Welcome, Guest. Please login or register.
Did you miss your activation email?
Jun 22, 2018, 09:00 PM
Pages: 1 ... 103 104 [105] 106 107 ... 115   Go Down
Print
Author Topic: NEWS ON SPACE AND OUR PLANETARY SYSTEM  (Read 315144 times)
0 Members and 4 Guests are viewing this topic.
Darja
Admin
Most Active Member
*****
Offline Offline

Posts: 5978


« Reply #1560 on: Dec 28, 2017, 05:47 AM »

Saturn’s rings are made of a shredded moon

Newsweek
28 Dec 2017 at 06:55 ET

How Saturn's rings came to be was one of the big puzzles scientists wanted to crack with the Cassini mission, the spacecraft that destroyed itself this past September. And just three months after its demise, researchers say they're more confident than ever that the rings are the crushed-up remains of an ill-fated moon.

The theory is based on some of the very last data Cassini gathered, and was presented at last week's annual conference of the American Geophysical Union and reported by  Science News.

For Saturn's rings, age and mass are closely linked: If they're smaller and less massive, they must be younger, because scientists know they would not have been able to survive a fierce pounding from debris billions of years ago, or at least not in their current form. So in order for them to be older, dating to around the same time Saturn itself was formed, they'd have to be larger.

But needless to say, it's a bit difficult for scientists to put the rings on a scale. That's why Cassini's last days were so crucial: The spacecraft danced its way through 22 loops between the rings and the planet itself. That meant scientists could compare the gravitational tug of the planet itself with that of the planet plus its rings—a roundabout way of calculating the mass of the rings themselves.

According to Science News, that analysis suggested that the rings fall on the lighter side: perhaps about 40 billion billion pounds (ok, it's all relative). There are still some mysteries in the numbers Cassini sent back to Earth, so that could be about a quarter of the real mass, tops. But either way, the rings are much too small to be very old.

And those results are underscored by analysis of the rings, themselves. They are constantly bombarded by a stream of debris, from meteors to tiny particles of dust, which should darken them over time. But according to other new Cassini analysis also presented at last week's conference, Saturn's rings are still shiny and new.

That makes scientists think the rings may be the remains of a moon that Saturn's enormous gravity ensnared about 200 million years ago and then shredded into the tiny, shiny bits.


* Saturn-800x430.jpg (63.38 KB, 800x430 - viewed 58 times.)
Logged
Darja
Admin
Most Active Member
*****
Offline Offline

Posts: 5978


« Reply #1561 on: Dec 29, 2017, 05:30 AM »

Saturn Has 'Kittens' in Its Ring and They Could Teach Us How Planets Form

By Meghan Bartels
Newsweek
12/29/2017

Meet Mittens, a hunk of ice and rock about 2,000 feet wide orbiting Saturn in the planet’s F ring—and the name of a deceased cat who belonged to planetary scientist Larry Esposito's daughter. Mittens has company: About 60 similar clumps scattered throughout the F ring. Not all of these features have nicknames, but those that do honor cats beloved by Saturn scientists—and more will likely be discovered in Cassini’s last data.

The very fact that these features have nicknames means that they’re scientifically interesting—their fluffy titles act as references so scientists can talk about individual lumps easily and without confusion. The naming scheme was the brainchild of Esposito, a professor at the University of Colorado, and his grad students. "I just gave them nicknames so I could keep them straight," he told Newsweek.

Esposito has spent 40 years studying Saturn’s rings—in fact, he’s the person who discovered the F ring in the first place. "The rings are beautiful, one of the most beautiful sights in the solar system," he says, but there’s more meat here than that. "As scientists, we're interested in what they can tell us about the history of the planet and the history of planetary formation." But as he and his students were analyzing these clumps, first spotted in 2005, they needed a way to refer to them. Enter Mittens.

Keep up with this story and more by subscribing now

Since the clumps are transient, Esposito said, "I thought they had multiple lives," like cats and their notorious nine lives. He also wanted to avoid stepping on the toes of the International Astronomical Union, which is in charge of approving official names for features in space. "If we're going to have nicknames for this, I don't want to be too serious, I want to be playful," Esposito said.

Fluffy nickname aside, Mittens and its Saturnine feline friends could help scientists answer a few stumpers about our solar system. First, cataloging them will help scientists make their estimate of the total mass of Saturn’s rings more accurate—and that has implications for their age; they can only be old if they’re massive.

And Mittens may even hold the clues to the origins of our own planet. That’s because before the planets of our solar system had formed, they were small clumps of rock strewn throughout a disk—not so different from kittens in Saturn’s rings. That means understanding how kittens form and fall apart could tell us how Earth and our neighbors formed too, Esposito says.

Mittens is too small to actually see in a photograph, but this is what the star occultation that discovered it would have looked like. NASA/JPL/University of Colorado

His theory is that while Mittens won’t be around forever, but there will always be a certain number of Mittens-like features. Esposito compares it to the way real cats like to hang out on the ruins of the Roman Forum. "The cats of course come and go, but there's always some cats in the Roman Forum, sitting on this ancient structure." The kittens are particularly dynamic near the two moons closest to the ring, Prometheus and Pandora, which to Esposito suggests that the phenomena are connected.

He says that models accounting for all of the physics at play are too large and complicated for computers to process, but that he’s developed a simplified model inspired by the boom-and-bust cycles seen in population ecology and economics. "The moons stir up the rings, the rings respond by clumping up, the clumps stir up the rings, that erodes the clumps and they disperse, so it's all cyclic," Esposito says.

That’s still a theory. "I definitely have an ax I'm grinding here, an idea I have in my head," he is quick to add. "Maybe most people wouldn't agree with that simple solution." But the only way to know for sure is to keep looking for kittens.

And how do you spot a kitten in outer space? The clumps are too small to show up in photographs. Watch a star pass behind the ring and look for dips in its brightness where the clump blocks its light. That’s a process called a star occultation, which Esposito and his colleagues on Cassini’s Ultraviolet Imaging Spectrograph instrument managed to do more than 150 times before the spacecraft’s mission ended earlier this month. And Esposito says he expects the instrument likely spotted more kittens during its grand finale dance through the rings, although he doesn’t have that data yet—so stay tuned for more of Mittens' kin.


* Capture.JPG (22.62 KB, 472x342 - viewed 53 times.)
Logged
Darja
Admin
Most Active Member
*****
Offline Offline

Posts: 5978


« Reply #1562 on: Dec 30, 2017, 06:42 AM »


Lockheed Martin unveils a re-usable water-powered lander to ferry humans to Mars

Orbiting space station would allow astronauts carry out explorations of the Red Planet.

By Aristos Georgiou
IBT
12/30/2017
 
This year's International Astronautics Congress in Adelaide has been abuzz with talk of future Mars missions. Today (29 September) Elon Musk finally announced SpaceX's plans to send humans to the Red Planet by the 2020s, and to eventually to set up a colony there.

But other intriguing ideas were also put forward for the exploration of our planetary neighbour. Not to be outdone, defence giant Lockheed Martin has unveiled plans for a reusable, water-powered Mars lander which will enable humans to explore the Red Planet from an orbiting 'base camp' by the 2030s.

The innovative lander forms part of Lockheed's Mars Base Camp project, essentially a planetary science lab which will put researchers in orbit around Mars, allowing them to perform extensive, real-time analysis of the surface before identifying suitable regions for humans to subsequently land.

The Mars orbiter space station will feature the world's only deep-space crew capsule – known as Orion - designed with long-duration life support systems and innovative deep space communications and navigation technology.

"Sending humans to Mars has always been a part of science fiction, but today we have the capability to make it a reality," said Lisa Callahan, vice president and general manager of Commercial Civil Space at Lockheed Martin.

The reusable lander would be able to descend to the surface of Mars using special propulsion systems with up to four astronauts on board. After the completion of the mission, which could last up to two weeks, the lander would ferry the astronauts back to the orbiter.

Furthermore, it would be powered by liquid nitrogen or liquid oxygen fuel which could be sourced from water deposits using another purpose-built spacecraft – the imaginatively named Water Delivery Vehicle.

There is currently intense interest in human exploration of the Red Planet. Nasa is currently preparing for the Mars 2020 rover mission which forms part of its long-term Mars Exploration Programme. Amongst other things, these missions will provide opportunities to gather knowledge about Mars in order to address the challenges of any future human expeditions.


* mars-lander.jpg (36.81 KB, 736x413 - viewed 54 times.)

* mars-base-camp.jpg (58.59 KB, 736x413 - viewed 54 times.)
Logged
Darja
Admin
Most Active Member
*****
Offline Offline

Posts: 5978


« Reply #1563 on: Jan 02, 2018, 05:17 AM »

U.F.O.s: Is This All There Is?

Dennis Overbye
NY Times
1/2/2018

Hey, Mr. Spaceman,

Won’t you please take me along?

I won’t do anything wrong.

Hey, Mr. Spaceman,

Won’t you please take me along for a ride?

So sang the Byrds in 1966, after strange radio bursts from distant galaxies called quasars had excited people about the possibility of extraterrestrial intelligence.

I recalled those words recently when reading the account of a pair of Navy pilots who were outmaneuvered and outrun by a U.F.O. off the coast of San Diego back in 2004. Cmdr. David Fravor said later that he had no idea what he had seen.

“But,” he added, “I want to fly one.”

His story was part of a bundle of material released recently about a supersecret $22 million Pentagon project called the Advanced Aerospace Threat Identification Program, aimed at investigating U.F.O.s. The project was officially killed in 2012, but now it’s being resurrected as a nonprofit organization.

Disgruntled that the government wasn’t taking the possibility of alien visitors seriously, a group of former defense officials, aerospace engineers and other space fans have set up their own group, To the Stars Academy of Arts & Science. One of its founders is Tom DeLonge, a former punk musician, record producer and entrepreneur, who is also the head of the group’s entertainment division.

For a minimum of $200, you can join and help finance their research into how U.F.O.s do whatever it is they do, as well as telepathy and “a point-to-point transportation craft that will erase the current travel limits of distance and time” by using a drive that “alters the space-time metric” — that is, a warp drive going faster than the speed of light, Einstein’s old cosmic speed limit.

“We believe there are transformative discoveries within our reach that will revolutionize the human experience, but they can only be accomplished through the unrestricted support of breakthrough research, discovery and innovation,” says the group’s website.

I’m not holding my breath waiting for progress on telepathy or warp drive, but I agree with at least one thing that one official with the group said. That was Steve Justice, a former engineer at Lockheed Martin’s famous Skunk Works, where advanced aircraft like the SR-71 high-altitude super-fast spy plane were designed.

“How dare we think that the physics we have today is all that there is,” he said in an interview published recently in HuffPost.

I could hardly agree more, having spent my professional life in the company of physicists and astronomers trying to poke out of the cocoon of present knowledge into the unknown, to overturn Einstein and what passes for contemporary science. Lately, they haven’t gotten anywhere.

The last time physicists had to deal with faster-than-light travel was six years ago, when a group of Italy-based physicists announced that they had seen the subatomic particles known as neutrinos going faster than light. It turned out they had wired up their equipment wrong.

So far Einstein is still the champ. But surely there is so much more to learn. A lot of surprises lie ahead, but many of the most popular ideas on how to transcend Einstein and his peers are on the verge of being ruled out. Transforming science is harder than it looks.

While there is a lot we don’t know, there is also a lot we do know. We know how to turn on our computers and let gadgets in our pocket navigate the world. We know that when physical objects zig and zag through a medium like air, as U.F.O.s are said to do, they produce turbulence and shock waves. NASA engineers predicted to the minute when the Cassini spacecraft would dwindle to a wisp of smoke in Saturn’s atmosphere last fall.

In moments like this, I take comfort in what the great Russian physicist and cosmologist Yakov Zeldovich, one of the fathers of the Soviet hydrogen bomb, once told me. “What science has already taken, it will not give back,” he said.

Scientists are not the killjoys in all this.

In the astronomical world, the border between science fact and science fiction can be very permeable, perhaps because many scientists grew up reading science fiction. And astronomers forever have their noses pressed up against the window of the unknown. They want to believe more than anybody, and I count myself among them.

But they are also trained to look at nature with ruthless rigor and skepticism. For astronomers, the biggest problem with E.T. is not the occasional claim of a mysterious light in the sky, but the fact that we are not constantly overwhelmed with them.

Half a century ago, the legendary physicist Enrico Fermi concluded from a simple back-of-the-envelope calculation that even without warp drive, a single civilization could visit and colonize all the planets in the galaxy in a fraction of the 10-billion-year age of the Milky Way.

“Where are they?” he asked.

Proponents of SETI, the search for extraterrestrial intelligence, have been debating ever since. One answer I like is the “zoo hypothesis,” according to which we have been placed off-limits, a cosmic wildlife refuge.

Another answer came from Jill Tarter, formerly the director of research at the SETI Institute in Mountain View, Calif. “We haven’t looked hard enough,” she said when I asked her recently.

If there was an iPhone sitting under a rock on the Moon or Mars, for example, we would not have found it yet. Our own latest ideas for interstellar exploration involve launching probes the size of postage stamps to Alpha Centauri.

In the next generation, they might be the size of mosquitoes. By contrast, the dreams of some U.F.O. enthusiasts are stuck in 1950s technology.

Still, we keep trying.

Last fall when a strange object — an interstellar asteroid now named Oumuamua — was found cruising through the solar system, astronomers’ thoughts raced to the Arthur C. Clarke novel “Rendezvous With Rama,” in which the object was an alien spaceship. Two groups have been monitoring Oumuamua for alien radio signals, so far to no avail.

Meanwhile, some astronomers have speculated that the erratic dimming of a star known as “Boyajian’s star” or “Tabby’s star,” after the astronomer Tabetha Boyajian, could be caused by some gigantic construction project orbiting the star. So far that has not worked out, but none of the other explanations — dust or a fleet of comets — have, either.

Logged
Darja
Admin
Most Active Member
*****
Offline Offline

Posts: 5978


« Reply #1564 on: Jan 03, 2018, 05:23 AM »

Here is what life on the moon will look like

Newsweek
1/3/2018 

President Donald Trump signed a directive this week that includes an initiative to send astronauts to the moon—and eventually to Mars. Humans have not been on the moon since 1972.

NASA focuses on individual missions rather than planning settlements on distant rocky spheres. But that doesn't mean visions of a moon colony are out of the question. To better understand what life on the moon would look like,  Newsweek spoke with  Robert P. Mueller, senior technologist at NASA with expertise in robotics, the construction of planetary outposts and many other nuts-and-bolt aspects of space exploration. 

What would housing on the moon look like?

So we divide structures into two categories. First we have 2-dimensional structures, and that’s things like landing pads, roads, parking lots, dust-free zones, even thermal areas that retain the heat for the lunar nights. Then we have 3-dimensional structures that obviously have volume—those are things like hangers, habitats, radiation shelters, micromedioid shelters. So it’s more of a shelter, a structure, that is pressurized where the crew can live and we can keep equipment.

What do scientists have to consider in designing architecture for these buildings? 

In summary, to build a habitat on the moon or Mars, you have to first consider the extreme environment and then once you have dealt with the design for the extreme environment, you have to deal with the constructability. And the constructability has to be robotic. Humans will not be there at the beginning. The robots will construct the base, and then the humans will come in and live in it. So there’s a lot of things to think about, and we’re certainly not capable of doing it today, but in the lab, we are developing solutions. I would say within 10 or 20 years we would be ready to do that.

What’s extreme about the environment?

First of all, on the moon for example, the thermal temperature swings are extreme. You can go from plus 125 Celsius to minus 130 Celsius [negative 202 to plus 257 degrees Fahrenheit] just by going from the lighted areas to the shadowed areas—temperature drops dramatically.

Then of course you’re in a vacuum. There’s no atmosphere. It’s a pure vacuum. Then on top of that, you have to deal with radiation from deep space. There’s two types of radiation—there’s solar particle vents come from the Sun and then there’s galactic cosmic rays coming from deep space. On top of that, there are micrometeorites that come in on the moon. There’s also moonquakes where you have to design your structures to be capable of surviving a small moonquake. And so, this is what we call an extreme environment. So anytime you design for extreme environments, it’s a new kind of a design.

What would buildings be made from?

So we plan to build all of those with local resources, indigenous materials. In the first phase, we’ll probably bring out modules that are fabricated on Earth and then we’ll put those underneath the shelters which are fabricated locally out of regolith—regolith is a crushed rock that you find on the surface of the moon and Mars. And then later on as the technology evolves, then we won’t bring anything from Earth anymore. We’ll be Earth independent. We’ll be completely self-sufficient and we’ll be able to send just a few robots up because we have large amounts of energy from the sun and large amounts of materials from the moon or the planet Mars.

3D printing seems to be the leading candidate right now for [building] these structures. It would be large robotic 3D printers that we deploy in space or we could even 3D print the 3D printer. So, bring a small 3D printer that 3D prints the components and then assemble a large 3D printer then use that large 3D printer to build a large structure. 

We’re developing the technology—we’re not ready to go today—but we’re developing the technology so in the future we could go and build infrastructure in space.

How would people grow food?

Turns out, that you can grow food very efficiently using LED lights. We’ve done research that shows that purple light is the best light—the certain wavelength spectrum of light that the plants grow very well in. We use hydroponics. We use aeroponics as well. And we’re researching maybe it’s even possible to grow the plants in the local soil that’s available on the moon and Mars, but that’s still research-level. That has not been proven yet.

We’re definitely going to have farms in space for two reasons. We need the food for the crew, and we also have significant psychological advantages to having plants in space. That's been proven on the International Space Station.

Where would people get water?

The water is available in space, but it has to be mined. The water is in the soil. You have to dig up the soil and extract the water from the soil. And then you have to purify it because the water has some contaminants in it. So once you’ve mined the soil that we call regolith, the crushed rock, but it also has water in it on Mars and the moon. So this is one of the main resources that we have. The other good thing about the water is if you take the water and you electrolyze it, you can turn it into hydrogen and oxygen, and that’s rocket propellant.

It’s the key to life, but it’s also the key to transportation in the solar system. So water is the key to everything. We’re really looking for water when we go into outer space. It’s the most important resource that we can find at this time.

How big would the first settlements be in the future?

At the beginning, it would be governments from many nations. Just like we have the International Space Station, we would send astronauts funded by the governments, and they would be the pioneers. And the pioneers would set up the base and prove that everything works and they are highly trained individuals that would get the base up and running.

Once we have the base proven and it works and everything is up and running, then we would open it up to other people commercial entities, tourists, researchers, scientists, and anybody really who has the money to go. And so then it would turn into a commercial enterprise after the initial stages.

Once the government has established that it’s possible, then it turns into a public-private partnership and it gets handed off to commercial space. And then the private market takes over, and then we start creating what we call cis-lunar economy—which is the space between the Earth and the moon that would become a new sphere of economic influence. So in other words, an economy would develop in space where we would use the local resources in space and commercial activity would start happening on the moon and in orbits, in the orbits of the moon, and eventually onto Mars.

Ths interview has been edited for length and clarity.


* moon_nasa-800x430.jpg (73.62 KB, 800x430 - viewed 52 times.)
Logged
Darja
Admin
Most Active Member
*****
Offline Offline

Posts: 5978


« Reply #1565 on: Jan 04, 2018, 05:27 AM »

Hubble spots spectacular auroras on ice giant Uranus

Auroras are well studied on Saturn and Jupiter, but less so on Uranus.

Léa Surugue
IBT
1/4/2018   

Nasa and the European Space Agency have released a stunning image showing auroras on Uranus.

This composite image of the giant icy planet was taken by Voyager 2, and combined with observations of the auroras captured by the Hubble space telescope.

Auroras can happen on planets other than Earth as long as they have an atmosphere and a magnetic field. They are caused by streams of charged particles originating from solar winds, moon volcanism or the planetary ionosphere.

When these particles become caught in magnetic fields and travel into the planet's atmosphere, they interact with atmospheric gases such as oxygen and nitrogen.

This interaction sets off the spectacular bursts of light that we call auroras.

Scientists have observed and studied auroras on Jupiter and Saturn for many years now, but their interest for Uranus' auroras is more recent, and many questions remain regarding the phenomenon.

But in 2011, the Nasa/ESA Hubble Space Telescope became the first Earth-based telescope to capture an image of the auroras on Uranus.

In 2012 and 2014, astronomers took another look at the auroras, this time using the ultraviolet capabilities of the Space Telescope Imaging Spectrograph (STIS) on Hubble.

This research led to an in-depth observation of auroras on Uranus, as the scientists studied the effects of two powerful bursts of solar wind travelling from the sun to the planet. They were able to observe the most intense auroras ever seen on Uranus and found out that they rotated with the planet.

This work on auroras also allowed the researchers to identify the planet magnetic field and to re-discover its magnetic poles – due to uncertainties in measurements, they had previously lost track of them after their discovery by Voyager 2 in 1986.

The new images of the auroras on Uranus will continue to enrich scientists' knowledge of the impressive phenomenon.


* uranus-hubble.jpg (20.91 KB, 736x622 - viewed 51 times.)
Logged
Darja
Admin
Most Active Member
*****
Offline Offline

Posts: 5978


« Reply #1566 on: Jan 05, 2018, 05:31 AM »

What is memory alloy? Nasa's next Mars rover will have wheels made of this wonder material

Memory alloy retains its original shape after any kind of stress.

By Immanuel Jotham
IBT
1/5/2018 

Nasa scientists at the John H Glenn Research Center, who have been working on new types of tyres and wheels for their upcoming rovers and land vehicles, have come up with a chainmail wheel made of a memory alloy that cannot be deformed.

Nasa is calling it Shape Memory Alloy (SMA), made of stoichiometric nickel titanium, that will get back to its original shape after it rolls over obstacles.

The new wheels and tyres are part of Nasa's efforts for a whole new Rover for future Mars missions. Described as a Winnebago-like vehicle, it may or may not look like an angry bat-mobile that was showcased a few months back.

The wheels were first showcased back in 2009. They showed good traction and durability, but over time, developed noticeable dents that could eventually get worse. It was designed in collaboration with Goodyear called "spring tyres". They were made entirely of interwoven steel mesh.

While they were found to be good performers, they could not hold up under extra weight and bad terrain. Scientists apparently realised that the tyre was a good design, but the materials used needed to be more than just steel.

This was when a chance encounter between Nasa engineer Colin Creager and material scientist Santo Padula reportedly took place. The scientist realised that the wheel would be better off with a memory alloy, in this case, nickel titanium. Atomic bonds of the SMA do not break under stress like it happens with steel; instead, they accommodate deformation as they always get back to their original shape.

Nasa's plan is to eventually take this wheel to Mars. Considering its strength and durability, it might be possible to build a heavier rover with a lot more instruments on board. Such a wheel could even support manned missions on the Red Planet. Mars rovers are also in need of better wheels and tyres as Curiosity's wheels have already started deteriorating after only about 10 miles on Mars. Its wheels are made of solid aluminium.

Will memory alloy tyres ever see use on Earth? Considering how much punishment it has proven to be able to take, it seems like a great way to cut back on tyre-replacement costs. Nasa also says that the SMA conforms to whatever terrain it moves over and is capable of absorbing energy from impacts at moderate to high speeds, so it seems like a great option for off-road and emergency response vehicles. There is, however, no word on whether it will be releases for commercial use any time soon.

There are a number of airless tyres that are under development, not just for Mars and the Moon, but also for Earth vehicles. Michelin, for example, is making a 3D-printed mesh tyre that is both light and durable.


* Close up of the chain mail like surface of the SMA.jpg (108.51 KB, 736x552 - viewed 63 times.)

* sma-wheel.jpg (150.34 KB, 736x1067 - viewed 57 times.)
Logged
Darja
Admin
Most Active Member
*****
Offline Offline

Posts: 5978


« Reply #1567 on: Jan 06, 2018, 06:36 AM »

2018 asteroid missions will bring space rock home

Newsweek
06 Jan 2018 at 07:36 ET     

There are plenty of exciting space missions planned for 2018, but one incredible pair will bring back the best present Earthlings could ask for—souvenirs of their journeys. Those two spacecraft are American and Japanese missions to visit and study asteroids, then carry samples back to scientists here on Earth to examine in the lab a couple years from now.

NASA's asteroid mission is formally known as the Origins-Spectral Interpretation-Resource Identification-Security-Regolith Explorer but goes by OSIRIS-REx. The spacecraft launched in 2016, did a little dance around Earth last year to pick up speed, and is now heading out to its target, which still lies about 460 million miles away.

That target is an asteroid called Bennu, a type B asteroid, which means that it's made primarily of organic compounds and clays. It's a fairly large target, taller than the Empire State Building, and scientists suspect that not much has happened to Bennu since it formed, which should mean they can use it as a type of time capsule of the early solar system. And the mission has a protective element as well: Although there's no immediate threat from Bennu, there's a chance its orbit in the late 22nd century, more than 150 years from now, could bring it crashing into Earth.

OSIRIS-REx is due to approach Bennu in August and begin studying it in October, which will last for more than a year. During that time, it will also land and carefully extract a small sample of Bennu, one that weighs at least 2.1 ounces, to carry home for scientists. OSIRIS-REx and its cargo are scheduled to touch down on Earth in 2023.

At the same time, Japan's space agency will be working with a mission called Hayabusa2, their second asteroid sample retrieval mission. The spacecraft launched in 2014 and this summer is due to meet its target, an asteroid called Ryugu.

Ryugu belongs to a different category of asteroids than Bennu does, class C, although it's also considered a primitive asteroid. Its name comes from a traditional Japanese tale in which the hero brings a casket back from a dragon's undersea castle, called Ryugu—just as Hayabusa2 will retrieve a sample from the asteroid, and those pebbles, like those gathered from Bennu, may well contain water.

The Ryugu samples will beat the Bennu samples to Earth, since they should arrive in 2020. Once they do, scientists will begin analyzing them to learn more about the early solar system—particularly those water molecules and organic compounds, which may help explain the biggest mystery of all, how life on Earth began.


* Asteroid-2017-AG13-inquisitr.com-1-800x430.jpg (84.69 KB, 800x430 - viewed 57 times.)
Logged
Darja
Admin
Most Active Member
*****
Offline Offline

Posts: 5978


« Reply #1568 on: Jan 08, 2018, 05:28 AM »


Nasa admits it can't afford to put humans on Mars

'Entry, descent and landing is a huge challenge for us for Mars,' said Nasa's chief of human spaceflight, William H. Gerstenmaier.

India Ashok
IBT
1/8/2018

For years, Nasa has been planning for an ambitious manned Mars mission. The space agency believes current unmanned missions like the Orion probe will further its chances of putting humans on the Red Planet.

However, Nasa has now reportedly acknowledged that the agency doesn't have enough funding to make the possibility of a manned Mars mission a reality, at least not in the near future.

"I can't put a date on humans on Mars, and the reason really is the other piece is, at the budget levels we described, this roughly 2 percent increase, we don't have the surface systems available for Mars," Nasa's chief of human spaceflight, William H. Gerstenmaier, said during a propulsion meeting of the American Institute for Aeronautics and Astronautics on Wednesday.

"And that entry, descent, and landing is a huge challenge for us for Mars."

Gerstenmaier's statements indicate that now, more than ever, the future of Mars colonisation may rest in the hands of private and commercial space companies.

Nasa appears to be aware of this, as indicated by Gerstenmaier's comments that one of the space agency's primary roles now is to act as an "orchestrator" in the commercial space industry to successfully realise deep space missions.

"Nasa doesn't have to do everything," Gerstenmaier said, highlighting the fact that the space agency already depends on private space companies like SpaceX to deliver cargo to the International Space Station (ISS).

Although the US Congress has so far been reluctant to expand Nasa's partnership with commercial space companies for deep space exploration, according to ArsTechnica's report, this may change in the future.

Nasa's human Mars mission will cost $450bn but it's not enough to explore the Red Planet

US Vice President Mike Pence, who recently visited Nasa, has reportedly intimated about the possibility of increasing Nasa's partnership with the private space exploration industry.

Even though Nasa currently doesn't have the budget required for extensive manned missions to Mars, according to Gerstenmaier, the Moon may be a much more affordable target, ArsTechnica reported.

"If we find out there's water on the Moon, and we want to do more extensive operations on the Moon to go explore that, we have the ability with Deep Space Gateway to support an extensive Moon surface program," he said. "If we want to stay focused more toward Mars, we can keep that."


* explorers-wanted-poster.jpg (125.42 KB, 736x1177 - viewed 59 times.)
Logged
Darja
Admin
Most Active Member
*****
Offline Offline

Posts: 5978


« Reply #1569 on: Jan 09, 2018, 05:49 AM »

The Great Red Spot Descends Deep Into Jupiter

By KENNETH CHANG
1/9/2018
NY Times

NEW ORLEANS — Jupiter's Great Red Spot is not just a skin-deep beauty mark.

Instead, the iconic storm descends at least 200 miles beneath the clouds and possibly much deeper.

That is one of the latest findings of NASA’s Juno spacecraft, which passed directly over the storm in July.

Juno is designed to peer beneath the clouds of Jupiter, the solar system’s largest planet, and its observations have upended scientists’ notions of how a big ball of hydrogen ought to behave. They have not yet come up with a new understanding of Jupiter.

“We just know enough to know we were wrong,” said Scott Bolton, a scientist at the Southwest Research Institute in San Antonio, Texas who is the mission’s principal investigator.
Interactive Feature: Jupiter and Its Moons

The Juno scientists presented their latest findings this week at a meeting of the American Geophysical Union in New Orleans.

Before Juno, astronomers could only observe the swirling of the cloud tops in the Great Red Spot, which is 10,000 miles wide — large enough to swallow Earth. Last year, scientists using an infrared telescope in Hawaii reported that the atmosphere 350 to 600 miles above the spot was exceptionally hot, averaging 2,500 degrees Fahrenheit.
  
But no one knew what was happening below the clouds. Scientists wondered whether the storm was shallow and confined to that slice of the atmosphere or if it descended hundreds or thousands of miles into the planet.

An instrument on Juno measures microwave emissions, which pass through the clouds into space. Warmer regions generate more microwaves, and the region below the Great Red Spot was warmer, even 200 miles down, the deepest that the microwave instrument could peer. The deep heat likely explains the source of the energy driving the storm.

Andrew P. Ingersoll, a professor of planetary science at the California Institute of Technology and a member of the Juno team, noted that the roots of the Great Red Spot go down 50 to 100 times deeper than the Earth’s oceans.

“It’s definitely warmer than its surroundings at that great depth,” Dr. Ingersoll said. “That is a new result. How deep it goes beyond that is still T.B.D.”

While the microwave instrument cannot answer that question, additional flyovers by Juno could help build a gravity map of the Great Red Spot region that could identify movements of mass hundreds of miles farther down. Mission managers are aiming for at least one more pass by Juno, which arrived at Jupiter last year and is one-quarter of the way through its mission.

The Great Red Spot has lasted at least 150 years and probably centuries longer. Additional data gathered by Juno could help scientists determine how long the storm will last.

Although it has been resilient, it has been shrinking, and its current size is considerably smaller than earlier measurements. In the late 1800s, it may have been 25,500 miles wide. When the two NASA Voyager spacecraft flew by in 1979, they measured the width at 14,500 miles.


* Capture.JPG (31.06 KB, 547x314 - viewed 55 times.)
Logged
Darja
Admin
Most Active Member
*****
Offline Offline

Posts: 5978


« Reply #1570 on: Jan 10, 2018, 06:47 AM »

Earth-like features on Saturn’s moon Titan

International Business Times
10 Jan 2018 at 06:46 ET

The oceans of liquid ethane and methane on the surface of Titan are certainly very different from the water bodies on Earth, but some of their properties and some of the other features on Saturn’s largest moon are much like those on our planet. Scientists have determined this fact using a topographic map created using data collected by the Cassini-Huygens mission.

The mission — a collaboration between NASA, the European Space Agency and the Italian Space Agency — came to an end when the Cassini spacecraft plunged to its death into the atmosphere of Saturn on Sept. 15, 2017. Huygens was a lander that successfully made it to the surface of Titan on Jan. 14, 2005.

Since the lander stopped transmitting data about 90 minutes after landing on Titan, it was chiefly data collected by the Cassini probe that researchers, led by Cornell University’s Paul Corlies, used to create the map. Only 9 percent of the moon has been imaged in high-resolution topography, while another 25-30 percent of it has been imaged in lower resolution. The remaining portion, over 60 percent, “was mapped using an interpolation algorithm and a global minimization process, which reduced errors such as those arising from spacecraft location,” according to a statement Wednesday by the university.

The map, whose main purpose Corlies said was to be used by the scientific community, revealed new mountains on Titan, all less than 700 meters in height. There are also two depressions in the moon’s equatorial region, which are either ancients seas now dried up, or cryovolcanic flows.

Cryovolcanoes are volcanoes that, instead of lava, spew out icy, salty water when they erupt, sometimes mixed with mud. They have been observed on other bodies in the solar system as well, such as on the dwarf planet Ceres.

“The map will be important for those modeling Titan’s climate, studying Titan’s shape and gravity, and testing interior models, as well as for those seeking to understand morphologic land forms on Titan,” according to the statement.

Saturn’s largest moon Titan is seen in this photo taken by NASA’s Cassini spacecraft. Photo: NASA/JPL-Caltech/Space Science Institute

A paper describing Titan’s topography was published in the journal Geophysical Research Letters, under the titled “Titan's Topography and Shape at the End of the Cassini Mission.”

Another paper published in the same journal used data from the map to report some important features about Titan’s topography. Titled "Topographic Constraints on the Evolution and Connectivity of Titan's Lacustrine Basins,” the paper’s lead author was Alex Hayes from Cornell.

One of the findings was that the oceans on Titan — three in all — have the same surface level, much like the oceans on Earth. It could be either because they are connected beneath the surface or because there are channels between them that allow the flow of liquid from one to the other. The second result concerns the numerous lakes on Titan, and is confirmation of Hayes’ earlier hypothesis that they all “communicate with each other through the subsurface.”

The third finding of the paper points to a new conundrum scientists will hopefully unravel in the future. Most of Titan’s lakes were found to be located in depressions with sharp edges and raised rims. Hayes said they “literally look like you took a cookie cutter and cut out holes in Titan’s surface.”

These formations are somewhat similar to karsts on Earth, but the raised ridges, hundreds of meters high in some places, do not feature in karsts that we find on our planet.


* Saturn-800x430.jpg (63.38 KB, 800x430 - viewed 52 times.)
Logged
Darja
Admin
Most Active Member
*****
Offline Offline

Posts: 5978


« Reply #1571 on: Jan 11, 2018, 05:06 AM »

Have scientists figured out these mystery signals through deep space ?

Newsweek
11 Jan 2018 at 14:54 ET

Billions of light-years away, short, sharp radio signals ripple through deep space. Lasting only a fraction of a second, most play out alone. Just one of these fast radio bursts has been found to flash again and again: FRB 121102. Now, scientists might have figured out the physical source of this mysterious extragalactic beep.

Published in Nature, results show the signals might emanate from a neutron star in an extreme environment of "unprecedented” power. It could be sitting near a massive black hole or in a particularly potent interstellar cloud, or nebula.

“Fast radio bursts are short-duration radio flashes that we think originate from very deep in extragalactic space," co-author and associate professor at the University of Amsterdam Jason Hessels, explained to Newsweek. "Only one of the 30 known fast radio burst (FRB) sources is known to repeat: FRB 121102.”

Researchers used the Arecibo Telescope in Puerto Rico and the Green Bank Telescope in West Virginia to detect the signals. “The radio flashes are very weak, so we need the world's largest radio telescopes to detect them,” Hessels said. “Radio telescopes have quite small fields of view so you have to be very lucky to be looking in the right direction at the right time.”

Last year, t he team localized the source of the weird signals to a star-forming region in a “puny” dwarf galaxy more than three billion light-years from Earth. The big mystery today, Hessels says, is what causes these repeating fast radio bursts.

“Almost unprecedented” astronomical source

The team’s data reveal that FRB 121102’s bursts are polarized. Scientists have observed an effect called the Faraday rotation, which “twists” the radio waves as they travel through a magnetic field. This is similar to the way polarized sunglasses filter bright light reflected off water. As Hessels explained, the stronger the field, the stronger the twisting of the waves.

"Here we see a twisting that is so extreme that it is almost unprecedented for an astronomical source of radio waves," he said. "No other FRB source has shown the extreme "twisting" of the radio waves that FRB 121102 has shown us.”

This suggests the signals are passing through an incredibly strong magnetic field. Based on observations from our own galaxy, this could mean the source is close to a powerful black hole.

“The only known sources in the Milky Way that are twisted as much as FRB 121102 are in the Galactic center, which is a dynamic region near a massive black hole. Maybe FRB 121102 is in a similar environment in its host galaxy,” Daniele Michilli, a doctoral candidate at the University of Amsterdam, said in a statement.

Alternatively, the source could be nestled in a powerful nebula or the remnant of a supernova.

A neutron star?

Hessels and team believe a neutron star sitting in one of these extreme magnetic environments could be the source itself. He says: “The bursts sometimes last for only a few tens of microseconds. The shorter the durations of the bursts, the smaller the region/object that is creating them, roughly speaking.”

Neutron stars are already known to produce radio flashes as pulsars. At only about 12 miles across, the team believe they are a natural candidate for the repeating radio bursts.

“What’s more, the polarization properties and shapes of these bursts are similar to radio emission from young, energetic neutron stars in our galaxy. This provides support to the models that the radio bursts are produced by a neutron star,” Andrew Seymour, an astronomer at Arecibo Observatory, said in a statement.
 
True source remains unknown

However, the mystery of FRBs is far from solved. “The interpretation of what produces that environment is a matter of debate,” Hassels said. “I'm sure that there will be many papers in the coming weeks that try to come up with other explanations for what we're seeing.”

The signals—whatever their cause—can teach scientists about the nature of space itself. “More broadly, fast radio bursts probe the extremes of the universe, which are important for understanding because extreme astronomical sources have a large role in shaping the way the universe looks,” Hessels said. “Think of them like a flashlight illuminating all the stuff we wouldn't otherwise see.”

One thing we do know is that FRB 121102 probably isn’t coming from little green men. Instead, Hessels adds: “We have lots of good ideas of natural sources that can produce this kind of emission."


* Universe-Shutterstock-www.shutterstock.com_-800x430.jpg (181.85 KB, 800x430 - viewed 51 times.)
Logged
Darja
Admin
Most Active Member
*****
Offline Offline

Posts: 5978


« Reply #1572 on: Jan 12, 2018, 04:56 AM »

Martian ice deposits could sustain human outposts in the future

Reuters
12 Jan 2018 at 18:27 ET                   

Scientists using images from an orbiting NASA spacecraft have detected eight sites where huge ice deposits near the Martian surface are exposed on steep slopes, a potential source of water that could help sustain future human outposts.

While scientists already knew that about a third of the surface of Mars contains shallow ground ice and that its poles harbor major ice deposits, the research published on Thursday described thick underground ice sheets exposed along slopes up to 100 yards (meters) tall at the planet’s middle latitudes.

“It was surprising to find ice exposed at the surface at these places. In the mid-latitudes, it’s normally covered by a blanket of dust or regolith,” loose bits of rock atop a layer of bedrock, said research geologist Colin Dundas of the U.S. Geological Survey’s Astrogeology Science Center in Flagstaff, Arizona, who led the study.

The latitudes were the equivalent on Earth of Scotland or the tip of South America.

The researchers used images from NASA’s Mars Reconnaissance Orbiter, which has studied the Martian atmosphere and terrain since 2006, including the history of apparent water flows on or near the surface.

The findings showed that ice may be more available than previously known for use as water to support future robotic or human exploration missions, perhaps even the establishment of a permanent Mars base. The water could be used for drinking and potentially conversion into oxygen to breathe.

“Humans need water wherever they go, and it’s very heavy to carry with you. Previous ideas for extracting human-usable water from Mars were to pull it from the very dry atmosphere or to break down water-containing rocks,” said planetary scientist Shane Byrne of the University of Arizona Lunar and Planetary Laboratory, a co-author of the study in the journal Science.

“Here we have what we think is almost pure water ice buried just below the surface. You don’t see a high-tech solution,” Byrne added. “You can go out with a bucket and shovel and just collect as much water as you need. I think it’s sort of a game-changer. It’s also much closer to places humans would probably land as opposed to the polar caps, which are very inhospitable.”

The deposits were found at seven geological formations called scarps, with slopes up to 55 degrees, in the southern hemisphere and one in the northern hemisphere.

“Our interpretation is that this is consolidated snow deposited in geologically recent times,” Dundas said.

(Reporting by Will Dunham; Editing by Sandra Maler)


* the-planet-mars-afp.jpg (40.55 KB, 800x430 - viewed 46 times.)
Logged
Darja
Admin
Most Active Member
*****
Offline Offline

Posts: 5978


« Reply #1573 on: Jan 13, 2018, 06:26 AM »

Where did ‘Oumuamua actually come from?

Newsweek
13 Jan 2018 at 08:20 ET 

One of the highlights of 2017 was the discovery of the first object in our solar system that definitely came from somewhere else. At first we thought it was a comet, then an asteroid, and now the International Astronomical Union has reclassified it as something new entirely: an interstellar object. The Hawaiian astronomers who discovered it aptly named it ‘Oumuamua, which means “a messenger from afar arriving first”, reflecting that this object is like a scout sent from the past to reach out to us.

Research has already helped us learn a lot about 'Oumuamua’s rare cigar-like shape, what it’s made of ( ice with a carbon-rich surface) and its highly unusual orbit, which will take it out of our solar system at a speed of around 16mp/s. The Breakthrough Listen research program has even investigated whether 'Oumuamua is an alien space ship by scanning the object for life forms with the Green Bank Telescope. No intelligent signals have been identified so far, though further observations are planned.

Now, my latest study gives us a glimpse of exactly where 'Oumuamua may have come from. Reconstructing the object’s motion, my research suggests it probably came from the nearby “Pleiades moving group” of young stars, also known as the “Local Association.” It was likely ejected from its home solar system and sent out to travel interstellar space.

Based on 'Oumuamua’s trajectory, I simulated how it has probably traveled through the galaxy and compared this to the motions of nearby stars. I found the object passed 109 stars within a distance of 16 light years. It went by five of these stars from in the Local Association (a group of young stars likely to have formed together), at a very slow speed relative to their movement.

It’s likely that when 'Oumuamua was first ejected into space, it was traveling at just enough speed to break away from the gravity of its planet or star of origin, rather than at a much faster speed that would require even more energy. This means we’d expect the object to move relatively slowly at the start of its interstellar journey, and so its slow encounters with these five stars suggests it was ejected from one of the group.

When was it kicked out of its home?

Stars typically move with an average speed when they are formed, and gradually change speed as they encounter very large objects, such as massive stars and molecular clouds and are affected by their gravity. Unlike most nearby stars, 'Oumuamua moves very slowly compared to the average motion of the rest of the galaxy. This suggests it has only been traveling in interstellar space for a relatively short time and hasn’t had a chance to encounter many massive objects that would speed it up.

We also have evidence for 'Oumuamua’s relatively young age from the color of its surface. Outside of the protection of a star’s magnetic field, objects in space are bombarded with cosmic rays and interstellar dust and gas that gradually alter their surfaces and turn them very red in color. But 'Oumuamua has a more neutral color, suggesting it has only been impacted by cosmic rays for, at most, hundreds of million years rather than for the billions of years that our solar system has existed.
How was it ejected?

'Oumuamua is extremely elongated and has quite a different shape from other objects in our solar system. It was probably formed by a relatively high-energy process such as a collision, or ejected from a forming star. Most objects in the outer part of a planetary system are made more of ice and most objects in the inner regions are made more of rocks. Since 'Oumuamua is a more even mix of ice and rocks, it’s likely it came from the middle part of a solar system, similar to the asteroid belt between Mars and Jupiter that features a mixture of icy and rocky asteroids.

Perhaps the most plausible scenario is that 'Oumuamua was ejected from a closely separated binary star system made of two stars closely orbiting each other. Objects orbiting one of the stars in a binary system will be strongly affected by the gravity of the other and so can be more easily ejected from the system than if it had just one star.

'Oumuamua is probably just the tip of the iceberg. My research suggests there are likely more than 46m similar interstellar objects crossing the solar system every year. Most of them will be too far away for us to see with our current telescopes. But new telescopes and surveys should soon be able to find these interstellar messengers, which may be sending us important information about how stars and planets formed. Studying more objects like 'Oumuamua will enable us to work out how much debris is left over from star formation and how much this adds to the mass of our galaxy.

Another reason to study these interstellar objects is that they could one day threaten to collide with the Earth and cause catastrophic events such as mass extinctions. The more we know, the better prepared we’ll be if that day ever comes.


* Oumuamua.jpg (87.61 KB, 800x430 - viewed 52 times.)
Logged
Darja
Admin
Most Active Member
*****
Offline Offline

Posts: 5978


« Reply #1574 on: Jan 15, 2018, 05:03 AM »

Life in the solar system likely exists

Newsweek
15 Jan 2018 at 08:34 ET

It’s one of the most compelling questions humanity has tried to answer: Is there life beyond Earth? Scientists are closer than ever to answering that question, thanks to a host of technological advances and each new spacecraft that launches—and sometimes even thanks to evidence falling right onto our laps.

Evidence like two meteorites that crashed into Earth in 1998. Nestled within those space rocks were tiny bright blue salt crystals, and inside of those crystals were tiny pockets of extraterrestrial water filled with organic compounds, the building blocks of life, according to new research published on Wednesday.

“I think it’s likely” that there is other life within our solar system, first author on that work,  Queenie Chan, a planetary scientist at Open University in the U.K., told Newsweek. And even better, she says, we’re doing the science that might finally find it. “That’s why we like searching missions, isn’t it?”

That means missions like NASA’s Dawn spacecraft, which has been studying the largest object in the asteroid belt, the dwarf planet Ceres. Chan and her co-authors believe the salt crystals they studied may have first been formed on Ceres or a similar object, so they have paid close attention to the results the Dawn spacecraft has gathered. That includes identifying sodium chloride, better known as table salt, and sulfur dioxide. “When I saw them I was like, ‘Hey, I saw that in our sample too,’” she said.

Although the Dawn mission will end later this year, there are plenty of successors on the way, like Europa Clipper, NASA’s plan to fly by Saturn’s icy moon after a 2020s launch. Scientists suspect that it could host life, thanks to the theory that the moon is hiding a giant salty ocean and volcanic activity under its icy shell. Life—as we know it, anyway— requires water, common chemicals like oxygen and carbon dioxide that scientists think could be forming on Europa's icy shell, and an energy source (on Earth, that's usually the sun, but on Europa it could be geological processes).

Chan says her new research supports these suspicions of life on Europa because the story she and her colleagues put together for the salt crystals they studied relies on conditions also believed to exist on this moon. In particular, they think the crystals found within the meteorite were shot off a particularly water-rich asteroid by cryovolcanism, a type of geologic activity that spews water or ice instead of lava.

Scientists suspect the cryovolcanism may occur on Europa as well. And unlike traditional geologic activity, these eruptions don't reach high temperatures that would irreparably toast these life-supporting chemicals. “Our study proves that, ok, this kind of scenario is similar to what we found on the meteorite,” Chan said of scientists’ hypotheses about what’s happening on Europa. “It is likely that inside this ocean world there is a whole wide range of chemical compounds.”

Read more: Ancient Meteorites That Crashed to Earth Carried Ingredients for Life, Including Water and Organic Compounds

Or consider Mars, currently the playground of science robot extraordinaire, Curiosity. We have a few precious pieces of Mars here on Earth in the form of Martian meteorites, which can be analyzed for the same basic compounds Chan went looking for in her asteroid-born samples. One of the key types of compounds scientists look for is amino acids—the building blocks of life—which Chan and her colleagues did find.

But even more exciting would be a particular subset of amino acids. Each type of amino acid comes in two flavors, which scientists call left- and right-hand forms. Living things only use the left-handed versions, called homochirality—those are the amino acids scientists hope to find as an indication of alien life.

The problem is, it’s ridiculously easy to contaminate meteorites here on Earth, so scientists don’t feel confident about the results they would get from such an analysis. On Mars, it’s a different story. “If they find homochirality of amino acids, that would be phenomenal,” Chan said of the Curiosity mission.

Chan says that all told, she thinks it’s likely there’s life tucked away somewhere else in the solar system waiting to be found. And if you expand the scope beyond our solar system, the odds of life existing get even better. “It’s easier to say that, the universe is so big,” she said.

Whether in our own neighborhood or beyond, scientists are looking for the same criteria. They may be rare, but they should be out there somewhere. “You have to have the right conditions,” Chan said. “A lot of boxes have to be ticked to make that feasible.

Logged
Pages: 1 ... 103 104 [105] 106 107 ... 115   Go Up
Print
Jump to: