Private rocket firm SpaceX has successfully launched a rocket carrying a cargo ship for the International Space Station following the postponement of take-off on Saturday because of technical problems.
Witnesses said the rocket was only briefly visible before making its way into the clouds.
The launch was made from the Kennedy Space Center in Florida.
The rocket booster successfully landed on the ground nine minutes after taking off.
The touchdown is part of the company’s strategy of returning rockets to earth so they can be reused rather than jettisoning them in the ocean after a single launch.
Moments after the rocket landed, the SpaceX Dragon supply ship successfully reached orbit, prompting cheers inside the SpaceX Mission Control room.
The Dragon is now making its way to the International Space Station, and is expected to arrive on Wednesday.
“The decline of Arctic sea-ice is much faster than the climate models can reproduce and we need better climate models to make better predictions for the future.
“There is a potential that in a few decades the Arctic will be ice free in summer. That would be a different world and we need to know about that in advance; we need to know is that going to happen or will that not happen?
The German scientist, who is affiliated to the Alfred Wegener Institute in Bremerhaven, said the €63m (£54m; $67m) expedition was very nearly all funded, and would have key contributions from international partners.
Other European states, such as the UK, are involved – so too the Americans, the Russians and the Chinese.
The mission has echoes of the Norwegian explorer Fridtjof Nansen’s attempt in the 1890s to be the first person to reach the North Pole by drifting in a ship locked in ice.
A schooner called Tara also traversed the frozen ocean – from Siberian waters to the Fram Strait – in the same way a decade ago.
But the RV Polarstern is an enormous science platform and its list of tasks and goals dwarfs those of all previous efforts to work in the region.
“We’re bringing a vessel full with equipment: many, many measurement containers and remote sensing in-situ instruments,” Prof Rex said.
“We’ll take water, ice and air samples. And we’ll set up camps on the sea-ice close to the Polarstern and others up to 20-30km away. And the whole set-up will drift across the Arctic. That will give us a new and absolutely fascinating insight into the climate system.”
The MOSAiC team even plans to make runways on the sea-ice so research planes can take to the air in support of the RV Polarstern.
It will, however, be a difficult expedition for the scientists involved, especially during the freezing midwinter period when the Sun will not get above the horizon. The researchers will also have to keep their eyes peeled for predatory polar bears.
But Prof Rex said the endeavour was vital to our understanding of this remote region and stressed the relevance to the wider public who live far from the North Pole.
“A warmer pole would affect weather patterns at mid-latitudes,” he told BBC News.
“A warming Arctic means that the temperature contrast between our latitudes and the North Pole will be reduced in the future. This means the flow of air, the wind, that blows around the Arctic will be less zonal in the future climate, and it will allow for more excursions of cold air from the Arctic to our latitudes, and more excursions of warm air from lower latitudes to the North Pole. That certainly will have a strong impact on our weather.”
RV Polarstern is expected to take up position ready to be captured in the sea-ice in the late summer or autumn of 2019, with the intention of being released a year later.
Jonathan.Amos-INTERNET@bbc.co.uk and follow me on Twitter: @BBCAmos
The head of the world’s largest scientific membership organisation has given his backing for a planned protest by researchers in Washington DC.
Rush Holt, of the American Association for the Advancement of Science (AAAS), said that people were “standing up for science”.
His remarks reflect growing concern among researchers that science is disregarded by President Trump
Scientists across the US plan to march in DC on 22 April.
“I’ve never seen anything like it in my entire career,” the former Democrat congressman told BBC News.
“To see young scientists, older scientists, the general public speaking up for the idea of science. We are going to work with our members and affiliated organisations to see that this march for science is a success.”
Mr Holt made his comments at the AAAS annual meting in Boston as President Trump appointed a fierce critic of the Environmental Protection Agency as its head. Scott Pruitt has spent years fighting the role and reach of the EPA.
Campaigners accuse him of being too close to the oil and gas industry, and allege that he is “lukewarm” on the threat posed by climate change.
Rush Holt says that the concern among US scientists has gone well beyond the usual uncertainty that comes with a change in the Oval Office.
“It is partly because of the previous statements of the president and his appointees on issues such as climate change and vaccination for children which have not been in keeping with good science,” the AAAS CEO told BBC News.
“But mostly by what we have seen since the new administration has come in, [which] is silence about science. Very few appointments to positions are filled by people who understand science, very few comments about the importance of science; there is no science advisor in the White House now and we don’t know whether there will be one.
“And so the silence is beginning to sound ominous.”
There has been unease among researchers ever since Mr Trump was elected in November. More than 600 professors from one of the country’s leading research Universities, MIT, signed an open letter before his inauguration expressing their concerns.
It stated: “The president-elect has appointed individuals to positions of power who have endorsed racism, misogyny and religious bigotry, and denied the widespread scientific consensus on climate change… Science is not a special interest; it is not optional. Science is a foundational ingredient in how we as a society analyse, understand, and solve the most difficult challenges that we face.”
Among the signatories’ worries are the president’s statement that climate change is a hoax, his alleged muzzling of environmental agencies and his apparent interest in setting up a commission to investigate whether vaccines cause autism.
Prof Nancy Kanwisher, who is a brain researcher at MIT, explained why she helped organise the petition.
“This is the most frightening and serious threat we have faced in my lifetime,” she told BBC News.
“The political tactic of denying scientific fact is a huge threat to the health of our people. It is also a huge threat to our planet from climate deniers.”
Sarah Schwettmann, who is a PhD student working with Prof Kanwisher, said that many of her fellow students felt just as strongly as their professors.
“Science has unfortunately taken a political beating,” she argued. “It has been drawn into a realm where we have to stand up for the necessity of science in informing public policy and potentially averting the global crisis we see in environmental change and climate change.”
Ms Schwettmann has designed black-hooded sweatshirts for protestors. On the back is “MIT” in the shape of a clenched fist. On the sleeves is the electrical symbol of resistance.
But President Trumps supporters, such as Myron Ebell, who is a director at a libertarian advocacy group, Competitive Enterprise Institute, accuses the academics of being an out-of-touch elite – and says they should listen to the electorate.
“The people in the heartland of America who make stuff, dig up stuff and grow stuff for a living voted for Donald J Trump as president,” he told BBC News.
“The people living in New York City and working in the university towns across America did not vote for him. They lost the election and they are going to have to get used to it.”
There is little sign of that happening. All across the country many scientists are preparing for their march for science on Washington. They are in a battle to win the hearts and minds of their countrymen.
August’s total solar eclipse in the US will almost certainly be the most watched such event in history.
More than 12 million people – from Oregon to South Carolina – live on the path of darkness that the Moon will cut as it sweeps in front of the Sun.
Nearly four times that many live within a two-hour’s drive. And then there are all the tourists who will flock to America to witness the spectacle.
It makes the eclipse a wonderful citizen science opportunity.
“By going out and looking at the Sun we take part in this time-honoured tradition of citizen science,” says astronomer and artist Prof Tyler Nordgren from the University of Redlands in California.
“Edmund Halley during an eclipse in 1715 in London asked people to go outside, look up and see if they could see the total solar eclipse and measure the length of totality, and by that he was able to help refine the orbit of the Moon,” he told BBC News.
You might think that with all the space telescopes trained on the Sun these days there is little the citizen or even the keen amateur can contribute. But total solar eclipses are special because they afford particularly favourable conditions to study the tenuous outer atmosphere of the Sun called the corona.
It is in this superheated “gas” of charged particles that the solar wind originates, and from which billions of tonnes of matter can occasionally burst towards the Earth to disrupt satellites, communications and even electricity grids.
The corona is outshone by the Sun’s surface, its photosphere. And satellites will block out this glare using devices called coronagraphs or occulters. But these are usually so wide that they also obstruct a doughnut of light immediately above the edge of the star.
“The spacecraft block out not only the Sun but also a whole lot of light around it, otherwise there would be scattering all over the image. And so we have that whole region uniquely to observe in white light from the ground at total solar eclipse,” says Jay Pasachoff from Williams College, a veteran of 65 eclipses.
And he wants members of the public to get in on the act.
It is making available 59 identical telescopes and digital cameras to universities, schools and astronomy clubs along the path of the eclipse (another 40 observing kits are available to purchase).
Participants are being trained to gather images of the corona from their locality that can then be spliced together with everyone else’s to produce an uninterrupted 90-minute video.
Citizen CATE will rely on dedicated, calibrated equipment. But a similar venture plans to make use of the countless photos that will be taken on the day with general pocket cameras and smartphones.
The Eclipse Mega Movie Project is supported by the US National Science Foundation (NSF) and a number of colleges, observatories, and corporations.
The initiative has a core band of photographers, but the public will be able to participate with the aid of an app that will offer advice on getting the best image quality and provide the means to upload pictures.
The 21 August event is the first coast-to-coast total solar eclipse in the US since 1918.
The Moon’s shadow begins its journey across Earth’s surface – the path of totality – out in the Pacific.
It makes landfall near Newport in Oregon at 10:16 local time (17:16 GMT; 18:16 BST); and leaves the continent close to the Atlantic coastal city of Charleston, South Carolina, at 14:49 local time (18:49 GMT; 19:49 BST).
The location that will experience full darkness for the “greatest duration” is just outside the town of Carbondale, Illinois. Totality there will last 2 minutes and 40.2 seconds.
Prof Nordgren works a lot with the National Parks Service: “I’m going to be at John Day Fossil Beds National Monument in eastern Oregon.
“They have six parking spaces and a porta-potty, and yet they’re expecting maybe 20,000 people to come there on that day.”
And taskforce colleague, Angela Speck from the University of Missouri, added: “We need to have communities ready for the influx of people that are coming, and that means things like emergency services, road traffic control, food and water. Especially water – the eclipse is in August.”
Nordgren, Speck, and Pasachoff were speaking here in Boston at the Annual Meeting of the American Association for the Advancement of Science (AAAS).
Jonathan.Amos-INTERNET@bbc.co.uk and follow me on Twitter: @BBCAmos
Scientists have extracted long-dormant microbes from inside the famous giant crystals of the Naica mountain caves in Mexico – and revived them.
The organisms were likely to have been encased in the striking shafts of gypsum at least 10,000 years ago, and possibly up to 50,000 years ago.
It is another demonstration of the ability of life to adapt and cope in the most hostile of environments.
“Other people have made longer-term claims for the antiquity of organisms that were still alive, but in this case these organisms are all very extraordinary – they are not very closely related to anything in the known genetic databases,” said Dr Penelope Boston.
The new director of Nasa’s Astrobiology Institute in Moffett Field, California, described her findings here at the annual meeting of the American Association for the Advancement of Science (AAAS).
First opened by miners looking for silver and other metals a hundred years ago, the deeply buried Naica caves are a key interest to scientists fascinated by extremophiles – microbes that can thrive in seemingly impossible conditions.
The environment is hot (40-60C), humid and acidic. With no light at depth, any lifeform must chemosynthesise to survive. That is, it must derive the energy needed to sustain itself by processing rock minerals.
Researchers had identified microbes living in the walls of the caves, but isolating them from inside the metres-long crystals is a surprise.
These outsized needles of gypsum have grown over millions of years. They are not perfect. In places they have defects – small voids where fluids have collected and become encased.
Using sterile tools, Dr Boston and colleagues opened these inclusions and sampled their contents.
Not only did they detect the presence of bacteria and archaea, but they were able also to re-animate these organisms in the lab.
The concern would be that these organisms might simply be the result of contamination, either introduced by the team or the mining operations. But the Nasa director said that the necessary protocols were followed.
Scientists have previously claimed to revive bugs thought to have been dormant for many millions of years. These organisms had been trapped inside salt or ice crystals. All such claims are contentious, but Dr Boston said she was minded to accept them after everything she had seen at Naica and in other similar environments.
What gives her confidence in the status of the Mexican caves is the great diversity of life that seems to exist there.
“Other groups have shown there are lots of viruses in these caves and what that says to me is that these are fully fledged microbial communities that have their viral load just like every other community does. So, that’s another aspect of this that argues against casual contamination,” she told reporters.
Working for Nasa as an astrobiologist, she is clearly interested in the relevance of such finds to the search for life beyond Earth.
“The astrobiological link is obvious in that any extremophile system that we’re studying allows us to push the envelope of life further on Earth, and we add it to this atlas of possibilities that we can apply to different planetary settings.”
Many scientists suspect that if life does exist elsewhere in the Solar System, it is most likely to be underground, chemosynthesising like the microbes of Naica.
Dr Boston said her team was about to submit a paper on the caves to a relevant journal.
In her discussion with reporters she lamented the fact that the crystal complex had become flooded following the recent cessation of mining activities, preventing any further access.
“It is tear inducingly beautiful down there. I wrote several poems about it actually.”
Jonathan.Amos-INTERNET@bbc.co.uk and follow me on Twitter: @BBCAmos
The long-planned LISA space mission to detect gravitational waves looks as though it will be green lit shortly.
Scientists working on a demonstration of its key measurement technologies say they have just beaten the sensitivity performance that will be required.
The European Space Agency (Esa), which will operate the billion-euro mission, is now expected to “select” the project, perhaps as early as June.
The LISA venture intends to emulate the success of ground-based detectors.
These have already witnessed the warping of space-time that occurs when black holes 10-20 times the mass of the Sun collide about a billion light-years from Earth.
LISA, however, aims to detect the coming together of truly gargantuan black holes, millions of times the mass of the Sun, all the way out to the edge of the observable Universe.
Researchers will use this information to trace the evolution of the cosmos, from its earliest structures to the complex web of galaxies we see around us today.
The performance success of the measurement demonstration was announced here in Boston at the annual meeting of the American Association for the Advancement of Science (AAAS).
It occurred on Esa’s LISA “Pathfinder” (LPF) spacecraft that has been flying for just over a year.
This probe is trialling parts of the laser interferometer that will eventually be used to detect passing gravitational waves.
When Pathfinder’s instrumentation was set running it was hoped it would get within a factor of 10 of the sensitivity that would ultimately be needed by the LISA mission, proper.
In the event, LPF not only matched this mark, but went on to exceed it after 12 months of experimentation.
“You can do the full science of LISA just based on what LPF has got. And that’s thrilling; it really is beyond our dreams,” Prof Stefano Vitale, Pathfinder’s principal investigator, told BBC News.
Gravitational waves – Ripples in the fabric of space-time
Gravitational waves are a prediction of the Theory of General Relativity
It took decades to develop the technology to directly detect them
They are ripples in the fabric of space and time produced by violent events
Accelerating masses will produce waves that propagate at the speed of light
Detectable sources ought to include merging black holes and neutron stars
LIGO fires lasers into long, L-shaped tunnels; the waves disturb the light
Detecting the waves opens up the Universe to completely new investigations
The first detection of gravitational waves at the US LIGO laboratories in late 2015 has been described as one of the most important physics breakthroughs in decades.
Being able to sense the subtle warping of space-time that occurs as a result of cataclysmic events offers a completely new way to study the Universe, one that does not depend on traditional telescope technology.
Rather than trying to see the light from far-off events, scientists would instead “listen” to the vibrations these events produce in the very fabric of the cosmos.
LIGO achieved its success by discerning the tiny perturbations in laser light that was bounced between super-still mirrors suspended in kilometres’ long, vacuum tunnels.
LISA would do something very similar, except its lasers would bounce between free-floating gold-platinum blocks carried on three identical spacecraft separated by 2.5 million km.
Laser science: Lisa Pathfinder’s technology demonstration
Lisa Pathfinder’s payload is a laser interferometer, which measures the behaviour of two free-falling blocks made from a platinum-gold alloy
Placed 38cm apart, these “test masses” are inside cages that are very precisely engineered to insulate them against all disturbing forces
When this super-quiet environment is maintained, the falling blocks will follow a “straight line” that is defined only by gravity
It is under these conditions that a passing gravitational wave would be noticed by ever so slightly changing the separation of the blocks
Lisa Pathfinder has demonstrated sub-femtometre sensitivity, but the satellite cannot itself make a detection of the ripples
To do this, a space-borne observatory would need to reproduce the same performance with blocks positioned 2.5 million km apart
In both cases, the demand is to characterise fantastically small accelerations in the measurement apparatus as it squeezed and stretched by the passing gravitational waves.
For LISA the projected standard is to characterise movements down below the femto-g level – a millionth of a billionth of the acceleration a falling apple experiences at Earth’s surface; and to do that over periods of minutes to hours.
LISA Pathfinder has just succeeded in achieving sub-femto sensitivity over timescales of half a day. Getting stability at the lowest frequencies is very important.
“The lower the frequency to which you go, the bigger are the bodies that generate gravitational waves; the more intense are the gravitational waves; and the more far away are the bodies. So, the lower the frequencies, the deeper into the Universe you go,” explained Prof Vitale, who is affiliated to Italian the Institute for Nuclear Physics and University of Trento.
To be clear, LPF cannot itself detect gravitational waves because the “arm length” of the system has been shrunk down from 2.5 million km to just 38 cm – to be able to fit inside a single demonstration spacecraft – but it augurs well for the full system.
This is unusual. Normally such calls attract a number of submissions from several groups all with different ideas for a mission. But in this instance, it is maybe not so surprising given that the LISA concept has been investigated for more than two decades.
Prof Karsten Danzmann, co-PI on LPF and the lead proposer of LISA, hopes a way can be found to fly his consortium’s three-spacecraft detection system earlier than 2034, perhaps as early as 2029. But that requires sufficient money being available.
“The launch date is only programatically dominated, not technically,” Prof Danzmann told BBC News.
“This would make perfect sense because we can tell the X-ray guys where to look, because we get the alert of any bright (black hole) merger immediately, and then we can tell them, ‘look in the next hour and you’ll see an X-ray flash’.”
“That would be tremendously exciting to do multi-messenger astronomy with LISA and Athena at the same time.”
LISA could be selected as a confirmed project at Esa’s Science Programme Committee in June. There would then be a technical review followed by parallel industrial studies to assess the best, most cost-effective way to construct the mission.
Agreement will also be sought with the Americans to bring them onboard. They are likely to contribute about $300-400m of the overall cost in the form of components, such as the lasers that will be fired between LISA’s trio of spacecraft.
The LPF demonstration experiments are due to end in May, or June at the latest.
Jonathan.Amos-INTERNET@bbc.co.uk and follow me on Twitter: @BBCAmos
Some 94% of that area is underwater with only a few islands and three major landmasses sticking out above the surface: New Zealand’s North and South Islands and New Caledonia.
You might think being above water is crucial to making the cut as a continent, but the researchers looked at a different set of criteria, all of which are met by the new kid in town.
elevation above the surrounding area
a well-defined area
a crust thicker than the regular ocean floor
The main author of the article, New Zealand geologist Nick Mortimer, said scientists have been researching data to make the case for Zealandia for more than two decades.
“The scientific value of classifying Zealandia as a continent is much more than just an extra name on a list,” the researchers explained.
“That a continent can be so submerged yet unfragmented” makes it useful for “exploring the cohesion and breakup of continental crust”.
So how then to get Zealandia into the canon of continents? Should text books authors get nervous again? After all, just a few years ago, Pluto got kicked off the list of planets, changing what had been taught in schools for decades.
There is in fact no scientific body that formally recognises continents. So it could only change over time if future research accepts Zealandia on par with the rest so that eventually we might be learning about eight, not seven, continents.
Prof Philip Nelson, chair of Research Councils UK and part of the British delegation, told BBC News: “We all reap the social and economic benefits when the best researchers in the world can freely collaborate and share ideas, knowledge and facilities.
“The US and the UK are two of the world’s preeminent science, research and innovation nations”.
The hope eventually is to develop ways to make it easier for researchers in the US and the UK to work together on big flagship projects.
The impetus for the deal came following the UK referendum result to leave the European Union.
British universities, in collaboration with small businesses, receive £850m in research grants each year from membership of the EU’s research programmes. EU membership also makes it easy to form collaborations.
But there are fears that much of the funding and collaborative work with EU scientists will be in jeopardy once the UK leaves the union.
British researchers are being encouraged to foster links with other nations. While most, if not all, research leaders are still dismayed by the referendum result, some are beginning to become excited by what they see as an opportunity for greater collaboration with America.
A spokesman for Britain’s Department for Business Enterprise and Industrial Strategy, which overseas science, said that developing scientific collaborations with countries outside the EU was a priority: “As we prepare to leave the EU, we are determined to secure the best possible outcome for our world-leading research base.
“Our international relationships make us a global centre of excellence and we want to enable UK researchers to partner with the best in the world, gaining access to large-scale facilities with unique resources.”
James Wilsdon, professor of research policy at the University of Sheffield welcomed the new initiative.
“We need to lift our sights and look beyond Europe, for opportunities to deepen and extend the collaborative networks that are so central to 21st Century science and innovation.
“The US and UK remain two of the world’s science superpowers, and researchers in both countries will grab with open arms any measures that can better enable fast and frictionless collaboration.
“I hope this is the first in a wave of new bilateral agreements, involving both EU and non-EU countries, that can restore vital connective tissue between UK and international research networks, that may otherwise be ripped apart by Brexit.”
Prof Venki Ramakrishnan, the current president of the Royal Society, is in Boston for the AAAS meeting.
He told BBC News: “Science is becoming increasingly international and the UK and US are already at the forefront of that.
“Greater cooperation between our two countries would undoubtedly be a good thing and would benefit everyone but it should be regarded as an addition to, rather than a substitute for, cooperation with our European colleagues.
“The prime minister has already highlighted the importance of continuing to collaborate with the EU in science and there is enough top quality research in the UK to expand collaboration with other international partners.”
Scientists are appealing for more people to donate their brains for research after they die.
They say they are lacking the brains of people with disorders such as depression and post-traumatic stress disorder.
In part, this shortage results from a lack of awareness that such conditions are due to changes in brain wiring.
The researchers’ aim is to develop new treatments for mental and neurological disorders.
The human brain is as beautiful as it is complex. Its wiring changes and grows as we do. The organ is a physical embodiment of our behaviour and who we are.
In recent years, researchers have made links between the shape of the brain and mental and neurological disorders.
More than 3,000 brains are storied at the Harvard Brain Tissue Resource Center at McLean Hospital just outside Boston. It is one of the largest brain banks in the world.
Most of their specimens are from people with mental or neurological disorders.
Samples are requested by scientists to find new treatments for Parkinson’s, Alzheimer’s and a whole host of psychiatric disorders.
But there is a problem. Scientists at McLean Hospital and at brain banks across the world do not have enough specimens for the research community.
According Dr Kerry Ressler, who is the chief scientific officer at McLean hospital, new treatments for many mental and neurological diseases are within the grasp of the research community. However, he says it is the lack of brain tissue that is holding back their development.
“We have the tools and the ability to do some great deep-level biology of the human brain now.
“What we are lacking are the tissues from those with the disorders we need to really understand.”
One donor visiting the hospital, who wished to be known only as Caroline, told BBC News that she decided to donate her brain for medical research partly because her sister has schizophrenia.
She hopes that her donation will help researchers find a cure – and she’s urging others to do the same.
“My parents were fine but why did my sister get schizophrenia? We are not sure where it came from. How are we going to find out if we don’t do the research on the brain, which is where the problem is.”
There is a shortage of brains from people with disorders that are incorrectly seen as psychological – rather than neurological in origin. These include depression and post-traumatic stress disorder.
Prof Sabina Berretta, the scientific director of the Harvard Brain Tissue Resource Centre, said: “If people think that there are no changes in the brain of somebody that suffers from major depression or post-traumatic stress disorder then there is no reason for them to donate their brain for research because (they think that) there is nothing there to find.
“This conception is radically wrong from a biological point of view.”
The commission said more than 400,000 people died prematurely in the EU every year as a result of poor air quality and that millions more suffered respiratory and cardiovascular diseases.
Under EU law, when air pollution limits are breached member states have to implement air quality plans to bring the levels back down.
Friends of the Earth said it was “shameful” that the UK had breached the limits and called for new domestic legislation to protect people from pollution once it leaves the European Union.
Asked whether the UK would remain bound by any legal proceedings after Brexit, Commission spokesman Alexander Winterstein said: “For as long as the UK is a member of the European Union, rights and obligations apply.