Nancy has been with Universe Today since 2004, and has published over 6,000 articles on space exploration, astronomy, science and technology. She is the author of two books: "Eight Years to the Moon: the History of the Apollo Missions," (2019) which shares the stories of 60 engineers and scientists who worked behind the scenes to make landing on the Moon possible; and "Incredible Stories from Space: A Behind-the-Scenes Look at the Missions Changing Our View of the Cosmos" (2016) tells the stories of those who work on NASA's robotic missions to explore the Solar System and beyond.
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Scientists caused quite a stir in 1996 when they announced a meteorite had been found in Antarctica that might contain evidence for microscopic fossils of Martian bacteria. While subsequent studies of the now famous Allen Hills Meteorite shot down theories that the Mars rock held fossilized alien life, both sides debated the issue and the meteorite is still being studied. Now, Craig Covault in Spaceflightnow.com reports that a new look at ALH84001 provides “evidence that supports the existence of life on the surface of Mars, or in subsurface water pools, early in the planet’s history.” Covault says we can expect a public announcement by NASA Headquarters within a few days.
Research using a more advanced High Resolution Electron Microscopy than was in existence when the initial findings were made 13 years ago has provided the new evidence. Covault reported that the “laboratory sensors are being focused directly on carbonate discs and associated tiny magnetite crystals present inside the meteorite Allen Hills ALH 84001.” The data reveal information that counters a “wide range of opposing theories as to why the finding should not be supported as biological in origin.”
The new findings were reported in the November issue of the respected journal Geochimica et Cosmochimica Acta, the journal of the Geochemical and Meteoritic Society. The authors include Kathie Thomas-Keprta, Simon Clement, David McKay (who led the original team), Everett Gibson and Susan Wentworth, all of the Johnson Space Center.
Covault said the new work centers on what is called magnetic bacteria that on Earth, and Mars as well, leave distinctively-shaped remnants in the rock. These features test with a high chemical purity more like a biological feature than geological.
Artist concept of a view inside a black hole. Credit: April Hobart, NASA, Chandra X-Ray Observatory
Very likely, the last image that comes to mind when thinking of black holes is that they need to be nurtured, coddled and protected when young. But new research reveals the first large black holes in the universe likely formed and grew deep inside gigantic, starlike cocoons that smothered their powerful x-ray radiation and prevented surrounding gases from being blown away.
“Until recently, the thinking by many has been that supermassive black holes got their start from the merging of numerous, small black holes in the universe,” said Mitchell Begelman, from the University of Colorado-Boulder. “This new model of black hole development indicates a possible alternate route to their formation.”
Ordinary black holes are thought to be remnants of stars slightly larger than our sun that used up their fuel and died.
But the first big black holes likely formed from very large stars that formed early in the Universe, probably within the first few hundred million years after the Big Bang. The unique process of these large stars becoming black holes includes the formation of a protective cocoon, made of gas.
“What’s new here is we think we have found a new mechanism to form these giant supermassive stars, which gives us a new way of understanding how big black holes may have formed relatively fast,” said Begelman.
These early supermassive stars would have grown to a huge size — as much as tens of millions of times the mass of our sun — and would have been short-lived, with its core collapsing in just in few million years.
The main requirement for the formation of supermassive stars is the accumulation of matter at a rate of about one solar mass per year, said Begelman. Because of the tremendous amount of matter consumed by supermassive stars, subsequent seed black holes that formed in their centers may have started out much bigger than ordinary black holes.
Begelman said the hydrogen-burning supermassive stars would had to have been stabilized by their own rotation or some other form of energy like magnetic fields or turbulence in order to facilitate the speedy growth of black holes at their centers.
After the seed black holes formed, the process entered its second stage, which Begelman has dubbed the “quasistar” stage. In this phase, black holes grew rapidly by swallowing matter from the bloated envelope of gas surrounding them, which eventually inflated to a size as large as Earth’s solar system and cooled at the same time, he said.
Once quasistars cooled past a certain point, radiation began escaping at such a high rate that it caused the gas envelope to disperse and left behind black holes up to 10,000 times or more the mass of Earth’s sun. With such a big head start over ordinary black holes, they could have grown into supermassive black holes millions or billions of times the mass of the sun either by gobbling up gas from surrounding galaxies or merging with other black holes in extremely violent galactic collisions.
Begelman said big black holes formed from early supermassive stars could have had a huge impact on the evolution of the universe, including galaxy formation, possibly going on to produce quasars — the very bright, energetic centers of distant galaxies that can be a trillion times brighter than our sun.
Begelman’s paper will be published in Monthly Notices of the Royal Astronomical Society.
The Mice galaxies, merging. Credit: Hubble Space Telescope
Here’s your chance to play online slot machines without risking your life savings. Plus it’s an opportunity to contribute to a citizen science project that is sure to revolutionize our understanding of galaxy mergers. Galaxy Zoo’s newest project asks for help in looking at colliding galaxies, and uses a tool akin to a cosmic slot machine to compare images of galactic pile-ups with millions of simulated mergers.
“The analogy I’ve been using is that it is like driving past a car crash,” said Galaxy Zoo team member Chris Lintott from Oxford University. “You get a snapshot of the action, but there are two things you want to know: what caused the crash (or what did things look like before it all went wrong), and you want to know what the outcome is going to be. We’re doing the same thing. We want to know what the galaxies looked like before the mergers started disrupting them, and we want to know how they are going to end up. Just like our other Galaxy Zoo projects, humans are much better at doing this than computers, and lots of humans are even better.”
The Galaxy Zoo mergers project goes live on November 24 at http://mergers.galaxyzoo.org
“This is another classic Galaxy Zoo problem,” Lintott told Universe Today. “We found 3,000 galaxy mergers from Galaxy Zoo 1, and we don’t have a good understanding of the processes that take place during and after the collisions. This new project will help us work that out.”
On the Galaxy Zoo Mergers page, there will be a real image of a galactic merger in the center and with eight randomly selected merger simulations filling the other eight ‘slots’ around it. Visitors to the site pick which animation best demonstrates what is happening in that collision. But if they don’t see a good simulation, they can “spin the wheel again,” Lintott said, until a good depiction of the merger shows up. A Grazing Encounter Between Two Spiral Galaxies (NGC 2207 and IC2163). Credit: HubbleSite
“By randomly cycling through the millions of simulated possibilities and selecting only the very best matches the users are helping to build up a profile of what kind of factors are necessary to create the galaxies we see in the Universe around us — and, hopefully, having fun too,” Lintott said.
There’s also the “enhance” option, where you can take control. “Once you have picked a simulation, you can take control of it directly, and change the parameters by hand such as the size, mass, the speed, for example. So, if you get impatient you can take control and see if you can do a better job than the slot machine,” Lintott explained.
For some of mergers, there will be a unique solution – only one way to get the merger we see today. For others there may be many different simulations that could provide the answer.
The Mergers project is a bit different than the regular Galaxy Zoo in that there will be, initially, just one daily challenge. “We’re aiming for one a day, but obviously if everyone who reads Universe Today turns up, we’ve got an idea of how many people we need to look at each one, so then we’ll change them out quicker,” Lintott said. “The more that people do, the more galaxies they’ll get to see.”
Of course, galaxy mergers are beautiful and amazing astronomical objects to behold, so the Galaxy Zoo team is hoping this will be a popular project.
“The point of Galaxy Zoo is to try and understand how we got the mix of galaxies that we see today,” Lintott said. “One of the mysteries is trying to work out how the ellipticals formed. We know that one way to form elliptical is to smash two spirals together. There’s the famous simulation of the Milky Way and Andromeda colliding and everyone assumes it will end up as a big elliptical that has used up all its gas. But actually it’s not clear how often that happens, and it’s not clear that you always get elliptical when you smash spirals together. In fact we know that in some cases they don’t. There is a lot of debate as to how important mergers are in this process.”
Right now, 3% of galaxies are in the process of merging, so, Lintott said, if most big galaxies undergo a merger every million years or so, this is clearly an important process.
“But we don’t understand what affects it has, and that’s what we hope to realize in this project.”
And Lintott admitted this newest Galaxy Zoo project is supposed to be fun and addictive. “Some people will love it, and some people will probably prefer the regular Galaxy Zoo. But it’s nice to have a range of scientific tasks that we have to work through.”
Why – and how — do brown dwarfs form? Since these cosmic misfits fall somewhere between planets and stars in terms of their temperature and mass, astronomers haven’t yet been able to determine how they form: are their beginnings like planets or stars? Now, the Spitzer Space Telescope has found what could be two of the youngest brown dwarfs. While astronomers are still looking to confirm the finding of these so-called “proto brown dwarfs” it has provided a preliminary answer of how these unusual stars form.
The baby brown dwarfs were found in Spitzer data collected in 2005. Astronomers had focused their search in the dark cloud Barnard 213, a region of the Taurus-Auriga complex well known to astronomers as a hunting ground for young objects.
“We decided to go several steps back in the process when (brown dwarfs) are really hidden,” said David Barrado of the Centro de Astrobiología in Madrid, Spain, lead author of the paper, published in the Astronomy & Astrophysics journal. “During this step they would have an (opaque) envelope, a cocoon, and they would be easier to identify due to their strong infrared excesses. We have used this property to identify them. This is where Spitzer plays an important role because Spitzer can have a look inside these clouds. Without it this wouldn’t have been possible.”
Barrado said the findings potentially solve the mystery about whether brown dwarfs form more like stars or planets. The team’s findings? Brown dwarfs form like low-mass stars.
Brown dwarfs are cooler and more lightweight than stars and more massive (and normally warmer) than planets. They are born of the same dense, dusty clouds that spawn stars and planets. But while they may share the same galactic nursery, brown dwarfs are often called “failed” stars because they lack the mass of their hotter, brighter stellar siblings. Without that mass, the gas at their core does not get hot enough to trigger the nuclear fusion that burns hydrogen — the main component of these molecular clouds — into helium. Unable to ignite as stars, brown dwarfs end up as cooler, less luminous objects that are more difficult to detect — a challenge that was overcome in this case by Spitzer’s heat-sensitive infrared vision. This artist's rendering gives us a glimpse into a cosmic nursery as a star is born from the dark, swirling dust and gas of this cloud. Image credit: NASA/JPL-Caltech
Young brown dwarfs also evolve rapidly, making it difficult to catch them when they are first born. The first brown dwarf was discovered in 1995 and, while hundreds have been found since, astronomers had not been able to unambiguously find them in their earliest stages of formation until now.
Spitzer’s longer-wavelength infrared camera penetrated the dusty natal cloud to observe STB213 J041757. The data, confirmed with near-infrared imaging from Calar Alto Observatory in Spain, revealed not one but two of what would potentially prove to be the faintest and coolest brown dwarfs ever observed.
The twins were observed from around the globe, and their properties were measured and analyzed using a host of powerful astronomical tools. One of the astronomers’ stops was the Caltech Submillimeter Observatory in Hawaii, which captured the presence of the envelope around the young objects. That information, coupled with what they had from Spitzer, enabled the astronomers to build a spectral energy distribution — a diagram that shows the amount of energy that is emitted by the objects in each wavelength.
From Hawaii, the astronomers made additional stops at observatories in Spain (Calar Alto Observatory), Chile (Very Large Telescopes) and New Mexico (Very Large Array). They also pulled decade-old data from the Canadian Astronomy Data Centre archives that allowed them to comparatively measure how the two objects were moving in the sky. After more than a year of observations, they drew their conclusions.
“We were able to estimate that these two objects are the faintest and coolest discovered so far,” Barrado said. This theory is bolstered because the change in brightness of the objects at various wavelengths matches that of other very young, low-mass stars.
While further study will confirm whether these two celestial objects are in fact proto brown dwarfs, they are the best candidates so far, Barrado said. He said the journey to their discovery, while difficult, was fun. “It is a story that has been unfolding piece by piece. Sometimes nature takes its time to give up its secrets.”
Lead image caption: This image shows two young brown dwarfs, objects that fall somewhere between planets and stars in terms of their temperature and mass. Image credit: NASA/JPL-Caltech/Calar Alto Obsv./Caltech Sub. Obsv.
And if you’re interested in looking back, here’s an archive to all the past Carnivals of Space. If you’ve got a space-related blog, you should really join the carnival. Just email an entry to [email protected], and the next host will link to it. It will help get awareness out there about your writing, help you meet others in the space community – and community is what blogging is all about. And if you really want to help out, let Fraser know if you can be a host, and he’ll schedule you into the calendar.
Finally, if you run a space-related blog, please post a link to the Carnival of Space. Help us get the word out.
Screens showing two beams in the LHC. Credit: CERN
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Two beams circulated simultaneously inside the Large Hadron Collider for the first time today, allowing for the first proton-proton collisions to take place. “It’s a great achievement to have come this far in so short a time,” said CERN Director General Rolf Heuer. “But we need to keep a sense of perspective – there’s still much to do before we can start the LHC physics program.”
The beams crossed at points where various detectors are stationed. The beams were made to cross at point 1, where the ATLAS all purpose detector is located, then at point five at the CMS (Compact Muon Solenoid) detector. Later, beams crossed at points 2 and 8, where the ALICE (heavy ion detector) and the LHCb (looking for heavy particles containing a bottom quark) are positioned.
The first collisions are allowing operators to test the synchronization of the beams.
“This is great news, the start of a fantastic era of physics and hopefully discoveries after 20 years’ work by the international community to build a machine and detectors of unprecedented complexity and performance,” said ATLAS spokesperson, Fabiola Gianotti at a press conference today.
“The events so far mark the start of the second half of this incredible voyage of discovery of the secrets of nature,” said CMS spokesperson Tejinder Virdee.
“It was standing room only in the ALICE control room and cheers erupted with the first collisions” said ALICE spokesperson Jurgen Schukraft. “This is simply tremendous.”
“The tracks we’re seeing are beautiful,” said LHCb spokesperson Andrei Golutvin, “we’re all ready for serious data taking in a few days time.”
The first collisions come just three days after the LHC restart. Since the start-up this weekend, the operators have been circulating beams around the ring alternately in one direction and then the other at the injection energy of 450 GeV (gigaelectron volts). The beam lifetime has gradually been increased to 10 hours, and today beams have been circulating simultaneously in both directions, still at the injection energy.
Next on the schedule is an intense commissioning phase aimed at increasing the beam intensity and accelerating the beams. If everything goes as planned, everyone at CERN hopes to obtain good quantities of collision data for all the experiments’ calibrations by Christmas, when the LHC should reach 1.2 TeV (terraelectron volts) per beam.
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The weird mystery of the flyby anomaly just got even weirder. Since the early 1990’s scientists and mission controllers have noticed that some spacecraft experience unexpected changes in speed during Earth-flybys. The unexplained variation is extremely small and has occurred as either speed gained or lost, but this variant is not predicted by fundamental physics. The anomaly doesn’t happen to every spacecraft but scientists were hoping to gain more insight into the anomaly when the Rosetta spacecraft swung by Earth on Nov. 13 to pick up a gravitational boost for its journey to rendezvous with a comet in 2014. However, in a major disappointment – which had deepened the mystery — the Rosetta spacecraft did not experience the flyby anomaly during this swingby of Earth, even though the same spacecraft did experience the anomaly when it flew by Earth 2005, but didn’t in 2007.
“It’s a mystery as to what is happening with these gravity events,” said Trevor Morley, lead flight dynamics specialist working on Rosetta. “Some studies have looked for answers in new interpretations of current physics. If this proves correct, it would be absolutely ground-breaking news.”
For the Earth swingbys where the anomaly has been detected, Morley said the main manifestation has been “the inability to get anything like a reasonable fit of an orbit to an arc of radiometric data that encompasses both the pre- and post-perigee (closest to the Earth) intervals.”
For those cases when an anomaly has been seen, the change has been very slight, but noticeable. “In every case, a reasonable data fit could be established only by inserting an artificial velocity change along the direction of the orbital velocity in the vicinity of perigee,” Morley said. Earth as seen by the Osiris camera on Rosetta. Credit: ESA
For this flyby, the team made allowances for the software to estimate an impulsive maneuver at perigee, aligned along the orbital velocity. But after analyzing the radiometric data gathered by ESA and NASA ground stations, nothing anomalous was seen.
“The difference in the quality of the data fit was absolutely negligible,” Morley said. “For Rosetta’s third and final Earth swingby, there was no anomaly.”
Several ideas have been tossed around in an attempt to explain why the anomaly occurs, but no one has been able to pin the cause down as of yet.
Ideas range from tidal effects of the near-Earth environment, atmospheric drag, or the pressure of radiation emitted or reflected by the Earth, to much more extreme possibilities, such as dark matter, dark energy or previously unseen variations in General Relativity.
One American research team, led by ex-NASA scientist John Anderson, is even looking at the possibility that Earth’s rotation may be distorting space-time – the fundamental fabric of our Universe – more than expected, and affecting nearby spacecraft. But there is as yet no explanation how this could happen.
Plus no one can explain why some flybys experience the anomaly and others don’t.
An enhanced network of river valleys on Mars. Credit: NIU, LPI
Did Mars once have a vast network of river valleys – “canals” if you will – and an ocean that covered most of the planet’s northern hemisphere? A new computer-generated map of the Red Planet provides a more detailed look at the valley networks on Mars, and indicates the networks are more than twice as extensive as had been previously depicted in the only other planet-wide map of the valleys. “All the evidence gathered by analyzing the valley network on the new map points to a particular climate scenario on early Mars,” said Wei Luo, from Northern Illinois University (NIU). “It would have included rainfall and the existence of an ocean covering most of the northern hemisphere, or about one-third of the planet’s surface.”
This is a global map depicting the dissection density of valley networks on Mars, in relation to the hypothesized northern ocean. Credit: NIU, LPI
NIU and the Lunar and Planetary Institute in Houston used an innovative computer program to produce the new map that shows regions dissected by the valley networks roughly form a belt around the planet between the equator and mid-southern latitudes, consistent with a past climate scenario that included precipitation and the presence of an ocean covering a large portion of Mars’ northern hemisphere.
Scientists have previously hypothesized that a single ocean existed on ancient Mars, but the issue has been hotly debated.
Luo and Tomasz Stepinski, a staff scientist at the Lunar and Planetary Institute, publish their findings in the current issue of the Journal of Geophysical Research — Planets.
“The presence of more valleys indicates that it most likely rained on ancient Mars, while the global pattern showing this belt of valleys could be explained if there was a big northern ocean,” Stepinski said.
The researchers created an updated planet-wide map of the valley networks by using a computer algorithm that uses topographic data from NASA satellites and recognizes valleys by their U-shaped topographic signature. “The basic idea behind our method is to flag landforms having a U-shaped structure that is characteristic of the valleys,” Stepinski added. “The valleys are mapped only where they are seen by the algorithm.”
Valley networks on Mars exhibit some resemblance to river systems on Earth, suggesting the Red Planet was once warmer and wetter than present.
The networks were discovered in 1971 by the Mariner 9 spacecraft, but scientists have debated whether they were created by erosion from surface water, which would point to a climate with rainfall, or through a process of erosion known as groundwater sapping. Groundwater sapping can occur in cold, dry conditions.
The large disparity between river-network densities on Mars and Earth had provided a major argument against the idea that runoff erosion formed the valley networks. But the new mapping study reduces the disparity, indicating some regions of Mars had valley network densities more comparable to those found on Earth. A zoomed-in area comparing the old map of valley networks and the new one. (Left) A satellite image, with color indicating elevation; (center) the old map of valley networks; (right) the new map of valley networks. Credit: Wei Luo, Northern Illinois University
“It is now difficult to argue against runoff erosion as the major mechanism of Martian valley network formation,” Luo said. “When you look at the entire planet, the density of valley dissection on Mars is significantly lower than on Earth,” he said. “However, the most densely dissected regions of Mars have densities comparable to terrestrial values. The relatively high values over extended regions indicate the valleys originated by means of precipitation-fed runoff erosion—the same process that is responsible for formation of the bulk of valleys on our planet.”
“The only other global map of the valley networks was produced in the 1990s by looking at images and drawing on top of them, so it was fairly incomplete and it was not correctly registered with current datum,” Stepinski said. “Our map was created semi-automatically, with the computer algorithm working from topographical data to extract the valley networks. It is more complete, and shows many more valley networks.”
The Martian surface is characterized by lowlands located mostly in the northern hemisphere and highlands located mostly in the southern hemisphere. Given this topography, water would accumulate in the northern hemisphere, where surface elevations are lower than the rest of the planet, thus forming an ocean, the researchers said.
“Such a single-ocean planet would have an arid continental-type climate over most of its land surfaces,” Luo said.
The northern-ocean scenario meshes with a number of other characteristics of the valley networks.
“A single ocean in the northern hemisphere would explain why there is a southern limit to the presence of valley networks,” Luo added. “The southernmost regions of Mars, located farthest from the water reservoir, would get little rainfall and would develop no valleys. This would also explain why the valleys become shallower as you go from north to south, which is the case.
“Rain would be mostly restricted to the area over the ocean and to the land surfaces in the immediate vicinity, which correlates with the belt-like pattern of valley dissection seen in our new map,” Luo said.
Raw images are already being returned from Cassini’s Nov. 21 “E-8” or eighth flyby of the tiger-striped moon Enceladus. Visible in this raw image are several plumes from fissures in the south polar region of the moon. These fissures spew jets of water vapor and other particles hundreds of kilometers from the surface. This flyby included a very different geometry to the flyby trajectory – and a different look at the plumes — approaching within 1,606 kilometers (997.9 miles) of the surface, buzzing over 82 degrees south latitude. This is the last look we’ll have for several years at this intriguing area of Enceladus before winter darkness blankets the area. See below for looks at Baghdad Sulcus, the “tiger stripe” that scientists were focusing on.
While Cassini was taking these high-resolution images of the southern part of the Saturn-facing hemisphere, the Composite Infrared Spectrograph (CIRS) instrument was collecting data to create a contiguous thermal map of Baghdad Sulcus. This image was taken approximately 1,858 kilometers away.
Here’s a look at Baghdad Sulcus from 3,556 kilometers away. And below is a 3-D version, created by Stu Atkinson. Stay tuned for more details on the data gathered from the flyby!
Enceladus canyon 3-D. Credit: NASA/JPL, 3-D by Stu Atkinson
Early Nov. 18th, eyewitnesses reported an explosion in the atmosphere above Colorado, Utah, Wyoming and Idaho in the western United States. Some said the fireball “turned night into day” and produced shock waves that shook the ground when it exploded just after midnight Mountain Standard Time. Infrasound recordings of the blast suggest a small asteroid hitting Earth’s atmosphere and exploding with an energy of 0.5 to 1 kiloton of TNT. As the sun rose in the morning, remnants of the explosion were visible as noctilucent clouds over the region. The best video of the extremely bright event was just recently released, from the University of Utah’s Eccles Observatory. Continue reading “Video of Utah Fireball”
