The Mars rovers have produced a collection of stunning photo-mosaics exotic enough to open a photography show at one of Manhattanâs trendiest galleries.
The dune field above lies at the bottom of Marsâ Endurance Crater, as seen in this false color image from NASAâs Mars Rover Opportunity. Image: NASA/JPL/CornellBut hard science edged out a purely esoteric appreciation of the Martian landscape this week, as NASA presented its best evidence that liquid water still continually flows on the red planet.
Two Martian gullies out of 10,000 observed by NASAâs Mars Global Surveyor were found to exhibit very recent evidence of liquid water.
As viewed in the image above, the gully trickle on the right appeared sometime during the last five years in this crater in Marsâ Centauri Montes region. Image: NASA/JPL/Malin Space Science SystemsMARTIAN ICE DAM
Flowing water thought to have run down this steep gully slope likely made its way from deep inside Marsâ interior. Once it breached the surface, Marsâ frigid temperatures initially froze the liquid water into something of an ice dam. Pressure from below eventually broke the dam and caused the release of yet another trickle of liquid water.
Thereâs already new speculation about how such liquid water might have helped spawn and nurture microbial life. But more immediately, researchers will be seeking answers to just how widespread such underground liquid water might be, and then what mechanisms might persist in causing it to remain in a liquid state.
FLASH FROM THE PAST
It may end with a whimper, but most cosmologists agree that our universe surely began with a bang; bursting forth from an infinite singularity and period of universal inflation en route to the cosmos that we continue to marvel over some 13.7 billion years later.
New images from NASA's Spitzer Space telescope are giving cosmologists their share of early times. The above figure shows how far Spitzer has gone in its survey of the Hubble Ultra Deep Field (HUDF), back approaching an epoch of some of the universe's earliest galaxies.BOTTOM UP AFTER ALL?
Theorists still scuffle over details involving the formation of the very first galaxies. Historically, galaxy formation sagas involved either a top down or bottom up scenario. The top down version has it that the first galactic structure in the universe formed from patterns imprinted on the fabric of the early cosmos itself.
The bottom up theory allows for galaxies to have formed piecemeal from an ongoing accretion of smaller structure such as dwarf galaxies into mature galaxies, like our own "grand design" spiral galaxy, that we see throughout the present day universe.Observations, however, are finally catching up with theory. Some cosmologists are continually surprised at how early in the history of the universe, the earliest galaxies formed.
This image shows one of two early galaxies studied with the combined efforts of NASA's Hubble and Spitzer space telescopes as it appeared an estimated 700 million years after the big bang.
Image: Ivo LabbÃ© and Rychard BouwensAs reported in a recent issue of
Astrophysical Journal Letters, researchers believe these baby galaxies could have formed only half a billion years after the big bang. They were certainly quick about it. But itâs unclear whether such new observations will quell debate over the ultimate mechanisms that affected how these galaxies first started their formation process.PRIMORDIAL BLACK HOLE SEEDLINGS
As David Koo, an observational cosmologist at the University of California at Santa Cruz told makkah998.com
, the debate is no longer top down or bottom up.
"Thereâs not too much question about the basic tenets of the bottom up theory,â said Koo. âThat means that usually you start off with smaller objects and over time things aggregate together to form larger and larger systems.â
Koo isnât even surprised to find galaxies at such early times. In fact, he believes that galaxies were probably forming even earlier than half a billion years after the big bang. The problem now is not that these galaxies are out there, but thereâs still no good census of them.The more interesting question, says Koo, is not that there were such galaxies so early in the universe, but rather did supermassive black holes precede them? And, if so, how did such primordial black holes form? Were they merely the product of random density fluctuations in the early universe?(Above) A NASA black hole computer simulation.
âFinding large numbers of supermassive black holes at very high redshift,â said Koo, âwould be interesting. That could indicate there may have been seeds of black holes back in the very beginning of the universe, which were fed gas and grew; in turn, becoming seeds of the earliest galaxies.â
STELLAR CANNIBALISM: TRUE TALES FROM THE GALACTIC CENTER
A stellar mass black hole in our galactic center has been caught in the rare act of cannibalizing its own binary companion.
A weeks-long gamma ray burst has been detected by the European Space Agency
This highly-energetic burst is thought to have been produced by the accretion of an active sun-like star being gradually ripped apart by its black hole companion. The starâs cannibalized gas surrounds the black hole in what is known as an accretion disk. But periodically, instabilities in this surrounding accretion disk will cause the starâs gas to be gobbled up by the black hole, releasing a burst of gamma rays that can last for days or weeks. Integral
will devote a few more weeks to looking for more of the same.
Unlike the massive elliptical galaxy featured in the previous post, this "topsy- turvy" starburst galaxy seen in this image by the European Southern Observatory
's Very Large Telescope
in Chile is a comparative lone wolf, undergoing an unusually large amount of stellar formation. Starburst galaxies usually result from mergers with other galaxies in galaxy clusters.
At a distance of some 15 million light years in the minor southern constellation of Reticulum, NGC 1313 shows no evidence of such mergers and it has no nearby neighbors.
Not only is it oddly asymmetrical and riddled with starbursts; deeper x-ray imaging reveals that NGC 1313
has at least two black holes, estimated to be hundreds of times the mass of our own sun. Our own Milky Way has a supermassive black hole in its center, and our galaxy is also rife with smaller black holes produced from massive single stars. But NGC 1313's intermediate-mass black holes as identified in images of ultra-luminous x-ray sources (ULX), can't be easily dismissed with current theory. That's mainly because astrophysical theory doesn't readily explain how such intermediate-sized black holes could form from a single binary (or double) star system.
FUZZY PIC OF OLE SAINT NICK?
No, it's not a bleary-eyed shot of Santa after a night out at the North Pole. It's the unusual phenomenon of twin supernovae captured in this image made by NASA's Swift satellite. The host galaxy, NGC 1316 (or Fornax A), a massive elliptical galaxy located some 75 million light years away, is now the most prodigious producer of galactic supernovae yet known.
Why would such an elliptical galaxy produce at least four supernovae in a little over a quarter of a century? That's a tough one. But some astronomers think that at least part of the fireworks may have been stirred up by Fornax A's recent merger with a nearby galactic spiral. Could be, since the galaxy is located on the fringes of the Fornax galaxy cluster in the southern constellation of Fornax (the Furnace). Massive elliptical galaxies are believed to form from the merger of one or more spiral galaxies. The devil remains in the details.
Image: courtesy NASA/Swift/Stefan Immler
PERE NOEL TO HIT YULETIDE LAUNCH PAD AT RUSSIA'S BAIKONUR SPACE CENTER
The French space agency, CNES, is planning a late December launch for a space telescope that will finally place some hard parameters on the number of terrestrial mass planets circling other stars. COROT is an acronym for Convection, Rotation and Planetary Transits, in honor of the 19th century painter Jean-Baptiste Camille Corot. The French impressionist's own work may not conjure images of "Starry Night"s as does the famous painting by his better known Dutch counterpart Vincent van Gogh. But Corot's telescopic namesake will lead the way for future terrestrial planet-finding space telescopes by surveying as many as 60,000 stars for rocky planets like our own. Kepler, an ambitious NASA follow-on mission, may see launch as early as 2008. Astrobiologists looking for earth-like analogues will likely have an exciting holiday season.
Planetary scientists are still scratching their heads over why Venus is so radically different from our own planet. An obvious explanation lies in its enigmatic atmosphere. But posing the questions isn't the same as pondering the answers. The planet's South Pole has a mysterious double-eyed vortex fueled by super-hurricane force winds.
Above: A night-side false color image of Venus' South Pole and its tumultuous and thick climatic system as taken by a visible and infrared spectrometer aboard the European Space Agency's Venus Express
spacecraft. Venus Express
is celebrating the first anniversary of its launch.
ORION EYED BY HUBBLE & SPITZER
This false color image
is a spectacular
composite of real
images taken by
NASA's Hubble and
Spitzer Space Telescopes.
The image illustrates the chaos surrounding young stars in the Trapezium, a collection of massive stars in the Orion Nebula, in the middle of Orion's sword. Researchers believe they've detected a plethora of PAHs, Polycyclic Hydrocarbons, which are thought to be a key to the evolution of carbon-based life.
Image: NASA HST/SSC
VIOLENCE ROCKS A CLUSTER
For the first time, an international team of astronomers has found observational evidence of shock waves and radio-emitting rings rippling around a giant galaxy cluster some 600 million light years away.
Observations made with the VLA (Very Large Array) radio telescope in New Mexico and with the European Space Agency's XMM-Newton x-ray observatory have confirmed the presence of both giant radio-emitting rings and magnetic shock waves around the galaxy cluster Abell 3376.
As reported in a recent issue of the journal Science, x-ray observations of Abell 3376 suggests that these emissions must have originated after the violent collision of smaller sub-clusters within the larger main cluster. These collisions are so powerful that researchers estimate that the resulting energy would be enough to keep our own sun alive and kicking for another 20 sextillion years. That's a 2 trailed by 22 zeroes.
Particle physicists and cosmologists alike are still puzzled over the origin of Ultra High Energy Cosmic Rays. Often the purview of science fiction, in reality, cosmic rays are highly-energetic atomic particles kicked up to speeds approaching that of light. While it's certain that the cluster Abell 3376 must be responsible for at least some cosmic rays, whether it is generating these ultra high energy rays is still open to debate.
Ultra High Energy Cosmic Rays --- some 100 million times more energetic than such particles created in the largest accelerators here on earth; have been detected by ground-based astronomers. But only future highly sensitive cosmic ray observatories will be able to determine if this far-flung galaxy cluster is the source of such ultra high energy particles. The bonafide origin of Ultra High Energy Cosmic Rays remains one of cosmology's greatest conundrums.
The above x-ray image from XMM-Newton shows a bullet-like supersonic
shock of x-rays emanating from gas superheated by
Abell 3376's sub-cluster collisions.
Image credit: Joydeep Bagchi, IUCAA, ESA
NO WATER ON MOON?
Radar observations made by the giant Arecibo radio telescope show no indication of water ice at the lunar South Pole. Lunar colonization advocates had hoped that the region could have harbored at least a small amount of H2O. Some researchers won't be completely convinced of this until boots hit the lunar regolith once again.
Shackleton crater pictured in this close-up image taken by the European Space Agency's SMART-1 lunar probe lies almost dead center on the lunar South Pole.
For more info:
Image: courtesy ESA
2009 IS INTERNATIONAL YEAR OF ASTRONOMY
Hello, Dolly! Have new visit authoritatively withdraw the Broadway comes back to featuring
the Red Sox completed that arrangement
Whether waxing, waning or at its fullest, our moon affects everyone who gazes skyward. It's been a fixture of our imaginations since time immemorial.
But the question of just how it formed remains in dispute.
The first edition of Cosmic Cast explores the possibilities.
NASA Johnson Space Center
with Dr. Ken Rumstay
Valdosta State University