NASA to launch Cold Atom Lab in Space

Free falling: NASA is putting ultracold atoms in space

A laboratory for cooling an atomic gas to just a billionth of a degree above absolute zero will soon be sent up to the International Space Station (ISS) by physicists working at NASA's Jet Propulsion Laboratory. The goal of the Cold Atom Lab (CAL) mission is to create long-lived Bose–Einstein condensates (BECs) that could lead to better sensors and atomic clocks for use on spacecraft. The BECs could even provide important insights into the nature of dark energy, according to the researchers.

First created in 1995, a BEC is made by trapping and cooling an atomic gas to an extremely low temperature so the atoms fall into the same low-energy quantum state. Instead of behaving like a collection of individual atoms, a BEC is essentially a large quantum object. This makes it very sensitive to disturbances such as stray magnetic fields and accelerations, and therefore BECs can be used to create extremely good sensors.

Falling down
Here on Earth, gravity puts an upper limit on the lifetime of a BEC – the atoms fall down and after a fraction of a second the BEC has dropped out of view of the experiment. In the microgravity environment of the ISS, however, NASA's Robert Thompson and colleagues reckon that their BECs should be observable for 5–10 s. As well as allowing physicists to make more precise measurements of the quantum properties of BECs, the longer lifetime should also make the BECs better sensors. With further development, the team believes that BECs in space could endure for hundreds of seconds.

Five scientific teams will do experiments using Cold Atom Lab, including one led by Eric Cornell of the University of Colorado – who shared the 2001 Nobel Prize for Physics for creating the first BECs.



As well as creating BECs, CAL will also cool fermionic atoms to create degenerative Fermi gases. These systems can be made to mimic the behaviour of electrons in solids and could provide important insights into phenomena such as superconductivity. Physicists will also study ultracold mixtures of bosonic and fermionic atoms. Other planned experiments include atom interferometry and very precise measurements of gravity itself.

Pervasive forces
"Studying these hyper-cold atoms could reshape our understanding of matter and the fundamental nature of gravity," says Thompson. "The experiments we'll do with the Cold Atom Lab will give us insight into gravity and dark energy – some of the most pervasive forces in the universe."



CAL will be contained within a package about the size of an "ice box". This will contain a vacuum chamber, lasers and electronics. It will also include an electromagnetic "knife", which will be used to cool the atoms. The lab is currently in the final stages of assembly and will be launched in August on a SpaceX CRS-12 rocket.
Author
Hamish Johnston is editor of physicsworld.com

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Biologists propose to sequence the DNA of all life on Earth

Can biologists sequence the genomes of all the plants and the animals in the world, including this greater bird of paradise in Indonesia?

When it comes to genome sequencing, visionaries like to throw around big numbers: There’s the UK Biobank, for example, which promises to decipher the genomes of 500,000 individuals, or Iceland’s effort to study the genomes of its entire human population. Yesterday, at a meeting here organized by the Smithsonian Initiative on Biodiversity Genomics and the Shenzhen, China–based sequencing powerhouse BGI, a small group of researchers upped the ante even more, announcing their intent
to, eventually, sequence “all life on Earth.”

Their plan, which does not yet have funding dedicated to it specifically but could cost at least several billions of dollars, has been dubbed the Earth Bio Genome Project (EBP). Harris Lewin, an evolutionary geneticist at the University of California, Davis, who is part of the group that came up with this vision 2 years ago, says the EBP would take a first step toward its audacious goal by focusing on eukaryotes—the group of organisms that includes all plants, animals, and single-celled organisms such as amoebas.



That strategy, and the EBP’s overall concept, found a receptive audience at BioGenomics2017, a gathering this week of conservationists, evolutionary biologists, systematisms, and other biologists interested in applying genomics to their work. “This is a grand idea,” says Oliver Ryder, a conservation biologist at the San Diego Zoo Institute for Conservation Research in California. “If we really want to understand how life evolved, genome biology is going to be part of that.”

Ryder and others drew parallels between the EBP and the Human Genome Project, which began as an ambitious, controversial, and, at the time, technically impossible proposal more than 30 years ago. That earlier effort eventually led not only to the sequencing of the first human genome, but also to entirely new DNA technologies that are at the center of many medical frontiers and the basis for a $20 billion industry. “People have learned from the human genome experience that [sequencing] is a tremendous advance in biology,” Lewin says.

Many details about the EBP are still being worked out. But as currently proposed, the first step would be to sequence in great detail the DNA of a member of each eukaryotic family (about 9000 in all) to create reference genomes on par or better than the reference human genome. Next would come sequencing to a lesser degree a species from each of the 150,000 to 200,000 genera. Finally, EBP participants would get rough genomes of the 1.5 million remaining known eukaryotic species. These lower resolution genomes could be improved as needed by comparing them with the family references or by doing more sequencing, says EBP co-organizer Gene Robinson, a behavioral genomics researcher and director of the Carl R. Woese Institute for Genomic Biology at the University of Illinois in Urbana.



The entire eukaryotic effort would likely cost about the same as it did to sequence that first human genome, estimate Lewin, Robinson, and EBP co-organizer John Kress, an evolutionary biologist at the Smithsonian National Museum of Natural History here. It took about $2.7 billion to read and order the 3 billion bases composing the human genome, about $4.8 billion in today’s dollars.

With a comparable amount of support, the EBP’s eukaryotic work might be done in a decade, its organizers suggest. Such optimism arises from ever-decreasing DNA sequencing costs—one meeting presenter from Complete Genomics, based in Mountain View, California, says his company plans to be able to roughly sequence whole eukaryotic genomes for about $100 within a year—and improvements in sequencing technology that make possible higher quality genomes, at reasonable prices. “It became apparent to me that at a certain point, it would be possible to sequence all life on Earth,” Lewin says. Although some may find the multibillion-dollar price tag hard to justify for researchers not studying humans, the fundamentals of matter, or the mysteries of the universe, the EBP has a head start, thanks to the work of several research communities pursuing their own ambitious sequencing projects.

These include the Genome 10K Project, which seeks to sequence 10,000 vertebrate genomes, one from each genus; i5K, an effort to decipher 5000 arthropods; and B10K, which expects to generate genomes for all 10,500 bird species. The EBP would help coordinate, compile, and perhaps fund these efforts. “The [EBP] concept is a community of communities,” Lewin says. There are also sequencing commitments from giants in the genomics field, such as China’s BGI, and the Wellcome Trust Sanger Institute in the United Kingdom. But at a planning meeting this week, it became clear that significant challenges await the EBP, even beyond funding. Although researchers from Brazil, China, and the United Kingdom said their nations are eager to participate in some way, the 20 people in attendance emphasized the need for the effort to be more international, with developing countries, particularly those with high biodiversity, helping shape the project’s final form.



They proposed that the EBP could help develop sequencing and other technological experts and capabilities in those regions. The Global Genome Biodiversity Network, which is compiling lists and images of specimens at museums and other biorepositories around the world, could supply much of the DNA needed, but even broader participation is important, says Thomas Gilbert, an evolutionary biologist at the Natural History Museum of Denmark in Copenhagen.

The planning group also stressed the need to develop standards to ensure high-quality genome sequences and to preserve associated information for each organism sequenced such as where it was collected and what it looked like. Getting DNA samples from the wild may ultimately be the biggest challenge—and the biggest cost, several people noted. Not all museum specimens yield DNA preserved well enough for high-quality genomes. Even recently collected and frozen plant and animal specimens are not always handled correctly for preserving their DNA, says Guojie Zhang, an evolutionary biologist at BGI and the University of Copenhagen. And the lack of standards could undermine the project’s ultimate utility, notes Erich Jarvis, a neurobiologist at The Rockefeller University in New York City: “We could spend money on an effort for all species on the planet, but we could generate a lot of crap.”



But Lewin is optimistic that won’t happen. After he outlined the EBP in the closing talk at BioGenomics2017, he was surrounded by researchers eager to know what they could do to help. “It’s good to try to bring together the tribes,” says Jose Lopez, a biologist from Nova Southeastern University in Fort Lauderdale, Florida, whose “tribe” has mounted “GIGA,” a project to sequence 7000 marine invertebrates. “It’s a big endeavor. We need lots of expertise and lots of people who can contribute.”

Source: Elizabeth Pennisi

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The Universe's largest supernova: a spinning, star eating black hole

By: Alexandria Addesso

According to the National Aeronautics and Space Administration (NASA), a supernova is defined as one of the largest explosions that take place in space, in particular the explosion of a star. A supernova usually manifests when there is a change in the core, or center, of a star.

The brightest supernova ever recorded, and actually categorized as a super-luminous supernova, was the explosion of an extremely massive star at the end of its life. It was named ASASSN-15lh. ASASSN-15 lhn, was first observed in 2015 by the All Sky Automated Survey for Super-Novae (ASAS-SN). It was twice as bright as the previous record holder, and at its peak was 20 times brighter than the total light output of the entire Milky Way.



"We observed the source for 10 months following the event and have concluded that the explanation is unlikely to lie with an extraordinarily bright supernova,” said Giorgos Leloudas the leader of the team that observed the event at the Weizmann Institute of Science in Israel. “Our results indicate that the event was probably caused by a rapidly spinning supermassive black hole as it destroyed a low-mass star."
After a series of further observations, it was discovered that the massive explosion took place about 4 billion light-years from Earth in a distant galaxy. It is believed that the star that the black hole consumed in order to produce such a massive explosion was its solar system's biggest star, comparable to our own sun. Since then rays have been observed traveling from the black hole towards us at the speed of light. These rays are forming a disc of gas around the black hole as it converts gravitational energy into electromagnetic radiation, producing a bright source of light visible on multiple wavelengths.



"Incredibly, this source is still producing X-rays and may remain bright enough for Swift to observe into next year," said David Burrows, the lead scientist of the team utilizing NASA's Swift satellite to monitor the massive black hole as well as a professor of astronomy at Penn State University. "It behaves unlike anything we've seen before."

Could such an explosion happen in our solar system with our own sun? This is a question scientists and inquiring minds are still trying to figure out.

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In Search of New Worlds: Using a new Spectrograph

A Next Generation RV Spectrograph in the Search for Earth-like Worlds. The new device has been built by Yale Scientist (ESPRESS): “To seek out new worlds and new civilizations…….”

The EXtreme PREcision Spectrograph (EXPRES) is an optical fiber fed echelle instrument being designed and built at the Yale Exoplanet Laboratory to be installed on the 4.3-meter Discovery Channel Telescope operated by Lowell Observatory. The primary science driver for EXPRES is to detect Earth-like worlds around Sun-like stars.



With this in mind, we are designing the spectrograph to have an instrumental precision of 15 cm/s so that the on-sky measurement precision (that includes modeling for RV noise from the star) can reach to better than 30 cm/s. This goal places challenging requirements on every aspect of the instrument development, including optomechanical design, environmental control, image stabilization, wavelength calibration, and data analysis.

In this paper we describe our error budget, and instrument optomechanical design. Keywords: precision radial velocity, white pupil spectrograph, double-scrambling, high resolution, laser frequency comb. The design and construction of EXPRES is funded by the National Science Foundation Major Research Instrumentation program.




The primary purpose will be to serve as the work-horse instrument for the 100 Earths Project. This project will search for planets that are similar in mass to our world, and that orbit their host stars at a similar distance where liquid water might flow in rivers and oceans. The NASA Kepler mission has been searching stars that are several hundred light years away and has demonstrated that Earth-sized planets are common. Armed with this important statistical information, we will take a census of the nearest neighboring stars to find terrestrial worlds.

These planets will be the targets of intense searches for life outside the solar system. The Path to Finding Earth Analogs A radial velocity (RV) measurement precision of 10 cm/s is required in order to detect Earth analogs. To reach this precision, the 100 Earths Project will build upon the state-of-the-art1 by advancing developments in six key areas: 1) instrument environmental stability, 2) stable light coupling, 3) high spectral resolution, line spread sampling, and signal to noise, 4) precision wavelength calibration, 5) removal of telluric contamination and stellar jitter, 6) near nightly observational cadence of target stars, and 7) new statistical treatment of stellar jitter.



The spectrograph optical bench will be under vacuum in a climate controlled room on a vibration isolated slab. EXPRES will have a resolving power of 150,000, and < 0.01 Å per pixel sampling to improve spectral line modeling and detecting and decorrelation stellar activity signals. The use of a Menlo Systems laser frequency comb (LFC) for wavelength calibration will enable access to the majority of the instrument free spectral range (380 to 680 nm), leading to higher Signal to Noise Ratio (SNR) and more information about stellar activity. Success is not only coupled to the instrument design, but the implementation of robust statistical and modeling techniques.

Source: Yale University

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