Nancy Atkinson, Author at Universe Today

March 3, 2008December 26, 2015 by Nancy Atkinson

Looking Down the Barrel of A Gamma Ray Burst

A team of astronomers from the University of Sydney in Australia have been keeping an eye on a binary star system called Wolf-Rayet 104, located in the constellation Sagittarius. Wolf-Rayet stars are hot, gargantuan, older stars that are losing their masses, and astronomers consider these stars as ticking bombs: they could go supernova at any time within the next few hundred thousand years. Thatâ€™s a relatively short fuse for astronomers. Images of this system from the Keck Telescope show an almost perfect spiral nebula formed by the two stars orbiting each other as they each blow off streams of gas. The way this system is spinning caught the eyes of these astronomers, who say Earth could be in the line of fire when the system blows.

Usually, a supernova explosion would be harmless at interstellar distances like the 8000 lightyears that this system lays from Earth, and it would just provide an impressive show for stargazers. But astronomers say the only way WR 104 could appear as an almost perfect spiral is if those of us on Earth were looking down the spin-axis of the system. Astronomer Peter Tuthill says that sometimes, supernovae focus their energy into a narrow beam of very destructive gamma-ray radiation along the axis of the system. A gamma-ray burst is a super-duper supernova that sometimes happens to massive stars, like the ones in WR 104.

As of now, no one can say for sure when the system will go supernova, or how massive and powerful the explosion might be. But the way these two stars are spinning about each other has astronomers thinking this system wonâ€™t provide just a run-of-the-mill explosion.

And an intensive gamma-ray burst at that distance could possibly be harmful to life on Earth.

But right now, this is all speculation, and more study on this system is needed before anyone needs to get worried. And this is all definitely very fascinating.

“I used to appreciate this spiral just for its beautiful form, but now I can’t help a twinge of feeling that it is uncannily like looking down a rifle barrel,” says Dr. Peter Tuthill.

With a sequence of 11 different images, the astronomers were able to portray how the spiral nebula of this system is rotating in a circle every 8 months.

Original News Source: University of Sydney Press Release

March 3, 2008December 26, 2015 by Nancy Atkinson

Latest Mars Images Round-up

With three orbiters and two rovers currently at Mars, there are always interesting images coming back from the Red Planet. Here’s a round-up of the latest images from the five different spacecraft. First up is a fascinating image from the Mars Odyssey spacecraft of dust devil tracks. It’s amazing just how many tracks there are in just this one image. Martian dust devils can be up to fifty times as wide and ten times as high as dust devils seen on Earth. This image was taken by Odyssey’s Thermal Emission Imaging System (THEMIS), and shows an area in the south polar region, just east of Daly Crater. Resolution is about 17 meters per pixel. Original Image link.

NASA’s Mars Exploration Rover Spirit has this view northward from the position at the north edge of the “Home Plate” plateau where the rover will spend its third Martian winter. And no, that’s not a pool of water in the image. It’s just rippled sand in the “El Dorado” sand dune field, and the image is shown in false color.

Husband Hill is on the horizon. Spirit used its panoramic camera (Pancam) to capture this image during the rover’s 1,448th Martian day, on January 29, 2008.
Original image link.

This view from the Opportunity rover shows a close-up of bedrock from the inside of Victoria Crater, where the rover is currently studying a stratigraphic layer of rocks. This area is informally named “Lyell,” which is the lowermost of three layers the rover has examined at a bright band around the inside of the Crater.

Opportunity used its panoramic camera (Pancam) to capture this image with low-sun angle at a local solar time of 3:21 p.m. during the rover’s 1,433rd Martian day, on February 4, 2008. This image, too, is in false color to highlight the ripples and bands in the bedrock.
Original Image link.

ESA’s Mars Express took snapshots of Candor Chasma, a valley in the northern part of Mar’s huge canyon, Valles Marineris, as it was in orbit above the region on 6 July 2006.

The High Resolution Stereo Camera on the orbiter obtained the data,with a ground resolution of approximately 20 m/pixel. Candor Chasma lies at approximately 6Â° south and 290Â° east.
Original Image link.

This image taken by the Mars Reconnaissance Orbiter (MRO) shows a volcanic vent. A volcanic vent is an opening in the crust of a planet that emits lava (molten rock) and volcanic gases. The rough texture of the plains surrounding the vent iindicates that it is lava.

There is a large number of snake-like features emanating from the vent. The parallel lines that outline the features are levees, which mark the edges of channels that carried molten lava. As lava flows, it moves slowest at its edges and bottom because the lava sticks to the non-flowing rocks, and as the lava slows, it cools off and hardens.

Levees form when the sides harden but the center of the flow keeps moving. As the eruption episode ends, and the lava drains, the center is left lower than the sides producing these high-standing structures. Of course, these lava flows are very, very old.
Original Image page.

February 28, 2008January 24, 2021 by Nancy Atkinson

Help Map Our Dark Skies

Have you ever really seen the night sky — a sky without any pollution from artificial light sources? Over half of Earthâ€™s population lives in urban areas, and have probably never seen a rich, dark sky full of ~~millions~~ thousands of stars. Not only does light pollution make it harder for amateur and professional astronomers to observe the night sky, but it affects other living things as well. Birds and other animals that are nocturnal can become disoriented from constant artificial light.

You can help track how light-polluted our skies have become by participating in the GLOBE at Night Program. All you need to do is go outside and look for the constellation Orion and compare your view with sky charts provided by GLOBE and report your findings. The programs runs from now until March 8.

The GLOBE website provides you with information and links on how to find your latitude and longitude and how to find Orion. You then match your nighttime sky to one of their magnitude charts and report your observation. Then you can compare your observation to thousands around the world. Last year about 8,500 people participated in this event. Phil and Emily have already posted on this, but Universe Today is now joining in to help GLOBE have their night sky biggest event yet.

Also available from the GLOBE site are downloadable family activity packets and information for teachers, offered in several different languages. Take this opportunity share the wonders of the night sky with young children while helping to track light pollution. It will only take a few minutes.

February 28, 2008December 26, 2015 by Nancy Atkinson

New NASA Animation Lets You Land on the Moon

Using new high resolution terrain mapping data obtained by the Deep Space Network, NASA has created some new animations that take viewers to the Moon’s south pole. The videos include a flyover of Shackleton Crater and a very nifty animation of descent to the lunar surface of a future human lunar lander.

“I have not been to the Moon, but this imagery is the next best thing,” said Scott Hensley, a scientist at JPL and lead investigator for obtaining the data. “With these data we can see terrain features as small as a house without even leaving the office.”

Here’s the descent and landing animation. Make sure you watch to the very end, because the ending is the most impressive part, when you realize where you’ve landed.

The rim of Shackleton Crater is considered a candidate landing site for a future human mission to the moon.

And there’s more:

The mapping data collected indicate that the region of the Moon’s south pole near Shackleton Crater is much more rugged than previously understood. Hereâ€™s an animation of a flyover of the lunar south pole

Another animation shows the amount of sunlight falling on the Moon’s south pole during one lunar day. Notice that the interior of some craters remain almost completely dark — no sunshine ever strikes these areas — and some scientists feel there could possibly be water ice inside these craters.

To create these animations scientists targeted the Moon’s south polar region three times during a six-month period in 2006, using Goldstone’s 70-meter (230-foot) radar dish. The antenna, three-quarters the size of a football field, sent a 500-kilowatt-strong, 90-minute-long radar stream 373,046 kilometers (231,800 miles) to the moon. The radar bounced off the rough-hewn lunar terrain over an area measuring about 644 kilometers by 402 kilometers (400 miles by 250 miles). Signals were reflected back to two of Goldstone’s 34-meter (112-foot) antennas on Earth. The roundtrip time, from the antenna to the Moon and back, was about two-and-a-half seconds.

For more images and animations go to NASAâ€™s Moon Exploration page.

February 27, 2008April 26, 2016 by Nancy Atkinson

Earth Life Forms Ejected on Asteroid Impact Could Survive and Return Again

Does this mean that, perhaps, we can go home again?

If an asteroid or comet impacted Earth, the resulting ejection of materials could contain life forms. According to a study published in the journal Astrobiology, these life forms could survive and then seed another planet or moon with life. Additionally, Earth could also be re-seeded with life by those same life forms.

Ah, there’s no place like home.

If rock fragments containing embedded microorganisms were ejected into space, at least some of those organisms might survive and reseed Earth or seed another planetary surface able to support life. This scenario, which is called lithopanspermia was examined in studies called systematic shock recovery experiments designed to simulate this type of situation where microorganisms are transported between planets via meteorites.

The researchers sandwiched dry layers of three kinds of biological test ingredients, including bacterial endospores, endolithic cyanobacteria, and epilithic lichens, into rocks analogous to rocks from Mars. They then simulated the shock pressures Martian meteorites experienced when they were ejected from Mars and determined the ability of the organisms to survive the harsh conditions.

The organisms are hardy examples of microbes that can withstand extreme environmental stress and represent potential ‘hitchhikers’ within impact-ejected rocks.

“Given that impacts have occurred on planetary bodies throughout the history of our solar system,” says Sherry L. Cady, PhD, Associate Professor in the Department of Geology at Portland State University, “the hypothesis that life in rock could have been transferred between planets at different times during the past 3.5 billion years is plausible.”

And not only is it plausible that Mars rocks could be transferred to Earth and vice versa, but ejected rocks from Earth could possibly return and land back on their home planet. Given the contemplation of the destruction of life on Earth, it’s somewhat comforting to think that we could perhaps start over again from our own ingredients.

Original News Source: Astrobiology Press Release

February 27, 2008December 26, 2015 by Nancy Atkinson

Nano-Engineered Liquid Mirror Telescopes

Some astronomers feel that rotating liquid mirror telescopes (LMT) may revolutionize astronomy. LMTs work because the basic laws of nature — gravity and centrifugal force — conspire together to give LMTs the perfect, parabolic shape needed for astronomical observing. And unlike ordinary telescopes with glass mirrors that are expensive to make and maintain, LMTs are quite cost effective because of low construction costs (current estimates have liquid mirrors at 1% the cost of a glass mirror) and they don’t need to be polished or housed in an expensive mount.

Ermanno Borra from Canada is one of the foremost experts on LMTs, and he has been constructing and testing different types of these telescopes since the early 1980’s. His latest research involves creating a tiltable LMT — previously thought to be almost impossible — by using a thin, reflective layer of self-assembling metallic nanoparticles.

LMTs are made by spinning a reflective liquid, usually mercury, on a bowl-shaped platform to form a parabolic surface, perfect for astronomical optics. A handful of LMTs are being used today, including a 6-meter LMT in Vancouver, Canada, and a 3-meter version that NASA uses for its Orbital Debris Observatory in New Mexico.

Borra and his colleagues have been experimenting by using different liquids to create LMTs, since part of their research has been geared toward studying the feasibility of constructing a large LMT on the Moon, and mercury freezes at temperatures found at the lunar poles. Since low temperature liquids like small hydrocarbons (such as ethane) are not shiny, Borra has been trying to deposit a reflective metal on the surface of these liquids. In 2007 Borra and his team successfully coated a low temperature ionic liquid (contains essentially only ions, such as ethylammonium nitrate) with silver by vaporizing it in a vacuum, something thatâ€™s never been done before in the field of optics.

But more recently, Borra’s team has used silver nano-particles known as Metal Liquid-Like Films, or MELLFs to coat hydrophilic (water bondable) liquids like ethylene glycol. In a recent paper outlining their research, the team says this is a significant improvement over their previous work where the reflecting layer was deposited on hydrophobic (water resistant) oils. Usually, creating MELLFs is very labor intensive and time consuming. But the team even created a small, simple, motorized, computer-controlled MELLF machine and can now make enough MELLF for a 1 meter mirror in about 30 hours. Through further tests and trials, the team found that spraying the highly reflecting MELLFs on the surface of the hydrophilic liquid produces the best results.

Usually, liquid mirrors have the limitation of that they can only point straight up, so it’s not like a standard telescope that can be pointed in any direction and track objects in the sky. It only looks at the area of sky that is directly overhead. But Borra has been working on creating a tiltable LMT, and by using the MELLF nanoparticles, has now been successful in producing an LMT that can be tilted 45 arc seconds.

Their goal is to be able to tilt the LMT by 10 degrees. To do this, they must find a higher viscosity hydrophilic liquid, which might have them returning again to try ionic liquids, of which there are wide variety to choose from.

“It will be worthwhile making the effort because, based on our experience so far, tiltable liquid mirrors promise to be very inexpensive and easy to make, ushering in an era of inexpensive telescopes and readily available telescope time.”
–from a paper by Borra, Gagne and Ritcey providing an update on their LMT research

A liquid mirror envisioned for a lunar telescope would be 20 to 100 meters in diameter, making it up to 1,000 times more sensitive than the proposed next generation of space telescopes. As Borra and his team continue their research, look for more updates from their work in the future.

Original News Source: Astronomy & Astrophysics

February 25, 2008December 26, 2015 by Nancy Atkinson

New ESA Rover Will Look For Life On Mars

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NASA’s Mars Exploration Rovers (MER) have been an outstanding success in their longevity and helping us to understand the role of water in Mars’ past. But Spirit and Opportunity don’t have the instruments on board to answer the question foremost in many people’s minds: Is there, or was there ever life on Mars?

A new spacecraft being readied by the European Space Agency (ESA) will have that ability. The rover for the ExoMars 2013 mission will have an on-board subsurface radar, a drill, and life-detection equipment as part of the scientific payload.

To help prepare for the mission, scientists at Aberystwyth University in Wales have simulated the surface of Mars in their lab to test the “roving” capabilities of the vehicle. Also being tested are the robotic arm for collecting samples and a panoramic camera.

The ExoMars mission will also have an orbiter that will scan for the best landing site for the rover. The rover is slated to travel to ten different locations in 6 months. The rover will use a radar system that can scan the surface and subsurface, a drill that can dig down 1-2 meters below the surface and gather a sample that will be brought to the onboard instruments that will look for life, past or present, in the Mars landscape.

A robotic arm that is part of this system is similar to arm that was part of the ill-fated Beagle 2 lander, that crashed on Mars surface in 2003. But the new arm has been improved, and it is hoped the arm will work with on-board cameras and to be able to acquire rock samples autonomously.

The rover will weigh about 140-180 kg, comparable to the NASA’s MER. The main scientific objectives of the ExoMars mission are to study the biological environment of Mars surface, to characterize the Mars geochemistry and water distribution and to identify possible surface hazards to future human missions.

The mission is scheduled to launch in 2013 and land on Mars in 2014.

Original News Source: BBC

February 25, 2008December 26, 2015 by Nancy Atkinson

Be A Carbon Hero

NASA is quite proud of its spinoffs technology developed for the space agency’s needs in space that in turn contribute to commercial innovations that improve life here on Earth. And rightly so. Just as a quick example, improvements in spacesuits have led to better protection for firefighters, scuba divers and people working in cold weather. But the list of NASA spinoffs is quite extensive.

Just like NASA, the European Space Agency (ESA) has a Technology Transfer office to help inventors and businesses use space technology for non-space applications. The latest invention touted as an ESA spinoff is a small hand-held device called a Carbon Hero that might help make people more aware of the carbon footprint they are leaving behind due to vehicle emissions.

Used in conjunction with a cell phone, the Carbon Hero receives data from navigation satellites to determine the mode of transportation being used. The device’s algorithm is able to use the speed and position of the user to determine how they are traveling, and how much CO2 they are generating. The user doesn’t have to enter any information, the data is computed automatically.

The user would get feedback on the environmental impact of different types of transportation – whether by train, plane, bike or by foot. The Carbon Hero lets the user compare one kind of travel with another and calculate the environmental benefits daily, weekly and monthly.

“If you go on a diet you want to see if all that effort has made a difference so you weigh yourself. The beauty of our system is that it’s easy; you have a “weighing scale” on you all the time giving you your carbon footprint. When you make the effort to walk instead of taking the car you can immediately see the result, so it feels more worthwhile doing it and you are more likely to stick with it,” says Andreas Zachariah, a graduate student from the Royal College of Art in London and inventor of Carbon Hero.

The device has been tested using the GPS system, but will be fully operational after Galileo, the European global navigation system is fully up and running.

Learn more about ESA’s Technology Transfer Programme Office.

Learn more about NASA Spinoffs.

Original News Source: ESA Press Release

February 22, 2008December 26, 2015 by Nancy Atkinson

Ulysses Spacecraft Dying of Natural Causes

“One equal temper of heroic heart
Made weak by time and fate, but strong in will
To strive, to seek, to find, and not to yield.”
—from the poem “Ulysses” by Alfred, Lord Tennyson

The Ulysses spacecraft has been heroically studying our sun for more than 17 years, almost four times its expected lifetime. But now, the mission might be finally succumbing to the harsh environment of space. Mission managers say the spacecraft will likely “die” in the next month or two.

“Little remains; but every hour is saved
From that eternal silence, something more,
A bringer of new things;
To Follow knowledge like a sinking star,
Beyond the utmost bound of human thought.”
(more from “Ulysses”)

Ulysses is a joint mission between ESA and NASA that was launched in 1990 during space shuttle mission STS-41. Ulysses was the first mission to study the environment of space above and below the poles of the Sun. The spacecraft has returned a huge amount of data that has changed the way scientists view the Sun and its effect on the space surrounding it.

Ulysses is in a six-year orbit around the Sun. Its long orbital path carries it out to Jupiter’s orbit and back again. The further it ventures from the Sun, the colder the spacecraft becomes. If it drops to 2ºC, the spacecraft’s hydrazine fuel will freeze.

This has not been a problem in the past because Ulysses carries heaters to maintain a workable on-board temperature. The spacecraft is powered by the decay of a radioactive isotope and over the 17-plus years, the power it has been supplying has been steadily dropping. Now, the spacecraft no longer has enough power to run all of its communications, heating and scientific equipment simultaneously.

“We expect certain parts of the spacecraft to reach 2ºC pretty soon,”says Richard Marsden, ESA’s Ulysses Project Scientist and Mission Manager. This will block the fuel pipes, making the spacecraft impossible to maneuver.

The ESA-NASA project team had tried to solve this problem by temporarily shutting of the main spacecraft transmitter, which would provide 60 watts of extra power that could be channeled back to the heater and science instruments. Unfortunately, the transmitter failed to turn back on.

“The decision to switch the transmitter off was not taken lightly. It was the only way to continue the science mission,”says Marsden, who is a 30-year veteran of the project, having worked on it for 12 years before the spacecraft was launched.

After many attempts, the Ulysses project team now consider it highly unlikely that the X-band transmitter will be recovered. They believe the fault can be traced to the power supply, meaning that the extra energy they hoped to gain cannot be routed to the heater and science instruments after all.

So, the spacecraft’s fuel lines are gradually freezing. This spells the end of this highly successful mission.

“Ulysses is a terrific old workhorse. It has produced great science and lasted much longer than we ever thought it would,” says Marsden. “This was going to happen in the next year or two, it has just taken place a little sooner than we hoped.”

The team plan to continue operating the spacecraft in its reduced capacity for as long as they can over the next few weeks. “We will squeeze the very last drops of science out of it,” says Marsden.

“Death closes all; but something ere the end,
Some work of noble note, may yet be done…
‘Tis not too late to seek a newer world…
To sail beyond the sunset.”
—more from “Ulysses” by Tennyson

Original News Source: ESA Press Release

February 22, 2008December 26, 2015 by Nancy Atkinson

An Elegant Proposal for Near Earth Asteroid Deflection

Although the chances of an asteroid hitting Earth appear to be small for any given year, the consequences of such an event would be monumental. The science community has come up with some ideas and proposals for ways to mitigate the threat of an incoming asteroid hitting the Earth. Some proposals suggest almost Hollywood type theatrics of launching nuclear weapons to destroy the asteroid, or slamming a spacecraft into a Near Earth Object to blow it apart. But other ideas employ more simple and elegant propositions to merely alter the trajectory of the space rock. One such plan uses a two-piece solar sail called a solar photon thruster that draws on solar energy and resources from the asteroid itself.

Physicist Gregory Matloff has been working with NASA’s Marshall Spaceflight Center to study the two-sail solar photon thruster which uses concentrated solar energy. One of the sails, a large parabolic collector sail would constantly face the sun and direct reflected sunlight onto a smaller, moveable second thruster sail that would beam concentrated sunlight against the surface of an asteroid. In theory, the beam would vaporize an area on the surface to create a ‘jet’ of materials that would serve as a propulsion system to alter the trajectory of the Near Earth Object (NEO.)

Changing the trajectory of a NEO exploits the fact that both the Earth and the impactor are in orbit. An impact occurs when both reach the same point in space at the same time. Since the Earth is approximately 12,750 km in diameter and moves at about 30 km per second in its orbit, it travels a distance of one planetary diameter in about seven minutes. The course of the object would be altered, or either delayed or advanced and cause it to miss the Earth.

But of course, the arrival time of the impactor must be known very accurately in order to forecast the impact at all, and to determine how to affect its velocity.

Additionally, the solar photon thruster’s performance would vary depending on the unique makeup of each NEO. For example, asteroids with a greater density, radius or rate of rotation would cause decreased performance of the solar photon thruster in acceleration and deflection.

Even though the solar photon thruster appears to be efficient in its performance, Matloff said that more than half of the solar energy delivered to the “hotspot” on the NEO would not be available to vaporize and accelerate the jet due to other thermodynamic processes such as conduction, convection, and radiation. As expected, a larger collector sail radius would increase the amount of energy available, and would increase acceleration of the NEO. Matloff said this system allows the sail craft to “tack” against the solar-photon breeze at a larger angle than conventional single solar sails can achieve.

This system of sails would not be attached to the NEO, but would be kept nearby the NEO “on station” either with its own thrusting capability or by auxiliary electric propulsion. More studies would be needed to ascertain if a supplementary propulsion system would be necessary.

The sails used in the study were both inflatable. However, Matloff believes it might be worth considering a small rigid thruster sail, which might simplify deployment and reduce occultation.

Said Matloff, “Hopefully, future design studies will resolve these uncertainties before application of NEO-diversion technology becomes necessary.”