NASA finds 20 potentially habitable worlds 'hiding in plain sight'

Stargazers have discovered 20 worlds "hiding in plain sight" which they believe could be habitable.

Analysis of data from the Kepler space telescope revealed a list of planets that orbit stars like our own sun.

Each potential new world comes with varying orbit times, including one that takes the equivalent of 395 Earth days to circle its star and another which takes just 18.

The exoplanet with a 395-day year is one of the most exciting, according to Jeff Coughlin, the Kepler team leader who helped analyse the data.

It is about 97 per cent the size of Earth but colder and more like our tundra regions.

Despite its chilly climate, it is still warm and large enough to hold liquid water - which is vital for life.

Coughlin told New Scientist: "If you had to choose one to send a spacecraft to, it’s not a bad option."

The planets will form part of an investigation from the Hubble Space Telescope.

Earlier this year the Kepler spacecraft has detected 219 new exoplanet candidates – and ten could be habitable.

There are around 4,034 observed potential planets in our galaxy, according to Nasa's Ames Research Center.

The centuries-old hunt for other worlds like our own was recently rejuvenated thanks to the Kepler Telescope, which is currently orbiting Earth.

Scientists have spotted thousands of contenders after sifting through data collected by the instrument.

They are hoping to find terrestrial planets - around one half to twice the size of our planet and in the habitable zone.

The Kepler telescope began observing a fixed point in the Milky Way back in 2009 but suffered a technical glitch that put an end to its work in 2013.

A second mission was launched again in 2014 and will continue to send data back until 2018.

There are high hopes that humans will soon colonise Mars, in our very own solar system.

Tesla billionaire has made public his bold plans to send humans to Mars by 2024.

Fireworks in Space: NASA’s Twins Study Explores Gene Expression

How Do Human Genes Act In Space?

NASA’s Twins Study preliminary results have revealed that space travel causes an increase in methylation, the process of turning genes on and off, and additional knowledge in how that process works.

“Some of the most exciting things that we’ve seen from looking at gene expression in space is that we really see an explosion, like fireworks taking off, as soon as the human body gets into space,” Twins Study Principal Investigator Chris Mason, Ph.D., of Weill Cornell Medicine, said. “With this study, we’ve seen thousands and thousands of genes change how they are turned on and turned off. This happens as soon as an astronaut gets into space, and some of the activity persists temporarily upon return to Earth.”

When retired twin astronaut Scott Kelly returned to Earth in March 2016, the Twins Study research intensified with investigators collecting samples from him and his twin brother, retired astronaut Mark Kelly. The researchers began combining the data and reviewing the enormous amount of information looking for correlations.

“This study represents one of the most comprehensive views of human biology,” Mason said. “It really sets the bedrock for understanding molecular risks for space travel as well as ways to potentially protect and fix those genetic changes.”

Final results for the Twins Study are expected to be published in 2018.

NASA's Human Research Program (HRP) is dedicated to discovering the best methods and technologies to support safe, productive human space travel. HRP enables space exploration by reducing the risks to astronaut health and performance using ground research facilities, the International Space Station, and analog environments. This leads to the development and delivery of a program focused on: human health, performance, and habitability standards; countermeasures and risk mitigation solutions; and advanced habitability and medical support technologies. HRP supports innovative, scientific human research by funding more than 300 research grants to respected universities, hospitals and NASA centers to over 200 researchers in more than 30 states.

Astronomers strike gold, witness massive cosmic phenomenon

Scientists witness huge cosmic crash, make major discoveries

By closely observing two stars in outer space, and watching as the stars crashed into each other, back in August, scientists in the U.S. and Europe say they've now been able to unlock multiple secrets.

It was a faint signal, but it told of one of the most violent acts in the universe, and it would soon reveal secrets of the cosmos, including how gold was created.

Forbes estimated that the collision created an estimated $10 octillion in gold, which is $10 billion, billion, billion.

What they witnessed in mid-August and revealed Monday was the long-ago collision of two neutron stars — a phenomenon California Institute of Technology's David H. Reitze called "the most spectacular fireworks in the universe."

The crash happened 130 million years ago, while dinosaurs still roamed on Earth, but the signal didn't arrive on Earth until Aug. 17 after traveling 130 million light-years. A light-year is 5.88 trillion miles.

"We already knew that iron came from a stellar explosion, the calcium in your bones came from stars and now we know the gold in your wedding ring came from merging neutron stars," said University of California Santa Cruz's Ryan Foley.

Measurements of the light and other energy emanating from the crash have helped scientists explain how planet-killing gamma ray bursts are born, how fast the universe is expanding, and where heavy elements like platinum and gold come from.

"This is getting everything you wish for," said Syracuse University physics professor Duncan Brown, one of more than 4,000 scientists involved in the blitz of science that the crash kicked off. "This is our fantasy observation."

It started in a galaxy called NGC 4993, seen from Earth in the Hydra constellation. Two neutron stars, collapsed cores of stars so dense that a teaspoon of their matter would weigh 1 billion tons, danced ever faster and closer together until they collided, said Carnegie Institution astronomer Maria Drout.

The crash, called a kilonova, generated a fierce burst of gamma rays and a gravitational wave, a faint ripple in the fabric of space and time, first theorized by Albert Einstein.

"This is like a cosmic atom smasher at a scale far beyond humans would be capable of building," said Andy Howell, a staff scientist at the Las Cumbres Observatory. "We finally now know what happens when an unstoppable force meets an immovable object and it's a kilonova."

Signals were picked up within 1.7 seconds of each other, by NASA's Fermi telescope, which detects gamma rays, and gravity wave detectors in Louisiana and Washington state that are a part of the LIGO Laboratory , whose founders won a Nobel Prize earlier this month. A worldwide alert went out to focus telescopes on what became the most well-observed astronomical event in history.

Before August, the only other gravity waves detected by LIGO were generated by colliding black holes. But black holes let no light escape, so astronomers could see nothing.

This time there was plenty to see, measure and analyze: matter, light, and other radiation. The Hubble Space Telescope even got a snapshot of the afterglow.

Finding where the crash happened wasn't easy. Eventually scientists narrowed the location down to 100 galaxies, began a closer search of those, and found it in the ninth galaxy they looked at.

It is like "the classic challenge of finding a needle in the haystack with the added challenge that the needle is fading away and the haystack is moving," said Marcelle Soares-Santos, an astrophysicist at Brandeis University.

"The completeness of this picture from the beginning to the end is unprecedented," said Columbia University physics professor Szabolcs Marka. "There are many, many extraordinary discoveries within the discovery."

The colliding stars spewed bright blue, super-hot debris that was dense and unstable. Some of it coalesced into heavy elements, like gold, platinum and uranium. Scientists had suspected neutron star collisions had enough power to create heavier elements, but weren't certain until they witnessed it.

"We see the gold being formed," said Syracuse's Brown.

Calculations from a telescope measuring ultraviolet light showed that the combined mass of the heavy elements from this explosion is 1,300 times the mass of Earth. And all that stuff — including lighter elements — was thrown out in all different directions and is now speeding across the universe.

Perhaps one day the material will clump together into planets the way ours was formed, Reitze said — maybe ones with rich veins of precious metals.

The crash also helped explain the origins of one of the most dangerous forces of the cosmos — short gamma ray bursts, focused beams of radiation that could erase life on any planet that happened to get in the way. These bursts shoot out in two different directions perpendicular to where the two neutron stars first crash, Reitze said.

Luckily for us, the beams of gamma rays were not focused on Earth and were generated too far away to be a threat, he said.

Scientists knew that the universe has been expanding since the Big Seed. By using LIGO to measure gravitational waves while watching this event unfold, researchers came up with a new estimate for how fast that is happening, the so-called Hubble Constant. Before this, scientists came up with two slightly different answers using different techniques. The rough figure that came out of this event is between the original two, Reitze said.

The first optical images showed a bright blue dot that was very hot, which was likely the start of the heavy element creation process amid the neutron star debris, Drout said. After a day or two that blue faded, becoming much fainter and redder. And after three weeks it was completely gone, she said.

This almost didn't happen. Eight days after the signal came through, the LIGO gravitational waves were shut down for a year's worth of planned upgrades. A month later the whole area where the crash happened would have been blocked from astronomers' prying eyes by the sun.

Scientists involved with the search for gravitational waves said this was the event they had prepared for over more than 20 years.

The findings are "of spectacular importance," said Penn State physicist Abhay Ashtekar, who wasn't part of the research. "This is really brand new."

Almost all of the discoveries confirmed existing theories, but had not been proven — an encouraging result for theorists who have been trying to explain what is happening in the cosmos, said France Cordova, an astrophysicist who directs the National Science Foundation.

"We so far have been unable to prove Einstein wrong," said Georgia Tech physics professor Laura Cadonati. "But we're going to keep trying."

There's Another Big Gravitational Wave Announcement on The Way

Brace yourselves: it looks like there's another big gravitational wave announcement coming.

LIGO and Virgo have announced that they're going to be holding a big press conference on Monday, 16 October at 10am EDT at the Press Club in Washington DC.

"The gathering will begin with an overview of new findings from LIGO, Virgo and partners that span the globe," the National Science Foundation announcement reads, "followed by details from telescopes that work with the LIGO and Virgo collaborations to study extreme events in the cosmos."

Gravitational waves were officially confirmed publicly for the first time in February 2016, when LIGO announced that it had detected the phenomenon caused by a collision between two black holes. Since then, gravitational waves have been detected three more times.

The most recent announcement was in September, when LIGO announced that its collaboration with interferometer Virgo had allowed a much more precise triangulation of the signal.

Prior to that announcement, speculation was flying that the discovery was a collision between two neutron stars, with visuals from optical telescopes.

This time, we're hesitant to make any speculation, other than it seems big. Representatives from 70 other observatories around the world will be at the event, and simultaneous briefings will also be taking place in London and Munich.

There will be two separate panel discussions at the main event, too. The first panel consists of directors and spokespersons from LIGO, Virgo and NASA.

The second panel includes people like David Sand, Nial Tanvir, Eleonora Troja and Andy Howell, who have all performed research into supernovas, and Marcelle Soares-Santos, who is pioneering the Dark Energy Survey's search for an optical counterpart to gravitational wave events.

We're getting pretty excited, you guys. Read more about the announcement here, and tune back into ScienceAlert for the big news on Monday!

Half the universe’s missing matter has just been finally found

The missing links between galaxies have finally been found

This is the first detection of the roughly half of the normal matter in our universe – protons, neutrons and electrons – unaccounted for by previous observations of stars, galaxies and other bright objects in space.

You have probably heard about the hunt for dark matter, a mysterious substance thought to permeate the universe, the effects of which we can see through its gravitational pull. But our models of the universe also say there should be about twice as much ordinary matter out there, compared with what we have observed so far.

Two separate teams found the missing matter – made of particles called baryons rather than dark matter – linking galaxies together through filaments of hot, diffuse gas.

“The missing baryon problem is solved,” says Hideki Tanimura at the Institute of Space Astrophysics in Orsay, France, leader of one of the groups. The other team was led by Anna de Graaff at the University of Edinburgh, UK.

Because the gas is so tenuous and not quite hot enough for X-ray telescopes to pick up, nobody had been able to see it before.

“There’s no sweet spot – no sweet instrument that we’ve invented yet that can directly observe this gas,” says Richard Ellis at University College London. “It’s been purely speculation until now.”

So the two groups had to find another way to definitively show that these threads of gas are really there.

Both teams took advantage of a phenomenon called the Sunyaev-Zel’dovich effect that occurs when light left over from the Big Seed passes through hot gas. As the light travels, some of it scatters off the electrons in the gas, leaving a dim patch in the cosmic microwave background – our snapshot of the remnants from the birth of the cosmos.

Stack ‘em up

In 2015, the Planck satellite created a map of this effect throughout the observable universe. Because the tendrils of gas between galaxies are so diffuse, the dim blotches they cause are far too slight to be seen directly on Planck’s map.

Both teams selected pairs of galaxies from the Sloan Digital Sky Survey that were expected to be connected by a strand of baryons. They stacked the Planck signals for the areas between the galaxies, making the individually faint strands detectable en masse.

Tanimura’s team stacked data on 260,000 pairs of galaxies, and de Graaff’s group used over a million pairs. Both teams found definitive evidence of gas filaments between the galaxies. Tanimura’s group found they were almost three times denser than the mean for normal matter in the universe, and de Graaf’s group found they were six times denser – confirmation that the gas in these areas is dense enough to form filaments.

“We expect some differences because we are looking at filaments at different distances,” says Tanimura. “If this factor is included, our findings are very consistent with the other group.”

Finally finding the extra baryons that have been predicted by decades of simulations validates some of our assumptions about the universe.

“Everybody sort of knows that it has to be there, but this is the first time that somebody – two different groups, no less – has come up with a definitive detection,” says Ralph Kraft at the Harvard-Smithsonian Center for Astrophysics in Massachusetts.

“This goes a long way toward showing that many of our ideas of how galaxies form and how structures form over the history of the universe are pretty much correct,” he says.

Journal references: arXiv, 1709.05024 and 1709.10378v1

3-D quantum gas atomic clock offers new dimensions in measurement

JILA's three-dimensional (3-D) quantum gas atomic clock consists of a grid of light formed by three pairs of laser beams. Multiple lasers of various colors are used to cool the atoms, trap them in a grid of light, and probe them for clock operation. A blue laser beam excites a cube-shaped cloud of strontium atoms. Strontium atoms fluorescence strongly when excited with blue light, as seen in the upper right corner behind the vacuum window. Credit: G.E. Marti/JILA

JILA physicists have created an entirely new design for an atomic clock, in which strontium atoms are packed into a tiny three-dimensional (3-D) cube at 1,000 times the density of previous one-dimensional (1-D) clocks. In doing so, they are the first to harness the ultra-controlled behavior of a so-called "quantum gas" to make a practical measurement device.

With so many atoms completely immobilized in place, JILA's cubic quantum gas clock sets a record for a value called "quality factor" and the resulting measurement precision. A large quality factor translates into a high level of synchronization between the atoms and the lasers used to probe them, and makes the clock's "ticks" pure and stable for an unusually long time, thus achieving higher precision.

Until now, each of the thousands of "ticking" atoms in advanced clocks behave and are measured largely independently. In contrast, the new cubic quantum gas clock uses a globally interacting collection of atoms to constrain collisions and improve measurements. The new approach promises to usher in an era of dramatically improved measurements and technologies across many areas based on controlled quantum systems.

The new clock is described in the Oct. 6 issue of Science.

"We are entering a really exciting time when we can quantum engineer a state of matter for a particular measurement purpose," said physicist Jun Ye of the National Institute of Standards and Technology (NIST). Ye works at JILA, which is jointly operated by NIST and the University of Colorado Boulder.

The clock's centerpiece is an unusual state of matter called a degenerate Fermi gas (a quantum gas for Fermi particles), first created in 1999 by Ye's late colleague Deborah Jin. All prior atomic clocks have used thermal gases. The use of a quantum gas enables all of the atoms' properties to be quantized, or restricted to specific values, for the first time.

"The most important potential of the 3-D quantum gas clock is the ability to scale up the atom numbers, which will lead to a huge gain in stability," Ye said. "Also, we could reach the ideal condition of running the clock with its full coherence time, which refers to how long a series of ticks can remain stable. The ability to scale up both the atom number and coherence time will make this new-generation clock qualitatively different from the previous generation."

Until now, atomic clocks have treated each atom as a separate quantum particle, and interactions among the atoms posed measurement problems. But an engineered and controlled collection, a "quantum many-body system," arranges all its atoms in a particular pattern, or correlation, to create the lowest overall energy state. The atoms then avoid each other, regardless of how many atoms are added to the clock. The gas of atoms effectively turns itself into an insulator, which blocks interactions between constituents.

The result is an atomic clock that can outperform all predecessors. For example, stability can be thought of as how precisely the duration of each tick matches every other tick, which is directly linked to the clock's measurement precision. Compared with Ye's previous 1-D clocks, the new 3-D quantum gas clock can reach the same level of precision more than 20 times faster due to the large number of atoms and longer coherence times.

JILA's 3-D quantum gas atomic clock offers new dimensions in measurement

The experimental data show the 3-D quantum gas clock achieved a precision of just 3.5 parts error in 10 quintillion (1 followed by 19 zeros) in about 2 hours, making it the first atomic clock to ever reach that threshold (19 zeros). "This represents a significant improvement over any previous demonstrations," Ye said.

The older, 1-D version of the JILA clock was, until now, the world's most precise clock. This clock holds strontium atoms in a linear array of pancake-shaped traps formed by laser beams, called an optical lattice. The new 3-D quantum gas clock uses additional lasers to trap atoms along three axes so that the atoms are held in a cubic arrangement. This clock can maintain stable ticks for nearly 10 seconds with 10,000 strontium atoms trapped at a density above 10 trillion atoms per cubic centimeter. In the future, the clock may be able to probe millions of atoms for more than 100 seconds at a time.

Optical lattice clocks, despite their high levels of performance in 1-D, have to deal with a tradeoff. Clock stability could be improved further by increasing the number of atoms, but a higher density of atoms also encourages collisions, shifting the frequencies at which the atoms tick and reducing clock accuracy. Coherence times are also limited by collisions. This is where the benefits of the many-body correlation can help.

The 3-D lattice design—imagine a large egg carton—eliminates that tradeoff by holding the atoms in place. The atoms are fermions, a class of particles that cannot be in the same quantum state and location at once. For a Fermi quantum gas under this clock's operating conditions, quantum mechanics favors a configuration where each individual lattice site is occupied by only one atom, which prevents the frequency shifts induced by atomic interactions in the 1-D version of the clock.

JILA researchers used an ultra-stable laser to achieve a record level of synchronization between the atoms and lasers, reaching a record-high quality factor of 5.2 quadrillion (5.2 followed by 15 zeros). Quality factor refers to how long an oscillation or waveform can persist without dissipating. The researchers found that atom collisions were reduced such that their contribution to frequency shifts in the clock was much less than in previous experiments.

"This new strontium clock using a quantum gas is an early and astounding success in the practical application of the 'new quantum revolution,' sometimes called 'quantum 2.0'," said Thomas O'Brian, chief of the NIST Quantum Physics Division and Ye's supervisor. "This approach holds enormous promise for NIST and JILA to harness quantum correlations for a broad range of measurements and new technologies, far beyond timing."

Depending on measurement goals and applications, JILA researchers can optimize the clock's parameters such as operational temperature (10 to 50 nanokelvins), atom number (10,000 to 100,000), and physical size of the cube (20 to 60 micrometers, or millionths of a meter).

Atomic clocks have long been advancing the frontier of measurement science, not only in timekeeping and navigation but also in definitions of other measurement units and other areas of research such as in tabletop searches for the missing "dark matter" in the universe.