Velocity?
In April of 2016, Russian billionaire Yuri Milner announced the creation of Breakthrough Starshot. As part of his non-profit scientific organization (known as Breakthrough Initiatives), the purpose of Starshot was to design a lightsail nanocraft that would be capable of achieving speeds of up to 20% the speed of light and reaching the nearest star system – Alpha Centauri (aka. Rigel Kentaurus) – within our lifetimes.
At this speed – roughly 60,000 km/s (37,282 mps) – the probe would be able to reach Alpha Centauri in 20 years, where it could then capture images of the star and any planets orbiting it. But according to a recent article by Professor Bing Zhang, an astrophysicist from the University of Nevada, researchers could get all kinds of valuable data from Starshot and similar concepts long before they ever reached their destination.
The article appeared in The Conversation under the title “Observing the universe with a camera traveling near the speed of light“. The article was a follow-up to a study conducted by Prof. Zhang and Kunyang Li – a graduate student from the Center for Relativistic Astrophysics at the Georgia Institute of Technology – that appeared in The Astrophysical Journal (titled “Relativistic Astronomy“).
To recap, Breakthrough Starshot seeks to leverage recent technological developments to mount an interstellar mission that will reach another star within a single generation. The spacecraft would consist of an ultra-light nanocraft and a lightsail, the latter of which would accelerated by a ground-based laser array up to speeds of hundreds of kilometers per second.
Such a system would allow the tiny spacecraft to conduct a flyby mission of Alpha Centauri in about 20 years after it is launched, which could then beam home images of possible planets and other scientific data (such as analysis of magnetic fields). Recently, Breakthrough Starshot held an “industry day” where they submitted a Request For Proposals (RFP) to potential bidders to build the laser sail.
According to Zhang, a lightsail-driven nanocraft traveling at a portion of the speed of light would also be a good way to test Einstein’s theory of Special Relativity. Simply put, this law states that the speed of light in a vacuum is constant, regardless of the inertial reference frame or motion of the source. In short, such a spacecraft would be able to take advantage of the features of Special Relativity and provide a new mode to study astronomy.
Based on Einstein’s theory, different objects in different “rest frames” would have different measures of the lengths of space and time. In this sense, an object moving at relativistic speeds would view distant astronomical objects differently as light emissions from these objects would be distorted. Whereas objects in front of the spacecraft would have the wavelength of their light shortened, objects behind it would have them lengthened.
This phenomenon, known as the “Doppler Effect”, results in light being shifted towards the blue end (“blueshift”) or the red end (“redshift”) of the spectrum for approaching and retreating objects, respectively. In 1929, astronomer Edwin Hubble used redshift measurements to determine that distant galaxies were moving away from our own, thus demonstrating that the Universe was in a state of expansion.
Because of this expansion (known as the Hubble Expansion), much of the light in the Universe is redshifted and only measurable in difficult-to-observe infrared wavelengths. But for a camera moving at relativistic speeds, according to Prof. Zhang, this redshifted light would become bluer since the motion of the camera would counteract the effects of cosmic expansion.
This effect, known as “Doppler boosting”, would cause the faint light from the early Universe to be amplified and allow distant objects to be studied in more detail. In this respect, astronomers would be able to study some of the earliest objects in the known Universe, which would offer more clues as to how it evolved over time. As Prof. Zhang explained to Universe Today via email, this would allow for some unique opportunities to test Special Relativity:
“In the rest frame of the camera, the emission of the objects in the hemisphere of the camera motion is blue-shifted. For bright objects with detailed spectral observations from the ground, one can observe them in flight. By comparing their blue-shifted flux at a specific blue-shifted frequency with the flux of the corresponding (de-blueshifted) frequency on the ground, one can precisely test the Doppler boosting prediction in Special Relativity.”
In addition, the frequency and intensity of light – and also the size of distant objects – would also change as far as the observer was concerned. In this respect, the camera would act as a lens and a wide-field camera, magnifying the amount of light it collects and letting astronomers observe more objects within the same field of view. By comparing the observations collected by the camera to those collected by a camera from the ground, astronomers could also test the probe’s Lorentz Factor.
This factor indicates how time, length, and relativistic mass change for an object while that object is moving, which is another prediction of Special Relativity. Last, but not least, Prof. Zhang indicates that probes traveling at relativistic speeds would not need to be sent to any specific destination in order to conduct these tests. As he explained:
“The concept of “relativistic astronomy” is that one does not really need to send the cameras to specific star systems. No need to aim (e.g. to Alpha Centauri system), no need to decelerate. As long as the signal can be transferred back to earth, one can learn a lot of things. Interesting targets include high-redshift galaxies, active galactic nuclei, gamma-ray bursts, and even electromagnetic counterparts of gravitational waves.”
However, there are some drawbacks to this proposal. For starters, the technology behind Starshot is all about accomplishing the dream of countless generations – i.e. reaching another star system (in this case, Alpha Centauri) – within a single generation.
And as Professor Abraham Loeb – the Frank B. Baird Jr. Professor of Science at Harvard University and the Chair and the Breakthrough Starshot Committee – told Universe Today via email, what Prof. Zhang is proposing can be accomplished by other means:
>“Indeed, there are benefits to having a camera move near the speed of light toward faint sources, such as the most distant dwarf galaxies in the early universe. But the cost of launching a camera to the required speed would be far greater than building the next generation of large telescopes which will provide us with a similar sensitivity. Similarly, the goal of testing special relativity can be accomplished at a much lower cost.”
Of course, it will be many years before a project like Starshot can be mounted, and many challenges need to be addressed in the meantime. But it is exciting to know that in meantime, scientific applications can be found for such a mission that go beyond exploration. In a few decades, when the mission begins to make the journey to Alpha Centauri, perhaps it will also be able to conduct tests on Special Relativity and other physical laws while in transit.
Further Reading: The Conversation, The Astrophysical Journal
A Spectacular Grazing Occultation for Aldebaran at Dawn
An unusual celestial spectacle unfolds for observers around the Great Lakes region next Tuesday at dawn. The Moon has been faithfully occulting (passing in front of) the bright star Aldebaran for every lunation now since January 29th, 2015. These split-second events have touched on nearly every farflung corner of the Earth. Now the United States and Canada get to see the penultimate event, as the waning crescent Moon occults Aldebaran one last time for North America.
Many news outlets are advertising this as the “last occultation of Aldebaran until 2033” which isn’t entirely true: the Moon will occult Aldebaran twice more worldwide, once on August 6th and September 3rd. Both of these events, however, involve a thin crescent Moon and occur over high Arctic climes, so I wouldn’t be surprised if they go unwitnessed by human eyes. The next cycle of Aldebaran occultations then resumes on August 18th, 2033.
Four stars brighter than +1st magnitude lie along the Moon’s celestial path in our current epoch: Antares in Scorpius, Regulus in Leo, Spica in Virgo, and Aldebaran in the eye of Taurus the Bull. Fun fact: this celestial situation is also slowly changing, partly because of the slow 26,000 year-plus long top-like wobble of the Earth’s axis known as the Precession of the Equinoxes, but also because of stellar proper motion, which is slowly bringing stars into and out of the Moon’s path over millennia. For example, until 117 BC, the Moon could also occult Pollux in the constellation of Gemini the Twins.
The circumstances for the July 10 event: The morning of July 10th sees the 11% illuminated, waning crescent Moon meet the +0.9 magnitude star Aldebaran under pre-dawn skies. When the Moon is waning, the bright limb leads the way, covering up the star during ingress and revealing once again during egress. The Moon moves its own half a degree (30 arcminute) diameter once every hour, and how long you’ll see Aldebaran covered up depends on your location. The geographic “sweet spot” for the occultation is eastern Minnesota, northeastern Iowa, northern Wisconsin, Lake Superior, the Upper Peninsula of Michigan, Ontario and northern Quebec… though the farther east you are, the brighter the skies will be, until the occultation begins under dark to twilight dawn skies and ends after sunrise.
Tales from the Graze Line
Folks based along a narrow path running for Iowa, across Wisconsin and Michigan into Ontario and Quebec are in for a very special treat, as Aldebaran just grazes in southern limb of the Moon. Instead of one single wink out, Aldebaran will flash multiple times, as it shines down through the jagged valleys along the limb of the Moon, an amazing sight to witness and catch on video.
Here are some times and circumstances for selected cities in the path of the occultation:
| Location | Ingress | Egress | Moon altitude | Sun altitude | Duration |
| Minneapolis | 8:30 | 8:47 | 1deg/3deg | -16deg/-14deg | 17 minutes |
| Green Bay | 8:39 | 8:40 | 5deg/5 deg | -13deg | <1 minute |
| Thunder Bay | 8:32 | 8:54 | 5deg/8 deg | -12deg/-9 deg | 22 minutes |
| Fort Dodge, Iowa | N/A | 8:37 | 0.1 deg | -18 deg | <1 minute |
Notes: all locations listed are in the Central (CDT) time zone (UT-5 for summer time). All times listed are in Universal Time (UT), with the Moon and Sun altitude listed for the beginning and end of the event, rounded to the nearest minute.
Not on the graze line? Well, the rest of us will see a very photogenic near miss on the morning of July 10th… and you might just be able to track Aldebaran up into the daytime sky (make sure you physically block the Sun out of view) if you’ve got clear blue, high contrast skies.
The Moon also occults several fainter stars across the V-shaped Hyades open star cluster around the same time worldwide, as well. One such notable event is the occultation of the +3.7 magnitude star Gamma Tauri for the United Kingdom:
You can follow the July 10th occultation using nothing more than a Mk-1 eyeball, as you can see both the star and the Moon… though binoculars or a telescope will definitely help, as Aldebaran will be tough to pick out against the bright limb of the Moon. Occultations—especially grazing events—really lend themselves to video astrophotography and are simple to capture through a telescope. Just be sure to balance the exposure setting so you can follow the star all the way up to the bright limb of the Moon.
Occultations have inspired those who witnessed them back through pre-telescopic times. A Greek coin from 120 BC may depict an occultation of Jupiter by the Moon. Sultan Alp Arslan was said to have been inspired by a close pairing of Venus and the crescent Moon after the Battle of Manzikert in 1071 AD, adopting the celestial spectacle of the star and crescent which adorns several national flags today.
Also, keep an eye out for an optical illusion described in The Rime of the Ancient Mariner (the poem, not the song by Iron Maiden inspired by the epic tale of the same name), where the protagonist witnesses:
“While clome above the Eastern Bar,
The horned Moon, with one bright Star,
Almost atween the tips.”
This illusion is often referred to as the Coleridge Effect.
Don’t miss this fine occultation of Aldebaran… it’ll be awhile before we see the Moon meet the star again.
-Extra credit: if anyone is planning a live stream of the occultation next Tuesday, let us know.
-The International Occultation Timing Association (IOTA) welcomes observations of any occultations worldwide… in the case of a lunar graze, observations can be used to map out the profile of mountains and valleys along the edge of the Moon.
Carnival of Space #568
This week’s Carnival of Space is hosted by Brian Wang at his NextBigCoins blog.
Click here to read Carnival of Space #568
Continue reading “Carnival of Space #568”
NASA Has Awarded a Contract to Study Flying Drones on Venus
In the coming decades, NASA and other space agencies hope to mount some ambitious missions to other planets in our Solar System. In addition to studying Mars and the outer Solar System in greater detail, NASA intends to send a mission to Venus to learn more about the planet’s past. This will include studying Venus’ upper atmosphere to determine if the planet once had liquid water (and maybe even life) on its surface.
In order to tackle this daunting challenge, NASA recently partnered with Black Swift Technologies – a Boulder-based company specializing in unmanned aerial systems (UAS) – to build a drone that could survive in Venus’ upper atmosphere. This will be no easy task, but if their designs should prove equal to the task, NASA will be awarding the company a lucrative contract for a Venus aerial drone.
In recent years, NASA has taken a renewed interest in Venus, thanks to climate models that have indicated that it (much like Mars) may have also had liquid water on its surface at one time. This would have likely consisted of a shallow ocean that covered much of the planet’s surface roughly 2 billion years ago, before the planet suffered a runaway Greenhouse Effect that left it the hot and hellish world it is today.
In addition, a recent study – which included scientists from NASA’s Ames Research Center and Jet Propulsion Laboratory – indicated that there could be microbial life in Venus’ cloud tops. As such, there is considerable motivation to send aerial platforms to Venus that would be capable of studying Venus’ cloud tops and determining if there are any traces of organic life or indications of the planet’s past surface water there.
As Jack Elston, the co-founded of Black Swift Technologies, explained in an interview with the Daily Camera:
“They’re looking for vehicles to explore just above the cloud layer. The pressure and temperatures are similar to what you’d find on Earth, so it could be a good environment for looking for evidence of life. The winds in the upper atmosphere of Venus are incredibly strong, which creates design challenge.”
To meet this challenge, the company intends to create a drone that will use these strong winds to keep the craft aloft while reducing the amount of electricity it needs. So far, NASA has awarded an initial six-month contract to the company to design a drone and provided specifications on what it needs. This contract included a $125,000 grant by the federal governments’ Small Business Innovation Research program.
This program aims to encourage “domestic small businesses to engage in Federal Research/Research and Development (R/R&D) that has the potential for commercialization.” The company hopes to use some of this grant money to take on more staff and build a drone that NASA would be confident about sending int Venus’ upper atmosphere, where conditions are particularly challenging.
As Elston explained to Universe Today via email, these challenges represent an opportunity for innovation:
“Our project centers around a unique aircraft and method for harvesting energy from Venus’s upper atmosphere that doesn’t require additional sources of energy for propulsion. Our experience working on unmanned aircraft systems that interact with severe convective storms on Earth will hopefully provide a valuable contribution to the ongoing discussion for how best to explore this turbulent environment. Additionally, the work we do will help inform better designs of our own aircraft and should lead to longer observation times and more robust aircraft to observe everything from volcanic plumes to hurricanes.”
At the end of the six month period, Black Swift will present its concept to NASA for approval. “If they like what we’ve come up with, they’ll fund another two-year project to build prototypes,” said Elston. “That second-phase contract is expected to be worth $750,000.”
This is not the first time that Black Swift has partnered with NASA to created unmanned aerial vehicles to study harsh environments. Last year, the company was awarded a second phase contract worth $875,000 to build a drone that could monitor the temperature, gas levels, winds and pressure levels inside the volcanoes of Costa Rica. After a series of test flights, the drone is expected to be deployed to Hawaii, where it will study the geothermal activity occurring there.
If BlackSwift’s concept for a Venus drone makes the cut, their aerial drone will join other mission concepts like the DAVINCI spacecraft, the Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy (VERITAS) spacecraft, the Venus Atmospheric Maneuverable Platform (VAMP), or Russia’s Venera-D mission – which is currently scheduled to explore Venus during the late 2020s.
A number of other concepts are being investigated for exploring Venus’ surface to learn more about its geological history. These include a “Steampunk” (i.e. analog) rover that would rely on no electronic parts, or a vehicle that uses a Stored-Chemical Energy and Power System (SCEPS) – aka. a Sterling engine – to conduct in-situ exploration.
All of these missions aim to reach Venus and brave its harsh conditions in order to determine whether or not “Earth’s Sister Planet” was once a more habitable planet, and how it evolved over time to become the hot and hellish place it is today.
Further Reading: The Drive, Daily Camera
Stunning First Ever Photograph of a Newly Forming Planet
For decades, the most widely-accepted view of how our Solar System formed has been the Nebular Hypothesis. According to this theory, the Sun, the planets, and all other objects in the Solar System formed from nebulous material billions of years ago. This dust experienced a gravitational collapse at the center, forming our Sun, while the rest of the material formed a circumstellar debris ring that coalesced to form the planets.
Thanks to the development of modern telescopes, astronomers have been able to probe other star systems to test this hypothesis. Unfortunately, in most cases, astronomers have only been able to observe debris rings around stars with hints of planets in formation. It was only recently that a team of European astronomers were able to capture an image of a newborn planet, thus demonstrating that debris rings are indeed the birthplace of planets.
The team’s research appeared in two papers that were recently published in Astronomy & Astrophysics, titled “Discovery of a planetary-mass companion within the gap of the transition disk around PDS 70” and “Orbital and atmospheric characterization of the planet within the gap of the PDS 70 transition disk.” The team behind both studies included member from the Max Planck Institute for Astronomy (MPIA) as well as multiple observatories and universities.
For the sake of their studies, the teams selected PDS 70b, a planet that was discovered at a distance of 22 Astronomical Units (AUs) from its host star and which was believed to be a newly-formed body. In the first study – which was led by Miriam Keppler of the Max Planck Institute for Astronomy – the team indicated how they studied the protoplanetary disk around the star PDS 70.
PDS 70 is a low-mass T Tauri star located in the constellation Centaurus, approximately 370 light-years from Earth. This study was performed using archival images in the near-infrared band taken by the Spectro-Polarimetric High-contrast Exoplanet REsearch instrument (SPHERE) instrument on the ESO’s Very Large Telescope (VLT) and the Near-Infrared Coronagraphic Imager on the Gemini South Telescope.
Using these instruments, the team made the first robust detection of a young planet (PDS 70b) orbiting within a gap in its star’s protoplanetary disc and located roughly three billion km (1.86 billion mi) from its central star – roughly the same distance between Uranus and the Sun. In the second study, led by Andre Muller (also from the MPIA) the team describes how they used the SPHERE instrument to measure the brightness of the planet at different wavelengths.
From this, they were able to determine that PDS 70b is a gas giant that has about nine Jupiter masses and a surface temperature of about 1000 °C (1832 °F), making it a particularly “Hot Super-Jupiter”. The planet must be younger than its host star, and is probably still growing. The data also indicated that the planet is surrounded by clouds that alter the radiation emitted by the planetary core and its atmosphere.
Thanks to the advanced instruments used, the team was also able to acquire an image of the planet and its system. As you can see from the image (posted at top) and the video below, the planet is visible as a bright point to the right of the blackened center of the image. This dark region is due to a corongraph, which blocks the light from the star so the team could detect the much-fainter companion.
As Miriam Keppler, a postdoctoral student at the MPIA, explained in a recent ESO press statement:
“These discs around young stars are the birthplaces of planets, but so far only a handful of observations have detected hints of baby planets in them. The problem is that until now, most of these planet candidates could just have been features in the disc.”
In addition to spotting the young planet, the research teams also noted that it has sculpted the protoplanetary disc orbiting the star. Essentially, the planet’s orbit has traced a giant hole in the center of the disc after accumulating material from it. This means that PDS 70 b is still located in the vicinity of its birth place, is likely to still be accumulating material and will continue to grow and change.
For decades, astronomers have been aware of these gaps in the protoplanetary disc and speculated that they were produced by a planet. Now, they finally have the evidence to support this theory. As André Müller explained:
“Keppler’s results give us a new window onto the complex and poorly-understood early stages of planetary evolution. We needed to observe a planet in a young star’s disc to really understand the processes behind planet formation.“
These studies will be a boon to astronomers, especially when it comes to theoretical models of planet formation and evolution. By determining the planet’s atmospheric and physical properties, the astronomers have been able to test key aspects of the Nebular Hypothesis. The discovery of this young, dust-shrouded planet would not have been were if not for the capabilities of ESO’s SPHERE instrument.
This instrument studies exoplanets and discs around nearby stars using a technique known as high-contrast imaging, but also relies on advanced strategies and data processing techniques. In addition to blocking the light from a star with a coronagraph, SPHERE is able to filter out the signals of faint planetary companions around bright young stars at multiple wavelengths and epochs.
As Prof. Thomas Henning – the director at MPIA, the German co-investigator of the SPHERE instrument, and a senior author on the two studies – stated in a recent MPIA press release:
“After ten years of developing new powerful astronomical instruments such as SPHERE, this discovery shows us that we are finally able to find and study planets at the time of their formation. That is the fulfillment of a long-cherished dream.”
Future observations of this system will also allow astronomers to test other aspects of planet formation models and to learn about the early history of planetary systems. This data will also go a long way towards determining how our own Solar System formed and evolved during its early history.
Further Reading: ESO, MPIA, Astronomy & Astrophysics, Astronomy & Astrophysics (2)