Venus is not a placid paradise — that much we know. In addition to searing surface temperatures, wind in the upper atmosphere howls as fast as 250 mph, carrying clouds around the planet once every four days.
Yet Venus itself spins very slowly: one rotation every 243 Earth days — in the wrong direction, no less, opposite to almost every other body in the solar system.
On the whole, the atmosphere on Earth rotates about the same speed as the planet. So why does the air on slow-spinning Venus speed around so much faster than the planet itself?
The Japanese space probe Akatsuki, now in orbit around Venus, seeks to solve the mystery of so-called super-rotation.
That is not just an idle trivia question for planetary scientists. Computer models of our own weather fail when applied to Venus, and knowledge of the planet’s workings could better our understanding of Earth’s.
‘‘We don’t know what is the missing point in meteorology,’’ said Masato Nakamura, Akatsuki’s project manager.
In recent years, Venus has been a backwater of planetary exploration, even though it is much closer in size to Earth than is Mars. For a long time, scientists imagined there could be a habitable tropical paradise beneath Venus’ thick clouds.
In the late 1950s, intense thermal emissions, measured by a radio telescope on Earth, told a different story. Venus broils.
The average surface temperature is more than 850 degrees — an extreme demonstration of the heat-trapping prowess of carbon dioxide, the primary constituent of the Venusian atmosphere. Clouds of sulfuric acid make it an even less appealing place to visit.
In the 1990s, NASA’s Magellan spacecraft precisely mapped the topography of Venus through radar. Except for a few flybys by spacecraft on the way to somewhere else, NASA has not returned to Venus, although the agency is considering two modest proposals.
A European mission, Venus Express, studied the planet from 2006 to 2014, discovering among other things a frigid layer of atmosphere, minus 280 degrees Fahrenheit at an altitude of 75 miles, sandwiched between two warmer layers.
But now Akatsuki, which entered orbit last December, has begun its work. Takehiko Satoh, one of the mission scientists, said that one of ‘‘the most exciting, most surprising results’’ so far came almost immediately after the spacecraft arrived.
The camera that captures long-wavelength infrared light from the cloud tops discovered an arc-shaped white streak that stretched 6,000 miles from nearly the south pole to nearly the north pole.
Curiously, this giant atmospheric feature does not move with the atmosphere. ‘‘It seems to be fixed to the ground,” Satoh said.
The arc sits above Aphrodite Terra, a highland region about the size of Africa that rises up nearly 3 miles from the surface. Scientists working on data from the Venus Express reported a similar finding in July.The small spacecraft — the main body is a box a bit bigger than a refrigerator — carries five cameras, collecting light at different wavelengths to monitor the Venusian atmosphere at different altitudes.
In another experiment, scientists will observe how the radio signal from the spacecraft to Earth is distorted when it passes through the atmosphere. That will reveal temperature, abundance of sulfuric acid vapor and other properties. By observing the atmosphere at different altitudes, they can detect wavelike features that rise and fall, like blobs in a lava lamp.That Akatsuki, which means ‘‘dawn’’ in Japanese, is there at all is the result of ingenuity and perseverance.
It launched in May 2010 and arrived at Venus seven months later. But when its main engine failed to fire properly, it sailed right past the planet. ‘‘It was a very sad moment,’’ Satoh said.
Within a day, Satoh said, calculations indicated that in six years, Akatsuki, in orbit around the sun instead of Venus, could meet up with Venus again. But it was not clear the spacecraft still would be able to slow down and enter orbit.
An investigation found that a valve in the engine had leaked, leading to the formation of salts that fused it shut. The engine, as it fired, had overheated beyond repair.
Akatsuki still had the maneuvering thrusters that were to be used after it entered orbit. They were not as powerful as the broken engine, but they could apply enough force to slow it down enough so that Venus’ gravity could capture it.The Akatsuki’s orbit is different from the one originally envisioned. Instead of being synchronized to the spinning atmosphere, which would have allowed scientists to better track small changes, the spacecraft now loops around Venus in a large elliptical orbit.
That provides different benefits. Instead of intently staring at one spot, seeing the smallest changes, scientists are now able to see what happens on a global scale, although they will miss some of the details.
Akatsuki is to continue operating until at least April 2018, depending on how much fuel it has left. ‘‘We know at least we have one kilogram of fuel,’’ said Nakamura, likening the uncertainty to an imprecise fuel gauge in a car.
If it turns out that Akatsuki has more, the spacecraft could continue operating for perhaps up to six years, he said.
China plans to become the first nation to land a probe on the far side of the Moon, according toXinhua News Agency, the country’s official press organization.
Launching possibly as early as 2018, the mission represents the next step in China’s plans to explore the Moon with robotic probes and, within the next decade, to return a couple of kilograms of lunar material to Earth. The proposed Chang’e-4 probe follows the successful soft landing of the Chang’e-3 probe on the near side of the Moon in December 2013.
Although the new probe was built as the engineering backup to the Chang’e-3 lander, Chinese officials said the structure could handle a larger payload. China plans to use the probe to study “geological conditions” on the far side of the moon. The Chang’e probes are named after the Chinese goddess of the Moon.China has also offered foreign countries the opportunity to participate in its lunar exploration programs. In contrast to NASA, Europe and Russia have both signaled their interest in further studying the Moon and likely landing humans there, before moving on to Mars. Many countries and businesses see potential value in ice at the lunar poles and rare minerals in the lunar soil. The US Congress recently passed a law to legalize the mining of these resources.
Humans have studied the far side of the Moon from above since 1959, when the Soviet Union’s Luna 3 spacecraft returned the first grainy images of its pockmarked surface. But no humans or robotic spacecraft have yet landed there.
Paris (AFP) – Scientists Wednesday announced the discovery of an Earth-sized planet orbiting the star nearest our Sun, opening up the glittering prospect of a habitable world that may one day be explored by robots.
Named Proxima b, the planet is in a “temperate” zone compatible with the presence of liquid water — a key ingredient for life.
The findings, based on data collected over 16 years, were reported in the peer-reviewed journal Nature.
“We have finally succeeded in showing that a small-mass planet, most likely rocky, is orbiting the star closest to our solar system,” said co-author Julien Morin, an astrophysicist at the University of Montpellier in southern France.
“Proxima b would probably be the first exoplanet visited by a probe made by humans,” he told AFP.
An exoplanet is any planet outside our Solar System.
Lead author Guillem Anglada-Escude, an astronomer at Queen Mary University London, described the find as the “experience of a lifetime”.
Working with European Southern Observatory telescopes in the north Chilean desert, his team used the so-called Doppler method to detect Proxima b and describe its properties.
The professional star-gazers spent 60 consecutive days earlier this year looking for signs of gravitational pull on its host star, Proxima Centauri.
Regular shifts in the star’s light spectrum — repeating every 11.2 days — gave a tantalising clue.
They revealed that the star alternately moved towards and away from our Solar System at the pace of a leisurely stroll, about five kilometres (three miles) per hour.
– Goldilocks zone –
After cross-checking an inconclusive 2000-2014 dataset and eliminating other possible causes, the researchers determined that the tug of an orbiting planet was responsible for this tiny to-and-fro.
“Statistically, there is no doubt,” Anglada-Escude told journalists in a briefing.
“We have found a planet around Proxima Centauri.”
Proxima b is a mere four light years from the Solar System, meaning that it is essentially in our back yard on the scale of our galaxy, the Milky Way.
It has a mass around 1.3 times that of Earth, and orbits about seven million kilometres (4.35 million miles) from its star.
A planet so near to our Sun — 21 times closer than Earth — would be an unlivable white-hot ball of fire.
But Proxima Centauri is a so-called red dwarf, meaning a star that burns at a lower temperature.
As a result, the newly discovered planet is in a “Goldilocks” sweet spot: neither so hot that water evaporates, nor so cold that it freezes solid.
But liquid water is not the only essential ingredient for the emergence of life.
An atmosphere is also required, and on that score the researchers are still in the dark.
It all depends, they say, on how Proxima b evolved as a planet.
“You can come up with formation scenarios that end up with and Earth-like atmosphere, a Venus-like atmosphere” — 96 percent carbon dioxide — “or no atmosphere at all,” said co-author Ansgar Reiners, an expert on “cold” stars at the University of Goettingen’s Institute of Astrophysics in Germany.
Computer models suggest the planet’s temperature, with an atmosphere, could be “in the range of minus 30 Celsius (-22 Fahrenheit) on the dark side, and 30C (80F) on the light side,” Reiners told journalists.
Like the Moon in relation to Earth, Proxima b is “tidally locked,” with one face always exposed to its star and the other perpetually in shadow.
Emerging life forms would also have to cope with ultraviolet and X-rays bombarding Proxima b 100 times more intensely than on Earth.
– Search for life –
An atmosphere would help deflect these rays, as would a strong magnetic field.
But even high doses of radiation do not preclude life, especially if we think outside the box, scientists say.
“We have to be very open-minded as to what we call ‘life’,” Jean Schneider, an expert on exoplanets at the Observatoire de Paris, told AFP.
Some 3,500 exoplanets have been discovered since the first confirmed sighting in 1995.
Most of these distant worlds — like our own Jupiter and Neptune — are composed of gas, an inhospitable environment for life.
Even the 10 percent that do have rocky surfaces are mostly too cold or too hot to host water in liquid form.
And — until today — the handful that are in a temperate zone are effectively beyond reach.
Last year, for example, NASA unveiled Kepler 452b, a planet about 60 percent larger than Earth that could have active volcanoes, oceans, sunshine like ours, and a year lasting 385 days.
But at a distance of 1,400 light-years, humankind would have little hope of reaching this Earth-twin any time soon.
By comparison, Proxima b is a stone’s throw away, though still too far away for humans to visit with present-generation chemical rockets.
“This is a dream for astronomers if we think about follow up observations,” said Reiners.
Why wait for the bus when you can hail a cab? That’s the idea behind a new commercial spaceflight startup founded by SpaceX founding team members Jim Cantrell and John Garvey. Vector Space Systems wants to shake up to the commercial space market by providing not tens, but hundreds of launches per year.
Vector Space-logo-black“We’re going to bring real economics to the launch platform,” Cantrell told TechCrunch in an interview. “And we can do that because we bring supply. We’re talking about building hundreds of these things.”
Vector isn’t looking to compete with SpaceX, or even smaller commercial launch platforms like Rocket Lab and Firefly. A launch with these companies might be booked years in advance, with dozens of sub-launches, deliveries, experiments, and what have you packed into a single rocket. It’s like a space bus. Vector wants to be the space taxi.
“I had this experience pounded into my brain with LightSail,” said Cantrell, referring to the Planetary Society’s experimental solar propulsion craft. “We built that thing — I think we finished in 2011 — and it’s still waiting around for launch, because you need a particular orbit and so on. And really nobody has addressed this problem.”
With small rockets carrying single 20-40 kg payloads launching weekly or even every few days, the company can be flexible with both prices and timetables. Such small satellites are a growing business: 175 were launched in 2015 alone, and there’s plenty of room to grow. It’ll still be expensive, of course, and you won’t be able to just buy a Thursday afternoon express ticket to low earth orbit — yet.
Customers will, however, reap other benefits. There are less restrictions on space: no more having to package your satellite or craft into a launch container so it fits into a slot inside a crowded space bus. Less of a wait between build and launch means hardware can be finalized weeks, not years, in advance — and expensive satellites aren’t sitting in warehouses waiting for their turn to go live and get that sweet return on investment.
The last few years have been spent on designing and testing the as-yet-unnamed launch vehicles Vector will be using. The first stage is designed to be reusable — nothing as fancy as SpaceX’s autonomous landings, but rather using a unique aerial recovery system Cantrell seemed excited (though guarded) about.
Dozens of sub-orbital flights have been made, and orbital deployment is the next test. If all goes well, Vector hopes to be making its first real flights in 2017.
Investors are knocking down the front door looking to get in, he said, though he declined to name any. Perhaps they smell profitability: Vector’s business plan has it cash positive after just a few launches. Government money is also in the mix: Cantrell noted humbly that “We’ve been talking with people high up at the Pentagon who want this for obvious reasons.”
A lot depends on successful demonstration of orbital deployment, which should be happening a little later this year. If things go as planned, it could work towards removing one of the most significant restraints currently holding back commercial spaceflight.
ASTRONAUTS SPEND YEARS training before they go into space. The same is true for their robot counterparts, two of which recently arrived in Massachusetts to be put through their paces in preparation for a long-off mission to Mars.
Valkyrie is built like a linebacker — 6’2” tall and 275 pounds. Its job is to go to Mars and maintain equipment in anticipation of the arrival of astronauts, potentially years after Valkyrie first touches down on the Red Planet.
“If you don’t start your car for two years, do you expect it will start when you return?” says Taskin Padir, a professor of engineering at Northeastern University who will be leading the university’s work with Valkyrie. “Humanoid robots will be part of the pre-deployment mission to Mars and will maintain equipment prior to the astronauts’ arrival.”
A manned mission to Mars is a high priority for NASA, which hopes to achieve the feat by the 2030s. As conceived, the expedition would require NASA to send equipment like rovers and a human habitat to Mars years before the astronauts launch. This is due to the relative orbits of Earth and Mars, which make it only practical to launch from here to there every two years.
“You need to pre-position assets like a habitat, a power supply. Whatever you need on the surface, all that’s done years before an astronaut gets there,” says William Verdeyen, NASA project manager for Valkyrie.
Valkyrie’s destination may be exotic, but the robot’s tasks will be mundane. The Johnson Space Center in Houston will beam instructions to Mars (the transmission takes about 20 minutes), and the robot will carry them out autonomously. Likely jobs include repairing electronic boards, cutting cords, and changing batteries — all maneuvers that require dexterity, which is complicated to engineer.
“A [good] analogy is replacing batteries in a flashlight,” says Padir. “If we can do that with Valkyrie at the end of two years, that would be a great accomplishment from our perspective.”
Over the next two years, the Northeastern team will work on improving Valkyrie’s performance, especially at these kinds of fine-motor maintenance tasks. A separate team at MIT will be doing similar work with another copy of the robot.
Most of Valkyrie’s movements will take place inside the human habitat — a known environment for the engineers, which makes it relatively easy to navigate. Sometimes, though, the robot will have to venture outside, like to brush dust off of solar panels. There, things get more treacherous. And if Valkyrie falls on the rough, uneven Martian surface, there’s always the risk it will never be able to get back up. Fortunately, though, in all these tasks, time is going to be on Valkyrie’s side.
“This robot will have a lot of free time on Mars,” says Padir. “If your task is to clean a few solar panels in the next week, you don’t have to run.”
Emily Calandrelli (@TheSpaceGal)
Compared to chemical propulsion (the type of propulsion that rockets use to escape Earth’s gravity well and reach orbit), SEP has lower thrust but is more fuel-efficient and can provide thrust for longer periods of time. For these reasons, SEP works well in the vacuum of space, particularly on spacecraft with long mission lifetimes.
SEP engines provide thrust by converting solar energy into electricity and using that electricity to accelerate ionized propellant at extremely high speeds. The iconic blue glow from a SEP thruster is created from photons released by the ions as they lose energy upon leaving the engine.
NASA has been working on SEP technology since the 1950s and they’ve used SEP on prior missions like the Dawn spacecraft, which is currently in orbit around the dwarf planet Ceres and is the first spacecraft to orbit around two extraterrestrial bodies.
Under the new contract, NASA hopes to double the thrust capability compared to current electric propulsion systems and increase the fuel efficiency by 10 times the current chemical propulsion.
One challenge with deep-space missions that use SEP is that as you travel deeper into the solar system (farther away from the sun), it becomes more difficult to effectively capture light from the sun to power the spacecraft. Because of this, NASA stated its current SEP research is funded in parallel with work to advance solar array technology.
During the 36-month contract, Aerojet Rocketdyne is responsible for constructing, testing and delivering an SEP product for testing and evaluation. Eventually, the goal is to have Aerojet Rocketdyne deliver four electric propulsion units that will fly in space.
“Through this contract, NASA will be developing advanced electric propulsion elements for initial spaceflight applications, which will pave the way for an advanced solar electric propulsion demonstration mission by the end of the decade.” Steve Jurczyk, associate administrator of NASA’s Space Technology Mission Directorate
In addition to this particular electric propulsion contract, Aerojet Rocketdyne is responsible for the chemical propulsion — the RS-25 engines — for NASA’s Space Launch System, the rocket designed to be used on missions related to NASA’s Journey to Mars initiative.
Aerojet Rocketdyne’s current contract is part of NASA’s overall push to advance SEP systems. NASA plans to test the largest and most advanced SEP system ever used in space on their Asteroid Redirect Mission, which is designed to capture an asteroid and place it in orbit around the moon. That mission is currently slated for the mid-2020s.
Cathal O’Connell explains the challenges that will face scientists when they break the biggest news story in history.
Detecting a signal from an extraterrestrial intelligence would be life changing for everyone on Earth – the biggest news story in history – and could potentially be dangerous, especially if badly handled.
Writing in the journal Acta Astronautica, scientists at the Search for Extra Terrestrial Intelligence (SETI) institute describe a protocol for how to break it to the world that we’re not alone in the Universe – without causing global mayhem.
Rather than a conspiracy of government cover-ups so beloved of sci-fi writes, the study strongly recommends openness as the key to having a “sane global conversation” about the discovery of ET.
Nobody knows how the world would react to the discovery of extraterrestrial intelligence. All we have to go on are the bizarre occurrences where the public thought they were hearing such news.
In 1938 Orson Welles’ radio-play based on HG Wells’s novel The War of the Worlds caused widespread panic in the United States (although the scale of that panic was likely exaggerated). In 1949, a Spanish language version of the same program incited rioting in Ecuador, leading to at least seven deaths, and possibly as many as 20.
Then there’s the risk of the media misreporting or exaggerating the importance of a tentative signal. In October 2015, for example, when a newly discovered extrasolar planet, KIC 8462852, was discovered to show a periodic dip in brightness, the mainstream media latched on to the most speculative, and least likely, explanation – namely that an “alien megastructure” was passing in front of its star. (The periodic dimming is more likely caused by a cloud of comets passing by.)
As a result of these excesses, scientists have been worried about how to break SETI news for decades.
In 1989, the International Academy of Astronautics drew up a set of guidelines for releasing information about a potential alien signal. But that was before the internet and social media transformed the way we consume news stories.
Now, Duncan Forgan and Alexander Scholz, from the University of St Andrew’s in Scotland, have prepared an updated protocol for how scientists should navigate the “unprecedented media onslaught”.
First, Forgan and Scholz advise, all scientists performing a SETI experiment should clearly outline their search methodology as well as define what makes a “discovery”, before the search even begins. This information should be published in a format the media can easily access, such as a blog post.
Then if a signal is detected, the discoverers should not to try to keep it under wraps – the potential fall-out from a leak would be too damaging. Much better to announce a tentative detection, but be clear that it must be assumed to be of natural or manmade origin until proved otherwise.
The scientists should submit their findings to a peer-reviewed journal, while simultaneously uploading all data so it can be pored over by other scientists – and potential known sources ruled out.
The problem is these verifications can take a long time. The best case-study is the so-called “Wow” signal, detected in 1977. That signal was exactly what SETI scientists had been looking for – being at the right frequency to hold an interstellar conversation, and being of unprecedented strength – and is still unexplained almost 39 years later. (Although in early 2016, a study published by the Washington Academy of Sciences suggested that comets could emit such a signal, and identified two comets that were in the right place at the right time in 1977. Future measurements of radio emission by comets should hopefully clear this up.)
In the case where the detection cannot be confirmed, say Forgan and Scholz, the SETI scientists should publish an announcement saying so.
In the case of the detection is confirmed, however, the SETI scientists should become deeply involved in the global conversation by engaging across as many social media platforms as possible – a role they would likely assume for the rest of their lives. They should also be prepared for the downsides of newfound fame – such as cyber attacks.
The latest polls (conducted in Germany, the UK and US last September) show that most people in developed countries believe intelligent aliens exist somewhere in the Universe. But that doesn’t mean we’re ready for a “first contact” event.
However unlikely such a discovery is, a signal from an alien intelligence would be the most momentous discovery the human species is ever likely to make. It’s worth a little thinking ahead.
Oceanographers may need to study alien worlds sooner than you think.
Observations by NASA‘s Cassini spacecraft indicate Saturn’s moon Titan is more Earth-like with its dense atmosphere, lake-filled surface and possible wetlands.
Other than our home planet Titan is the only known world in the solar system with stable liquid on its surface, according to NASA.
Since 2004, Cassini has found more than 620,000 square miles of Titan’s surface covered in liquid, about two percent of its globe. Planetary scientists have theorized about what elements fill Titan’s liquid bodies, but thanks to Cassini they now have answers
A new study using Cassini’s radar instrument to study Titan’s second largest sea, known as Ligeia Mare, between 2007 and 2015 reveals it’s a filled with methane.
The study published in the Journal of Geophysical Research: Planets confirms what planetary scientists have thought about Titan’s seas for some time.
Using Cassini’s radar instrument to detect echoes from the seafloor of Ligeia Mare scientists used the depth-sounding information to observe temperatures, which helped give clues to their composition, according to the news release.
“Before Cassini, we expected to find that Ligeia Mare would be mostly made up of ethane, which is produced in abundance in the atmosphere when sunlight breaks methane molecules apart. Instead, this sea is predominantly made of pure methane,” said Alice Le Gall, a Cassini radar team member and lead author of the new study.
Ligeia Mare is the about the size of Lake Huron and Lake Michigan together, according to NASA and from Cassini’s flybys scientists were able to determine the sea is 525 feet deep in some areas.
All of Titan’s seas are named for mythical sea creatures. The largest sea, Kraken Mare is about 680 miles long.
Another similarity between our home planet and Titan is they both have nitrogen atmospheres, but Titan is lacking much oxygen. Titan’s atmosphere is mostly methane with trace amounts of ethane and because of the distance from the sun, meaning cold temperatures, the methane and ethane remain in liquid form instead of escaping, according to NASA.
Le Gall offered a few possibilities of how Ligeria Mare became mostly methane filled, instead of ethane as Cassini’s team originally thought.
“Either Ligeia Mare is replenished by fresh methane rainfall, or something is removing ethane from it,” said Le Gall. “It is possible that the ethane ends up in the undersea crust, or that it somehow flows into the adjacent sea, Kraken Mare, but that will require further investigation.”
The study also found Ligeia Mare’s shoreline may warm quicker than in the sea, similar to a beach on Earth.
“It’s a marvelous feat of exploration that we’re doing extraterrestrial oceanography on an alien moon,” said Steve Wall, deputy lead of the Cassini radar team. “Titan just won’t stop surprising us.”
Inflatable room attached to space station
A giant addition that one day may be used to support life on Mars has been deployed and is set to undergo a two-year test.It will be expanded to 5 times its size »