Artist's sketch of a supernova explosion (credit: Adam Burn / Deviant art).
New observations confirm that young Nathan Gray’s discovery is indeed a supernova explosion, albeit a rather peculiar one. Nathan Gray, age 10, discovered a new cosmic source on October 30th that emerged in the constellation of Draco, and it was subsequently classified as a supernova candidate. Evidence available at the time was sufficiently convincing that Nathan was promptly heralded as the youngest individual to discover a supernova.
The discovery garnered world-wide attention, however, confirmation via a spectrum from a large telescope was necessary to unambiguously identify the target as a supernova. In addition, that observation would enable astronomers to determine the supernova class and identify the progenitor of the exploding star. In other words, was the star initially comparable in mass to the Sun and a member of a binary system, or was the original star significantly more massive and a neutron star is potentially all that remains?
The new observations were acquired by Lina Tomasella and Leonardo Tartaglia of the Padova-Asiago Supernova Group, and imply that the supernova stems from a star significantly more massive than the Sun. Andrea Pastorello, a member of that group, noted that the target’s spectrum displays the presence of hydrogen (specifically H-alpha emission), which rules out the scenario of a lower-mass progenitor in a binary system (those are classified as type Ia).
Features present in the observations led the astronomers to issue a preliminary supernova classification of type II-pec (peculiar). The blue spectral continuum is typical of a type IIn supernova, but the expansion velocity inferred from the hydrogen line (3100 km/s) is an order of magnitude larger than expected, which motivated the team to issue the aforementioned classification. Pastorello further noted that the target is somewhat similar to SN 1998s, and in general type II supernovae exhibit heterogeneous observational properties.
Observations confirming that young Nathan Gray’s cosmic discovery is a supernova were obtained from the Asiago 1.82-m Copernico Telescope (image credit: L.C. / Istituto Nazionale di Astrofisica).
Nathan had been scanning astronomical images sent by David J. Lane (Saint Mary’s University) for months, and identified some potential sources that proved to be false detections or previous discoveries. However, the Padova-Asiago Supernova Group has now confirmed that isn’t the case this time. Indeed, the discovery means that Nathan officially unseats his sister Kathryn as the youngest person to discover a supernova, yet she is elated for her bother (see Nancy Atkinson’s article regarding Kathryn’s discovery).
Nathan, his sister, and parents Paul and Susan, formed a supernova search team in partnership with Lane. The original discovery images were obtained from the Abbey Ridge Observatory, which is stationed in Lane’s backyard.
Those desiring additional information on supernovae will find the videos below pertinent.
Image of NGC 6872 (left) and companion galaxy IC 4970 (right) locked in a tango as the two galaxies gravitationally interact. The galaxies lie about 200 million light-years away in the direction of the constellation Pavo (the Peacock). Image credit: Sydney Girls High School Astronomy Club, Travis Rector (University of Alaska, Anchorage), Ángel López-Sánchez (Australian Astronomical Observatory/Macquarie University), and the Australian Gemini Office.
Galaxy modelling is complicated, and even more so when different computer models don’t agree on how the factors come together. This makes it hard to understand the nature of our universe. One new project called AGORA (Assembling Galaxies of Resolved Anatomy) aims to resolve the discrepancies and make the results more consistent. Basically, the project aims to compare different codes against each other and also against observations.
“The physics of galaxy formation is extremely complicated, and the range of lengths, masses, and timescales that need to be simulated is immense,” stated Piero Madau, professor of astronomy and astrophysics at the University of California, Santa Cruz and co-chair of the AGORA steering committee.
“You incorporate gravity, solve the equations of hydrodynamics, and include prescriptions for gas cooling, star formation, and energy injection from supernovae into the code. After months of number crunching on a powerful supercomputer, you look at the results and wonder if that is what nature is really doing or if some of the outcomes are actually artifacts of the particular numerical implementation you used.”
This is especially important when it comes to modelling the effect of dark matter on the universe. Since the entity is hard for us to see and therefore to identify, physicists rely on models to make predictions about its effect on galaxies and other forms of more ordinary matter.
Nine codes, nine galaxy formation scenarios: this is the sort of problem that AGORA is devoting itself to resolving by comparing different supercomputer simulations. Credit: Simulations performed by Samuel Leitner (ART-II), Ji-hoon Kim (ENZO), Oliver Hahn (GADGET-2- CFS), Keita Todoroki (GADGET-3), Alexander Hobbs (GADGET-3-CFS and GADGET-3-AFS), Sijing Shen (GASOLINE), Michael Kuhlen (PKDGRAV-2), and Romain Teyssier (RAMSES)
“One big challenge, however, has been numerically modeling astrophysical processes over the vast range of size scales in the Universe. Supercomputer simulations are designed with three different size scales relevant to three different phenomena: star formation, galaxy formation, and the large scale structure of the universe,” stated the University of California High-Performance Astrocomputing Center.
This means that models of stars coming to be inside of galaxies have one scale of resolution — enough to look at what the gas and dust is made of, for example — but when looking at the entire universe, the computer is more limited to looking at “simple gravitational interactions of dark matter”, the university added. Of course, the more resolution you can get in a computer model, the better — especially because star formation is affected by processes such as how galaxies interact with surrounding gas.
AGORA’s will first aim to “model a realistic isolated disk galaxy” UCSC states, and then compare the codes used to see what they come up with. You can read more about the project’s aims at this Arxiv pre-print paper (led by the University of California, Santa Cruz’s Ji-hoon Kim) or on the AGORA website.
This colorized composite shows more than half of Earth’s disk over the coast of Argentina and the South Atlantic Ocean as the Juno probe slingshotted by on Oct. 9, 2013 for a gravity assisted acceleration to Jupiter. The mosaic was assembled from raw images taken by the Junocam imager. Credit: NASA/JPL/SwRI/MSSS/Ken Kremer/Marco Di Lorenzo
Um, something in my eye. This wonderful video details a what took place when the Jupiter-bound Juno spacecraft swung past Earth on Oct. 9, 2013 for a gravity assist, and amateur radio operators around the world sent a Morse Code saying “HI” to the spacecraft.
“We wanted to know, if this were an interplanetary spacecraft, could they we tell there was intelligent life on Earth?” said Bill Kurth, co-investigator for the Juno Waves Investigation from the University of Iowa.
Watch the video to find out if it worked.
“We obviously haven’t heard anything like this from any other planet,” said Scott Bolton, Juno principal investigator, speaking during a press briefing from the American Geophysical Union conference today in San Fransisco.
NASA's Robonaut 2 with "climbing legs" intended to let the robot rove around in the microgravity environment aboard the International Space Station. This version is being tested on the ground for eventual use in space. Credit: NASA
There was much excitement two years ago when the astronauts on space station unpackaged Robonaut 2 (or R2), which is supposed to help with simple tasks. Trouble was, the robot was basically anchored in place and had to be moved around for different tasks. Well, that’s about to change. R2 is getting some “climbing” legs.
After the legs are brought to station and installed — likely sometime early in the new year — Robonaut will be capable of doing tasks both inside and outside (well, outside once a few more unspecified upgrades are finished). This reduces the human risks during spacewalks and frees up the astronauts to do more complicated tasks, NASA said.
“Once the legs are attached to the R2 torso, the robot will have a fully extended leg span of 9 feet, giving it great flexibility for movement around the space station,” NASA stated.
“Each leg has seven joints and a device on what would be the feet called an end effector, which allow the robot to take advantage of handrails and sockets inside and outside the station. A vision system for the end effectors also will be used to verify and eventually automate each limb’s approach and grasp.”
By the way, end effectors were famously used on the Canadarm series of robotic arms that were originally used for grappling satellites. Who knew back in the 1970s that this could be extended to humanoid robots?
An artist's conception of future Mars astronauts. Credit: NASA/JPL-Caltech
While asking questions about habitability on Mars, one thing that scientists also need to consider is whether it’s safe enough for humans to even do exploration there. Radiation is definitely a big factor — in a press conference yesterday (Dec. 9) for the American Geophysical Union’s conference, scientists said the environment is unlike anything we are used to naturally on Earth.
Radiation on Mars comes from two sources: galactic cosmic rays (over the long term) and solar energetic particles (in short bursts of activity when the sun gets super-active). Of note, the sun has had a muted peak to its solar cycle, so that’s affecting the expected amount of particles on Mars. But the Mars Curiosity rover, in its first 300 Earth days of roaming, has plenty of data on galactic cosmic rays.
On the Martian surface, the average dose is about 0.67 millisieverts (mSv) per day, at least between the measurement period of August 2012 and June 2013. The journey to Mars had a dose of 1.8 mSv per day inside the spaceship. So what does that means for NASA’s human health consideration concerns?
NASA’s Mars rover Curiosity took this self-portrait, composed of more than 50 images using its robotic arm-mounted MAHLI camera, on Feb. 3. The image shows Curiosity at the John Klein drill site. A drill hole is visible at bottom left. Credit: NASA / JPL / MSSS / Marco Di Lorenzo / Ken Kremer- kenkremer.com
With a 500-day trip on the surface and the journey to and from Mars (which would take 180 days each way), NASA is saying the total dosage for the mission would be about 1 Sv. Population studies over the long term have shown that increases the fatal cancer risk by 5%. Current NASA guidelines for low-Earth orbit don’t allow for a more than 3% increase, but 1 Sv is within the guidelines for several other space agencies.
But don’t rule out the trip to Mars yet, NASA states: “[NASA] does not currently have a limit for deep space missions, and is working with the National Academies Institute of Medicine to determine appropriate limits for deep space missions, such as a mission to Mars in the 2030s.”
Besides, other entities are thinking about going, such as Mars One.
Read more about the radiation findings in this Dec. 9 article on Science. The research was led by Don Hassler, a Southwest Research Institute program director and principal investigator of Curiosity’s radiation assessment detector (RAD).
Molecular hydrogen in the Whirlpool Galaxy M51. The blueish features show the distribution of hydrogen molecules in M51, the raw material for forming new stars. The PAWS team has used this data to create a catalogue of more then 1,500 molecular clouds. The background is a color image of M51 by the Hubble Space Telescope. Superimposed in blue is the CO(1-0) radiation emitted by carbon monoxide (CO) molecules, as measured for the PAWS study using the millimeter telescopes of the Institut de Radioastronomie Millimétrique. The CO molecules are used as tracers for molecular hydrogen. Credit: PAWS team/IRAM/NASA HST/T. A. Rector (University of Alaska Anchorage)
It didn’t happen overnight. By studying the properties of giant molecular clouds in the Whirlpool Galaxy for several years with the millimeter telescopes of IRAM, the Institut de Radioastronomie Millimétrique, astronomers have been given a whole, new look at star formation. Encompassing 1,500 maps of molecular clouds, this new research has found these building blocks of future suns to be encased in a sort of molecular hydrogen mist. This ethereal mixture appears to be far denser than speculated and is found throughout the galactic disc. What’s more, it would appear the pressure created by the molecular fog is a critical factor in determining whether or not stars are able to form within the clouds.
Stars form in the molecular clouds housed within all galaxies. These formations are vast areas of hydrogen molecules with masses which total from a thousand to several million times that of the Sun. When an area of the cloud folds under the weight of its own gravity, it collapses. Pressure and temperature rise and nuclear fusion begins. A star is born.
This exciting new research is changing the way astronomers think about starbirth regions. Study leader Eva Schinnerer (Max Planck Institute for Astronomy) explains: “Over the past four years, we have created the most complete map yet of giant molecular clouds in another spiral galaxy similar to our own Milky Way, reconstructing the amounts of hydrogen molecules and correlating them with the presence of new or older stars. The picture that is emerging is quite different from what astronomers thought these clouds should be like.” The survey, known as PAWS, targeted the Whirlpool galaxy, also known as M51, at a distance of about 23 million light-years in the constellation Canes Venatici – the Hunting Dogs.
Annie Hughes, a post-doctoral researcher at MPIA involved in the study, says: “We used to think of giant molecular clouds as solitary objects, drifting within the surrounding interstellar medium of rarified gas in isolated splendor; the main repository of a galaxy’s supply of hydrogen molecules. But our study shows that 50% of the hydrogen is outside the clouds, in a diffuse, disk-shaped hydrogen fog permeating the galaxy!”
Not only does the enveloping gas play a critical part in star formation, but galaxy structure does as well. One galactic feature in particular is key – spiral arm structure. They sweep slowly around the core area like hands on a clock and are more populated with stars than the remainder of the galactic disk. Sharon Meidt, another MPIA post-doctoral researcher involved in the study, says: “These clouds are definitely not isolated. On the contrary, interactions between clouds, fog, and overall galactic structure appear to hold the key to whether or not a cloud will form new stars. When the molecular fog moves relative to the galaxy’s spiral arms, the pressure it exerts on any clouds within is reduced, in line with a physical law known as Bernoulli’s principle. Clouds feeling this reduced pressure are unlikely to form new stars. According to the press release, Bernoulli’s law is also thought to be responsible for part of the well-known shower-curtain effect: shower curtains blowing inward when one takes a hot shower, another display of reduced pressure.
Jerome Pety of the Institut de Radioastronomie Millimétrique (IRAM), which operates the telescopes used for the new observations, says: “It’s good to see our telescopes live up to their full potential. A study that needed such extensive observation time, and required both an interferometer to discern vital details and our 30 m antenna to put those details into a larger context, would not have been possible at any other observatory.”
Schinnerer concludes: “So far, the Whirlpool galaxy is one example which we have studied in depth. Next, we need to check that what we have found also applies to other galaxies. For our next steps, we hope to profit from both the extension NOEMA of the compound telescope on the Plateau de Bure and from the newly opened compound telescope ALMA in Chile, which will allow in-depth studies of more distant spiral galaxies.”
Outcrops in Yellowknife Bay are being exposed by wind driven erosion. These rocks record superimposed ancient lake and stream deposits that offered past environmental conditions favorable for microbial life. This image mosaic from the Mast Camera instrument on NASA's Curiosity Mars rover shows a series of sedimentary deposits in the Glenelg area of Gale Crater, from a perspective in Yellowknife Bay looking toward west-northwest. The "Cumberland" rock that the rover drilled for a sample of the Sheepbed mudstone deposit (at lower left in this scene) has been exposed at the surface for only about 80 million years. Credit: NASA/JPL-Caltech/MSSS
NASA’s Curiosity rover has discovered evidence that an ancient Martian lake had the right chemical ingredients that could have sustained microbial life forms for long periods of time – and that these habitable conditions persisted on the Red Planet until a more recent epoch than previously thought.
Furthermore researchers have developed a novel technique allowing Curiosity to accurately date Martian rocks for the first time ever – rather than having to rely on educated guesses based on counting craters.
All that and more stems from science results just announced by members of the rover science team.
Researchers outlined their remarkable findings in a series of six new scientific papers published today (Dec. 9) in the highly respected journal Science and at talks held today at the Fall 2013 Annual Meeting of the American Geophysical Union (AGU) in San Francisco.
The Curiosity team also revealed that an investigation of natural Martian erosion processes could be used to direct the rover to spots with a higher likelihood of holding preserved evidence for the building blocks of past life – if it ever existed.
View of Yellowknife Bay Formation, with Drilling Sites
This mosaic of images from Curiosity’s Mast Camera (Mastcam) shows geological members of the Yellowknife Bay formation, and the sites where Curiosity drilled into the lowest-lying member, called Sheepbed, at targets “John Klein” and “Cumberland.” The scene has the Sheepbed mudstone in the foreground and rises up through Gillespie Lake member to the Point Lake outcrop. These rocks record superimposed ancient lake and stream deposits that offered past environmental conditions favorable for microbial life. Rocks here were exposed about 70 million years ago by removal of overlying layers due to erosion by the wind. Credit: NASA/JPL-Caltech/MSSS
The ancient fresh water lake at the Yellowknife Bay area inside the Gale Crater landing site explored earlier this year by Curiosity existed for periods spanning perhaps millions to tens of millions of years in length – before eventually evaporating completely after Mars lost its thick atmosphere.
Furthermore the lake may have existed until as recently as 3.7 Billion years ago, much later than researchers expected which means that life had a longer and better chance of gaining a foothold on the Red Planet before it was transformed into its current cold, arid state.
NASA’s Mars rover Curiosity took this self-portrait, composed of more than 50 images using its robotic arm-mounted MAHLI camera, on Feb. 3. The image shows Curiosity at the John Klein drill site. A drill hole is visible at bottom left. Credit: NASA / JPL / MSSS / Marco Di Lorenzo / Ken Kremer- kenkremer.com
Researchers also announced that they are shifting the missions focus from searching for habitable environments to searching for organic molecules – the building blocks of all life as we know it.
Why the shift? Because the team believes they have found a way to increase the chance of finding organics preserved in the sedimentary rock layers.
“Really what we’re doing is turning the corner from a mission that is dedicated to the search for habitable environments to a mission that is now dedicated to the search for that subset of habitable environments which also preserves organic carbon,” Curiosity Principal Investigator John Grotzinger, of the California Institute of Technology in Pasadena, said at an AGU press conference today.
“That’s the step we need to take as we explore for evidence of life on Mars.”
Earlier this year, Curiosity drilled into a pair of sedimentary Martian mudstone rock outcrops at Yellowknife Bay known as “John Klein” and “Cumberland” – for the first time in history.
Grotzinger said the ancient lake at Yellowknife Bay was likely about 30 miles long and 3 miles wide.
Powdered samples deposited into the rovers miniaturized chemistry labs – SAM and CheMin – revealed the presence of significant levels of phyllosilicate clay minerals.
These clay minerals form in neutral pH water that is ‘drinkable” and conducive to the formation of life.
“Curiosity discovered that the fine-grained sedimentary rocks preserve evidence of an environment that would have been suited to support a Martian biosphere founded on chemolithoautotrophy,” according to one of the science papers co-authored by Grotzinger.
“This aqueous environment was characterized by neutral pH, low salinity, and variable redox states of both iron and sulfur species.”
The rover has detected key elements required for life including carbon, hydrogen, oxygen, sulfur nitrogen and phosphorous.
The team is still looking for signatures of organic molecules.
Right now the researchers are driving Curiosity along a 6 mile path to the base of Mount Sharp -the primary mission destination – which they hope to reach sometime in Spring 2014.
But along the way they hope to stop at a spot where wind has eroded the sedimentary rocks just recently enough to expose an area that may still preserve evidence for organic molecules – since it hasn’t been bombarded by destructive cosmic radiation for billions of years.
Stay tuned here for Ken’s continuing Curiosity, Chang’e 3, LADEE, MAVEN and MOM news.
Dec 11: “Curiosity, MAVEN and the Search for Life on Mars”, “LADEE & Antares ISS Launches from Virginia”, Rittenhouse Astronomical Society, Franklin Institute, Phila, PA, 8 PM
With remote-sensing satellites, scientists have found the coldest places on Earth, just off a ridge in the East Antarctic Plateau. The coldest of the cold temperatures dropped to minus 135.8 F (minus 93.2 C) -- several degrees colder than the previous record.
Image Credit: Ted Scambos, National Snow and Ice Data Center.
What is the coldest place on Earth? Scientists say it’s a place so cold that ordinary mercury or alcohol thermometers won’t work there. If you were there, every breath would be painful, your clothing would crackle every time you moved, and if you threw hot water into the air, it would fall to the ground as tiny shards of ice. At this place, the new record of minus 136 F (minus 93.2 C) was set on Aug. 10, 2010. Researchers analyzed data from several satellite instruments and found the coldest place on Earth in the past 32 years is … a high ridge in Antarctica between Dome Argus and Dome Fuji, two summits on the ice sheet known as the East Antarctic Plateau. Temperatures in several hollows were found to dip to the new record.
“We had a suspicion this Antarctic ridge was likely to be extremely cold,” said Ted Scambos, from the National Snow and Ice Data Center in Boulder, Colorado. “With the launch of Landsat 8, we finally had a sensor capable of really investigating this area in more detail.”
This beats out the previous low of minus 128.6 F (minus 89.2 C), set in 1983 at the Russian Vostok Research Station in East Antarctica. The coldest permanently inhabited place on Earth is northeastern Siberia, where temperatures in the towns of Verkhoyansk and Oimekon dropped to a bone-chilling 90 degrees below zero Fahrenheit (minus 67.8 C) in 1892 and 1933, respectively.
Scambos and his team made the discovery while analyzing the most detailed global surface temperature maps to date, developed with data from remote sensing satellites. The new findings were reported at the American Geophysical Union meeting in San Francisco.
The pursuit to find the coldest place on Earth started when the researchers were studying large snow dunes, sculpted and polished by the wind, on the East Antarctic Plateau. When the scientists looked closer, they noticed cracks in the snow surface between the dunes, possibly created when wintertime temperatures got so low the top snow layer shrunk. This led scientists to wonder what the temperature range was, and prompted them to hunt for the coldest places using data from two types of satellite sensors.
They used data from the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments on NASA’s Terra and Aqua satellites and the Advanced Very High Resolution Radiometer (AVHRR) on several National Oceanic and Atmospheric Administration satellites. These sensitive instruments can pick up thermal radiation emitted from Earth’s surface, even in areas lacking much heat.
Using these sensors to scan the East Antarctic Plateau, Scambos detected extremely cold temperatures on a 620-mile stretch of the ridge at high elevations between Argus and Fuji, and even colder temperatures lower elevations in pockets off the ridge. Then, with the higher resolution of the Thermal Infrared Sensor (TIRS) aboard Landsat 8, the research team pinpointed the record-setting pockets.
The team compared the sites to topographic maps to explore how it gets so cold. Already cold temperatures fall rapidly when the sky clears. If clear skies persist for a few days, the ground chills as it radiates its remaining heat into space. This creates a layer of super-chilled air above the surface of the snow and ice. This layer of air is denser than the relatively warmer air above it, which causes it to slide down the shallow slope of domes on the Antarctic plateau. As it flows into the pockets, it can be trapped, and the cooling continues.
“By causing the air to be stationary for extended periods, while continuing to radiate more heat away into space, you get the absolute lowest temperatures we’re able to find,” Scambos said. “We suspected that we would be looking for one magical site that got extremely cold, but what we found was a large strip of Antarctica at high altitude that regularly reached these record low temperatures.”
The Moon, via the Scientific Visualization Studio.
Here’s how the Moon will look to us on Earth during the entire year of 2014. Using data from the Lunar Reconnaissance Orbiter, the Goddard Space Flight Center Scientific Visualization Studio can project how the Moon will appear, and compresses one month into 24 seconds and a year to about 5 minutes. Above is the video where Celestial north is up, corresponding to the view from the northern hemisphere, and below is how the Moon will look from the southern hemisphere.
While the Moon always keeps the same face to us, it’s not exactly the same face. Because of the tilt in its axis and shape of its orbit, we see the Moon from slightly different angles over the course of a month, and the year. Normally, we don’t see how the Moon “wobbles” in its orbit, but seeing the Moon’s year this quickly, we can see the changes in libration, and axis tilt — as well as the most noticeable changes, the Moon’s phases.
Find out more at this SVS page, where you can also “Dial a Moon” — put in a specific date and see how the Moon will look on that day.
Universe Today also has a great app for your iPhone or Android that can also show you how the Moon will look any day in the past or present.
The morning zodiacal as seen from near Rodeo, New Mexico, looking east at 5:00 am December 6, 2013. Credit and copyright: Alan Dyer/Amazing Sky Photography.
Sometimes, if you are lucky, dawn comes before the dawn. The zodiacal light – or false dawn, as it is sometimes called – is an ethereal light extending up from the horizon, sometimes seen about an hour before sunrise or an hour after sunset. At one time, it was thought this was an atmospheric phenomenon, but it’s more cosmic than that! Zodiacal light is sunlight reflecting off dust grains in space. These dust grains are likely left over from the same process that created Earth and the other planets of our solar system 4.5 billion years ago.
Alan Dyer captured this beautiful view of the zodiacal light on a recent trip to New Mexico. If you look closely you can see some other cosmic phenomena as well: “Mars is above centre and Saturn is just rising over the mountain ridge,” Alan wrote on Flickr. “Comet Lovejoy C/2013 R1 is at far left. The image includes the position (left of centre, above the mountains left of the Zodiacal Light) where Comet ISON (C/2012 S2) would have been had it survived passage around the Sun.”
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