Universe Today

May 20, 2009December 24, 2015 by Anne Minard

A Benevolent Sort of Asteroid Bombardment?

Celestial impacts can bring life as well as wipe it out, say the authors of a new study out of the University of Colorado at Boulder.

A case in point: the bombardment of Earth nearly 4 billion years ago by asteroids as large as Kansas would not have had the firepower to extinguish potential early life on the planet and may even have given it a boost.

In a new paper in the journal Nature, Oleg Abramov and Stephen Mojzsis report on their study of impact evidence from lunar samples, meteorites and the pockmarked surfaces of the inner planets. The evidence paints a picture of a violent environment in the solar system during the Hadean Eon 4.5 to 3.8 billion years ago, particularly through a cataclysmic event known as the Late Heavy Bombardment about 3.9 billion years ago.

Although many believe the bombardment would have sterilized Earth, the new study shows it would have melted only a fraction of Earth’s crust, and that microbes could well have survived in subsurface habitats, insulated from the destruction.

“These new results push back the possible beginnings of life on Earth to well before the bombardment period 3.9 billion years ago,” Abramov said. “It opens up the possibility that life emerged as far back as 4.4 billion years ago, about the time the first oceans are thought to have formed.”

Because physical evidence of Earth’s early bombardment has been erased by weathering and plate tectonics over the eons, the researchers used data from Apollo moon rocks, impact records from the moon, Mars and Mercury, and previous theoretical studies to build three-dimensional computer models that replicate the bombardment. Abramov and Mojzsis plugged in asteroid size, frequency and distribution estimates into their simulations to chart the damage to the Earth during the Late Heavy Bombardment, which is thought to have lasted for 20 million to 200 million years.

The 3-D models allowed Abramov and Mojzsis to monitor temperatures beneath individual craters to assess heating and cooling of the crust following large impacts in order to evaluate habitability. The study indicated that less than 25 percent of Earth’s crust would have melted during such a bombardment.

The CU-Boulder researchers even cranked up the intensity of the asteroid barrage in their simulations by 10-fold — an event that could have vaporized Earth’s oceans. “Even under the most extreme conditions we imposed, Earth would not have been completely sterilized by the bombardment,” said Abramov.

Instead, hydrothermal vents may have provided sanctuaries for extreme, heat-loving microbes known as “hyperthermophilic bacteria” following bombardments, said Mojzsis. Even if life had not emerged by 3.9 billion years ago, such underground havens could still have provided a “crucible” for life’s origin on Earth, Mojzsis said.

Geologic evidence suggests that life on Earth was present at least 3.83 billion years ago, said Mojzsis. “So it is not unreasonable to suggest there was life on Earth before 3.9 billion years ago. We know from the geochemical record that our planet was eminently habitable by that time, and this new study sews up a major problem in origins of life studies by sweeping away the necessity for multiple origins of life on Earth.”

The results also support the potential for microbial life on other planets like Mars and perhaps even rocky, Earth-like planets in other solar systems that may have been resurfaced by impacts, said Abramov.

Source: Eurekalert

May 20, 2009December 24, 2015 by Tammy Plotner

Flying Saucers? The Fun Is For Real…

On a recent trip to Canada in the great province of Ontario, I found a quiet corner on Lundy’s Lane. I had been enjoying the scenic beauty of Niagara Falls and to break away for the tourist aspect seemed like a welcome respite. How could someone who lives, eats and breathes space 24/7 pass up an opportunity to visit a place like this? The answer was… I couldn’t.

For any one old enough to remember and still too young to resist, the retro-styling and drive-in atmosphere of this super clean diner was enough to make you smile the moment you stopped in the parking lot. Glittering multi-colored lights and a welcoming glow was all I needed to take a chance. Once inside I was transported back to all of my childhood fantasies, and despite having a well stocked refreshment area – all you really wanted was a cold soda or a milk shake. Why spoil the fun?

When the menu came, my grin got even wider. There’s nothing that delights me more than a sense of humor… and to combine it with good food makes the experience even more extraordinary. Needless to say, I didn’t just stop by this place on a whim. I’d researched my restaurants in advance and every sample around the family table proved to be just as tasty and well prepared as the reviews promised. The “Jupiter Burgers” were absolutely among the finest I’ve ever eaten and the clam chowder didn’t come out of can, my friends. Even though the hour was late, I had a delightful time talking to the “natives” who were patient with my questions and seemed to enjoy the company as much as we enjoyed theirs!

Right down to the little stuffed aliens…

So what’s a less than serious piece about finding a flying saucer restaurant doing in a serious astronomical webpage like Universe Today? It’s to remind you to take a chance on what you love. If you love astronomy and having dinner in a restaurant shaped like a flying saucer looks like fun? Do it! You may end up in some remote corner of Iowa having the worst cup of coffee you’ve ever tasted… Or you might end up in a quiet corner of Niagara Falls surrounded by your laughing family enjoying diner food at it’s best.

Because the fun is what’s for real…

Thanks to Richard Weiss for the additional image!

May 20, 2009December 24, 2015 by Anne Minard

New, Deep Image of Virgo Cluster Reveals Galaxy Cut Short in its Youth

Astronomers have peered deep inside the Virgo cluster, and measured the size of one of its most famous members — Messier 87 — with surprising results.

The giant elliptical galaxy isn’t quite as giant as previously believed.

This deep image of the Virgo Cluster, obtained by Chris Mihos of Case Western Reserve University and his colleagues using the university’s Burrell Schmidt telescope, shows the diffuse light between the galaxies belonging to the cluster. North is up, east to the left. The dark spots indicate where bright foreground stars were removed from the image.

At a distance of approximately 50 million light-years, the Virgo Cluster is the nearest galaxy cluster. It is located in the constellation of Virgo (the Virgin) and is a relatively young and sparse cluster. The cluster contains many hundreds of galaxies, including giant and massive elliptical galaxies, as well as more homely spirals like our own Milky Way.

Using ESO’s Very Large Telescope, astronomers have succeeded in measuring the size of giant galaxy Messier 87 and were surprised to find that its outer parts have been stripped away by still unknown effects. The galaxy also appears to be on a collision course with another giant galaxy in this very dynamic cluster.

The new observations reveal that Messier 87’s halo of stars has been cut short, with a diameter of about a million light-years, significantly smaller than expected, despite being about three times the extent of the halo surrounding our Milky Way. Beyond this zone only few intergalactic stars are seen.

This research is presented in a paper to appear in Astronomy and Astrophysics: “The Edge of the M87 Halo and the Kinematics of the Diffuse Light in the Virgo Cluster Core,” led by Michelle Doherty at the Max-Planck-Institute for Extraterrestrial Physics in Garching, Germany.

“This is an unexpected result,” said study co-author Ortwin Gerhard. “Numerical models predict that the halo around Messier 87 should be several times larger than our observations have revealed. Clearly, something must have cut the halo off early on.”

The team used FLAMES, the super-efficient spectrograph at ESO’s Very Large Telescope at the Paranal Observatory in Chile, to make ultra-precise measurements of a host of planetary nebulae in the outskirts of Messier 87 and in the intergalactic space within the Virgo Cluster of galaxies, to which Messier 87 belongs. FLAMES can simultaneously take spectra many sources, spread over an area of the sky about the size of the Moon.

The observed light from a planetary nebula in the Virgo Cluster is as faint as that from a 30-Watt light bulb at a distance of about 6 million kilometres (about 15 times the Earth–Moon distance). Furthermore, planetary nebulae are thinly spread through the cluster, so even FLAMES’s wide field of view could only capture a few tens of nebulae at a time.

“It is a little bit like looking for a needle in a haystack, but in the dark,” said team member Magda Arnaboldi. “The FLAMES spectrograph on the VLT was the best instrument for the job.”

The astronomers have proposed several explanations for the discovered “cut-off” of Messier 87’s, such as collapse of dark matter nearby in the galaxy cluster. It might also be that another galaxy in the cluster, Messier 84, came much closer to Messier 87 in the past and dramatically perturbed it about a billion years ago. “At this stage, we can’t confirm any of these scenarios,” said Arnaboldi. “We will need observations of many more planetary nebulae around Messier 87.”

One thing the astronomers are sure about, however, is that Messier 87 and its neighbor Messier 86 are falling towards each other. “We may be observing them in the phase just before the first close pass,” said Gerhard. “The Virgo Cluster is still a very dynamic place and many things will continue to shape its galaxies over the next billion years.”

Source: ESO. A PDF version of the paper is available here.

May 20, 2009December 24, 2015 by Nancy Atkinson

New International Astronauts Introduced

Simonetta Di Pippo, center, with the new ESA astronauts. Credit: ESA

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ESA proudly presented today six new astronauts from five different European countries who will soon begin training for missions to the International Space Station. The last time ESA selected astronauts, back in the early 1990’s, those astronauts were not guaranteed to have any actual flights in space. But the astronauts introduced today, which include three military pilots, two engineers, and one scientist, are slated to be part of at least seven opportunities to fly on a 6-month increment on the ISS. Additionally, an ESA official said he also hopes they can be part of an international lunar exploration program.

“This is the culmination of a life- long dream,” said Andreas Mogensen, Denmark’s first-ever astronaut. “Your parents and teachers always tell you to dream big, and to follow your dream. But no one tells you what it is like to achieve that dream. I think we’re all in a stsate of shock, but we just have to enjoy the moment. I’m absolutely thrilled to be sitting here today.”

In addition to Mogensen, the other astronauts are:

Samantha Cristoforetti, Italy
Alexander Gerst, Germany
Luca Parmitano, Italy
Timothy Peake, UK
Thomas Pesquet, France

Bios and pictures of the new astronauts.

They were selected following a Europe-wide recruitment process that started last year, which saw 8,413 valid applications. They are the first new recruits to join the European Astronaut Corps since 1992 under this second-ever astronaut selection carried out by ESA.

The earliest any of the new astronauts could fly to space would be 2013, said ESA Director General Jean-Jacques Dordain. The new recruits will begin general astronaut training in September, which lasts for 18 months. After they receive flight assignments, astronauts then train for two years prior to flying in space.

“We are at a turning point in ESA’s human spaceflight activities. Last year, with the launch of the Columbus laboratory and the Jules Verne Automated Transfer Vehicle, ESA became a fully-fledged member of the International Space Station partnership. We are now entering a new phase of utilisation of the unique capabilities offered by the ISS and preparation for international exploration of the Moon and beyond,” said Dordain.

“This is a very important day for human spaceflight in Europe,” said Simonetta Di Pippo, ESA Director of Human Spaceflight. “These young men and women are the next generation of European space explorers. They have a fantastic career ahead, which will put them right on top of one of the ultimate challenges of our time: going back to the Moon and beyond as part of the global exploration effort.”

British journalists at the press conference expressed excitement but surprise that a UK citizen was chosen, as Britain does not contribute financially to ESA’s human spaceflight program. But Dourdain said that Peake’s qualifications stood out. “We took the best candidates, it didn’t matter which country they were from.”

Source: ESA, press conference

May 19, 2009May 19, 2009 by Nancy Atkinson

Astronauts Release Hubble — Watch the Video

After five spacewalks on consecutive days to bring new life to the Hubble Space Telescope, astronauts on space shuttle Atlantis said goodbye to the venerable observatory, releasing it back to its orbital home. Watching it float out of the cargo bay was a bittersweet moment for everyone involved with the mission, and space enthusiasts, too, as even though Hubble is in great shape and now set to look out farther than ever before, this is that last time humans will visit, touch and care for the world’s most famous telescope. “It’s a sad moment but a great moment, because we put the Hubble in the best posture and and best performance in can be in,” said Jon Morse, NASA Astrophysics division director.
Continue reading “Astronauts Release Hubble — Watch the Video”

May 19, 2009December 24, 2015 by Nancy Atkinson

Flying Carpets in Space: Yes. Folding Laundry: No

Japanese astronaut Koichi Wakata demonstrating a 'magical flying carpet' Photo: GETTY

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Astronauts in orbit have said it time and time again: some things are easier in the microgravity environment in space, other things are harder. Japanese astronaut Koichi Wakata, current resident of the International Space Station recently gave a video demonstration of a few odd tasks in space, showing how simple, everyday jobs here on Earth, such as folding laundry and using eye drops, can become difficult in space. But he also proved how one “impossible” action for us landlubbers is fairly simple to do on board the ISS. He soared on a magic carpet.

Wakata filmed 16 different tasks in space as part of a series of zero-gravity challenges submitted by the public.

Albeit, he couldn’t use just any carpet; it had to be magic. Or in this case, a carpet with a little rigidity worked the best, and he had one more secret to his success: adhesive tape (not sure if it was duct tape). Here’s the video clip of posted by the Japan Aerospace Exploration Agency (Jaxa).

Wakata is shown gliding smoothly, after a fashion, through a cabin of the International Space Station, as if snowboarding.

“I flew on this magic carpet by using adhesive tape so that the soles of my feet stayed on it,” the 45-year-old astronaut said. The tasks were selected from ideas sent to the space agency by hundreds of members of the Japanese public, from nursery school pupils to a 90-year-old man. Wakata performed the tasks in the Japanese laboratory Kibo (Hope) of the ISS on May 15. He also filmed a series of other tasks in April, including push-ups.

He handled the awkward task of folding laundry in microgravity, struggling with a shirt and then, for added difficulty, the floating arms and legs of a blue space overall. Finally, a bungee cord was necessary to keep the uncooperative overall from unfolding.

Tackling another challenge, Wakata showed how to use eye drops in zero gravity, squeezing out a tiny ball of liquid and letting it perch at the tip of the container before carefully bringing it to his eye.

Source: The Telegraph

May 19, 2009December 24, 2015 by Nancy Atkinson

Cosmologists Improve on Standard Candles Measurement

The warm colors in this diagram stand for strong correlations of the brightness ratios between two wavelengths and a Type Ia supernova's absolute magnitude. (Diagram colors are unrelated to those in the spectrum itself.) Wavelengths are in nanometers. The upper left triangle shows correlations with uncorrected magnitudes; at lower right are correlations using color-corrected data. Credit: Nearby Supernova Factory

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Cosmologists have found a new and quicker technique that establishes the intrinsic brightness of Type Ia supernovae more accurately than ever before. These exploding stars are the best standard candles for measuring cosmic distances and are the tools that made the discovery of dark energy possible. An international team has found a way to do the job of measuring stellar distances in just a single night as opposed to months of observations by simply measuring the ratio of the flux (visible power, or brightness) between two specific regions in the spectrum of a Type Ia supernova. With this new method, a supernova’s distance can be determined to better than 6 percent uncertainty.

Using classic methods, which are based on a supernova’s color and the shape of its light curve – the time it takes to reach maximum brightness and then fade away – the distance to Type Ia supernovae can be measured with a typical uncertainty of 8 to 10 percent. But obtaining a light curve takes up to two months of high-precision observations. The new method provides better correction with a single night’s full spectrum, which can be scheduled based on a much less precise light curve.

Members of the international Nearby Supernova Factory (SNfactory), a collaboration among the U.S. Department of Energy’s Lawrence Berkeley National Laboratory, a consortium of French laboratories, and Yale University, searched the spectra of 58 Type Ia supernovae in the SNfactory’s dataset and found the key spectroscopic ratio.

The new brightness-ratio correction appears to hold no matter what the supernova’s age or metallicity (mix of elements), its type of host galaxy, or how much it has been dimmed by intervening dust.

Team member Stephen Bailey from the Laboratory of Nuclear and High-Energy Physics (LPNHE) in Paris, France, says that the SNfactory’s library of high-quality spectra is what made his successful results possible. “Every supernova image the SNfactory takes is a full spectrum,” he says. “Our dataset is by far the world’s largest collection of excellent Type Ia time series, totaling some 2,500 spectra.”

The most accurate standardization factor Bailey found was the ratio between the 642-nanometer wavelength, in the red-orange part of the spectrum, and the 443-nanometer wavelength, in the blue-purple part of the spectrum. In his analysis he made no assumptions about the possible physical significance of the spectral features. Nevertheless he turned up multiple brightness ratios that were able to improve standardization over current methods applied to the same supernovae.

SNfactory member Rollin Thomas of Berkeley Lab’s Computational Research Division, who analyzes the physics of supernovae, says, “While the luminosity of a Type Ia supernova indeed depends on its physical features, it also depends on intervening dust. The 642/443 ratio somehow aligns those two factors, and it’s not the only ratio that does. It’s as if the supernova were telling us how to measure it.”

The Nearby Supernova Factory describes the discovery of the new standardization technique in an article in the forthcoming issue of the journal Astronomy & Astrophysics, and the abstract is available online.

Source: Berkeley

May 19, 2009December 24, 2015 by Nancy Atkinson

Herschel Phones Home — Literally

ESA's 35-metre deep-space ground station at New Norcia, Australia. Credit: ESA

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For the first time in spaceflight history, a satellite has used mobile phone technology to radio back to Earth. The Herschel spacecraft – which launched on May 14, called home two days later using the same technology used in GSM mobile phone networks to send test data to ESA’s deep space tracking station. “Herschel’s 1.5-Mbps test transmission – roughly the same data rate provided by a home broadband Internet connection – was picked up at ESA’s ESTRACK station at New Norcia, Australia, on Saturday, as the satellite was travelling some 280 000 km from Earth,” said John Dodsworth, the Herschel-Planck Flight Operations Director.

This marks the first-ever use of Gaussian Minimum Shift Keying (GMSK) modulation in space. GMSK is commonly used in Global System for mobile Communication (GSM) mobile phone networks due to its very efficient use of bandwidth and power.

Plot showing Herschel's mobile phone call received at New Norcia station

In a typical GSM mobile phone network, the same technology transmits data at a somewhat lower speed. The Planck spacecraft that was launched along with Herschel also uses GMSK technology, and its transmission capability will be tested later during the satellite’s commissioning phase.

During their missions, the GMSK-based radio links will be used by both spacecraft to transfer data gathered by their scientific instruments and on-board subsystems, providing information on flight status and overall health.

The development was driven by the need to use bandwidth more efficiently in view of the growing number of ESA missions that require X-band communications via the Agency’s deep space ground stations.

The GSM standard is the most popular modulation standard for mobile phone networks in the world. According to the GSM Association, terrestrial GSM networks now cover more than 80% of the world’s population in more than 212 countries and territories – and will soon extend 1.5 million kms further to L2, Herschel and Plank’s final orbital destination.

Source: ESA

May 18, 2009December 24, 2015 by Nancy Atkinson

‘Tremendous Adventure’ Gives Hubble New Life

ohn Grunsfeld works on Hubble during the 5th spacewalk of the STS-125 mission. Credit: NASA

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Almost like Benjamin Button, the Hubble Space Telescope is now more vigorous and capable than with its original complement of instruments. “This is a tremendous adventure we’ve been on,” said astronaut John Grunsfeld at the end of Monday’s very successful EVA to repair and refurbish the famous space telescope. “This has been a very challenging mission. Hubble isn’t just a satellite, but it’s about humanity’s quest for knowledge.”

Grunsfeld and Drew Feustel installed a set of the observatory’s batteries, replaced a fine-guidance sensor that helps keep the telescope’s gaze precisely fixed on astronomical targets, and also replaced three thermal blankets protecting Hubble’s electronics.

“With today’s EVA Hubble is returned to flagship status with a full complement of instrument and tools for astronomers to use for the next several years,” saidJon Morse, Astrophyscis Division Director as NASA. “It is bittersweet to know this is our last visit to Hubble, but we have a saying in the science mission directorate: science never sleeps. So our work is just beginning. We have literally thousands of astronomers waiting to use Hubble, chomping at the bit to get their data.”

A view of Hubble from inside the shuttle Atlantis. Credit: NASA

Monday’s 7 hour and 2 minute-long spacewalk marked the end of the five scheduled spacewalks for the STS-125 servicing mission. However the spacewalking team of Mike Massimino and Mike Good will be ready to go outside if any issues crop up Tuesday morning when all the systems are checked out before Hubble is released by the shuttle crew. Mission managers hope to have Atlantis back on the ground by Friday.
Earlier spacewalks overcame stubborn bolts and problematic tools, but all the mission objectives were achieved, much to the delight of everyone at NASA.

“This must be what it’s like to win the superbowl,” said Preston Burch, Hubble Program Manager. “As those of you who have followed us the past five days, working in space is challenging and there is a fine line between things that look easy and things that are impossible. The crew just never gave up.”

Lead flight director, Tony Ceccacci reminded everyone at a press conference following the EVA that Monday’s spacewalk was the last planned EVA out of the shuttle airlock. “It was both a very happy day and a sad day. We looked at each other and knew that was the last planned EVA out of the shuttle airlock. We’ve been working on this for over 2 ½ years, and we looked at each other and said, ‘wow this is really over.'”

Drew Feustal floats free near Hubble, while Grunsfeld is perched on the robotic arm. Credit: NASA TV

The only glitch in the otherwise smooth EVA came at the very end when Grunsfeld – a self-proclaimed “Hubble Hugger” inadvertently bumped into one of the observatory’s two low-gain antennas with his foot, breaking off a small end cap. Grunsfeld felt terrible about the accident. “OK. I’m sick,” he said. However, the antenna still worked normally, mission control radioed up to him.

Grusnfeld and Feustel placed a protective cover over the cone-shaped device for added insulation before ending the spacewalk.

“Sorry, Mr. Hubble,” Grunsfeld said as he headed back to Atlantis’ airlock. “Have a good voyage.”

“Consider it a goodbye kiss, John,” Massimino radioed from inside the shuttle.

As Grunsfeld prepared to head back inside the shuttle he asked to say a few words.

“On this mission, we tried some things that some people said were impossible,” Grunsfeld said later. “We’ve achieved that, and we wish Hubble the very best.”

A replay of highlights from the 5th spacewalk is available.

May 18, 2009December 24, 2015 by Nancy Atkinson

First Observations of Biological Particles in High-Altitude Clouds

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A team of atmospheric chemists has moved closer to what’s considered the “holy grail” of climate change science: the first-ever direct detections of biological particles within ice clouds. Ice in Clouds Experiment – Layer Clouds (ICE-L) team mounted a mass spectrometer onto a C-130 aircraft and made a series of high-speed flights through a type of cloud known as a wave cloud. Analysis of the ice crystals revealed that the particles that started their growth were made up almost entirely of either dust or biological material such as bacteria, fungal spores and plant material. While it has long been known that microorganisms become airborne and travel great distances, this study is the first to yield direct data on how they work to influence cloud formation.

The team, led by Kimberly Prather and Kerri Pratt of the University of California at San Diego, Scripps Institution of Oceanography, performed in-situ measurements of cloud ice crystal residues and found that half were mineral dust and about a third were made up of inorganic ions mixed with nitrogen, phosphorus and carbon–the signature elements of biological matter.

The second-by-second speed of the analysis allowed the researchers to make distinctions between water droplets and ice particles. Ice nuclei are rarer than droplet nuclei.

The team demonstrated that both dust and biological material indeed form the nuclei of these ice particles, something that previously could only be simulated in laboratory experiments.

“This has really been kind of a holy grail measurement for us,” said Prather.

“Understanding which particles form ice nuclei, and which have extremely low concentrations and are inherently difficult to measure, means you can begin to understand processes that result in precipitation. Any new piece of information you can get is critical.”

The findings suggest that the biological particles that get swept up in dust storms help to induce the formation of cloud ice, and that their region of origin makes a difference. Evidence is increasingly suggesting that dust transported from Asia could be influencing precipitation in North America, for example.

Researchers hope to use the ICE-L data to design future studies timed to events when such particles may play a bigger role in triggering rain or snowfall.

“If we understand the sources of the particles that nucleate clouds, and their relative abundance, we can determine their impact on climate,” said Pratt, lead author of the paper.

The effects of tiny airborne particles called aerosols on cloud formation have been some of the most difficult aspects of weather and climate for scientists to understand.

In climate change science, which derives many of its projections from computer simulations of climate phenomena, the interactions between aerosols and clouds represent what scientists consider the greatest uncertainty in modeling predictions for the future.

“By sampling clouds in real time from an aircraft, these investigators were able to get information about ice particles in clouds at an unprecedented level of detail,” said Anne-Marie Schmoltner of NSF’s Division of Atmospheric Sciences, which funded the research.

Source: EurekAlert