NASA WISE: Mysteries of 'Interstellar' Space revealed

This enormous mosaic of the Milky Way galaxy from NASA's Wide-field Infrared Survey Explorer (WISE), shows dozens of dense clouds, called nebulae. 

Many nebulae seen here are places where new stars are forming, creating bubble like structures that can be dozens to hundreds of light-years in size.

Image Credit: NASA

The new Paramount film "Interstellar" imagines a future where astronauts must find a new planet suitable for human life after climate change destroys the Earth's ability to sustain us.

Multiple NASA missions are helping avoid this dystopian future by providing critical data necessary to protect Earth.

Yet the cosmos beckons us to explore farther from home, expanding human presence deeper into the solar system and beyond.

For thousands of years we've wondered if we could find another home among the stars. We're right on the cusp of answering that question.

If you step outside on a very dark night you may be lucky enough to see many of the 2,000 stars visible to the human eye.

They're but a fraction of the billions of stars in our galaxy and the innumerable galaxies surrounding us.

Multiple NASA missions are helping us extend humanity's senses and capture starlight to help us better understand our place in the universe.

Largely visible light telescopes like Hubble show us the ancient light permeating the cosmos, leading to groundbreaking discoveries like the accelerating expansion of the universe.

Through infrared missions like Spitzer, SOFIA and WISE, we've peered deeply through cosmic dust, into stellar nurseries where gases form new stars.

With missions like Chandra, Fermi and NuSTAR, we've detected the death throes of massive stars, which can release enormous energy through supernovas and form the exotic phenomenon of black holes.

Yet it was only in the last few years that we could fully grasp how many other planets there might be beyond our solar system.

Some 64 million miles (104 kilometers) from Earth, the Kepler Space Telescope stared at a small window of the sky for four years.

As planets passed in front of a star in Kepler's line of view, the spacecraft measured the change in brightness.

Kepler was designed to determine the likelihood that other planets orbit stars. Because of the mission, we now know it's possible every star has at least one planet.

Solar systems surround us in our galaxy and are strewn throughout the myriad galaxies we see.

Though we have not yet found a planet exactly like Earth, the implications of the Kepler findings are staggering, there may very well be many worlds much like our own for future generations to explore.

NASA also is developing its next exoplanet mission, the Transiting Exoplanet Survey Satellite (TESS), which will search 200,000 nearby stars for the presence of Earth-size planets.



The Transiting Exoplanet Survey Satellite (TESS) will discover thousands of exoplanets in orbit around the brightest stars in the sky.

In a two-year survey of the solar neighbourhood, TESS will monitor more than 500,000 stars for temporary drops in brightness caused by planetary transits.

This first-ever spaceborne all-sky transit survey will identify planets ranging from Earth-sized to gas giants, around a wide range of stellar types and orbital distances. No ground-based survey can achieve this feat.

Spectacular Type la supernova's mysteries revealed

Galaxy M82 in which the supernova exploded. 

Credit: NASA, ESA, & Hubble Heritage

New research by a team of UK and European-based astronomers is helping to solve the mystery of what caused a spectacular supernova in a galaxy 11 million light years away, seen earlier this year.

The supernova, a giant explosion of a star and the closest one to the Earth in decades, was discovered earlier this year by chance at the University of London Observatory.

These phenomena are extremely important to study because they provide key information about our universe, including how it is expanding and how galaxies evolve.

The new research into its cause, published in the latest issue of the Astrophysical Journal, used vast networks of radio telescopes in the UK and across Europe including the seven telescopes of e-MERLIN operated from The University of Manchester's Jodrell Bank Observatory.

These enabled them to obtain extremely deep images revealing a lack of radio emission from the supernova.

Known as 2014J, this was a Type la supernova caused by the explosion of a white dwarf star, the inner core of star once it has run out of nuclear fuel and ejected its outer layers.

A white dwarf star can explode if its mass increases to about 1.4x times that of the Sun. At this point its core temperature reaches the point where carbon starts to undergo nuclear fusion.

This spreads rapidly through the star resulting in a catastrophic thermonuclear explosion which rips the star apart, causing it to appear like a brilliant 'new star' shining billions of times brighter than the Sun.

For decades there has been a dispute about how this happens but these new results rule out the vast majority of models and show the merger of two white dwarf stars is by far the most likely cause.

The research was led by Miguel Pérez-Torres, researcher of the Spanish National Research Council who explained: "Supernovae play a fundamental role in the chemistry of galaxies and their evolution, as they are responsible for ejecting most of the heavy elements we see around us, including elements that cannot be formed in the interior of normal stars."

"A Nobel Prize was awarded in 2011 for the use of Type Ia supernovae to discover that the expansion of the Universe is accelerating. Yet, the basic question of what causes a Type Ia supernova was still a mystery".

Rob Beswick, a co-author of the research paper from the University of Manchester's Jodrell Bank Centre for Astrophysics added: "The explosion of a Type Ia supernova is a rare event in the nearby Universe."

"Supernova 2014J is the closest Type Ia supernova to Earth since 1986, and it's likely that more than a hundred years will pass until we see another such supernova so close to us."

"This was an amazing opportunity to learn more about these extremely important astrophysical phenomena and their underlying cause."

More information: "Constraints on the progenitor system and the environs of SN 2014J from deep radio observations" By M. A. Perez-Torres, P. Lundqvist, R. J. Beswick, C. I. Bjornsson, T. W. B. Muxlow, Z. Paragi, S. Ryder, A. Alberdi, C. Fransson, J. M. Marcaide, I. Marti-Vidal, E. Ros, M. K. Argo, J. C. Guirado are published in The Astrophysical Journal. iopscience.iop.org/0004-637X/792/1

NASA Van Allen Probes: Mysteries of Earth's radiation belts uncovered

The twin Van Allen Probes were launched on August 30, 2012 into elliptical, near-equatorial orbits around the Earth. 

Remarkably, rather than seeing just the well-known two-belt structure, the mission found almost immediate evidence of the clear three-belt structure portrayed in green in this diagram. 

Image courtesy of Andy Kale, University of Alberta.

Just over a year since launch, NASA's Van Allen Probes mission continues to unravel longstanding mysteries of Earth's high-energy radiation belts that encircle our planet and pose hazards to orbiting satellites and astronauts.

Derived from measurements taken by a University of New Hampshire-led instrument on board the twin spacecraft, the latest discovery reveals that the high-energy particles populating the radiation belts can be accelerated to nearly the speed of light in conjunction with ultra-low frequency electromagnetic waves operating on a planetary scale.

This mode of action, as detailed in a paper recently published in the journal Nature Communications, is analogous to that of a cyclical particle accelerator like the Large Hadron Collider (LHC).

However, in this case, the Earth's vast magnetic field, or magnetosphere, which contains the Van Allen belts, revs up drifting electrons to ever-higher speeds as they circle the planet from west to east.

The recent finding comes on the heels of a related discovery—also made by the UNH-led Energetic Particle, Composition, and Thermal Plasma (ECT) instrument suite—showing similar particle acceleration but on a microscopic rather than a planetary scale.

Harlan Spence

"The acceleration we first reported operates on the scale size of an electron's gyromotion—it is a really local process, maybe only a few hundred meters in size," notes Harlan Spence, director of the UNH Institute for the Study of Earth, Oceans, and Space, principal scientist for the ECT, and coauthor on the Nature Communications paper.

"Now we're seeing this large-scale, global motion involving ultra low-frequency waves pulsing through Earth's magnetosphere and operating across vast distances up to hundreds of thousands of kilometers."

And, Spence adds, "in all likelihood both processes are occurring simultaneously to accelerate particles to relativistic speeds."

Understanding the complex dynamics of the particle acceleration will help scientists make better predictions of space weather conditions and, thus, offer better protections to orbiting satellites crucial to modern-day society.

Having twin spacecraft making simultaneous measurements in different regions of nearby space is a key part of the mission as it allows the scientists to look at data separated in both space and time.

"With the Van Allen Probes, I like to think there's no place for these particles to hide because each spacecraft is spinning and 'glimpses' the entire sky with its detector 'eyes', so we're essentially getting a 360-degree view in terms of direction, position, energy, and time," Spence says.

ALMA probes mysteries of jets from giant black holes

This detailed view shows the central parts of the nearby active galaxy NGC 1433. 

The dim blue background image, showing the central dust lanes of this galaxy, comes from the NASA/ESA Hubble Space Telescope. 

The coloured structures near the centre are from recent ALMA observations that have revealed a spiral shape, as well as an unexpected outflow, for the first time. 

Credit: ALMA (ESO/NAOJ/NRAO)/NASA/ESA/F. Combes

Two international teams of astronomers have used the power of the Atacama Large Millimeter/submillimeter Array to focus on jets from the huge black holes at the centers of galaxies and observe how they affect their surroundings.

They have respectively obtained the best view yet of the molecular gas around a nearby, quiet black hole and caught an unexpected glimpse of the base of a powerful jet close to a distant black hole.

There are supermassive black holes—with masses up to several billion solar masses—at the hearts of almost all galaxies in the Universe, including our own galaxy, the Milky Way.

In the remote past, these bizarre objects were very active, swallowing enormous quantities of matter from their surroundings, shining with dazzling brilliance, and expelling tiny fractions of this matter through extremely powerful jets.

In the current Universe, most supermassive black holes are much less active than they were in their youth, but the interplay between jets and their surroundings is still shaping galaxy evolution.

Two new studies, both published today in the journal Astronomy & Astrophysics, used ALMA to probe black hole jets at very different scales: a nearby and relatively quiet black hole in the galaxy NGC 1433 and a very distant and active object called PKS 1830-211.

Françoise Combes

"ALMA has revealed a surprising spiral structure in the molecular gas close to the centre of NGC 1433," says Françoise Combes (Observatoire de Paris, France), who is the lead author of the first paper.

"This explains how the material is flowing in to fuel the black hole. With the sharp new observations from ALMA, we have discovered a jet of material flowing away from the black hole, extending for only 150 light-years. This is the smallest such molecular outflow ever observed in an external galaxy."

The discovery of this outflow, which is being dragged along by the jet from the central black hole, shows how such jets can stop star formation and regulate the growth of the central bulges of galaxies.

Ivan Marti-Vidal

In PKS 1830-211, Ivan Marti-Vidal (Chalmers University of Technology, Onsala Space Observatory, Onsala, Sweden) and his team also observed a supermassive black hole with a jet, but a much brighter and more active one in the early Universe.

It is unusual because its brilliant light passes a massive intervening galaxy on its way to Earth, and is split into two images by gravitational lensing.

From time to time, supermassive black holes suddenly swallow a huge amount of mass, which increases the power of the jet and boosts the radiation up to the very highest energies.

Now ALMA has, by chance, caught one of these events as it happens in PKS 1830-211.

More information: These research projects are presented in two papers, "ALMA observations of feeding and feedback in nearby Seyfert galaxies: an AGN-driven outflow in NGC1433", by F. Combes et al. and "Probing the jet base of the blazar PKS 1830−211 from the chromatic variability of its lensed images: Serendipitous ALMA observations of a strong gamma-ray flare, by I. Marti-Vidal et al. Both papers are appeared in the journal Astronomy & Astrophysics.

NASA CREPT Instrument Examines Mysteries of Van Allen Belt

The tiny CREPT instrument will augment the science of NASA’s Van Allen Probes, formerly known as the Radiation Belt Storm Probes. 

This artist’s rendering of the Van Allen Probes mission shows the path of its two spacecraft through the radiation belts that surround Earth, which are made visible in false color. 

Credit: NASA.

Using data from a NASA satellite, a team of scientists led by the Los Alamos National Laboratory in New Mexico and involving the University of Colorado Boulder have discovered a massive particle accelerator in the heart of one of the harshest regions of near-Earth space, a region of super-energetic, charged particles surrounding the globe known as the Van Allen radiation belts.

The new results from NASA's Van Allen Probes mission show the acceleration energy is in the belts themselves.

Local bumps of energy kick particles inside the belts to ever-faster speeds, much like a well-timed push on a moving swing.

Knowing the location of the acceleration within the radiation belts will help scientists improve predictions of space weather, which can be hazardous to satellites near Earth. The results were published July 25 in the journal Science.

"Until the 1990s, we thought the Van Allen belts were pretty well-behaved and changed slowly," says Geoff Reeves, lead author on the paper and a radiation belt scientist at Los Alamos National Laboratory in Los Alamos, N.M.

"With more and more measurements, however, we realized how quickly and unpredictably the radiation belts change. They are basically never in equilibrium, but in a constant state of change."

Recent observations by NASA’s twin Van Allen Probes show that particles in the radiation belts surrounding Earth are accelerated by a local kick of energy, helping to explain how these particles reach speeds of 99 percent the speed of light. 

Credit: G. Reeves/M. Henderson

For scientists to understand such changes better, the twin Van Allen Probes fly straight through this intense area of space.

One of the top priorities for the mission, launched last August, is to understand how particles in the belts are accelerated to ultra-high energies.

Daniel Baker

"We see case after case where the very high energy electrons appear suddenly right in the heart of the outer belt," said CU-Boulder Professor Daniel Baker, director of the Laboratory for Atmospheric and Space Physics and a study co-author.

"But now we can prove where the electrons originate from and we can see the waves -- and the lower energy 'seed' particles -- from which the relativistic electrons grow. We can essentially peer into the inner workings of our local cosmic accelerator with unprecedented clarity."

By taking simultaneous measurements with advanced technology instruments, the Van Allen Probes were able to distinguish between two broad possibilities on what accelerates the particles to such amazing speeds.

The possibilities are radial acceleration or local acceleration. In radial acceleration, particles are transported perpendicular to the magnetic fields that surround Earth, from areas of low magnetic strength far from Earth to areas of high magnetic strength closer to Earth.

Physics dictates particle speeds in this scenario will increase as the magnetic field strength increases. The speed of the particles would increase as they move toward Earth, much the way a rock rolling down a hill gathers speed due to gravity.

The local acceleration theory proposes the particles gain energy from a local energy source, similar to the way warm ocean water can fuel a hurricane above it.

Read the full article here

Dark energy and dark matter mysteries - Update

The Mysteries currently facing the Dark Energy Scientists can be compiled into a small list.

• Gravity acting across vast distances does not seem to explain what astronomers see
• Galaxies, for example, should fly apart; some other mass must be there holding them together
• Astrophysicists have thus postulated "dark matter" - invisible to us but clearly acting on galactic scales
• At the greatest distances, the Universe's expansion is accelerating
• Thus we have also "dark energy" which acts to drive the expansion, in opposition to gravity
• The current theory holds that 73% of the Universe is dark energy, 23% is dark matter, and just 4% the kind of matter we know well

For decades, the strange substance called dark matter has teased physicists, challenging conventional notions of the cosmos.

Today, though, scientists believe that with the help of multi-billion-dollar tools, they are closer than ever to piercing the mystery -- and the first clues may be unveiled just weeks from now.

"We are so excited because we believe we are on the threshold of a major discovery," said Michael Turner, director of the Kavli Institute for Cosmological Physics at the University of Chicago, at an annual conference of the American Association for the Advancement of Science (AAAS).

Dark matter throws down the gauntlet to the so-called Standard Model of physics.

Elegant and useful for identifying the stable of particles and forces that regulate our daily life, the Standard Model only tells part of the cosmic story.

For one thing, it does not explain gravity, although we know how to measure gravity and exploit it for our needs.

And the Standard Model has been found to account for only around four or five percent of the stuff in the Universe.

The rest is dark matter, making up 23 percent, and dark energy, an enigmatic force that appears to drive the expansion of the Universe, which accounts for around 72 or 73 percent.

"On the cosmology side we now understand that this mysterious dark matter holds together our galaxy and the rest of the Universe," said Turner.

"And the tantalizing thing on the cosmology side is that we have an airtight case that the dark matter is made of something new... there is no particle in the Standard Model that can account for dark matter."

nited Kingdom Infrared Telescope (UKIRT): Mysteries Of Massive Star Formation

A false colour image of a massive star forming region shows outflows associated with IRAS 05137+3919. The image is constructed from J (1.25 micron, blue), H (1.65 micron, green) and H2 (2.122 micron, red). The shocked regions of the outflows rich in line emission appear red here. The blue objects are mostly foreground stars. IRAS 05137+3919 is a luminous Young Stellor Object (YSO) of late-O spectral type. We detect two bipolar outflows here, emanating from the central double star. Credit: JAC/UKIRT.

Using the United Kingdom Infrared Telescope (UKIRT) astronomers have found the leading mechanism by which most of the massive stars form in our Galaxy.

The largest near-infrared survey of massive star forming regions to date has revealed that a major fraction of these massive stars form by collecting matter onto disks around their equatorial regions.

This was revealed by the detection of gas outflows and shocked regions associated with massive young stars in formation, located in clouds of gas and dust in our Galaxy.

The survey was carried out by a team lead by Dr. Watson Varricatt from the Joint Astronomy Centre and included Dr. Chris Davis (Joint Astronomy Centre), Dr. Suzanne Ramsay (ESO, Germany) and Dr. Stephen Todd (UKATC, Edinburgh, UK).

We know that lower-mass stars like our Sun form by gravitational collapse of material inside clouds of gas and dust in space.

The gas and dust spiral down onto the equatorial regions of the young star via a process known as accretion.

At the same time these accreting young stars drive high velocity jets of gas outwards at thousands of miles per hour.

These "outflows" radiate at infrared wavelengths (this emission is actually produced by hydrogen molecules heated to thousands of degrees). Consequently, observations in the infrared can be used to search for not only the youngest stars, but also evidence of the accretion process.

The big question is, do the massive stars form the same way, or do they form using a different process?

For massive stars, with masses larger than 10 times the mass of our Sun, it has been proposed that the extreme energy output of these young stars, which start nuclear burning in their cores even before they complete their growth through accretion, will prevent further growth by blowing away the accretion disks.

Hence, alternate scenarios like mergers of lower mass stars have been suggested as the main mechanism for massive star formation.

The presence or absence of outflows from massive young stars will tell us whether accretion or some other methods lead to their formation.