Universe Today

May 6, 2008December 24, 2015 by Fraser Cain

Asteroid Impact Created a Worldwide Rain of Carbon Beads

When a large enough asteroid strikes the Earth, the devastation effects the entire globe. And the dinosaur-killing asteroid that smashed into the Yucatan peninsula 65 million years ago was no exception. According to researchers, just one outcome from the strike: carbon in the Earth’s crust was liquified and formed tiny beads that rained back down across the entire planet.

These beads are known to geologists as carbon cenospheres, and they’re produced during the burning of coal and crude oil. They’re a classic indicator of industrial activity. But 65 million years ago, there were no power plants, so scientists proposed that asteroid impact-driven forest fires could get hot enough to make them too.

As the asteroid struck, huge chunks of molten rock fell back to Earth, igniting forest fires across the planet. It’s here that scientists find evidence of charcoal from the fires, but not the cenospheres.

New evidence, reported in this month’s edition of the journal Geology, shows that natural fires can’t make the microscopic spheres.

Instead, the international team of researchers propose that they had to have been formed from an asteroid strike. A key additional piece of evidence is that the carbon cenospheres are deposited right next to a think layer of the element iridium.

It was this layer of iridium that helped to give scientists the evidence they needed to point to asteroids as the cause of the dinosaur extinction 65 million years ago. Since iridium is much more likely to be formed in the Solar System asteroids than in the Earth’s crust, a concentrated layer of the stuff had to come from off planet.

And the cenospheres have been discovered around the planet next to the iridium layer, in Canada, Spain, Denmark and New Zealand. The key discovery is that the cenospheres get smaller as you move away from the impact site. This matches the prediction that the heavier particles would rain back down to Earth closer to the impact, while the lightest particles would be carried across the entire planet.

The researchers were able to calculate the total amount of carbon injected into the atmosphere from an asteroid impact, and put the number at 900 trillion tonnes. This helps scientists get a better estimate of the impact size and damage.

Original Source: Indiana University

May 6, 2008December 24, 2015 by Nancy Atkinson

Water in Interstellar Space

Water: it covers 70% of our own planet, it makes up 65% of our human bodies, and as far as we know, water seems to be essential for life. Water is also found in space, and in fact water ice is the most abundant solid material out there. But how did it get there, and how could water molecules possibly form in the freezing darkness of interstellar space? Japanese researchers trying to answer those questions say they have created water for the first time in conditions similar to interstellar space.

Water ice has been detected in our solar system on other planets and their moons, as well as in comets. A group of scientists at Japan’s Institute of Low Temperature Science at Hokkaido University say, “Since the solar system evolved from an interstellar molecular cloud, icy objects in the solar system originated from the water ice formed in the interstellar molecular cloud.” Their research was an attempt to gain an understanding of the origin of water molecules in interstellar clouds.

Water does form easily here in the warmth and abundance of Earth when oxygen and atomic hydrogen come together. But there’s not a lot of those elements floating around as gas in interstellar dust clouds. From their research, the group from Japan has concluded that water must form when atomic hydrogen interacts with frozen solid oxygen on a solid surface, such as dust grains in interstellar clouds.

They recreated this process by creating a layer of solid oxygen on an aluminum substrate at 10 degrees Kelvin and then added hydrogen. With infrared spectroscopy, they confirmed that both water and hydrogen peroxide formed, and in the right quantities to explain the abundance of water seen in interstellar clouds.

It’s interesting to note that the first water molecules in the universe must have started in this way, and that eventually led to water on Earth, then life, and then eventually people on Earth, who like to research, discuss and contemplate how it all began.

Original News Source: ArXiv, ArXiv blog

May 6, 2008December 24, 2015 by Nancy Atkinson

XMM-Newton Discovers Part of Missing Matter in the Universe

We’re getting the numbers down pretty well now about how much we don’t know about the universe: Only about 5% of our universe consists of normal matter, made of atoms. The rest of our universe is composed of elusive matter that we don’t understand: dark matter (23%) and dark energy (72%). And of that 5% of normal matter, well, we don’t know what half of that is, either. All the stars, galaxies and gas observable in the universe account for less than a half of all the matter that should be around.

About 10 years ago, scientists predicted that the missing half of â€˜ordinaryâ€™ or normal matter exists in the form of low-density gas, filling vast spaces between galaxies. The European Space Agency announced today that the orbiting X-ray observatory XMM-Newton has uncovered this low density, but high temperature gas.

The universe has been described as a cosmic web. The dense part of the web is made of clusters of galaxies, which are the largest objects in the universe. Astronomers suspected that low-density gas filled in the filaments of the web. But the low density of the gas has made it difficult to detect. With the XMM-Newtonâ€™s high sensitivity, astronomers have discovered the hottest parts of this gas.

Astronomers using XMM-Newton were observing a pair of galaxy clusters, Abell 222 and Abell 223, located 230 million light-years from Earth, when the images and spectra of the system revealed a bridge of hot gas connecting the clusters.

“The hot gas that we see in this bridge or filament is probably the hottest and densest part of the diffuse gas in the cosmic web, believed to constitute about half the baryonic matter in the universe,” says Norbert Werner from SRON Netherlands Institute for Space Research, leader of the team reporting the discovery.

The discovery of this hot gas will help better understand the evolution of the cosmic web.

“This is only the beginning,” said Werner. “To understand the distribution of the matter within the cosmic web, we have to see more systems like this one. And ultimately launch a dedicated space observatory to observe the cosmic web with a much higher sensitivity than possible with current missions. Our result allows to set up reliable requirements for those new missions.”

Original News Source: ESA Press Release

May 5, 2008December 24, 2015 by Ian O'Neill

Digging for Dark Matter: The Large Underground Xenon (LUX) Detector

The Hubble Space Telescope distribution of dark matter - indirect observations (HST)

How do you catch a WIMP? No, I’m not talking about bullying the weakest kid in class, I’m talking about Weakly Interacting Massive Particles (those WIMPs). Well, it isn’t easy. Although they are “massive” by definition, they do not interact with the electromagnetic force (via photons) so they cannot be “seen” and they do not interact with the strong nuclear force, so they cannot be “felt” by atomic nuclei. If we cannot detect WIMPs via these two forces, how can we possibly ever hope to detect them? After all, WIMPs are theorized to be flying through the Earth without hitting anything, they are that weakly interacting. But sometimes, they might collide with atomic nuclei but only if they collide head-on. This is a very rare occurrence, but the Large Underground Xenon (LUX) detector will be buried 4,800 feet (1,463 meters, or nearly a mile) underground in an old South Dakota goldmine and scientists are hopeful that when an unlucky WIMP bumps into a xenon atom, a flash of light will be captured, signifying the first ever experimental evidence of dark matter…

Galaxies observed from Earth have some strange qualities. The biggest problem for cosmologists has been to explain why galaxies (including the Milky Way) appear to have more mass than can be observed by counting stars and accounting for interstellar dust alone. In fact, 96% of the Universe’s mass cannot be observed. 22% of this missing mass is thought to be held in “dark matter” (74% is held as “dark energy”). Dark matter is theorized to take on many forms. Massive Astronomical Compact Halo Objects (astronomical bodies containing ordinary baryonic material that cannot be observed; like neutron stars or orphaned planets), neutrinos and WIMPS all are thought to contribute toward this missing mass. Many experiments are in progress to detect each contributor. Black holes can be indirectly detected by observing the interactions in the centre of galaxies (or gravitational lensing effects), neutrinos can be detected in huge tanks of fluid buried deep underground, but how can WIMPs be detected? It seems a WIMP detector needs to take a leaf out of the neutrino detector’s books – it needs to start digging.

To avoid interference from radiation such as cosmic rays, low energy detectors such as neutrino “telescopes” are buried well below the Earth’s surface. Old mine shafts make ideal candidates as the hole is already there for the instrumentation to be set up. Neutrino detectors are huge containers of water (or some other agent) with highly sensitive detectors positioned around the outside. One such example is the Super Kamiokande neutrino detector in Japan which contains a vast amount of ultra-purified water, weighing in at 50,000 tons (pictured left). As a weakly interacting neutrino hits a water molecule in the tank, a flash of Cherenkov radiation is emitted and a neutrino is detected. This is the basic principal behind the new Large Underground Xenon (LUX) detector that will use 600 pounds (272 kg) of liquid xenon suspended in a 25 foot high tank of pure water. If WIMPs exist beyond the realms of theory, it is hoped that these weakly interacting massive particles will collide head-on with a xenon atom, and like their light-weight cousins, emit a flash of light.

Robert Svoboda and Mani Tripathi, UC Davis professors, have secured $1.2 million in National Science Foundation (NSF) and U.S. Department of Energy funding for the project (this is 50% of the total required). When compared with the Large Hadron Collider (LHC) costing billions of Euros to build, LUX is a highly economic project considering the scope of what it might discover. Should there be experimental evidence of a WIMP interaction, the consequences will be enormous. We will be able to begin to understand the origins of WIMPs and their distribution as the Earth sweeps through the possible dark matter halo that is indirectly observed to exist in the Milky Way.

Detecting dark matter “would be the biggest deal since finding antimatter in the 1930s.” – Professor Mani Tripathi, LUX co-investigator, UC Davis.

The gold mine in South Dakota was closed in 2000 and in 2004 work began to develop the site into an underground laboratory. LUX will be the first large experiment to be housed there. It is hoped that the installation will start late summer, after water has been pumped out of the mine.

Original source: UC Davis News

May 5, 2008December 24, 2015 by Nancy Atkinson

Another (Better) Opportunity to Send Your Name to Space

It’s a great idea, so all the missions might as well join in. Earlier today, Ian reported on how the Lunar Reconnaissance Orbiter mission is offering the chance for the public to ‘ride along’ to the moon by sending their names to be added to a computer chip which will be embedded on the spacecraft. Well, not to be outdone, the upcoming Kepler mission that will search for Earth-sized exoplanets is offering the same chance. But this is no sluff opportunity where you just fill in your name and you’re done: you’ve got to work a little and be creative! The Kepler folks would like you to also state in 100 words or less why you think the Kepler mission is important. I think that’s a great idea, and I’m going to add my name and statement right away. But there’s more reasons why I prefer the Kepler mission’s approach to sending your name to space:

Your name will be in an exciting Earth-trailing heliocentric orbit, going around the sun every 372.5 days.

This activity is done in association with the International Year of Astronomy 2009.

Your name will be on the spacecraft that will likely identify the first Earth-sized or smaller planet orbiting another star.

Your name will be launched on board a Delta II rocket.

Your name will be part of the mission that will determine the frequency of terrestrial and larger planets in or near the habitable zone of a wide variety of spectral types of stars.

Oh, the list goes on, but as you can see the Kepler mission will be THE mission to have your name be included.

So, here’s where you can add your name, as well as your statement of the importance of the Kepler mission. The deadline is November 1, 2008. And learn more about the mission here. Current plans are for a February 2009 launch for Kepler.

Original News Source: JPL press release

May 5, 2008December 24, 2015 by Astronomy Cast

Podcast: The End of the Universe Part 2: The End of Everything

Hopefully you’ve all recovered from part 1 of this set, where we make you sad about the future of the humanity, the Earth, the Sun and the Solar System. But hang on, we’re really going to bring you down. Today we’ll look far far forward into the distant future of the Universe, at timescales that we can barely comprehend.

If you haven’t heard it, here’s a link to Part 1.

Click here to download the episode

The End of the Universe Part 2: The End of Everything – Show notes and transcript

Or subscribe to: astronomycast.com/podcast.xml with your podcatching software.

May 5, 2008December 24, 2015 by Nancy Atkinson

Satellite Views of Deadly Cyclone in Myanmar

The cyclone that ravaged the southeast Asian country of Myanmar over the weekend was an incredibly deadly and destructive storm. News reports say at least 10,000 people were killed, and thousands more were missing as of May 5. Cyclone Nargis made landfall with sustained winds of 130 mph and gusts of 150-160 mph, which is the equivalent of a strong Category 3 or minimal Category 4 hurricane. This was the first cyclone of the 2008 season. Above is an image from NASA’s Terra satellite, and specifically the Moderate Resolution Imaging Spectroradiometer (MODIS.) You can see this storm was a whopper, however, by the time MODIS acquired this image on May 3 at 10:55 am local time the cyclone had lost much of its original strength and was at tropical storm strength. Even more astounding are the images available from MODIS of the landscape of Myanmar both before and after the cyclone hit.

The top image was taken on April 15, 2008, well before the storm and shows a calm landscape where rivers and lakes are visible, as well as the green of vegetation. In the lower image, taken on May 5, the entire coastal plain is flooded. News reports say the agricultural areas have been especially hard hit. But cities as well were affected. For example, RangÃ´n, with a population over 4 million is almost completely surrounded by floods. Several other large cities with populations of 100,000â€“500,000 are also in the area affected by the cyclone.

The MODIS Rapid Response Team has been processing the images as soon as they are available from the spacecraft in order to provide information about the storm and the region.

The blue dot on the globe below marks the Andaman Sea and the area affected by Cyclone Nargis.

Original News Source: NASA’s Earth Observatory

May 5, 2008May 10, 2022 by Nancy Atkinson

Titan’s Hydrocarbon “Sand Dunes

Even before the Cassini spacecraft entered the Saturn system, scientists were predicting that Saturn’s moon Titan would be quite Earth-like. And every image that’s been returned of Titan’s clouds, lakes, rivers, and other landforms is proving them right. In 2005 Cassini’s imaging radar discovered a massive area of sand dunes around Titan’s equatorial region. Although these dark, windblown dunes look much like sand dunes on Earth (they’ve been compared to mountainous drifts of coffee grounds), scientists are finding that the dunes are likely made of organic molecules that are not anything at all like sand.

Titan is known to have massive amounts of hydrocarbons. New observations of Titan’s sand dunes raise the possibility that much of the sand grows from hydrocarbon particulates fallen from Titan’s thick atmosphere. Once on the ground, the particulates join together and become sand grain-size particles.

This process is called sintering â€“ where the particles are heated enough to melt together. Scientist Jason W. Barnes of NASA’s Ames Research Center says that this sintering may produce particles that are about the same size as sand grains – between 0.18-0.25 millimeters, which are perfect for blowing in the wind and drifting into dunes.

So, this process is quite the opposite of what happens to sand on Earth, which comes from silicates, gypsum, or rock that have broken down to finer grains. But on Titan, the small hydrocarbon particulates grow together into larger grains. Barnes says the process is extremely slow, but Titan has been around long enough for this to have occurred.

Based on measurements from Cassini, the dunes are 100-200 meters high and are between 1 and 79 kilometers long. Not all over Titan’s surface has been imaged, but scientists believe up to 20 % of Titan’s surface could be covered by these hydrocarbon dunes.

Original News Source: JPL

May 5, 2008December 24, 2015 by Ian O'Neill

Send Your Name to the Moon

The Lunar Reconnaissance Orbiter - artistic impression (NASA)

Have you ever dreamt of travelling to the Moon? Unfortunately, for the time being, this will be a privilege only for an elite few astronauts and robotic explorers. But NASA has just released news that you will have the opportunity to send your name to the Moon on board their next big Moon mission, the Lunar Reconnaissance Orbiter. So get over to the mission site and send your name that will be embedded into a computer chip, allowing a small part of you to orbit our natural satellite over 360,000 km (220 000 miles) away…

Last month I looked into how long it would take to travel to the Moon and the results were wide-ranging. From an impressive eight hour zip past the Moon by the Pluto mission, New Horizons to a slow spiral route taken by the SMART-1 lunar probe, taking over a year. The next NASA mission, the Lunar Reconnaissance Orbiter (LRO), is likely to take about four days (just a little longer than the manned Apollo 11 mission in July 1969). It is scheduled for launch on an Atlas V 401 rocket in late 2008 and the mission is expected to last for about a year.

Thank goodness we’re not travelling by car, according to the LRO mission facts page, it would take 135 days (that’s nearly 5 months!) to get there when travelling at an average speed of 70 miles per hour.

The LRO is another step toward building a Moon base (by 2020), the stepping stone toward colonizing Mars. The craft will orbit the Moon at an altitude of 50 km (31 miles), taking global data, constructing temperature maps, high-resolution colour imaging and measuring the Moon’s albedo. Of course, like all planetary missions to the Moon and Mars, the LRO will look out for water. As the Moon will likely become mankind’s first extra-terrestrial settlement, looking for the location of Moon water will be paramount when considering possible locations for colonization.

This is all exciting stuff, but what can we do apart from watch the LRO launch and begin sending back data? Wouldn’t it be nice if we could somehow get involved? Although we’re not going to be asked to help out at mission control any time soon, NASA is offering us the chance to send our names to the Moon. But how can this be done? First things first, watch the NASA trailer, and then follow these instructions:

Go to “NASA’s Return to the Moon” page.
Type in your first name and last name.
Click “continue” and download your certificate – your name is going to the Moon!

But how will your name be taken to the Moon? It won’t be engraved into the LRO’s bodywork (although that would have been nice!); it will be held on a microchip embedded into the spaceship’s circuitry. The database of names will be taken on board the LRO and will remain with it for the entire duration of the mission. Anyone who submits their name will be exploring the Moon in their own small way. I’ve signed up (see my certificate, pictured) and you have until June 27, 2008 to do the same.

Will see you on board the LRO!

Sources: LRO mission site, Press release

May 5, 2008April 26, 2016 by Tammy Plotner

IC 2944 – Astrophotography by Ken Crawford

Do you think you’re seeing a Hubble Image? Then think again. Just revealed at last weekend’s NEAF gathering at Rockland College in Suffern, New York, this incredible image of IC 2944 was taken by Ken Crawford at Macedon Ranges Observatory and shows so much more than just pretty sky scenery. In this edition of the Universe Today Astronomy Photo of the week, we’ll take a deeper look into the science behind the picture as you discover an anomaly known as “Thackeray’s Globules”…

The photographic artistry of Ken Crawford takes us on a visual journey ever deeper into the busy star-forming region, IC 2944. While the view of this incredible emission nebula is some 6,000 light years away, Ken’s work takes us directly in for close up views of Thackeray’s Globules in ways that stagger the imagination.

IC 2948 is sprawling cloud of gas and dust that is illuminated and heated by a loose cluster of massive stars known as IC 2944. These stars are much hotter and much more massive than our Sun and their strong stellar winds carve out unique shapes in the noble hydrogen gases. These busy star forming HII regions are home to curious dark masses which we really don’t know a whole lot about – except their association. Dark globules like these have been known since Dutch-American astronomer Bart Jan Bok first began documenting them in 1947 and astronomer A.D. Thackeray first spied the globules in IC 2944 in 1950.

The largest of the globules in IC 2944 could possibly be two separate clouds that appear to partially overlap along our line of sight. Each cloud is nearly 1.4 light-years along its longest dimension and a combination of both clouds contain enough material to equal over 15 solar masses. When you take a closer look, you’ll see the globules appear almost shattered – as if strong forces were pulling them apart. In the case of IC 2944, seeing is believing because when radio astronomers observed the faint hiss of molecules within the globules, they realized Thackeray’s million year old discovery is in constant, aggressive motion, moving along in a supersonic dance. Like a water droplet sprayed against hot metal, this dance may be caused by the powerful ultraviolet radiation from the luminous, massive stars. When the region of glowing hydrogen gas is heated, it expands and streams against these dark masses, causing their annihilation.

According the research done by Bo Reipurth, Patrice Corporon, Michael Olberg and Guillermo Tenorio-Tagle: “We believe that the globules are the remnants of an elephant-trunk observed from behind, originating as a Rayleigh-Taylor instability in an expanding neutral shell powered by the hot HII region. The globule complex is now in an advanced stage of disintegration. We have found no evidence for star formation in any of the globules.”

Often known as the Running Chicken Nebula or the Lambda Cen Nebula, IC 2944 and IC 2948 is nestled between the Southern Cross and the star-thick Carina area on the southern border of Centaurus (RA 11:36.6 Dec -63:02). With an average magnitude of 4.5 and spanning around 75 arc minutes, its collection of bright stars is also referred to as Collinder 249 and was given the designation of Caldwell 100 by Sir Patrick Moore. Don’t expect to see a vision in either eyepiece or binoculars. The cluster is easy… But the nebula is very vague!

Image Details: IC 2944
Taken at: MACEDON RANGES OBSERVATORY
AP130 @ F6 / Paramount ME
Apogee Alta 16803
AstroDon – (5nm Ha & SII) & OIII 3nm Filters
Ha =180 minutes mapped to Green
SII =180 minutes Mapped to Red
OIII = 240 minutes Mapped to Blue
CCDAutoPilot for unattended imaging With MaxDL 4