Curiosity Captures Gravity Wave Shaped Clouds On Mars

Curiosity Captures Gravity Wave Shaped Clouds On Mars

This week, from March 20th to 24th, the 48th Lunar and Planetary Science Conference will be taking place in The Woodlands, Texas. Every year, this conference brings together international specialists in the fields of geology, geochemistry, geophysics, and astronomy to present the latest findings in planetary science. One of the highlights of the conference so far has been a presentation about Mars’ weather patterns.

As a team of researchers from the Center for Research in Earth and Space Sciences (CRESS) at York University, demonstrated, Curiosity obtained of some rather interesting images of Mars’ weather patterns over the past few years. These included changes in cloud cover, as well as the first ground-based view of Martian clouds shaped by gravity waves.

When it comes to cloud formations, gravity waves are the result of gravity trying to restore them to their natural equilibrium. And while common on Earth, such formation were not thought to be possible around Mars’ equatorial band, where the gravity waves were seen. All of this was made possible thanks to Curiosity’s advantageous position inside the Gale Crater.

Cirrus clouds in the Martian atmosphere may have helped keep Mars warm enough for liquid water to sculpt the Martian surface. Image: Mars Exploration Rover Mission, Cornell, JPL, NASA

Panoramic image showing cirrus clouds in the Martian atmosphere, taken by the Opportunity rover in 2006. Credit: NASA/JPL/Cornell

Located near Mars’ equator, Curiosity has managed to consistently record what is known as the Aphelion Cloud Belt (ACB).  As the name would suggest, this annually-recurring phenomena appears during the aphelion season on Mars (when it is farthest from the Sun) between the latitudes of 10°S and 30°N. During aphelion, the point farthest from the Sun, the planet is dominated by two cloud systems.

These include the aforementioned ACB, and the polar phenomena known as Polar Hood Clouds (PHCs). Whereas PHCs are characterized by clouds of carbon dioxide, clouds that form around Mars’ equatorial band are made up water-ice. These cloud systems them dissipate as Mars gets closer to the Sun (perihelion), where increases in temperature lead to the creation of dust storms that limit cloud formation.

During the nearly five years that Curiosity has been operational, the rover has recorded over 500 movies of the equatorial Martian sky. These movies have taken the form of both Zenith Movies (ZMs) – which involve the camera being pointed vertically – and Supra-Horizon Movies (SHM), which were aimed at a lower angle of elevation to keep the horizon in frame.

Using Curiosity’s navigation camera, Jacob Kloos and Dr. John Moores – two researchers from CRESS – made eight recordings of the ACB over the course of two Martian years – specifically between Mars Years 31 and Mars Years 33 (ca. 2012 to 2016). By comparing ZM and SHM movies, they were able to discern changes in the clouds that were both diurnal (daily) and annual in nature.

What they found was that between 2015 and 2016, Mars’ ACB underwent changes in opacity (aka. changes in density) during its diurnal cycle. After periods of enhanced early morning activity, the clouds would reach a minimum by late morning. This is followed by a second, lower peak in the late afternoon, which indicated that Mars’ early morning hours are the most favorable time for the formation of thicker clouds.

Hubble images show cloud formations (left) and the effects of a global dust storm on Mars. Credit: NASA/James Bell (Cornell Univ.), Michael Wolff (Space Science Inst.), and Hubble Heritage Team (STScI/AURA)

As for inter-annual variability, they found that between 2012 and 2016, when Mars moved away from aphelion, there was a corresponding 38% increase in the number of higher-opacity clouds. However, believing these results to be the result of a statistical bias caused by an uneven distribution of videos, they concluded that the difference in opacity was more along the lines of about 5%.

These variations were all of this is consistent with tidal temperature variations, where cooler daytime or seasonal temperatures result in greater levels of condensation in the air. The trend of increasing clouds throughout the day was unexpected, however, as higher temperatures should lead to a decrease in saturation. However, as they explained during their presentation, this too could be attributed to daily changes:

“One explanation for the afternoon enhancement put forth by Tamppari et. al. is that as atmospheric temperatures increase the throughout the day, enhanced convection lifts water vapor to the saturation altitude, therefore increasing the likelihood of cloud formation. In addition to water vapor, dust could also be lifted, which act as condensation nuclei, allowing for more efficient cloud formation.”

However, what was most interesting was the fact that during one of day of observation – Sol 1302, or April 5th, 2016 – the team managed to observe something surprising. When looking at the horizon during an SHM, the NavCam caught sight of parallel rows of clouds which all pointed in the same direction. While such ripples are known to happen in the polar regions (where PHCs are concerned), spotting them over the equator was unexpected.

Sunset photographed from Gale Crater by the Mars Curiosity rover on April 15, 2015 taken using the left eye of the rover’s Mastcam. Credit: NASA/JPL-Caltec

But as Moore explained in an interview with Science Magazine, seeing an Earth-like phenomenon on Mars is consistent with what we’ve seen so far from Mars. “The Martian environment is the exotic wrapped in the familiar,” he said. “The sunsets are blue, the dust devils enormous, the snowfall more like diamond dust, and the clouds are thinner than what we see on the Earth.”

At present, it is not clear which mechanism could be responsible for creating these ripples in the first place. On Earth, they are caused by disturbances below in the troposphere, solar radiation, or jet stream sheer. Knowing what could account for them on Mars will likely reveal some interesting things about its atmosphere’s dynamics. At the same time, further research is necessary before scientists can say definitely that gravity waves were observed here.

But in the meantime, these findings are fascinating, and are sure to help advance our knowledge of the Red Planet’s atmosphere and the water cycle on Mars. As ongoing research has shown, Mars still experiences flows of liquid salt water on its surface, and even experiences limited precipitation. And in telling us more about Mars’ present-day meteorology, it could also reveal things about the planet’s watery past.

Further Reading: USRA, Science Magazine

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SpaceX Outbids ULA for Military GPS Contract Igniting Fierce Launch Competition

SpaceX Outbids ULA for Military GPS Contract Igniting Fierce Launch Competition

Upgraded SpaceX Falcon 9 blasts off with Thaicom-8 communications satellite on May 27, 2016 from Space Launch Complex 40 at Cape Canaveral Air Force Station, FL. 1st stage booster landed safely at sea minutes later. Credit: Ken Kremer/kenkremer.com

KENNEDY SPACE CENTER, FL – The fierce competition for lucrative launch contracts from the U.S. Air Force just got more even intense with the announcement that SpaceX outbid arch rival United Launch Alliance (ULA) to launch an advanced military Global Positioning System (GPS III) navigation satellite to orbit in approx. 2 years.

The U.S. Air Force has announced that SpaceX has won the national security contract to launch a single next generation GPS III satellite to Earth orbit in the first half of 2019. The contract award is valued at $96.5 million.

“SpaceX is proud to have been selected to support this important National Security Space Mission,” Gwynne Shotwell, President & COO, told Universe Today in a statement in response to the GPS III award.

“Space Exploration Technologies Corp., Hawthorne, California, has been awarded a $96,500,490 firm-fixed-price contract for launch services to deliver a GPS III satellite to its intended orbit,” the Air Force announced in a statement.

There could be as many as 15 Air Force launch contracts awarded this year in competitive bidding between ULA and SpaceX.

The upshot is that ULA’s decade long near monopoly on national security launches has now been broken several times in the past year with SpaceX outbidding ULA based on the price of their newer Falcon family of rockets compared to ULA’s long established Atlas and Delta rocket families.

Last year SpaceX won the competition to launch the first GPS-III satellite on a Falcon 9 rocket in 2018 after ULA decided not to enter a bid.

“We appreciate the confidence that the U.S. Air Force has placed in our company and we look forward to working together towards the successful launch of another GPS-III mission,” Shotwell elaborated to Universe Today.

ULA did not bid on the first GPS III contract citing the lack of availability of “any Atlas engines available to bid” and other contract factors as the reason for not submitting a bid for the 2018 launch based on the request for proposals (RFP) for the global positioning satellite.

The Atlas V is powered by Russian made RD-180 engines, who’s import for military uses had been temporarily restricted by Congress following the Russian invasion of the Crimea.

The launch price was a deciding factor in the winning bid.

“Each contractor had to prove through their proposal that they could meet the technical, the schedule and the risk criteria,” said Claire Leon,
director of the launch enterprise directorate at the Air Force’s Space and Missile Systems Center, during a media briefing.

“SpaceX was able to do that. I wouldn’t say that they were necessarily better. They adequately met our criteria.”
The Air Force expects SpaceX to achieve a rapid turnaround from winning the bid to actually launching the GPS satellite by April 2019.

“Contractor will provide launch vehicle production, mission integration, launch operations, spaceflight worthiness and mission unique activities for a GPS III mission. Work will be performed at Hawthorne, California; Cape Canaveral Air Force Station, Florida; and McGregor, Texas, and is expected to be complete by April 30, 2019,” said the Air Force.

Only SpaceX and ULA bid on the GPS III satellite launch contract.

“This award is the result of a competitive acquisition with two offers received. Fiscal 2016 space procurement funds in the amount of $96,500,490 are being obligated at the time of award.”

The Air Force opened up military launch contracts to competitive bidding in 2015 after certifying SpaceX as a qualified bidder to launch the nation’s most critical and highly valuable national security satellites on their Falcon 9 booster.

Until 2015, ULA had a near sole source contract with the USAF as the only company certified to bid on and launch those most critical national security satellites. New space upstart SpaceX, founded by billionaire CEO Elon Musk, then forced the bidding issue by filing a lawsuit suing the Air Force.

In response to the lost GPS-III bid, ULA touted their demonstrated record of 100 percent success launching more than 115 satellites.

“United Launch Alliance continues to believe a best value launch service competition with evaluation of mission success and assurance, and past performance including demonstrated schedule reliability, is appropriate and needed for the Phase 1A missions given the technical complexities of rocket launch services and their critical significance to the war fighter and U.S. national security,” ULA spokeswoman Jessica Rye told Universe Today.

“Over the past decade, ULA has provided unmatched reliability with 100 percent mission success and ensured more than 115 satellites were delivered safely to their orbits each and every time. We look forward to continuing to provide the best value launch services to enable our customers’ critical missions.”

ULA Delta IV rocket streaks to orbit carrying the Wideband Global SATCOM (WGS-9) tactical communications satellite for the U.S. Air Force and international partners from Cape Canaveral Air Force Station, Fl, at 8:18 p.m. EDT on Mar. 18, 2017, in this long exposure photo taken on base. Credit: Ken Kremer/kenkremer.com

The most recent ULA launch for the Air Force took place days ago involving the stunning Delta blastoff of the WGS-9 high speed communications satellite on March 18, 2017.

SpaceX has suffered a pair of calamitous Falcon 9 rocket failures in June 2015 and Sept. 2016, destroying both the rocket and payloads for NASA and the AMOS-6 communications satellite respectively.

Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.

Ken Kremer

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New Study Wants To Rip T-Rex From Its Place On Dino Tree

New Study Wants To Rip T-Rex From Its Place On Dino Tree

To kids, there are only two kinds of dinosaurs: meat-eaters and plant-eaters. But to paleontologists, those are just diet distinctions. Paleontologists divide dinos into two different groups based largely on pelvic structure: reptile-hipped saurischians, and bird-hipped ornithischians.

Those two categories are called ‘clades’, and they’re fundamental to the study of dinosaurs. But a new study is casting doubt on those two groups, as well as moving the infamous Tyrannosaurus Rex to a new spot on the dinosaur family tree.

The study, by Matthew G. Baron, David B. Norman & Paul M. Barrett, was published in the journal Nature. If the findings in this study are accepted by paleontologists, then it will upset our understanding of the family tree that was first established in Victorian times.

Pelvic Structure of a reptile-hipped saurischian. Image: By Fred the Oyster, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=35371104

Pelvic structure of a bird-hipped ornithischian. Image: By Fred the Oyster, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=35371104

The T. Rex is the most famous member of the reptile-hipped saurischians. Many other carnivorous theropods are saurischians too, like Giganotosaurus and Spinosaurus. Other famous dinosaurs, like Stegosaurus, are bird-hipped ornithischians. The distinction between the saurischians and the ornithischians has been workable for a long time. But there were always problems with the two clades of dinosaurs.

The Dinosaur Family Tree. Image: By Evolution_of_dinosaurs_by_Zureks.svg: Zureksderivative work: Woudloper (talk) – Evolution_of_dinosaurs_by_Zureks.svg, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=6321464

Some of the earliest ornithischian dinosaurs in the Triassic period had some theropod qualities: they were bipedal and probably meat-eaters. This clouded the separation between ornithischians and saurischians. There are also the herrerasaurids, small dinosaurs not larger than 4 meters long. They were some of the earliest dinosaurs, carnivores that look like both sauropods and theropods, and even though they appear early in the fossil record, they are not considered ancestors to any other group of dinosaurs. They show a mixture of both primitive and derived traits.

Huge plant-eating sauropods like the Brontosaurus and the Diplodocus are included in the reptile-hipped saurischians with the meat-eating theropods, even though there are some key skeletal differences between the two groups.

Another problem centers around birds. Believe it or not, birds have theropods as ancestors, even though theropods are in the reptile-hipped clade, rather than the bird-hipped clade.

Are You Confused Yet?

If this all seems kind of confusing, let’s back up for a minute.

When we think of dinosaurs, we tend to think of full-scale rebuilt skeletons of the type on display in museums around the world. But for paleontologists, the reality is much different. Many dinosaur species are known only by a few bones or teeth. These samples are studied in great detail. Any groove in a bone or slightly different shape in a tooth is analyzed, and out of this a dinosaur family tree is constructed.

It’s hard work, and our fossil record is spotty at best. Some new dinosaur taxa are proposed based only on the discovery of isolated teeth in the fossil record. With all of this in mind, you can see that the dinosaur family tree is an ongoing work in progress.

The authors of the study say that many ornithischian dinosaurs were overlooked in the past, because paleontologists didn’t really know what to do with them. Many of the ornithischians had weird traits like extra chin bones and molar-like teeth in their cheeks. These ornithischian dinos were thought of as oddities, early offshoots from other species.

New Clades

The authors studied 457 traits in 74 taxa, looking at details like the shapes of tiny eye-socket bones and grooves on femurs. They found that Theropods, even though they have reptile-like hips, don’t belong in the saurischian clade. They’re suggesting that Theropods are a sister clade to the ornithischians. The revised grouping of Ornithischia and Theropoda has been named the Ornithoscelida. The authors are also proposing that the herrerasaurids did not branch off as early as previously thought, and should form a sister clade with the sauropods.

But this study does even more. It’s been long understood by paleontologists that dinosaurs appeared in the southern hemisphere first. That’s where the herrerasaurids were found, dating back to 240 million years ago. The authors remind us that there are very few Herrerasaurus skeletons and bones, and there are uncertainties in the age of the Triassic fossil beds where herrerasaurids are found. A nearly complete skeleton was found in Argentina, and less complete ones have been found in North America.

But this shuffling of the family tree moves the herrerasaurids further away from the base of the tree. Remember, the herrerasaurids look like both sauropods and theropods, and they show both derived and primitive traits. If it’s accepted that the herrerasaurids did not appear as early as thought, that might mean that dinos did not appear first in the southern hemisphere. The authors say that some enigmatic fossils found in the northern hemisphere should be re-examined in case they are earlier than the ones found in the south.

Enter the Saltopus

A fossil of a cat-like creature found in Scotland, called the Saltopus, is a part of the shake-up of the dinosaur family tree. It was considered a pre-cursor to dinosaurs, rather than a true dinosaur. As part of their analysis, the Saltopus has been re-positioned in the earliest part of the dinosaur lineage, as the first true dinosaur. This supports the idea that dinosaurs appeared first in the northern hemisphere rather than the south.

The Saltopus, a small cat-sized dinosaur found in Scotland. If it is the first dinosaur, that means dinosaurs originated in the northern hemisphere rather than the south. Image: By Nobu Tamura email:nobu.tamura@yahoo.com http://spinops.blogspot.com/ http://paleoexhibit.blogspot.com/ – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=50251442

If this new family tree for dinosaurs is accepted, it will change our understanding of the way dinosaurs evolved. We’ve relied on similarity in hip shape to ascertain ancestry, but that may be a little simplistic.

Our understanding of dinosaurs changes frequently. Remember when dinosaurs were slow, dim-witted creatures with tiny brains and huge bodies? Now we think of dinosaurs as feathered and fast, using cunning and perhaps teamwork to hunt in packs. Remember when the prevailing wisdom was that some dinosaurs got so large and spiny that they were doomed to extinction? That was proven false as well.

If it does stick, this new family tree will be a huge change in paleontology, a field where knowledge is overturned on a regular basis, sometimes by little more than a few teeth.

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Astronauts Capture Great Views of Mount Etna Eruption

Astronauts Capture Great Views of Mount Etna Eruption

Mount Etna is Europe’s most active volcano, and it’s been spouting off since late February 2017. It spewed lava and gas with a rather big eruption last week, where 10 people were actually injured. The Expedition 50 crew on board the International Space Station have been able to capture both day and nighttime views of the activity from orbit.

The stunning view, above, was taken on March 17, 2017. The original photo, which you can see on NASA’s Gateway to Astronaut Photography of Earth website is actually a bit hard to make out. But space enthusiast Riccardo Rossi from Modena, Italy enhanced the original with color correction and increased the contrast with Photoshop. You can see the full version of Rossi’s enhancements on Flickr. .

ESA astronaut Thomas Pesquet took the image below on March 19, and shared it on Twitter, writing, “Mount Etna, in Sicily. The volcano is currently erupting and the molten lava is visible from space, at night! (the red lines on the left).”

A nighttime view from orbit of Mount Etna, erupting on March 19, 2017, taken by ESA astronaut Thomas Pesquet. The red streaks on the lower left are molten lava. See detail below. Credit: NASA/ESA.

This crop shows the glowing lava:

A crop of the above image, showing detail of the glowing lava at night from Mount Etna’s recent activity. Credit: NASA/ESA.

Mount Etna towers above the city of Catania on the island of Sicily. Scientists estimate it has been active for about 500,000 years. The first recorded eruption dates back to 1500 B.C., and it has erupted over 200 times since then.

NASA’s Suomi NPP satellite also spotted nighttime activity from orbit. The image was acquired by the Visible Infrared Imaging Radiometer Suite (VIIRS), using its “day-night band,” which detects light in a range of wavelengths and uses filtering techniques to observe signals such as gas flares, city lights, and reflected moonlight. In this image, it detected the nighttime glow of molten lava.

A view of Sicily and Mount Etna during the dark morning hours of March 16, 2017, taken by the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite. Credit: NASA.

Further reading:
NASA Image of the Day
NASA Earth Observatory

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Curiosity’s Battered Wheels Show First Breaks

Curiosity’s Battered Wheels Show First Breaks

Since it landed on August 6th, 2012, the Curiosity rover has spent a total of 1644 Sols (or 1689 Earth days) on Mars. And as of March 2017, it has traveled almost 16 km (~10 mi) across the planet and climbed almost a fifth of a kilometer (0.124 mi) uphill. Spending that kind of time on another planet, and traveling that kind of distance, can certainly lead to its share of wear of tear on a vehicle.

That was the conclusion when the Curiosity science team conducted a routine check of the rover’s wheels on Sunday, March 19th, 2017. After examining images taken by the Mars Hand Lens Imager (MAHLI), they noticed two small breaks in the raised treads on the rover’s left middle wheel. These breaks appeared to have happened since late January, when the last routine check of the wheels took place.

To get around, the Curiosity rover relies on six solid aluminum wheels that are 40 cm (16 in) wide. The skin of the wheels is thinner than a US dime, but each contains 19 zigzag-shaped treads that are about 0.75 cm (three-quarters of an inch) thick. These “grousers”, as they are called, bear most of the rover’s weight and provide most of the wheel’s traction.

Close-up image of the broken grousers on Curiosity’s left-middle wheel. Credit: NASA/JPL-Caltech/MSSS

Ever since the rover was forced to cross a stretch of terrain that was studded with sharp rocks in 2013, the Curiosity team has made regular checks on the rover’s wheels using the MAHLI camera. At the time, the rover was moving from the Bradbury Landing site (where it landed in 2012) to the base of Mount Sharp, and traversing this terrain caused holes and dents in the wheels to grow significantly.

However, members of Curiosity’s science team emphasized that this is nothing to be worried about, as it will not affect the rover’s performance or lifespan. As Jim Erickson, the Curiosity Project Manager at NASA’s Jet Propulsion Laboratory, said in a recent NASA press statement:

“All six wheels have more than enough working lifespan remaining to get the vehicle to all destinations planned for the mission. While not unexpected, this damage is the first sign that the left middle wheel is nearing a wheel-wear milestone.”

In addition to regular monitoring, a wheel-longevity testing program was started on Earth in 2013 using identical aluminum wheels. These tests showed that once a wheel got to the point where three of its grousers were broken, it had passed about 60% of its lifespan. However, Curiosity has already driven more than 60% of the total distance needed for it to make it to all of its scientific destinations.

Graphic depicting aspects of the driving distance, elevation, geological units and time intervals of NASA’s Curiosity Mars rover mission, as of late 2016. Credit: NASA/JPL-Caltech

Curiosity’s Project Scientist – Ashwin Vasavada, also at JPL – was similarly stoic in his appraisal of this latest wheel check:

“This is an expected part of the life cycle of the wheels and at this point does not change our current science plans or diminish our chances of studying key transitions in mineralogy higher on Mount Sharp.”

At present, Curiosity is examining sand dunes in the geographical region known as the Murray Buttes formation, which is located on the slope of Mount Sharp. Once finished, it will proceed up higher to a feature known as “Vera Rubin Ridge”, inspecting a layer that is rich in the mineral hematite. From there, it will proceeded to even higher elevations to inspect layers that contain clays and sulfates.

Getting to the farthest destination (the sulfate unit) will require another 6 km (3.7 mi) of uphill driving. However, this is a short distance compared to the kind of driving the rover has already performed. Moreover, the science team has spent the past four years implementing various methods designed to avoid embedded rocks and other potentially hazardous terrain features.

MRO image of Gale Crater illustrating the landing location and trek of the Rover Curiosity. Credits: NASA/JPL, illustration, T.Reyes

It is expected that this drive up Mount Sharp will yield some impressive scientific finds. During its first year on Mars, Curiosity succeeded in gathering evidence in the Gale Crater that showed how Mars once had conditions favorable to life. This included ample evidence of liquid water, all the chemical elements needed for life, and even a chemical source of energy.

By scaling Mount Sharp and examining the layers that were deposited over the course of billions of years, Curiosity is able to examine a living geological record of how the planet has evolved since then. Luckily, the rover’s wheels seem to have more than enough life to make these and (most likely) other scientific finds.

Further Reading: NASA – Mars Exploration

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Why Doesn’t Earth Have Rings?

Why Doesn’t Earth Have Rings?

Before we really get started on today’s episode, I’d like to share a bunch of really cool pictures created by my friend Kevin Gill. Kevin’s a computer programmer, 3-D animator and works on climate science data for NASA.

And in his spare time, he uses his skills to help him imagine what the Universe could look like. For example, he’s mapped out what a future terraformed Mars might look like based on elevation maps, or rendered moons disturbing Saturn’s rings with their gravity.

Earth’s Rings over San Bernadino. Credit: Kevin Gill (CC BY-SA 2.0)

But one of my favorite sets of images that Kevin did were these. What would it look like if Earth had rings? Kevin and his wife went to a few cool locations, took some landscape pictures, and then Kevin did the calculations for what it would look like if Earth had a set of rings like Saturn.

And let me tell you, Earth would be so much better. At least you’d think so, but actually, it might also suck.

Last time I checked, we don’t have rings like this. In fact, we don’t have any rings at all.

Why not? Considering the fact that Saturn, Jupiter, Uranus and Neptune all have rings, don’t we deserve at least something?

Did we ever have rings in the past, or will we in the future? What’s it going to take for us to join the ring club? Short answer, an apocalypse.

Before we get into the inevitable discussion of death and devastation, let’s talk a bit about rings.

A lovely view of Saturn and its rings as seen by the Cassini spacecraft on Aug. 12, 2009. Credit: NASA/JPL-Caltech/Space Science Institute.

Saturn is the big showboat, with its fancy rings. They’re made of water ice, with chunks as big as a mountain, or as small as a piece of sand. Astronomers have been arguing about where they came from and how old they are, but the current consensus – sort of – is that the rings are almost as ancient as Saturn itself: billions of years old. And yet, some process is weathering the rings, grinding the particles so they appear much younger.

Jupiter’s rings. Image Credit: University of Maryland

Jupiter’s rings are much fainter, and we didn’t even know about them until 1979, when the Voyager spacecraft made their flybys. The rings seem to be created by dust blown off into space by impacts on the planet’s moons.

Hey, we’ve got a moon, that’s a sign.

Uranus imaged by Voyager 2 in 1986. Credit: NASA

The rings around Uranus are bigger and more complex than Jupiter’s rings, but not as substantial as Saturn’s. They’re much younger, perhaps only 600 million years old, and appear to have been caused by two moons crashing into each other, long ago.

Again, another sign. We still have the potential for stuff to crash around us.

The labeled ring arcs of Neptune as seen in newly processed data. The image spans 26 exposures combined into a equivalent 95 minute exposure, and the ring trace and an image of the occulted planet Neptune is added for reference. Credit: M. Showalter/SETI Institute

The rings around Neptune are far dustier than any of the other ring systems, and much younger than the Solar System. And like the rings around Uranus, they were probably formed when two or more of its moons collided together.

Now what about our own prospects for rings?

The problem with icy rings is that the Earth orbits too closely to the Sun. There’s a specific point in the Solar System known as the “frost line” or “snow line”. This is the point in the Solar System where deposits of ice could have survived for long periods of time. Any closer and the radiation from the Sun sublimates the ice away.

This point is actually located about 5 astronomical units away from the Sun, in the asteroid belt. Mars is much closer, so it’s very dry, while Jupiter is beyond the frost line, and its moons have plenty of water ice.

The Earth is a mere 1 AU from the Sun. That’s the very definition of an astronomical unit, which means it’s well within the frost line. The Earth itself can maintain water because the planet’s magnetosphere acts like a shield against the solar wind. But the Moon is bone dry (except for the permanently shadowed craters at its poles).

And if there was an icy ring system around the Earth, the solar wind would have blasted it away long ago.

Instead, let’s look at another kind of ring we can have. One made of rock and dust, containing death and sorrow, from a pulverized asteroid or moon. In fact, billions of years ago, we definitely had a ring when a Mars-sized planet crashed into the Earth and spewed out a massive ring of debris. This debris collected together into the Moon we know today. That impact turned the Earth’s surface inside out. It was all volcanoes, everywhere, all the time.

Credit: Kevin Gill (CC BY-SA 2.0)

It’s also possible we had a second moon in the ancient past, which collided with our current Moon. That would have generated an all new ring of material for millions of years until it was recaptured by the Moon, kicked out of orbit, or fell down onto the Earth.

It’s that “fell down onto Earth” part that’s apocalyptic. As mountains of ring material entered the Earth’s atmosphere, it would increase the temperature, baking and boiling away any life that couldn’t burrow deep underground.

It’s kind of like the book Seveneves, which you should totally read if you haven’t already. It talks about what we would see if the Moon broke apart into a ring, and the terrible terrible thing that happens next.

Earth’s Rings from New Hampshire. Credit: Kevin Gill (CC BY-SA 2.0)

If Earth did get a set of rings, they’d be pretty, but they’d also be a huge pain for astronomers. As you saw in Kevin’s original pictures, the rings take up a huge chunk of the sky for most observers. The farther north or south you go, the more dramatically the rings will ruin your view. Only if you were right at the equator, you’d have a thin line, which would be borderline acceptable.

Furthermore, the rings themselves would be incredibly reflective, and completely ruin the whole concept of dark skies. You know how the Moon sucks for astronomy? Rings would be way way worse.

Finally, rings would interfere with our ability to launch spacecraft and maintain satellites. It depends on how far they extend, but we wouldn’t be able to have any satellites in that region or cross the ring plane. Oh, and that fiery death apocalypse I mentioned earlier.

We know that the Moon is drifting away from the Earth right now thanks to the conservation of angular momentum. But in the distant future, billions of years from now, there might be a scenario that turns everything around.

The Sun’s habitable zone in its red giant phase. Credit: NASA/Goddard Space Flight Center Conceptual Image Lab

As you know, when it runs out of fuel in its core, the Sun is going to bloat up as a red giant, consuming Mercury and Venus. Scientists are on the fence about Earth. Some think that Earth will be fine. The Sun will blast off its outer layers, but not actually envelop Earth. Others think that at the Sun’s largest point, we’ll be orbiting within the outer atmosphere of the Sun. Ouch, that’s hot.

The orbiting Moon will experience drag as it goes around the Earth, slowing down its orbital velocity, and causing it to spiral inward. Once it reaches the Roche Limit of the Earth, about 9,500 km, our planet’s gravity will tear the Moon apart into a ring. The chunks in the ring will also experience drag in the solar atmosphere and continue to spiral inward until they crash into the planet.

The Moon tearing apart to become a ring around Earth. Credit: Universe Sandbox ²

That would be considered a very bad day, if it wasn’t for the fact that we were already living inside the atmosphere of the Sun. No amount of terraforming will fix that.

Sadly, the Earth doesn’t have rings like Saturn, and it probably never did. It might have had rings of rock and dust for periods, but they weren’t that majestic to look at. In fact, seeing rings around the planet would mean we’d lost a moon, and our planet was about go through a period of bombardment. I’ll pass.

The post Why Doesn’t Earth Have Rings? appeared first on Universe Today.

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SpaceX & NASA Studying 2020 Landing Sites For Dragon

SpaceX & NASA Studying 2020 Landing Sites For Dragon

As part of their effort to kick-start the eventual colonization of Mars, SpaceX is sending an unmanned Dragon spacecraft to Mars. Initially, that mission was set for 2018, but is now re-scheduled for 2020. Now, SpaceX says they’re working with NASA to select a suitable landing site for their first Dragon mission to Mars.

At a presentation in Texas on March 18th, Paul Wooster of SpaceX said that they have been working with scientists at NASA’s Jet Propulsion Laboratory (JPL) to identify candidate landing sites on the surface of Mars. In order to aid colonization, the sites need to be:

  • near the equator, for solar power
  • near large quantities of ice, for water
  • at low elevation, for better thermal conditions

But finding a site that meets those conditions is difficult.

According to SpaceNews, the study done with NASA initially recognized 4 regions in Mars’ northern hemisphere, all within 40 degrees of the equator. They are Deuteronilus Mensae, Phlegra Montes, Utopia Planitia, and Arcadia Planitia.

Deuteronilus Mensae

Deuteronilus Mensae (DM) is located between older, cratered highlands and low plains. DM shows evidence of glacial activity in its surface features. In fact, there are still glaciers there, which makes it a desirable source of ice.

Deuteronilus Mensae (DM)has many rough surface features. The Mars Reconnaissance Orbiter has shown that many areas in DM are sub-surface glaciers covered by a thin layer of debris. Image: NASA/JPL/University of Arizona

Phlegra Montes

Phlegra Montes (PM) is a system of mountains on the Martian surface, over 1300 km across. It’s a complex system of basins, hills, and ridges. They are likely tectonic in origin, rather than volcanic, and the region probably contains large quantities of water ice, perhaps 20 meters below the surface.

This tongue shaped flow of material at Phlegra Montes may have been formed by a flow of ice-rich material. Image: NASA/JPL/University of Arizona

Utopia Planitia

Utopia Planitia (UP) is the region where the Viking 2 lander set down in 1976. At 3300 km in diameter, UP is the largest impact basin in the Solar System. In 2016, NASA found a huge deposit of underground ice there. The water is estimated to be the same volume as Lake Superior.

Periglacial features in a small crater in Utopia Planitia. Periglacial refers to the seasonal thawing of snow and ice which refreezes in other shapes. Image: NASA/JPL/University of Arizona

Arcadia Planitia

Arcadia Planitia (AP) is a smooth plain containing fresh lava flows. It also has a large region that was shaped by periglacial processes. This supports the idea that ice is present just beneath the surface, making it a candidate for colonization efforts.

Arcadia Planitia likely has ice just beneath its surface. The knobby pattern is probably caused by the uneven seasonal melting of sub-surface ice. Image: NASA/JPL/University of Arizona

The image below shows the Arcadia Planitia region in relation to some of its surroundings. Colonists at AP might have a great view of Olympus Mons, the largest volcano in the Solar System.

Colonists in Arcadia Planitia (upper left in map) might have a great view of Olympus Mons.

The four areas looked suitable in images from a medium resolution camera (CTX) on the Mars Reconnaissance Orbiter (MRO). But when the High Resolution Imaging Science Experiment (HiRISE) camera on the same orbiter was used to look more closely, the first three locations appeared to be much rockier. According to SpaceNews, Wooster said ““The team at JPL has been finding that, while the areas look very flat and smooth at CTX resolution, with HiRISE images, they’re quite rocky. That’s been unfortunate in terms of the opportunities for those sites.”

The fourth area, Arcadia Planitia, is a more promising site. HiRISE images showed that it is much less rocky and could be a suitable site for the first Dragon mission to Mars.

The Dragon mission to Mars is just the first step for SpaceX. They see themselves as an interplanetary transportation company eventually. SpaceX intends to send a craft to Mars every two years, when the launch window is optimal. SpaceX says they’ll have the ability to deliver one ton of payload to the Martian surface with each Dragon mission.

Their Interplanetary Transport System (ITS) might have the capability to make it to Mars in as little as 80 days, while carrying a payload of up to 450 tons. While still in the very initial stages of design, it may eventually revolutionize our ability to colonize Mars in any meaningful or enduring way. SpaceX envisions a fleet of craft in the ITS which will constantly make the return to trip to Mars.

If that ever happens, we may look at the first Dragon mission to Arcadia Planitia, or another eventual landing site, as the first step.

The post SpaceX & NASA Studying 2020 Landing Sites For Dragon appeared first on Universe Today.

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What’s the Difference Between a Rocket and Space Plane? Amazing Hand-Drawn Animations Explain It All

What’s the Difference Between a Rocket and Space Plane? Amazing Hand-Drawn Animations Explain It All

You gotta love Earth’s atmosphere. It basically makes life (as we know it) possible on our planet by providing warmth and air to breathe, as well as protecting us from nasty space things like radiation and smaller asteroids. But for studying space (i.e., astronomy) or coming back to Earth from space, the atmosphere is a pain.

Last year, we introduced you to freelance animator and storyboard artist Stanley VonMedvey, who started creating short, hand-drawn videos to explain a complex topic: how spacecraft work. These videos are wonderfully concise, clear and easy to understand. Plus Stan’s hand-drawn animations are incredible.

His series, “Stan Draws Spaceships” now has a new video that shows the complexities of how spacecraft return to Earth through our atmosphere, comparing the partially reusable Falcon 9 and fully reusable Skylon. Take a look below. Again, the hand-drawn animations are impeccable and Stan’s explanations are just captivating.

I was trying to think of sufficient accolades for Stan’s work, but I can’t do any better than one commentor on Stan’s YouTube Channel. MarsLettuce said, “The attention to detail here is insane. The air intake being shorn off by drag was especially great. The sequence of her hands making the paper plane was subdued, but it added a lot. The characters were really well done, too. I love the reaction of Stan being hit by the paper airplane. It’s hilarious.”

Stan’s earlier videos explain expendable launch vehicles and the space shuttle.

He describes himself as “completely obsessed with and fascinated by space exploration,” and he wants to share what he’s learned over the years about spaceflight.

Stan would like the opportunity and resources to make more videos, and has started a Patreon page to help in this process. Right now, he creates the videos on his own (he told us he uses the time-honored home-recording technique of draping a blanket over his head) in his home office. It takes him roughly 2.5 months to produce a 5 minute episode.

“I’d like to make a lot more videos,” he writes on Patreon, “explaining things like Hohmman transfers and laser propulsion and the construction techniques of O’Neill cylinders. I want to make long form videos (2-3 minutes) that explain a general idea, and short form videos (30 seconds) that cover a single word, like “ballistics” or “reaction control.”

An artist’s conception of Reaction Engines’ Skylon spacecraft. Credit: Reaction Engines

So, check out Stan’s videos and his Patreon page. If you’d like to see more, consider supporting his work. See more of his drawings at his website.

The post What’s the Difference Between a Rocket and Space Plane? Amazing Hand-Drawn Animations Explain It All appeared first on Universe Today.

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Rosetta Images Show Comet’s Changing Surface Close Up

Rosetta Images Show Comet’s Changing Surface Close Up

The Rosetta spacecraft learned a great deal during the two years that it spent monitoring Comet 67P/Churyumov-Gerasimenko – from August 6th, 2014 to September 30th, 2016. As the first spacecraft to orbit the nucleus of a comet, Rosetta was the first space probe to directly image the surface of a comet, and observed some fascinating things in the process.

For instance, the probe was able to document some remarkable changes that took place during the mission with its OSIRIS camera. According to a study published today (March. 21st) in Science, these included growing fractures, collapsing cliffs, rolling boulders and moving material on the comet’s surface that buried some features and exhumed others.

These changes were noticed by comparing images from before and after the comet reached perihelion on August 13th, 2015 – the closets point in its orbit around the Sun. Like all comets, it is during this point in 67P/Churyumov-Gerasimenko’s orbit that the surface experiences its highest levels of activity, since perihelion results in greater levels of surface heating, as well as increased tidal stresses.

Images taken by Rosetta’s OSIRIS camera show changes in the surface between 2015 and 2016. Credit: ESA/Rosetta/NAVCAM (top center images); ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA (all others)

Basically, as comets gets closer to the Sun, they experience a combination of in-situ weathering and erosion, sublimation of water-ice, and mechanical stresses arising from an increased spin rate. These processes can be either unique and transient, or they can place over longer periods of time.

As Ramy El-Maarry, a scientist from the Max-Planck Institute for Solar System Research and the lead author of the study, said in an ESA press statement:

“Monitoring the comet continuously as it traversed the inner Solar System gave us an unprecedented insight not only into how comets change when they travel close to the Sun, but also how fast these changes take place.”

For instance, in-situ weathering occurs all over the comet and is the result of heating and cooling cycles that happen on both a daily and a seasonal basis. In the case of 67P/Churyumov-Gerasimenko’s (6.44 Earth years), temperatures range from 180 K (-93 °C; -135 °F) to 230 K (-43 °C; -45 °F) during the course of its orbit. When the comet’s volatile ices warm, they cause consolidated material to weaken, which can cause fragmentation.

Combined with the heating of subsurface ices – which leads to outgassing – this process can result in the sudden collapse of cliff walls. As other photographic evidence that was recently released by the Rosetta science team can attest, this sort of process appears to have taken place in several locations across the comet’s surface.

Images showing a new fracture and boulder movement in Anuket. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/ID

Similarly, comets experience increased stress because their spin rates speed up as they gets closer to the Sun. This is believed to be what caused the 500 meter-long (1640 ft) fracture that has been observed in the Anuket region. Originally discovered in August of 2014, this fracture appeared to have grown by 30 meters (~100 ft) when it was observed again in December of 2014.

This same process is believed to be responsible for a new fracture that was identified from OSIRIS images taken in June 2016. This 150-300 meter-long (492 – 984 ft) fracture appears to have formed parallel to the original. In addition, photographs taken in February of 2015 and June of 2016 (shown above) revealed how a 4 meter-wide (13 ft) boulder that was sitting close to the fractures appeared to have moved by about 15 meters (49 ft).

Whether or not the two phenomena are related is unclear. But it is clear that something very similar appears to have taken place in the Khonsu region. In this section of the comet (which corresponds to one of its larger lobes), images taken between May of 2015 and June 2016 (shown below) revealed how a much larger boulder appeared to have moved even farther between the two time periods.

Images showing a moving boulder in the Khonsu region. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

This boulder – which measures some 30 meters (98 ft) across and weighs an estimated 12,800 metric tonnes (~14,100 US tons) – moved a distance of about 140 meters (~460 ft). In this case, outgassing during perihelion is believed to be the culprit. On the one hand, it could have caused the surface material to erode beneath it (thus causing it to roll downslope) or by forcibly pushing it.

For some time, it has been known that comets undergo changes during the course of their orbits. Thanks to the Rosetta mission, scientists have been able to see these processes in action for the first time. Much like all space probes, vital information continues to be discovered long after the Rosetta mission officially came to an end. Who knows what else the probe managed to witness during its historic mission, and which we will be privy to?

Further Reading: ESA

The post Rosetta Images Show Comet’s Changing Surface Close Up appeared first on Universe Today.

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Large Hadron Collider Discovers 5 New Gluelike Particles

Large Hadron Collider Discovers 5 New Gluelike Particles

Since it began its second operational run in 2015, the Large Hardon Collider has been doing some pretty interesting things. For example, starting in 2016, researchers at CERN began using the collide to conduct the Large Hadron Collider beauty experiment (LHCb). This is investigation seeks to determine what it is that took place after the Big Bang so that matter was able to survive and create the Universe that we know today.

In the past few months, the experiment has yielded some impressive results, such as the measurement of a very rare form of particle decay and evidence of a new manifestation of matter-antimatter asymmetry. And most recently, the researchers behind LHCb have announced the discovery of a new system of five particles, all of which were observed in a single analysis.

According to the research paper, which appeared in arXiv on March 14th, 2017, the particles that were detected were excited states of what is known as a “Omega-c-zero” baryon. Like other particles of its kind, the Omega-c-zero is made up of three quarks – two of which are “strange” while the third is a “charm” quark. The existence of this baryon was confirmed in 1994. Since then, researchers at CERN have sought to determine if there were heavier versions.

The LHCb collaboration team. Credit: lhcb-public.web.cern.ch

And now, thanks to the LHCb experiment, it appears that they have found them. The key was to examine the trajectories and the energy left in the detector by particles in their final configuration and trace them back to their original state. Basically, Omega-c-zero particles decay via the strong force into another type of baryon (Xi-c-plus) and then via the weak force into protons, kaons, and pions.

From this, the researchers were able to determine that what they were seeing were Omega-c-zero particles at different energy states (i.e. of different sizes and masses). Expressed in megaelectronvolts (MeV), these particles have masses of 3000, 3050, 3066, 3090 and 3119 MeV, respectively. This discovery was rather unique, since it involved the detection of five higher energy states of a particle at the same time.

This was made possible thanks to the specialized capabilities of the LHCb detector and the large dataset that was accumulated from the first and second runs of the LHC – which ran from 2009 to 2013, and since 2015, respectively. Armed with the right equipment and experience, the researchers were able to identify the particles with an overwhelming level of certainty, ruling out the possibility that it was a statistical fluke in the data.

The discovery is also expected to shed light on some of the deeper mysteries of subatomic particles, like how the three constituent quarks are bound inside a baryon by the “strong force” – i.e. the fundamental force that is responsible for holding the insides of atoms together. Another mystery that this could help resolve in the correlation between different quark states.

The Large Hadron Collider is the world’s largest and most powerful particle accelerator Credit: CERN

As Dr Greig Cowan – a researcher from the University of Edinburgh who works on the LHCb experiment at Cern’s LHC – explained in an interview with the BBC:

“This is a striking discovery that will shed light on how quarks bind together. It may have implications not only to better understand protons and neutrons, but also more exotic multi-quark states, such as pentaquarks and tetraquarks.

The next step will be to determine the quantum numbers of these new particles (the numbers used to identify the properties of a specific particle) as well as determining their theoretical significance. Since it came online, the LHC has been helping to confirm the Standard Model of particle physics, as well as reaching beyond it to explore the greater unknowns of how the Universe came to be, and how the fundamental forces that govern it fit together.

In the end, the discovery of these five new particles could be a crucial step along the road towards a Theory of Everything (ToE), or just another piece in the very big puzzle that is our existence. Stay tuned to see which!

Further Reading: CERN, LHCb, arXiv

The post Large Hadron Collider Discovers 5 New Gluelike Particles appeared first on Universe Today.

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