The mystery surrounding the closure of the Sunspot Solar Observatory has been (mostly) cleared up. After being closed and vacated on Sept. 6th due to an unspecified security threat, the facility is now open, and will resume normal scientific activities next week.
In a statement, Shari Lifson, spokesperson for the Association of Universities for Research in Astronomy (AURA), the body that operates the Sunspot Observatory, said that the facility was closed as a “precautionary measure.”
We can’t seem to get enough of Saturn. It’s the most visually distinct object in our Solar System (other than the Sun, of course, but it’s kind of hard to gaze at). The Cassini mission to Saturn wrapped up about a year ago, and since then we’re relying on the venerable Hubble telescope to satisfy our appetite for images of the ringed planet.
Even if you know nothing about hurricanes, an unavoidable sense of doom and destruction overtakes you when you look at this image of Hurricane Florence as it moves inexorably toward North and South Carolina.
Even if you didn’t know that the powerful storm is forecast to gain strength as it hits the coast on Friday, or that it will dump several months of rain onto the region in a mere few days, or that the storm surge could reach as high as 9 to 13 ft. If you didn’t know all those things, the picture of Florence taken from space would still fill you with foreboding.
The world’s most powerful telescopes have a lot of work to do. They’re tasked with helping us unravel the mysteries of the universe, like dark matter and dark energy. They’re burdened with helping us find other habitable worlds that might host life. And they’re busy with a multitude of other tasks, like documenting the end of a star’s life, or keeping an eye on meteors that get too close to Earth.
A new study based on data from the Cassini mission is revealing something surprising in the atmosphere of Saturn. We’ve known about the storm at the gas giant’s north pole for decades, but now it appears that this massive hexagonal storm could be a towering behemoth hundreds of kilometers in height that has its base deep in Saturn’s atmosphere.
What if our Solar System had another generation of planets that formed before, or alongside, the planets we have today? A new study published in Nature Communications on April 17th 2018 presents evidence that says that’s what happened. The first-generation planets, or planet, would have been destroyed during collisions in the earlier days of the Solar System and much of the debris swept up in the formation of new bodies.
This is not a new theory, but a new study brings new evidence to support it.
The evidence is in the form of a meteorite that crashed into Sudan’s Nubian Desert in 2008. The meteorite is known as 2008 TC3, or the Almahata Sitta meteorite. Inside the meteorite are tiny crystals called nanodiamonds that, according to this study, could only have formed in the high-pressure conditions within the growth of a planet. This contrasts previous thinking around these meteorites which suggests they formed as a result of powerful shockwaves created in collisions between parent bodies.
“We demonstrate that these large diamonds cannot be the result of a shock but rather of growth that has taken place within a planet.” – study co-author Philippe Gillet
Models of planetary formation show that terrestrial planets are formed by the accretion of smaller bodies into larger and larger bodies. Follow the process long enough, and you end up with planets like Earth. The smaller bodies that join together are typically between the size of the Moon and Mars. But evidence of these smaller bodies is hard to find.
One type of unique and rare meteorite, called a ureilite, could provide the evidence to back up the models, and that’s what fell to Earth in the Nubian Desert in 2008. Ureilites are thought to be the remnants of a lost planet that was formed in the first 10 million years of the Solar System, and then was destroyed in a collision.
Ureilites are different than other stony meteorites. They have a higher component of carbon than other meteorites, mostly in the form of the aforementioned nanodiamonds. Researchers from Switzerland, France and Germany examined the diamonds inside 2008 TC3 and determined that they probably formed in a small proto-planet about 4.55 billion years ago.
Philippe Gillet, one of the study’s co-authors, had this to say in an interview with Associated Press: “We demonstrate that these large diamonds cannot be the result of a shock but rather of growth that has taken place within a planet.”
According to the research presented in this paper, these nanodiamonds were formed under pressures of 200,000 bar (2.9 million psi). This means the mystery parent-planet would have to have been as big as Mercury, or even Mars.
The key to the study is the size of the nanodiamonds. The team’s results show the presence of diamond crystals as large as 100 micrometers. Though the nanodiamonds have since been segmented by a process called graphitization, the team is confident that these larger crystals are there. And they could only have been formed by static high-pressure growth in the interior of a planet. A collision shock wave couldn’t have done it.
But the parent body of the ureilite meteorite in the study would have to have been subject to collisions, otherwise where is it? In the case of this meteorite, a collision and resulting shock wave still played a role.
The study goes on to say that a collision took place some time after the parent body’s formation. And this collision would have produced the shock wave that caused the graphitization of the nanodiamonds.
The key evidence is in what are called High-Angle Annular Dark-Field (HAADF) Scanning Transmission Electron Microscopy (STEM) images, as seen above. The image is two images in one, with the one on the right being a magnification of a part of the image on the left. On the left, dotted yellow lines indicate areas of diamond crystals separate from areas of graphite. On the right is a magnification of the green square.
The inclusion trails are what’s important here. On the right, the inclusion trails are highlighted with the orange lines. They clearly indicate inclusion lines that match between adjacent diamond segments. But the inclusion lines aren’t present in the intervening graphite. In the study, the researchers say this is “undeniable morphological evidence that the inclusions existed in diamond before these were broken into smaller pieces by graphitization.”
To summarize, this supports the idea that a small planet between the size of Mercury and Mars was formed in the first 10 million years of the Solar System. Inside that body, large nanodiamonds were formed by high-pressure growth. Eventually, that parent body was involved in a collision, which produced a shock wave. The shock wave then caused the graphitization of the nanodiamonds.
It’s an intriguing piece of evidence, and fits with what we know about the formation and evolution of our Solar System.
When Elon Musk of SpaceX tweets something interesting, it generates a wave of excitement. So when he tweeted recently that SpaceX might be working on a way to retrieve upper stages of their rockets, it set off a chain of intrigued responses.
SpaceX will try to bring rocket upper stage back from orbital velocity using a giant party balloon
SpaceX has been retrieving and reusing their lower stages for some time now, and it’s lowered the cost of launching payloads into space. But this is the first hint that they may try to do the same with upper stages.
Twitter responders wanted to know exactly what SpaceX has in mind, and what a “giant party balloon” might be. Musk hasn’t elaborated yet, but one of his Twitter followers had something interesting to add.
If you're proposing what I think you are, an ultra low ballistic entry coefficient decelerator, then you and @SpaceX should come see what we have at the @UofMaryland . We've been working on this for awhile and just finished some testing pic.twitter.com/nJBvyUnzaK
Universe Today contacted Mr. Kupec to see if he could help us understand what Musk may have been getting at. But first, a little background.
An “ultra low ballistic entry coefficient decelerator” is a bit of a mouthful. The ballistic coefficient measures how well a vehicle can overcome air resistance in flight. A high ballistic coefficient means a re-entry vehicle would not lose velocity quickly, and would reach Earth at high speeds. An ultra low ballistic entry coefficient decelerator would lose speed quickly, meaning that a vehicle would be travelling at low, subsonic speeds before reaching the ground.
To recover an upper stage booster, low speeds are desirable, since they generate less heat. But according to Kupec, there’s another problem that must be overcome.
“What happens when these things slow down to landing velocities? If your center of gravity is offset significantly behind your center of drag, as would be the case with a returning upper stage, it can get unstable. If the center of gravity of the re-entry vehicle is too high, it can become inverted, which is obviously not desirable.”
So the trick is to lower the speed of the re-entry vehicle to the point where the heat generated by reentry isn’t damaging the booster, and to do it without causing the vehicle to invert or otherwise become unstable. This isn’t a problem for the main stage boosters that SpaceX now routinely recovers; they have their own retro-rockets to guide their descent and landing. But for the upper stage boosters, which reach orbital velocities, it’s an obstacle that has to be overcome.
“My research is specifically focused on how high you can push the center of gravity and still maintain the proper flight configuration,” said Kupec.
But what about the “giant party balloon” that Musk tweeted about?
Musk could be referring, in colorful terms, to what’s called a ballute. The word is a combination of the words balloon and parachute. They were invented in the 1950’s by Goodyear Aerospace. They can arrest the descent of entry vehicles and provide stability during the descent.
“…the balloon would have to be 120 ft. in diameter, and made of a high-temperature fabric…” – Professor Dave Akin, University of Maryland
Universe Today contacted Professor Dave Akin of the University of Maryland for some insight into Musk’s tweet. Professor Akin has been working on reentry systems for over 2 decades.
In an e-mail exchange, Professor Akin told us, “There have been concepts proposed for deploying a large balloon on a cable that is towed behind you on entry. The balloon lowers your ballistic coefficient, which means you decelerate higher in the atmosphere and the heat load is less.” So the key is to scrub your speed before you get closer to Earth, where the atmosphere is thicker and generates more heat.
But according to Professor Akin, this won’t necessarily be easy to do. “To get the two orders of magnitude reduction in ballistic coefficient that Elon has been talking about the balloon would have to be 120 ft. in diameter, and made of a high-temperature fabric, so it’s not going to be all that easy.”
But Musk’s track record shows he doesn’t shy away from things that aren’t easy.
Retrieving upper rocket stages isn’t all about lowering launch costs, it’s also about space junk. The European Space Agency estimates that there are over 29,000 pieces of space junk orbiting Earth, and some of that junk is spent upper stage boosters. There have been some collisions and accidents already, with some satellites being pushed into different orbits. In 2009, the Iridium 33 communications satellite and the defunct Russian Cosmos 2251 communications satellite collided with each other, destroying both. If SpaceX can develop a way to retrieve its upper stage boosters, that means less space junk, and fewer potential collisions.
There’s a clear precedent for using balloons to manage reentry. With people like Professor Akin and Quinn Kupec working on it, SpaceX won’t have to reinvent the wheel. But they’ll still have a lot of work to do.
Musk tweeted one other thing shortly after his “giant party balloon” tweet:
Are you ready for a luxury hotel in space? We all knew it was coming, even though it seems impossibly futuristic. But this time it’s not just science fiction; somebody actually has a plan.
The space hotel will be called “Aurora Station” and the company behind it is Orion Span, a Silicon Valley and Houston-based firm. Orion Span aims to deliver the astronaut experience to people, by delivering the people into space. The catch?
“We developed Aurora Station to provide a turnkey destination in space. Upon launch, Aurora Station goes into service immediately, bringing travelers into space quicker and at a lower price point than ever seen before, while still providing an unforgettable experience” – Frank Bunger, CEO and founder of Orion Span.
First of all, a 12 day stay aboard Aurora Station for two people will cost $19 million US, or $9.5 million per person. Even so, you can’t just buy a ticket and hop on board. Guests must also sign up for three months of Orion Span Astronaut Certification (OSAC). Then they’ll be trained at a facility in Houston, Texas.
So once their cheque has cleared, and once they’re trained, what awaits guests on Aurora Station?
Aurora Station will orbit Earth at 320 km (200 m) and will make the trip around Earth every 90 minutes. If you do the math, that’s 16 sunrises and sunsets each day, and guests will enjoy this slideshow for 12 days. Other than this compressed schedule of 96 sunsets and 96 sunrises during their 12 day stay, guests will also be treated to stunning views of the Earth rolling by underneath them, thanks to the unprecedented number of windows Aurora Station will have.
Aurora Station is the brain-child of Orion Span’s CEO, Frank Bunger. “We developed Aurora Station to provide a turnkey destination in space. Upon launch, Aurora Station goes into service immediately, bringing travelers into space quicker and at a lower price point than ever seen before, while still providing an unforgettable experience,” said Bunger.
Guests won’t be alone on the station, of course. The space hotel will have room for 6 people in total, meaning 4 guests and 2 crew. (You didn’t think you’d be alone up there, did you?) Each pair of guests will still have some alone time though, in what Orion Span calls luxurious private suites for two.
There’s no doubt that staying on a space hotel for 12 days will be the experience of a lifetime, but still, 12 days is a long time. The space station itself will be 5600 square feet, with two suites that can be configured to four. Each suite will be about the size of a small bedroom. Once you’ve gotten used to seeing Earth below you, and you’re used to your suite, what will you do?
Well, there’ll be Wi-Fi of course. So if you’re the type of person who gets bored of orbiting the only planet that we know of that hosts life, and the only planet on which every human civilization has lived and died on, you can always surf the web or watch videos. Aurora Station will also have a virtual-reality holodeck, the cherry-on-top for this science-fiction-come-to- life space resort.
But apparently, boredom won’t be a problem. In an interview with the Globe and Mail, Orion Span CEO Frank Bunger said, ““We talked to previous space tourists, they said 10 days aboard the space station was not enough.” Maybe the extra 2 days in space that Aurora Station guests will enjoy will be just the right amount.
As far as getting guests to the station, that will be up to other private space companies like SpaceX. SpaceX has plans to send tourists on trips around the Moon, and they have experience docking with the International Space Station, so they should be able to transport guests to and from a space hotel.
It doesn’t seem like there’s any shortage of customers. Aurora Station was introduced on April 5th 2018, and the first four months of reservations sold out within 72 hours, with each guest paying a deposit of $80,000 US.
There’s another side to Aurora Station, though. Other than just a nice get-away for people who can afford it, there’s a research aspect to it. Orion Span will offer Aurora Station as a platform for micro-gravity research on a pay-as-you-go basis. It will also lease capacity for in-situ manufacturing and 3D printing research.
But Aurora Station would hardly be in the news if it was only a research endeavour. What’s got people excited is the ability to visit space. And maybe to own some real estate there.
Orion Span is designing Aurora Station to be expandable. They can attach more stations to the original without disrupting anything. And this leads us to Orion Span’s next goal: space condos.
As it says on Orion Span’s website, “Like a city rising from the ground, this unique architecture enables us to build up Aurora Station in orbit dynamically – on the fly – and with no impact to the remainder of Aurora Station. As we add capacity, we will design in condos available for purchase.”
I think we all knew this would happen eventually. If you have the money, you can visit space, and even own a condo there.
The European Southern Observatory (ESO) has released a stunning collection of images of the circumstellar discs that surround young stars. The images were captured with the SPHERE (Spectro-Polarimetric High-contrast Exoplanet REsearch) instrument on the ESO’s Very Large Telescope (VLT) in Chile. We’ve been looking at images of circumstellar disks for quite some time, but this collection reveals the fascinating variety of shapes an sizes that these disks can take.
We have a widely-accepted model of star formation supported by ample evidence, including images like these ones from the ESO. The model starts with a cloud of gas and dust called a giant molecular cloud. Within that cloud, a pocket of gas and dust begins to coalesce. Eventually, as gravity causes material to fall inward, the pocket becomes more massive, and exerts even more gravitational pull. More gas and dust continues to be drawn in.
The material that falls in also gives some angular momentum to the pocket, which causes rotation. Once enough material is accumulated, fusion ignites and a star is born. At that point, there is a proto-star inside the cloud, with unused gas and dust remaining in a rotating ring around the proto-star. That left over rotating ring is called a circumstellar disc, out of which planets eventually form.
There are other images of circumstellar discs, but they’ve been challenging to capture. To image any amount of detail in the disks requires blocking out the light of the star at the center of the disk. That’s where SPHERE comes in.
SPHERE was added to the ESO’s Very Large Telescope in 2014. It’s primary job is to directly image exoplanets, but it also has the ability to capture images of circumstellar discs. To do that, it separates two types of light: polarized, and non-polarized.
Light coming directly from a star—in these images, a young star still surrounded by a circumstellar disc—is non-polarized. But once that starlight is scattered by the material in the disk itself, the light becomes polarized. SPHERE, as its name suggests, is able to separate the two types of light and isolate just the light from the disk. That is how the instrument captures such fascinating images of the disks.
Ever since it became clear that exoplanets are not rare, and that most stars—maybe all stars—have planets orbiting them, understanding solar system formation has become a hot topic. The problem has been that we can’t really see it happening in real time. We can look at our own Solar System, and other fully formed ones, and make guesses about how they formed. But planet formation is hidden inside those circumstellar disss. Seeing into those disks is crucial to understanding the link between the properties of the disk itself and the planets that form in the system.
The discs imaged in this collection are mostly from a study called the DARTTS-S (Discs ARound T Tauri Stars with SPHERE) survey. T Tauri stars are young stars less than 10 million years old. At that age, planets are still in the process of forming. The stars range from 230 to 550 light-years away from Earth. In astronomical terms, that’s pretty close. But the blinding bright light of the stars still makes it very difficult to capture the faint light of the discs.
One of the images is not a T Tauri star and is not from the DARTTS-S study. The disc around the star GSC 07396-00759, in the image above, is actually from the SHINE (SpHere INfrared survey for Exoplanets) survey, though the images itself was captured with SPHERE. GSC 07396-00759 is a red star that’s part of a multiple star system that was part of the DARTTS-S study. The puzzling thing is that red star is the same age as the T TAURI star in the same system, but the ring around the red star is much more evolved. Why the two discs around two stars the same age are so different from each other in terms of time-scale and evolution is a puzzle, and is one of the reasons why astronomers want to study these discs much more closely.
We can study our own Solar System, and look at the positions and characteristics of the planets and the asteroid belt and Kuiper Belt. From that we can try to guess how it all formed, but our only chance to understand how it all came together is to look at other younger solar systems as they form.
The SPHERE instrument, and other future instruments like the James Webb Space Telescope, will allow us to look into the circumstellar discs around other stars, and to tease out the details of planetary formation. These new images from SPHERE are a tantalizing taste of the detail and variety we can expect to see.
One of the technological hurdles of our age is to get people and equipment into space more cheaply. SpaceX gets a lot of the headlines around that, with their reusable rockets. And so does Blue Origin, to some degree. Now a small start-up affiliated with Purdue University is tackling the problem and making some headway.
The company is called Leo Aerospace LLC and they’re using balloons to lower the cost of putting micro-satellites into orbit, rather than reusable rockets. The balloons will be reusable, but the rockets won’t.
Leo Aerospace plans to revive a decades-old method of putting satellites into space. They’re using hot air balloons to lift the rocket and its micro-satellite payload 18 km (11 miles) above Earth. At that altitude, there’s 95% less atmosphere. This means much less drag on the rocket, which translates into smaller rockets with less fuel. This is an intriguing idea, if not for the unfortunate name.
The rockoons will be used to launch rockets into sub-orbital and orbital flights. Sub-orbitals are often used by researchers because it gives them access to zero gravity and to vacuum, both of which are necessary for some experiments. According to Leo Aerospace, there’s something revolutionary about their plans.
“We’re targeting the microsatellites by saying, ‘You don’t have to ride-share with anyone. We can guarantee you will be our only payload and we will be focused on you.’” – Drew Sherman, Leo Aerospace’s Head of Vehicle Development.
They intend on targeting micro-satellite developers. Micro-satellites are often hitch-hikers on larger payloads, which basically means they’re second-class customers. They have to wait until there’s room for their micro-satellite on a traditional rocket carrying a larger payload. This can mean long delays of several months, and that micro-satellite developers have to compromise when it comes to the orbits they can obtain. It can also make micro-satellite missions difficult to plan and execute efficiently and economically. Micro-satellites are becoming more and more capable, so having a launch system tailor-made for them could indeed be revolutionary.
“We’re targeting the microsatellites by saying, ‘You don’t have to ride-share with anyone. We can guarantee you will be our only payload and we will be focused on you,’” said Drew Sherman, Leo Aerospace’s head of vehicle development. “‘We will work with you exclusively to get you into orbit. You won’t have to worry about other payloads or getting dropped off in the wrong spot.’”
The flexibility of the rockoon system that Leo Aerospace is developing will be intriguing for micro-satellites. Rockoons will give micro-satellites the flexibility they need to operate efficiently. The launch can be scheduled and adapted to the needs of the individual satellite. “Our goal is to give people access to space. The only way to do that right now is to help people get their satellite into orbit. That’s where we want to leave our mark,” said Abishek Murali, Head of Mission Engineering at Leo Aerospace.
“Our goal is to give people access to space.” – Abishek Murali, Head of Mission Engineering at Leo Aerospace
The rockoon itself is a hybrid of a balloon and a rocket. The hybrid design takes advantage of physics by using the balloon to float the rocket 18 km high before launching the rocket. The rockoon has Leo Aerospace’s own patent-pending technology to control the pitch and angle of the launch, allowing for precision launches.
Rockoons were first used by the US Air Force back in the 1950s. But this next generation of rockoons, coupled with modern micro-satellites, will be much more capable than the 1950s technology.
Currently, Leo Aerospace is in the development and funding phase. They’ve obtained some funding from the National Science Foundation, and from a venture capital firm. They have about half of the $250,000 they need. They plan to conduct their first sub-orbital flight in 2020, and to launch their first micro-satellite into orbit in 2022. They intend to use existing approved launch sites.
Leo Aerospace was founded by five then-students at Purdue University. Leo started as a club, but the former students have turned it into a business. And that business seems to have a bright future. They conducted a customer discovery and market validation study and found a large demand for a better way to launch micro-satellites.
“We want to be part of the space market,” Murali said. “People are interested in space and creating technologies that not only can operate in space but also help people back on Earth. What we’re trying to do is help them get there.”
But they still need a better name than “rockoons.”