Category: Space Exploration

After an almost five-year journey to the solar system’s largest planet, NASA’s Juno spacecraft successfully entered Jupiter’s orbit during a 35-minute engine burn. Confirmation that the burn had completed was received on Earth at 8:53 p.m. PDT (11:53 p.m. EDT) Monday, July 4.

“Independence Day always is something to celebrate, but today we can add to America’s birthday another reason to cheer — Juno is at Jupiter,” said NASA administrator Charlie Bolden. “And what is more American than a NASA mission going boldly where no spacecraft has gone before? With Juno, we will investigate the unknowns of Jupiter’s massive radiation belts to delve deep into not only the planet’s interior, but into how Jupiter was born and how our entire solar system evolved.”

Confirmation of a successful orbit insertion was received from Juno tracking data monitored at the navigation facility at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, as well as at the Lockheed Martin Juno operations center in Littleton, Colorado. The telemetry and tracking data were received by NASA’s Deep Space Network antennas in Goldstone, California, and Canberra, Australia.

“This is the one time I don’t mind being stuck in a windowless room on the night of the 4th of July,” said Scott Bolton, principal investigator of Juno from Southwest Research Institute in San Antonio. “The mission team did great. The spacecraft did great. We are looking great. It’s a great day.”

Preplanned events leading up to the orbital insertion engine burn included changing the spacecraft’s attitude to point the main engine in the desired direction and then increasing the spacecraft’s rotation rate from 2 to 5 revolutions per minute (RPM) to help stabilize it..

The burn of Juno’s 645-Newton Leros-1b main engine began on time at 8:18 p.m. PDT (11:18 p.m. EDT), decreasing the spacecraft’s velocity by 1,212 miles per hour (542 meters per second) and allowing Juno to be captured in orbit around Jupiter. Soon after the burn was completed, Juno turned so that the sun’s rays could once again reach the 18,698 individual solar cells that give Juno its energy.

“The spacecraft worked perfectly, which is always nice when you’re driving a vehicle with 1.7 billion miles on the odometer,” said Rick Nybakken, Juno project manager from JPL. “Jupiter orbit insertion was a big step and the most challenging remaining in our mission plan, but there are others that have to occur before we can give the science team the mission they are looking for.”

Over the next few months, Juno’s mission and science teams will perform final testing on the spacecraft’s subsystems, final calibration of science instruments and some science collection.

“Our official science collection phase begins in October, but we’ve figured out a way to collect data a lot earlier than that,” said Bolton. “Which when you’re talking about the single biggest planetary body in the solar system is a really good thing. There is a lot to see and do here.”

Juno’s principal goal is to understand the origin and evolution of Jupiter. With its suite of nine science instruments, Juno will investigate the existence of a solid planetary core, map Jupiter’s intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet’s auroras. The mission also will let us take a giant step forward in our understanding of how giant planets form and the role these titans played in putting together the rest of the solar system. As our primary example of a giant planet, Jupiter also can provide critical knowledge for understanding the planetary systems being discovered around other stars.

The Juno spacecraft launched on Aug. 5, 2011 from Cape Canaveral Air Force Station in Florida. JPL manages the Juno mission for NASA. Juno is part of NASA’s New Frontiers Program, managed at NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate. Lockheed Martin Space Systems in Denver built the spacecraft. The California Institute of Technology in Pasadena manages JPL for NASA.

Source: NASA news release used in accordance with public domain rights and in compliance with the NASA Media Usage Guidelines.

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NASA’s Juno spacecraft will be maneuvering into orbit around Jupiter today at 11:00 PM Eastern Time. A pre-orbit insertion briefing is now in progress on NASA TV. Juno will be completing a 5-year journey when it reaches Jupiter today.

As the craft was approaching the gassy planet, it trained its cameras on Jupiter and its moons, and this morning NASA released the short video below compiled from images taken prior to June 30 and just before the instruments were turned off in order to begin executing the complex orbital insertion.

See NASA’s website for more details and coverage of the Juno mission.

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Some of the wind-sculpted sand ripples on Mars are a type not seen on Earth, and their relationship to the thin Martian atmosphere today provides new clues about the atmosphere’s history.

The determination that these mid-size ripples are a distinct type resulted from observations by NASA’s Curiosity Mars rover. Six months ago, Curiosity made the first up-close study of active sand dunes anywhere other than Earth, at the “Bagnold Dunes” on the northwestern flank of Mars’ Mount Sharp.

“Earth and Mars both have big sand dunes and small sand ripples, but on Mars, there’s something in between that we don’t have on Earth,” said Mathieu Lapotre, a graduate student at Caltech in Pasadena, California, and science team collaborator for the Curiosity mission. He is the lead author of a report about these mid-size ripples published in the July 1 issue of the journal Science.

Both planets have true dunes — typically larger than a football field — with downwind faces shaped by sand avalanches, making them steeper than the upwind faces.

Earth also has smaller ripples — appearing in rows typically less than a foot (less than 30 centimeters) apart — that are formed by wind-carried sand grains colliding with other sand grains along the ground. Some of these “impact ripples” corrugate the surfaces of sand dunes and beaches.

Images of Martian sand dunes taken from orbit have, for years, shown ripples about 10 feet (3 meters) apart on dunes’ surfaces. Until Curiosity studied the Bagnold Dunes, the interpretation was that impact ripples on Mars could be several times larger than impact ripples on Earth. Features the scale of Earth’s impact ripples would go unseen at the resolution of images taken from orbit imaging and would not be expected to be present if the meter-scale ripples were impact ripples.

“As Curiosity was approaching the Bagnold Dunes, we started seeing that the crest lines of the meter-scale ripples are sinuous,” Lapotre said. “That is not like impact ripples, but it is just like sand ripples that form under moving water on Earth. And we saw that superimposed on the surfaces of these larger ripples were ripples the same size and shape as impact ripples on Earth.”

Besides the sinuous crests, another similarity between the mid-size ripples on Mars and underwater ripples on Earth is that, in each case, one face of each ripple is steeper than the face on the other side and has sand flows, as in a dune. Researchers conclude that the meter-scale ripples are built by Martian wind dragging sand particles the way flowing water drags sand particles on Earth — a different mechanism than how either dunes or impact ripples form. Lapotre and co-authors call them “wind-drag ripples.”

“The size of these ripples is related to the density of the fluid moving the grains, and that fluid is the Martian atmosphere,” he said. “We think Mars had a thicker atmosphere in the past that might have formed smaller wind-drag ripples or even have prevented their formation altogether. Thus, the size of preserved wind-drag ripples, where found in Martian sandstones, may have recorded the thinning of the atmosphere.”

The researchers checked ripple textures preserved in sandstone more than 3 billion years old at sites investigated by Curiosity and by NASA’s Opportunity Mars rover. They found wind-drag ripples about the same size as modern ones on active dunes. That fits with other lines of evidence that Mars lost most of its original atmosphere early in the planet’s history.

Other findings from Curiosity’s work at the Bagnold Dunes point to similarities between how dunes behave on Mars and Earth.

“During our visit to the active Bagnold Dunes, you might almost forget you’re on Mars, given how similar the sand behaves in spite of the different gravity and atmosphere. But these mid-sized ripples are a reminder that those differences can surprise us,” said Curiosity Project Scientist Ashwin Vasavada, of NASA’s Jet Propulsion Laboratory in Pasadena.

After examining the dune field, Curiosity resumed climbing the lower portion of Mount Sharp. The mission is investigating evidence about how and when ancient environmental conditions in the area evolved from freshwater settings favorable for microbial life, if Mars has ever hosted life, into conditions drier and less habitable.

Source: Republished from NASA.gov under public domain rights and in observance of the NASA multimedia guidelines. 

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By Leigh Fletcher, University of Leicester.

A burst of flame will streak across the skies of Jupiter in the early hours of July 5 as humankind’s newest robotic explorer arrives at the giant planet. NASA’s Juno spacecraft will be entering the unknown, penetrating deep into the radiation-filled heart of the Jupiter system in a bold attempt to unlock the secrets of the gas giant’s origins.

This ambitious mission could completely reshape our understanding of how the solar system’s largest world came to be – and how it influenced the evolution of other planets. But this is only if Juno survives the perils of exploring an environment that no spacecraft has dared venture into before.

So far, only the Galileo mission has orbited Jupiter, parachuting a probe into its churning, cloud-filled atmosphere in 1995. Despite its successes, there remain huge gaps in our knowledge of how Jupiter formed and whether it contains a planetary core, a remnant of our early solar system. Indeed, Jupiter’s powerful gravity has forever entrapped the original material from which it formed, making it an enormous time capsule that records the conditions that existed when our solar system was young.

The formation of this giant planet played a crucial role in shaping the architecture of the solar system as we see it today. With its immense gravity, Jupiter could have been both our destroyer and our saviour. That’s because its early motion through the young solar system could have destroyed the forming terrestrial worlds, leading to cataclysmic collisions that threatened Earth’s very existence.

Later on, Jupiter’s gravity is thought to have shepherded debris such as comets and asteroids that may have delivered the essential ingredients for life to our home planet. The story of Jupiter’s origins is therefore key to understanding our place in the solar system, and the tantalising possibility that similar events unfolded elsewhere.

Crucial measurements

Just like Jupiter’s mythological counterpart, who veiled himself in clouds to hide his mischief, the giant planet will not give up its secrets easily. Juno’s suite of sophisticated instruments must probe deeper than ever before, to regions beneath the churning cloud decks that are invisible to our Earth-bound telescopes. After a five-year journey, the solar-powered spacecraft will embark on a series of fortnightly orbits around the planet, taking it high above the planet’s poles and then skimming within 5,000 kilometres of the cloud tops.

These close passes will permit precise measurements of Jupiter’s gravity and magnetic fields, probing its inner structure and its density. This will help examine the exotic interior of the gas giant, where simple hydrogen gas is compressed under immense, crushing pressures to become metallic and conducting (a state only glimpsed fleetingly in laboratories on Earth). These measurements could potentially provide the first glimpses of a core, if one exists at all.

If our theories of planetary formation are correct, then Jupiter’s heavier elements, such as carbon, nitrogen and sulphur, should have been delivered as molecules trapped in water ice cages, frozen in the cold outer reaches of our young solar system. That should have left behind a huge amount of water in Jupiter, but as water condenses in the frigid conditions of the planet’s atmosphere, we have never had a reliable estimate of how much is really down there. If there isn’t enough water present, then the prevailing theory of Jupiter’s formation would have to undergo a complete revision.

In the coming months, Juno will answer this question. It carries an instrument that can map Jupiter at microwave wavelengths, allowing it to reveal the distribution of water deep below the clouds for the first time. Combined with the gravity measurements, Juno will peel back the layers of Jupiter to finally test our theories of how giant planets form – is a heavy planetary embryo required, or can these enormous worlds form directly from the collapse of the gases surrounding a young star?

Juno’s unique orbit will also provide our first direct views of Jupiter’s poles, exploring the powerful auroras and dynamic atmosphere. The spinning spacecraft (three rotations per minute) will sweep the array of sensors through the radiation environment to explore the immense plasma and magnetic fields. Its camera will target atmospheric features, such as erupting storms and spinning vortices, at breathtaking resolutions. In addition to the scientific instruments, Juno also carries the first Jupiter camera to be aimed primarily at education and outreach, with the public invited to suggest the targets.

To add to this intense scrutiny, an army of professional and amateur observers, including those here at the University of Leicester, are engaged in an international campaign to support the mission. These observations will provide global views of the planet to support Juno’s up-close observations; reveal how Jupiter’s dynamic atmosphere changes throughout the mission, and observe it in wavelengths of light that Juno cannot access. An example of the incredible capabilities of Earth-based observers is shown by our recent images from the Very Large Telescope in Chile.

But during all of these unique observations, the intrepid Juno spacecraft will be taking a pummelling from the high-energy particles within Jupiter’s harsh radiation belts, equivalent to 100m dental X-rays in the first year alone. No spacecraft has ever had to cope with such severe conditions. Even with the instrument components shielded in a vault with 1cm thick titanium walls, there will still be an accumulation of radiation damage and a degradation of equipment.

No one knows exactly how the instruments will fare as the long-suffering spacecraft heroically battles on to complete its 20-month mission. But one thing is certain – Jupiter’s cloak of clouds will no longer shroud its mischief, as Juno’s instruments gaze down into the heart of the giant for the first time.

Leigh Fletcher, Royal Society Research Fellow, University of Leicester

This article was originally published on The Conversation. Read the original article.

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Like a cosmic lava lamp, a large section of Pluto’s icy surface is renewed by a process called convection that replaces older ices with fresher material.

Combining computer models with topographic and compositional data gathered by NASA’s New Horizons spacecraft last summer, New Horizons team members have been able to determine the depth of this layer of solid nitrogen ice within Pluto’s distinctive “heart” feature—a large plain informally known as Sputnik Planum—and how fast that ice is flowing.

Mission scientists used state-of-the-art computer simulations to show that the surface of Sputnik Planum is covered with icy, churning, convective “cells” 10-30 miles across, and less than a million years old. The findings offer additional insight into the unusual and active geology on Pluto and, perhaps, other bodies like it on the planetary outskirts of the solar system.

“For the first time, we can really determine what these strange welts of the icy surface of Pluto really are,” says William B. McKinnon, professor of earth and planetary sciences at Washington University in St. Louis, who led the study. “We found evidence that even on a distant cold planet billions of miles from Earth, there is sufficient energy for vigorous geological activity, as long as you have something as soft and pliable as nitrogen ice.” McKinnon is also deputy lead for geology, geophysics, and imaging for New Horizons.

McKinnon and colleagues believe the pattern of these cells stems from the slow thermal convection of the nitrogen-dominated ices that fill Sputnik Planum. In a reservoir that’s likely several miles deep in some places, the solid nitrogen is warmed by Pluto’s modest internal heat, becomes buoyant, and rises up in great blobs—think of a lava lamp—before cooling off and sinking again to renew the cycle.

The computer models show that ice need only be a few miles deep for this process to occur, and that the convection cells are very broad. The models also show that these blobs of overturning solid nitrogen can slowly evolve and merge over millions of years. Ridges that mark where cooled nitrogen ice sinks back down can be pinched off and abandoned, resulting in Y- or X-shaped features in junctions where three or four convection cells once met.

“I was very surprised that what I learned about convection during my recent PhD work at Washington University could be applied to Pluto, because nobody thought Pluto was so active (or convecting at all),” says Teresa Wong, a postdoctoral research associate at Washington University and a coauthor on the study.

These convective surface motions average only a few centimeters a year—about as fast as your fingernails grow—which means cells recycle their surfaces every 500,000 years or so. Slow on human clocks, but a rapid clip on geological timescales.

“This activity probably helps support Pluto’s atmosphere by continually refreshing the surface of ‘the heart,’” McKinnon says. “It wouldn’t surprise us to see this process on other dwarf planets in the Kuiper Belt. Hopefully, we’ll get a chance to find out someday with future exploration missions there.”

New Horizons also could potentially take a close-up look at a smaller, more ancient object much farther out in the Kuiper Belt: the disk-shaped region beyond the orbit of Neptune believed to contain comets, asteroids, and other small, icy bodies. New Horizons flew through the Pluto system on July 14, 2015, making the first close observations of Pluto and its family of five moons.

The spacecraft is on course for an ultra-close flyby of another Kuiper Belt object, 2014 MU69, on Jan. 1, 2019, should NASA approve funding for an extended mission.

This study is published in the journal Nature.

Source: Republished from Futurity.org as a derivative work under the Attribution 4.0 International license. Original article posted to Futurity by  Diana Lutz-WUSTL. 

Featured Image Credit: Ged Carroll/flickr

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NASA has released the first global digital model of Mercury’s peaks and valleys, revealing in stunning detail the topography of the innermost planet.

The model, compiled from more than 100,000 images taken by the Messenger probe during more than four years in orbit around Mercury, is represented in an animation showing the planet’s high and low points and everything in between.

The model and other new data pave the way to explore and fully explain the planet’s geologic history, scientists say.

“The wealth of these data … will continue to enable exciting scientific discoveries about Mercury for decades to come,” says Susan Ensor, manager of the Messenger science operations center and a software engineer at the Johns Hopkins University Applied Physics Laboratory.

The model shows that Mercury’s highest elevation is 4.48 kilometers (2.78 miles) above average elevation, at a point just south of the equator in some of the planet’s oldest terrain. The lowest, 5.38 kilometers (3.34 miles) below Mercury’s average, is on the floor of Rachmaninoff basin, an area suspected to host some of the most recent volcanic deposits on the planet.

Messenger launched in 2004 and in 2011 became the first spacecraft to orbit the planet closest to the sun. After circling the planet for more than four years—a mission three years longer than initially planned—it fell to the surface on April 30, 2015. Johns Hopkins APL built and operated the spacecraft and manages the mission for NASA.

Although Mercury is rocky like Earth, Venus, and Mars, the planet is quite different from Earth in other ways—far smaller, denser, and, because of a lack of atmosphere, far hotter on its sun-facing side and colder on the night side. It also has the oldest surface among the terrestrial planets. Understanding how it is different from Earth is crucial to understanding the formation and evolution of planets in the solar system.

Researchers have also released a new map providing an unprecedented view of the region near Mercury’s north pole.

“Messenger had previously discovered that past volcanic activity buried this portion of the planet beneath extensive lavas, more than a mile deep in some areas and covering a vast area equivalent to approximately 60 percent of the continental United States,” says Nancy Chabot of APL.

Because the region is near Mercury’s north pole, the sun is always low on the horizon there, casting long shadows that can obscure the color of the rocks. The new map is produced from photos by Messenger’s Mercury Dual Imaging System, carefully captured through five different narrow-band color filters when the shadows were relatively short. The map reveals Mercury’s northern volcanic plains in striking color.

“This has become one of my favorite maps of Mercury,” says Chabot, instrument scientist for the imaging system. “Now that it is available, I’m looking forward to it being used to investigate this epic volcanic event that shaped Mercury’s surface.”

Follow this link to learn more about the 100,000 images taken by the Messenger probe and the Messenger mission.

Source: Republished from Futurity.org as a derivative work under the Attribution 4.0 International license. Original article posted to Futurity by Paulette Campbell-Johns Hopkins. 

Featured Image Credit: NASA/JHUAPL/Carnegie Institution of Washington

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Jupiter’s moon Europa is under a constant gravitational assault. As it orbits, its icy surface heaves and falls with the pull of Jupiter’s gravity. Scientists now believe that as it does so, it creates enough heat to support a salty ocean beneath the moon’s solid shell.

Now, experiments suggest that the process—called tidal dissipation—could create far more heat in Europa’s ice than scientists had previously thought. The findings could ultimately help researchers to better estimate the thickness of moon’s outer shell.

The largest Jovian moons—Io, Europa, Ganymede, and Callisto—were first discovered by Galileo in the early 1600s. When NASA sent spacecraft to Jupiter in the 1970s and 1990s, those moons proved to be full of surprises.

“[Scientists] had expected to see cold, dead places, but right away they were blown away by their striking surfaces,” says Christine McCarthy, a faculty member at Columbia University who led the new research while a graduate student at Brown University. “There was clearly some sort of tectonic activity—things moving around and cracking. There were also places on Europa that look like melt-through or mushy ice.”

The only way to create enough heat for these active processes so far from the sun is through tidal dissipation. The effect is a bit like what happens when someone repeatedly bends a metal coat hanger, McCarthy says.

“If you bend it back and forth, you can feel it making heat at the junction. The way it does that is that internal defects within that metal are rubbing past each other, and it’s a similar process to how energy would be dissipated in ice.”

However, the details of the process in ice aren’t very well understood, and modeling studies that try to capture those dynamics on Europa had yielded some puzzling results.

“People have been using simple mechanical models to describe the ice,” McCarthy says. While those calculations suggested liquid water under Europa’s surface, “they weren’t getting the kinds of heat fluxes that would create these tectonics. So we ran some experiments to try to understand this process better.”

Working with Reid Cooper, professor of earth, environmental, and planetary sciences at Brown, McCarthy loaded ice samples into a compression apparatus and subjected them to cyclical loads similar to those acting on Europa’s ice shell. When the loads are applied and released, the ice deforms and then rebounds to a certain extent. By measuring the lag time between the application of stress and the deformation of the ice, McCarthy could infer how much heat is generated.

The experiments yielded surprising results.

Modeling approaches had assumed that most of the heat generated by the process comes from friction at the boundaries between the ice grains. That would mean that the size of the grains influences the amount of heat generated. But McCarthy found similar results even when she substantially altered the grain size in her samples, suggesting that grain boundaries are not the primary heat-generators in the process.

The findings, published in Earth and Planetary Science Letters,  suggest that most of the heat actually comes from defects that form in the ice’s crystalline lattice as a result of deformation. Those defects create more heat than would be expected from the grain boundaries.

“Christine discovered that, relative to the models the community has been using, ice appears to be an order of magnitude more dissipative than people had thought,” Cooper says. More dissipation equals more heat, and that could have implications for Europa.

“The beauty of this is that once we get the physics right, it becomes wonderfully extrapolative,” Cooper says. “Those physics are first order in understanding the thickness of Europa’s shell. In turn, the thickness of the shell relative to the bulk chemistry of the moon is important in understanding the chemistry of that ocean. And if you’re looking for life, then the chemistry of the ocean is a big deal.”

The NASA Program in Planetary Geology and Geophysics and the NSF Program in Geophysics supported the study which is published in Earth and Planetary Science Letters.

Source: Republished from Futurity.org as a derivative work under the Attribution 4.0 International license. Original article posted to Futurity by Kevin Stacey-Brown.

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A recent article on the NASA website reveals that a revolutionary technology for powering spacecraft by riding the solar wind and propelling themselves to the edge of the solar system in record time. Called the Heliopause Electrostatic Rapid Transit System (HERTS), this amazing technology sounds like something out a science fiction novel, but in fact, modeling and testing of this solar e-sail concept has started at NASA’s Marshall Space Flight Center in Huntsville, Alabama.

The fascinating details of the design and testing of this revolutionary propulsion system are described in a very interesting and detailed article on the NASA website:

The test results will provide modeling data for the Heliopause Electrostatic Rapid Transit System (HERTS). The proposed HERTS E-Sail concept, a propellant-less propulsion system, would harness solar wind to travel into interstellar space.

“The sun releases protons and electrons into the solar wind at very high speeds — 400 to 750 kilometers per second,” said Bruce Wiegmann an engineer in Marshall’s Advanced Concepts Office and the principal investigator for the HERTS E-Sail. “The E-Sail would use these protons to propel the spacecraft.”

Extending outward from the center of the spacecraft, 10 to 20 electrically charged, bare aluminum wires would produce a large, circular E-Sail that would electrostatically repel the fast moving protons of the solar wind. The momentum exchange produced as the protons are repelled by the positively charged wires would create the spacecraft’s thrust. Each tether is extremely thin, only 1 millimeter — the width of a standard paperclip — and very long, nearly 12 and a half miles — almost 219 football fields. As the spacecraft slowly rotates at one revolution per hour, centrifugal forces will stretch the tethers into position.

The testing, which is taking place in the High Intensity Solar Environment Test system, is designed to examine the rate of proton and electron collisions with a positively charged wire. Within a controlled plasma chamber simulating plasma in a space, the team is using a stainless steel wire as an analog for the lightweight aluminum wire. Though denser than aluminum, stainless steel’s non-corrosive properties will mimic that of aluminum in space and allow more testing with no degradation.

Engineers are measuring deflections of protons from the energized charged wire within the chamber to improve modeling data that will be scaled up and applied to future development of E-Sail technology. The tests are also measuring the amount of electrons attracted to the wire. This information will be used to develop the specifications for the required electron gun, or an electron emitter, that will expel excess electrons from the spacecraft to maintain the wire’s positive voltage bias, which is critical to its operation as a propulsion system.

This concept builds upon the electric sail invention of Dr. Pekka Janhunen of the Finnish Meteorological Institute, and the current technologies required for an E-Sail integrated propulsion system are at a low technology readiness level. If the results from plasma testing, modeling, and wire deployer investigations prove promising after the current two-year investigation, there is still a great deal of work necessary to design and build this new type of propulsion system. The earliest actual use of the technology is probably at least a decade away.

NASA scientists believe that this e-sail design could propel a spacecraft to the heliosphere in just a 10-year journey. By comparison, it took the Voyager spacecraft 35 years to travel to the solar system’s edge.

In this video, NASA reveals the general concepts behind the HERTS E-sail:

https://youtu.be/ntMDcWD7-jQ

For more details links to additional resources about the HERTS E-sail, see the fascinating article on the NASA website.

Source: NASA.gov – “NASA Begins Testing of Revolutionary E-Sail Technology” 

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The Science Rocks My World team sends out a hearty “CONGRATULATIONS!” to SpaceX and Elon Musk for successfully accomplishing their historical goal of landing the Falcon 9 reusable first stage on their drone ship!

Great work! And when you pause to think about it, what incredible technology and an amazing feat of aerospace engineering.

Watch it happen in this short video snipped from SpaceX’s live stream of the mission:

Video Credit: Jonny Dowe/YouTube

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Massive mounds more than a mile high on Mars were carved by winds over billions of years, new research suggests. Their location helps pin down when water on the Red Planet dried up during a global climate change event.

The findings highlight the importance of wind in shaping the Martian landscape, a force that, on Earth, is overpowered by other processes, says lead author Mackenzie Day, a graduate student at the University of Texas at Austin Jackson School of Geosciences.

“On Mars there are no plate-tectonics, and there’s no liquid water, so you don’t have anything to overprint that signature and over billions of years you get these mounds, which speaks to how much geomorphic change you can really instigate with just wind. Wind could never do this on Earth because water acts so much faster, and tectonics act so much faster.”

First spotted during NASA’s Viking program in the 1970s, the mounds are at the bottom of craters. Recent analysis by the Mars rover Curiosity of Mount Sharp, a mound over three miles high inside Gale Crater, has revealed that the thickest ones are made of sedimentary rock, with bottoms made of sediments carried by water that used to flow into the crater and tops made of sediments deposited by wind. However, how the mounds formed inside craters that were once full of sediments was an open question.

“There’s been a theory out there that these mounds formed from billions of years of wind erosion, but no one had ever tested that before,” Day says. “So the cool thing about our paper is we figured out the dynamics of how wind could actually do that.”

To test whether wind could create a mound, the researchers built a miniature crater 30 centimeters wide and 4 centimeters deep, filled it with damp sand, and placed it in a wind tunnel. They tracked the elevation and the distribution of sand in the crater until all of it had blown away. The model’s sediment was eroded into forms similar to those observed in Martian craters, forming a crescent-shaped moat that deepened and widened around the edges of the crater. Eventually all that was left of the sediment was a mound—which, in time, also eroded away.

“We went from a filled crater layer cake to this mounded shape that we see today,” Day says.

To understand the wind dynamics, researchers also built a computer model that simulated how the wind flowed through the crater at different stages of erosion.

The mounds’ structure helps link their formation to climate change on Mars, with the bottom being built during a wet time, and the top built and mound shaped in a dry time, says Jackson School researcher Gary Kocurek.

“This sequence signals the change from a dominance of depositional processes by water during a wetter time, to wind reworking of these water-laid sediments with the onset of aridity, followed by wind erosion once these sediment supplies have been exhausted,” he says. “Overall, we are seeing the complete remaking of the sedimentary cycle on Mars to the one that characterizes the planet today.”

The research, published in the journal Geophysical Research Letters, helped scientists home in on Mars’ Noachian period, a geologic era that began about 3.7 billion years ago, as the period when Mars started to change from a wet world to a dry one. Scientists were able to link the climate change to the Noachian by studying the location of more than 30 mounds and finding that sedimentary mounds were only present on terrain that was exposed during that period.

NASA, the National Science Foundation, and the University of Texas at Dallas funded the work.

Source: Republished from Futurity.org as a derivative work under the Attribution 4.0 International license. Original article posted to Futurity by Anton Caputo-UT Austin.

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