Gamma Ray Bursts and Recent Results from the Fermi Mission

Representing nature's biggest explosions since the Big Bang itself, gamma-ray bursts were first accidentally spotted in the 1960s by Department of Defense satellites hunting for terrestrial nuclear blasts. In this talk Prof. Berger describes the ensuing decades-long quest to decipher the origin and energy source of these mysterious explosions. He explains how gamma-ray bursts are now used to probe the first generation of stars and galaxies formed less than a billion years after the Big Bang.

Gamma ray burst could be a dangerous problem. We should start more seriously with developing science and at least become type 1 civilization by developing nuclear fusion reactors. Maybe they could generate enough energy to shield our planet.

Part 1 of the Special Relativity series

Here's Part 2: The Light that will Lead the Way - Time Dilation


Are You REALLY Standing Still?


Frame of Essence: Episode 6

Image credits:

Einstein


Maxwell


Hubble Deep Field
from Drbogdan on Wikipedia

(Thank you NASA)

Michelson


Morley


Music in this video (downloaded from the YouTube Audio Library):
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A team of scientists studying the afterglow of a gamma-ray burst tell us that their findings will re-write scientific theories. Using the Very Large Array Telescope, the team examined the afterglow of a gamma ray burst which mainstream astronomers assume is formed by a so-called shockwave. What they observed does not match the theoretical predictions of the standard model. Wal Thornhill tells listeners how the Electric Universe paradigm would view the findings. Story:

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Neil Gehrels, chief, Astroparticle Physics Laboratory, NASA/Goddard Space Flight Center, is principal investigator for the SWIFT gamma-ray burst MIDEX mission. The SWIFT Explorer is an astronomical satellite that is observing gamma-ray bursts, the birth cries of black holes. Come hear about new results and about the amazing properties of black holes.

Armed with state-of-the-art supercomputer models, scientists have shown that colliding neutron stars can produce the energetic jet required for a gamma-ray burst. Earlier simulations demonstrated that mergers could make black holes. Others had shown that the high-speed particle jets needed to make a gamma-ray burst would continue if placed in the swirling wreckage of a recent merger.

Now, the simulations reveal the middle step of the process--how the merging stars' magnetic field organizes itself into outwardly directed components capable of forming a jet. The Damiana supercomputer at Germany's Max Planck Institute for Gravitational Physics needed six weeks to reveal the details of a process that unfolds in just 35 thousandths of a second--less than the blink of an eye.

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The cosmic microwave background (CMB) has spectacularly advanced our understanding of the origin, composition, and evolution of our universe. Yet there is still much to glean from this, the oldest light in the universe. Powerful telescopes are plying the skies in a quest to discover new physics. This talk concentrates on measurements by cutting-edge CMB telescopes which offer a glimpse into an exhilarating, and largely unexplored branch of astrophysics: the search for unique signatures in the polarization of the CMB. Professor Keating will explain how the CMB can constrain phenomena such as primordial magnetism, elementary particle masses, and even the origin of the universe itself. Further phenomena, such as tantalizing bounds on parity-violating effects such as cosmic birefringence — the rotation of the polarization plane of cosmic photons — will be discussed. He will describe early attempts to measure cosmic parity violation using distant galaxies as well as state-of the-art measurements made by the POLARBEAR telescope, which he co-leads. He will close by previewing the upcoming Simons Array, an advanced array of three millimeter-wave CMB telescopes in the Atacama Desert of Northern Chile.

About 1200 years ago, Earth may have experienced one of the rarest and most powerful cosmic events a planet can be exposed to: a gamma-ray burst. If it did, well, let’s just say that we, as living things on Earth, are lucky it wasn’t worse.

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How the Universe Works is a mini-series that originally aired on the Discovery Channel April 25, 2010 to May 24, 2010. It was narrated by Mike Rowe.

This is just a small part from my favorite episode Black Holes (original air date May 2, 2010) directed by Peter Chinn.

I can definitely recommend you to watch this amazing & fascinating TV Show. Definitely worth it. Recommended in High Definition!
_________________________

Black Holes Masters of the universe, Without black holes, we wouldn't be here!

The Solar System furnishes the most familiar planetary architecture: many planets, orbiting nearly coplanar to one another. We can examine the composition and atmospheres of the Solar System planets in detail, even occasionally in situ. Studies of planets orbiting other stars (exoplanets), in contrast, only begin to approach the precision of humanity's knowledge of Earth five hundred years ago. I will describe a two-pronged approach to the study of exoplanets. One approach involves time-intensive investigations of individual planets to eke out bulk density or single molecules in the planetary atmosphere. Another involves studies of the ensemble properties of planetary systems, and addresses the question of a typical planetary system in the Milky Way. In an era with thousands of exoplanet discoveries in hand and thousands more to follow in short order, a judicious combination of these approaches is emerging. I'll showcase some of my own detailed findings of other worlds (placing Earth in context), in addition to wider-field studies of typical planet occurrence and formation. I'll close with an opportunity, using an existing data set, to make inroads into the singular question driving much of exoplanetary science: the detectability of signatures of life.

Dr. Mullally will present the 7th catalog of Planet Candidates found by Kepler. Uniformly vetted lists of detected planet candidates are a key step towards measuring the occurrence rates of planets, as well as providing interesting individual objects for potential follow-up. The 7th catalog includes 8826 objects of interest, of which 4696 are deemed viable planet candidates.

This catalog is the first to be uniformly vetted in an entirely objective manner by algorithm, instead of by manual inspection. This algorithmic approach enables us to test our results against simulated data sets allowing us to measure our performance for the first time. Dr. Mullally will discuss some novel features of the vetting pipeline, discuss the performance and limitations, and highlight some interesting individual planets.

#HowTheUniverseWorks
Think of it like a cosmic ray gun. The energy released from a gamma ray burst is equivalent to a hundred trillion nuclear weapons going off every second for a hundred billion years. They can reduce planets to vapor.
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Epic. Cosmic BLITZAR GAMMA-RAY BURST finally seen in real time
SEEN in REAL TIME BLITZAR Gamma-Ray Burst caught IN THE ACT.
A gigantic but fleeting burst of radio waves has been caught in the act for the first time, helping to narrow down the vast array of things that might cause them. Figuring out what these fast radio bursts – sometimes called blitzars – are or where they come from could help answer some of the biggest cosmological questions.

Blitzars last about a millisecond but give off as much energy as the sun does in a million years, all seemingly in a tight band of radio-frequency waves.

Their source is a mystery, but whatever causes them must be huge, cataclysmic and up to 5.5 billion light years away, says Emily Petroff of Swinburne University in Melbourne, Australia.

A top contender is the collapse of an oversized neutron star that should have given way to a black hole long ago, but was spinning so fast that relativity made it seem lighter. But other possibilities include a flare from a magnetar, a type of neutron star with an extremely strong magnetic field.

A total of nine blitzars have been reported since the first was discovered in 2007, but all of them were found weeks or years after the actual event by sifting through old data. (New Scientist, Jan 19, 2015)
~~
Links:
1) Epic cosmic radio burst finally seen in real time New Scientist - Space, 19 January 2015 by Michael Slezak.

2) Cosmos and Culture,

3) NPR Astronomy

4) ‘Blitzars’ could explain those mysterious intergalactic radio bursts, George Dvorsky, 7/09/13

5) Gamma ray Burst, Wikipedia

6) Wikimedia Commons Images Blitzars -
image - Blitzar NASA)
q=blitzars&biw;=1366&bih;=600&tbm;=isch&tbo;=u&source;=univ&sa;=X&ei;=Jhi-VJ_eG6SpyQPe2YLQAg&ved;=0CDoQsAQ#imgdii=_
7) Music: Youtube Audio Library
Into the Depths by Jingle Punks

Could an alien civilization build unusual super-structures to attract the attention of other worlds? Could we detect such an anomaly using the Kepler telescope?

This excerpt is from a 2013 SETI talk by Jason Wright of Penn. State suggests an alternate way for ET to send a signal.

Watch the full video at

John Rather, RCIG

Based on present space science and engineering, interstellar travel remains highly unlikely. Applying synergistic emerging technologies to enhance capabilities for accelerated space development in the solar system may catalyze possible steps to the stars. A stepwise sequence of plausible projects will be proposed. The remarkable present progress in diverse applied sciences can be a game changer.

Use the URL: for 10% with a new website and support this channel. Also make your life easier. Thanks a lot to Squarespace for supporting the show!

There are cosmic snipers firing at random into the unvierse. What are they and what happens if they hit us?

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Death From Space — Gamma-Ray Bursts Explained

Help us caption & translate this video!

A pulsar is a rapidly spinning neutron star, which is the small incredibly dense remnant of much more massive star. A teaspoon of matter from a neutron star weighs as much as Mount Everest and the neutron star is so compact That a ball about fifteen miles across contains more matter than our sun. Neutron stars spin between seven and forty thousand times a minute and form with incredibly strong magnetic fields. Rapid spin and intense magnetic fields drive powerful beams of electromagnetic radiation including gamma rays. As the pulsar rotates, these beams sweep the sky like a lighthouse. To a distant observer, the pulsar appears to blink on and off. Pulsars slow down as they age but some of the oldest pulsars spin hundreds of times a second. Each of these millisecond pulsars orbits a normal star. Over time, the impact of gas pulled from the normal star has spun the pulsar up to incredible speeds. This accretion may be the cause of their weaker magnetic fields. Despite this, these pulsars also emit gamma rays.

Gamma rays are the highest energy form of light.

Dave Thompson: There's the light we see with our eyes, but their lots of other types of light. Gamma rays are the most energetic form of light, the most powerful.

Valerie Connaughton: Gamma rays are the part of what we call the electromagnetic spectrum which starts in radio, at very long wavelengths, goes through optical, then through x-rays, and then gamma rays are the very highest energy form of that type of radiation.

Neil Gehrels: The reason that it's important to look at the high-energy gamma rays is that many objects, the most violent and some of the most interesting objects in the universe emit most of their light in this high-energy gamma ray part.

Phil Plait: And the only thing that can generate gamma rays are incredibly violent events, incredibly energetic events. And we're talking stars exploding and neutron stars with really strong magnetic fields and really exotic and strange objects like that. Isabelle Grenier: It's like a Christmas tree it's shining, and it's flaring and their are eruptions every day.

Peter Michelson: Gamma-ray bursts being an example of something that, for a brief instant of time outshines the entire rest of the universe. Chip Meegan: These are the biggest explosions in the universe.

The Fermi Gamma-ray Space Telescope is a powerful space observatory that opens a wide window on the universe. Gamma rays are the highest-energy form of light, and the gamma-ray sky is spectacularly different from the one we perceive with our own eyes. With a huge leap in all key capabilities, Fermi is enabling scientists to observe some of the universes most powerful phenomena, including supermassive black holes, pulsars, and gamma-ray bursts, which briefly outshine whole galaxies. Fermi has two instruments for observing gamma rays. It's Large Area Telescope, or LAT, maps gamma rays over the entire sky every three hours and is Fermi's main detector. The other instrument is called the Gamma Ray Burst Monitor or GBM. It looks for spectacular flashes of gamma rays from, among other things, the birth of black holes far across the universe.

credit: NASA/Goddard Space Flight Center

source:

Speaker: Dan Akerib, SLAC National Accelerator Laboratory

Dark Matter remains a profound mystery at the intersection of particle physics, astrophysics, and cosmology. One of the leading candidates, the Weakly Interacting Massive Particle, or WIMP, may be detectable using terrestrial particle detectors. Recent technological advances are enabling very rapid increases in sensitivity in the search for these particles. I will talk about the LUX experiment, a liquid xenon time projection chamber, which currently holds the best upper limit over much of the WIMP mass range. I will also discuss plans for a larger follow up experiment, LZ, which will just begin to measure a background neutrino signal that will set a fundamental limit our ability to search for WIMP dark matter.

Gamma ray bursts are the most energetic explosions in the Universe, outshining the rest of their entire galaxy for a moment. So, it stands to reason you wouldn't want to be close when one of these goes off.

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If comics have taught me anything, it’s that gamma powered superheroes and villains are some of the most formidable around.

Coincidentally, Gamma Ray bursts, astronomers say, are the most powerful explosions in the Universe. In a split second, a star with many times the mass of our Sun collapses into a black hole, and its outer layers are ejected away from the core.

Twin beams blast out of the star. They’re so bright we can see them for billions of light-years away. In a split second, a gamma ray burst can release more energy than the Sun will emit in its entire lifetime.

It’s a super-supernova.

You’re thinking “Heck, if the gamma exposure worked for Banner, surely a super-supernova will make me even more powerful than the Hulk.”

That’s not exactly how this plays out.

For any world caught within the death beam from a gamma ray burst, the effects are devastating. One side of the world is blasted with lethal levels of radiation.

Our ozone layer would be depleted, or completely stripped away, and any life on that world would experience an extinction level event on the scale of the asteroid that wiped out the dinosaurs.

Astronomers believe that gamma ray bursts might explain some of the mass extinctions that happened on Earth.

The most devastating was probably one that occurred 450 million years ago causing the Ordovician–Silurian extinction event. Creatures that lived near the surface of the ocean were hit much harder than deep sea animals, and this evidence matches what would happen from a powerful gamma ray burst event.

Considering that, are we in danger from a gamma ray burst and why didn’t we get at least one Tyrannosaurus Hulk out of the deal?

There’s no question gamma ray bursts are terrifying. In fact, astronomers predict that the lethal destruction from a gamma ray burst would stretch for thousands of light years. So if a gamma ray burst went off within about 5000-8000 light years, we’d be in a world of trouble.

Astronomers figure that gamma ray bursts happen about once every few hundred thousand years in a galaxy the size of the Milky Way.

And although they can be devastating, you actually need to be pretty close to be affected.

It has been calculated that every 5 million years or so, a gamma ray burst goes off close enough to affect life on Earth. In other words, there have been around 1,000 events since the Earth formed 4.6 billion years ago.

So the odds of a nearby gamma ray burst aren’t zero, but they’re low enough that you really don’t have to worry about them. Unless you’re planning on living about 5 million years in some kind of gamma powered superbody.

We might have evidence of a recent gamma ray burst that struck the Earth around the year 774. Tree rings from that year contain about 20 times the level of carbon-14 than normal. One theory is that a gamma ray burst from a star located within 13,000 light-years of Earth struck the planet 1,200 years ago, generating all that carbon-14.

Clearly humanity survived without incident, but it shows that even if you’re halfway across the galaxy, a gamma ray burst can reach out and affect you.

So don’t worry. The chances of a gamma ray burst hitting Earth are minimal. In fact, astronomers have observed all the nearby gamma ray burst candidates, and none seem to be close enough or oriented to point their death beams at our planet. You’ll need to worry about your exercise and diet after all.

So what do you think? What existential crisis makes you most concerned, and how do gamma ray bursts compare?

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Dr. Neil Gehrels discusses Gamma-Ray Bursts and the Birth of Black Holes as part of the Library's series in conjunction with NASA.

Speaker Biography: Neil Gehrels is chief of the Astroparticle Physics Laboratory at NASA Goddard Space Flight Center and principal investigator for the SWIFT satellite mission.

Gamma-ray bursts are the most luminous explosions in the cosmos. Astronomers think most occur when the core of a massive star runs out of nuclear fuel, collapses under its own weight, and forms a black hole. The black hole then drives jets of particles that drill all the way through the collapsing star at nearly the speed of light. Artist's rendering.

Credit: NASA's Goddard Space Flight Center

This video is public domain and can be downloaded at:

Brown dwarfs are sub-stellar objects that occupy the region of parameter space between gas giant planets, like Jupiter, and the smallest bona fide stars. Since brown dwarfs never achieve sustained core hydrogen fusion, they are destined to cool over cosmic timescales from thousands to hundreds of degrees Kelvin. Observations and models of these strange worlds reveal hydrogen-dominated atmospheres with a variety of trace molecular species, as well as metal, dust, and salt condensates.

Recent surveys and targeted observations have revealed that a substantial fraction of brown dwarfs have a brightness that varies in time, with some variations as large as 30% at certain wavelengths. In this presentation, Dr. Robinson will review the atmospheric physics of brown dwarfs and the current state of variability observations, and he will discuss the various processes that likely cause brown dwarf variability, which include dynamical effects, temporally- and spatially-varying clouds, and associated atmospheric temperature fluctuations.

Gamma-ray bursts are not only incredible to study, but their discovery has an epic story all its own. Today Phil takes you through some Cold War history and then dives into what we know. Bursts come in two rough varieties: Long and short. Long ones are from hypernovae, massive stars exploding, sending out twin beams of matter and energy. Short ones are from merging neutron stars. Both kinds are so energetic they are visible for billions of light years, and both are also the birth announcements of black holes.

Crash Course Astronomy Poster:

--

Table of Contents
Gamma-Ray Were Discovered During the Cold War 0:47
Bursts Come in Two Varieties: Long and Short 8:35
Long Bursts Are From Hypernovae, Massive Stars Exploding 6:46
Short Ones Are From Merging Neutron Stars 9:00
Both Are The Birthplace of Black holes 9:55

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PHOTOS/VIDEOS
Nuclear Bomb Images via Wikimedia Commons:
Operation Upshot Knothole
Ivy Mike
Castle Bravo
Upshot Knothole GRABLE
President Kennedy signs the Limited Nuclear Test Ban Treaty [credit: Wikimedia Commons]
Vela [credit: USAF]
The Crab Nebula [credit: NASA, ESA, J. Hester, A. Loll (ASU)]
Solar Flare [credit: NASA/SDO/AIA]
Gamma Ray Burst [credit: NASA/Goddard Space Flight Center Conceptual Image Lab]
Four ALMA antennas on the Chajnantor plain [credit: ESO/José Francisco Salgado (josefrancisco.org)]
Gamma Ray Burst 970228 [credit: Andrew Fruchter (STScI), Elena Pian (ITSRE-CNR), and NASA/ESA]
HST/STIS Image of the optical afterglow of w:GRB 970508 [credit: STScI/NASA]
Black Holes: Monsters in Space [credit: NASA/JPL-Caltech]
Naked-Eye Gamma-ray Burst Model for GRB 080319B [credit: NASA/Swift/Cruz deWilde]
2008 GRB [credit: NASA/Swift/Stefan Immler, et al.]
GRB Data [credit: NASA]
Imagine two massive stars born together as a binary star [credit: NASA/GSFC/D. Berry]
Colliding Binary Neutron stars [credit: NASA/D.Berry]
Black Hole Devours a Neutron Star [credit: NASA/D.Berry]
Eta Carinae [credit: Jon Morse (University of Colorado) & NASA Hubble Space Telescope]
WR 104: A Pinwheel Star System [credit: P. Tuthill (U. Sydney) & J. Monnier (U. Michigan), Keck Obs., ARC, NSF]
Swift HD Beauty Shot [credit: NASA/Goddard Space Flight Center]
Swift's 500 Gamma-ray Bursts [credit: NASA/Goddard Space Flight Center]

What do we know about the composition, surface, depth and distribution of liquid on Saturn's largest moon, Titan?

Stanford University's Howard Zebker uncovers some of the mysteries of Titan's lakes by analyzing data from the Cassini altimeter and radiometer.

Present technology does not enable us to view images of these kilometer-sized infalling bodies, but the evaporation of gaseous products liberated from exocomets that occurs close to a star can potentially cause small disruptions in the ambient circumstellar disk plasma. For circumstellar disks that are viewed “edge-on” this evaporating material may be directly observed through transient (night-to-night and hour-to-hour) gas absorption features seen at rapidly changing velocities. Using high resolution spectrographs mounted to large aperture ground-based telescopes, we have discovered 15 young stars that harbor swarms of exocomets. In this lecture we briefly describe the physical attributes of comets in our own solar system and the instrumental observing techniques to detect the presence of evaporating exocomets present around stars with ages in the 10 – 100 Myr range. We note that this work has particular relevance to the dramatic fluctuations in the flux recorded towards “Tabby’s star” by the NASA Kepler Mission, that may be explained through the piling up of swarms of exocomets in front of the central star.

This animation tracks several gamma rays through space and time, from their emission in the jet of a distant blazar to their arrival in Fermi's Large Area Telescope (LAT). During their journey, the number of randomly moving ultraviolet and optical photons (blue) increases as more and more stars are born in the universe. Eventually, one of the gamma rays encounters a photon of starlight and the gamma ray transforms into an electron and a positron. The remaining gamma-ray photons arrive at Fermi, interact with tungsten plates in the LAT, and produce the electrons and positrons whose paths through the detector allows astronomers to backtrack the gamma rays to their source.

This animation tracks several gamma rays through space and time, from their emission in the jet of a distant blazar to their arrival in Fermi's Large Area Telescope (LAT). During their journey, the number of randomly moving ultraviolet and optical photons (blue) increases as more and more stars are born in the universe. Eventually, one of the gamma rays encounters a photon of starlight and the gamma ray transforms into an electron and a positron. The remaining gamma-ray photons arrive at Fermi, interact with tungsten plates in the LAT, and produce the electrons and positrons whose paths through the detector allows astronomers to backtrack the gamma rays to their source.

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In 1990, at the request of Carl Sagan, Voyager 1 turned and took a picture of Earth from a distance of 6 billion kilometers. This produced the famous “pale blue dot” image of our planet. Several mission concepts are being studied to obtain similar images of Earth-like exoplanets (exo-Earths) around other stars. It is commonly thought that directly imaging a potentially habitable exoplanet requires telescopes with apertures of at least 1 meter, costing at least $1B, and launching no earlier than the 2020s. A notable exception to this is Alpha Centauri (A and B), which is unusually close for a Sun-like star. A ~30-45cm visible light space telescope equipped with a modern high performance coronagraph is sufficient to resolve the habitable zone at high contrast and directly image any potentially habitable planet that may exist in the system.

Dr. Belikov will describe the challenges involved with direct imaging of Alpha Centauri planetary systems with a small telescope and how new technologies currently being developed can solve them. He will also show examples of small coronagraphic mission concepts currently being developed to take advantage of this opportunity, and in particular a mission concept called “ACESat: Alpha Centauri Exoplanet Sattellite” submitted to NASA’s small Explorer (SMEX) program in December of 2014.

Saturn's ring system is an astrophysical disk that is neither light-years away nor billions of years in the past. We can visit this disk at close range and observe a number of phenomena that also operate in disks of other kinds. As a result, we see small-scale processes that shape ring texture, connect those processes to the bodies and structures that cause them, and watch closely as the disk changes with time.

We will discuss recent Cassini observations that elucidate disk processes including 1) self-gravity wakes and spiral density waves, both of which were originally proposed for galaxies but are observed with exquisite precision in Saturn's rings, 2) propeller features caused by 100-meter to km-sized moonlets embedded in the disk; these are the first objects ever to have their orbits tracked while embedded in a disk, rather than orbiting in free space, and hold the potential of deepening our understanding of planetary migration, and 3) irregular edge shapes in the gaps opened up by larger moons (10 km and more), which may hold clues to angular momentum transport.

Dr. Gary H. Blackwood earned his BS, MS and PHD in Aeronautical and Astronautical Engineering from MIT. He has been an employee at NASA's Jet Propulsion Laboratory in Pasadena, CA since 1988 and has worked on technology development for precision astronomical instruments and astrophysics missions including the Hubble Wide/Field Planetary Camera-2, the StarLight formation-flying interferometer, the Space Interferometry Mission and the Terrestrial Planet Finder. Since 2012 he has served as the Program Manager for the NASA Exoplanet Exploration Program, managed by JPL for the Astrophysics Division of the NASA Science Mission Directorate.

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A startling discovery in science in the past few decades is most mass in the universe is in dark matter- some very clever form of matter capable of speeding up the motion of stars and galaxies while eluding direct detection at the same time. Dr. Ma will summarize the evidence for the existence of dark matter, discuss what it can and cannot be, and describe ongoing research on this mysterious component of the universe.

Stars are the atoms of the universe. The process by which stars form is at the nexus of astrophysics since they are believed to be responsible for the re-ionization of the universe, they created the heavy elements, they play a central role in the formation and evolution of galaxies, and their formation naturally leads to the formation of planets. Whereas early work on star formation was based on the assumption that it is a quiescent process, it is now believed that turbulence plays a dominant role. In this overview, I shall discuss the evolution of our understanding of how stars form and current ideas about the stellar initial mass function, the rate of star formation, the formation of massive stars, the role of magnetic fields, and the formation of the first stars.

Asteroid impacts were a hazard to any life on the Hadean Earth. A traditional approach to geochemical models of the asteroid impactors uses the concentration of highly siderophile elements including the Pt-group in the silicate Earth. These elements occur in roughly chondritic relative ratios, but with absolute concentrations less than 1% chondrite. This veneer component implies addition of chondrite-like material with 0.3-0.7% mass of the Earth’s mantle or an equivalent planet-wide thickness of 5-20 km. The veneer thickness, 200-300 m, within the lunar crust and mantle is much less. The accretion of a large number of small bodies would provide comparable thicknesses to both bodies, as the effect of gravity is modest.

Decades of planetary exploration have revealed widespread evidence for ancient fluvial activity on the surface of Mars, including deeply incised valleys, paleolake basins, and an extensive sedimentary rock record. Acquisition of high-resolution remote sensing data of the martian surface (e.g., images and topography) over the past 5-10 years have allowed for quantitative analysis of the large-scale sedimentary structures of martian sedimentary deposits.

In this talk, Dr. Goudge will focus on a detailed study of the stratigraphic architecture and channel deposit geometries of the Jezero crater delta deposit on Mars. Results from this study are used to reconstruct a scenario for the evolution of the Jezero crater delta and paleolake in which it formed. This delta deposit is a representative example of fluvial stratigraphy on early Mars, and these results can help to improve our understanding of ancient martian fluvial activity.

Fermi’s Large Area Telescope (LAT) is the spacecraft’s main scientific
instrument. This animation shows a gamma ray (purple) entering the LAT,
where it is converted into an electron (red) and a positron (blue). The
paths of the particles point back to the gamma-ray source. The LAT maps
the whole sky every three hours. (Credit: NASA/Goddard Space Flight
Center Conceptual Image Lab)

Abstract: With its subsurface water ocean and relatively young icy surface Europa is among the top candidates in the search for habitable environments in our solar system. Existence of water vapor plumes on Europa has long been speculated and could possibly provide accessibility of subsurface liquid reservoirs.
Images of auroral emissions obtained in December 2012 by the Hubble Space Telescope (HST) revealed coincident signals from hydrogen and oxygen pointing to the existence of transient water vapor near the moon's south pole. The aurora is excited by impinging charged particles from Jupiter's huge magnetosphere, which interacts with Europa's atmosphere and interior water ocean.
Dr. Roth will provide an overview of the complex interaction between Europa and Jupiter's magnetosphere, the generation of the plume aurora signals and our HST detection method, and the important implications of the plume discovery for the future exploration of Europa and its hidden water ocean.

Shape Dynamics is a new theory of gravity which removes the notion of local relativistic time from the guiding principles of gravity in the universe. It is a very promising approach which has been shown to be equivalent to Einstein's Theory of General Relativity, without being embedded in time. It is inspired by adherence to Mach's Principle, which is violated by Einstein's theory.

Shape Dynamics provides new tools in the quest for a theory that describes quantum gravity.

In the first part of the talk Dr. Gomes will review some of the Machian motivations for shape dynamics and sketch its construction. In the second half, Dr. Gomes will talk about recent developments on black holes in this formulation, and discuss some positive aspects of its ongoing quantization program.

Tom Banks, UC Santa Cruz

The theory called Holographic Space-time is an attempt to generalize String Theory so that one can discuss local regions of space-time. It's key feature is a mapping between quantum concepts and the geometry of space-time. Causality conditions are imposed, as in quantum field theory, by insisting that things which cannot have mutual quantum interference are things that are causally separated. Geometrical sizes are encoded via the Holographic Principle: the number of quantum states in a region is determined by the area of a certain surface surrounding that region. In 1995, Jacobson showed that one could derive Einstein's equations by imposing this principle in every space-time region. Einstein's equations are the hydrodynamic equations of a system whose statistics obeys the Holographic connection between space-time and the number of quantum states. Dr. Banks will outline the application of these ideas to a new model of the early inflationary universe, as well as to a rough prediction of the masses of supersymmetric particles.

This visualization shows gravitational waves emitted by two black holes (black spheres) of nearly equal mass as they spiral together and merge. Yellow structures near the black holes illustrate the strong curvature of space-time in the region. Orange ripples represent distortions of space-time caused by the rapidly orbiting masses. These distortions spread out and weaken, ultimately becoming gravitational waves (purple). The merger timescale depends on the masses of the black holes. For a system containing black holes with about 30 times the sun’s mass, similar to the one detected by LIGO in 2015, the orbital period at the start of the movie is just 65 milliseconds, with the black holes moving at about 15 percent the speed of light. Space-time distortions radiate away orbital energy and cause the binary to contract quickly. As the two black holes near each other, they merge into a single black hole that settles into its ringdown phase, where the final gravitational waves are emitted. For the 2015 LIGO detection, these events played out in little more than a quarter of a second. This simulation was performed on the Pleiades supercomputer at NASA's Ames Research Center.
Credits: NASA/J. Bernard Kelly (Goddard), Chris Henze (Ames) and Tim Sandstrom (CSC Government Solutions LLC)

The alpha Centauri system - our next door neighbor in space - represents a very attractive target for exoplanet searches. Owing to its proximity, a planet found around any of the three stars in the system would be an ideal target for detailed follow-up studies with next generation ground- and space-based telescopes. In this talk Dr Endl will review past and current planet search efforts that targeted the alpha Centauri system. He will focus on his team's program, an intensive multi-year observing campaign carried out at Mt John University Observatory in New Zealand. He will describe the strategy, the challenges, and current results from this campaign.

A central question in understanding the possibilities for life in the universe is what fundamental constraints and tradeoffs organize evolution. In this talk Dr. Kempes will discuss how power-laws in biology highlight common underlying constraints––often basic physical laws––across the diversity of life on our planet. He will then describe how work that we have done shows how these relationships can be derived and used to predict or interpret a range of phenomena including major evolutionary tradeoffs and ecological response. Specifically, Dr. Kempes will focus on energetic limitations in microbial life which allow us to predict the smallest possible bacteria and several other evolutionary transitions. Notably, he predicts that the smallest bacteria are limited by fundamental maintenance metabolism along with general space requirements. Dr. Kempes will also describe how similar work in vascular plants can be used to predict ecological structure from resource constraints and how this provides a range of tools for constraining and potentially detecting vegetation in a range of exoplanetary environments.

Learn about an exciting new exoplanet discovery—a Jupiter-like planet called “51 Eri b” that orbits a star a 100 light years away in the constellation of Eridanus.

Using a powerful new imaging device, astronomers have spied a Jupiter-like exoplanet 100 light-years distant in the constellation of Eridanus. Unlike most planets found around other stars, 51 Eri b has been seen directly. The instrument employed to make the discovery has also made a spectroscopic analysis of the light reflected from the planet, and has detected gases similar to those in Jupiter’s atmosphere.

Because GPI not only images exoplanets but also spreads their light for chemical analysis, astronomers can search for such common gases as water and methane in their atmospheres. Researchers had expected to see methane in directly-imaged exoplanets based on the temperature and chemistry of these worlds, but had failed to detect these molecules in large quantities using earlier instruments. However, the observations of 51 Eri b made with GPI have clearly revealed a methane-dominated atmosphere similar to that of Jupiter.

An extraordinarily complex instrument the size of a small car, GPI is attached to one of the world’s biggest telescopes – the 8-meter Gemini South instrument in Chile. It began its survey of stars last year.

The host star, 51 Eri, is very young, a mere 20 million years old, and is slightly hotter than the Sun. The exoplanet 51 Eri b, whose mass is estimated to be roughly twice that of Jupiter, appears to orbit its host star at a distance 13 times greater than the Earth-Sun distance. If placed in our own solar system, 51 Eri b’s orbit would lie between those of Saturn and Neptune.

A neutron bomb or officially known as one type of Enhanced Radiation Weapon is a low yield fission-fusion thermonuclear weapon (hydrogen bomb) in which the burst of neutrons generated by a fusion reaction is intentionally allowed to escape the weapon, rather than being absorbed by its other components. The weapon's radiation case, usually made from relatively thick uranium, lead or steel in a standard bomb, are instead made of as thin a material as possible to facilitate the greatest escape of fusion produced neutrons. The usual nuclear weapon yield—expressed as kilotons of TNT equivalent—is not a measure of a neutron weapon's destructive power. It refers only to the energy released (mostly heat and blast), and does not express the lethal effect of neutron radiation on living organisms.
Compared to a pure fission bomb with an identical explosive yield, a neutron bomb would emit about ten times the amount of neutron radiation. In a fission bomb at sea level, the total radiation pulse energy which is composed of both gamma rays and neutrons is approximately 5% of the entire energy released; in the neutron bomb it would be closer to 40%. Furthermore, the neutrons emitted by a neutron bomb have a much higher average energy level (close to 14 MeV) than those released during a fission reaction (1–2 MeV). Technically speaking, all low yield nuclear weapons are radiation weapons, that is including the non-enhanced variant. Up to about 10 kilotons in yield, all nuclear weapons have prompt neutron radiation as their most far reaching lethal component, after which point the lethal blast and thermal effects radius begins to out-range the lethal ionizing radiation radius. Enhanced radiation weapons also fall into this same yield range and simply enhance the intensity and range of the neutron dose for a given yield.


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The age of Saturn's rings and the source of Enceladus's hydrothermal energy have been hotly debated topics for years. Recently the age of Saturn's moons interior to Titan, previously thought to be as old as Saturn, also became actively debated. I will show how computer simulations of the past orbital dynamics of Saturn's moons Tethys, Dione and Rhea can tell us how long they have been around. It appears that the inner moons and rings of Saturn are only about 100 million years, equivalent to the Cretaceous period on Earth. I will also discuss how the present moons likely originated from debris resulting from a major orbital instability in which the previous generation of icy moons was destroyed.

On July 20, 2015, the 46th anniversary of the Apollo 11 moon landing, the Breakthrough Prize Foundation announced in London, UK a new initiative to study life in the universe. The announcement was made by Silicon Valley billionaire Yuri Milner and physicist Steven Hawking. The Breakthrough Initiatives currently consist of two primary elements, Breakthrough Listen which is a $100M renewed search for intelligent extraterrestrial signals, and Breakthrough Message, a global competition with a $1M prize to create, but not sent a message representing humanity. S. Pete Worden, the former Center Director of the NASA Ames Research Center, is the Chairman of the Breakthrough Prize Foundation. He will talk about these initiatives in the broader context of our search for life in the universe.

Jason Rowe, Senior Research Scientist at the SETI Institute

Jason gives an overview of the Kepler 138 system, the Kepler Mission in general, transit-timing-variations, in particular the gravitational tug-of-war, and mass-radius relationships.