Nancy Atkinson, Author at Universe Today

January 29, 2008December 26, 2015 by Nancy Atkinson

Are We Living in a New Geologic Epoch?

Have humans changed our planet Earth so much in the past 200 years that we are now living in a new geological age? A group of geologists believes this is the case. They have formally proposed designating a new geologic epoch, the Anthropocene, which would encompass the past 200 years or so of geologic history. The action is appropriate, they say, because during the past 2 centuries, human activity has caused most of the major changes in Earth’s topography and climate.

Like rings in a tree, each layer in Earth’s geologic record reflects the conditions of the time it was deposited and offers a glimpse into Earth’s past. In this geologic history that is written in the rocks and soil of our planet, researchers have differentiated the layers into classifications of time called eons, eras, periods, epochs, and ages that reflect characteristic conditions. For example, the Carboniferous period, which lasted from 360 million to 300 million years ago, is known for the vast deposits of coal that formed from jungles and swamps. Even some of the longer stretches have been named based on biology, such as the Paleozoic (“old life”) and the Cenozoic (“recent life”).

Earth has been has always been subject to the same kinds of physical forces–wind, waves, sunlight–throughout the planet’s existence. But the life that has arisen on the planet has had a much more varied impact such as the rise of plants that has shaped the planet in dramatic ways. But in the past 200 years, ever since the human population has reached 1 billion, our influences have affected the composition of Earth’s strata, altering the physical and chemical nature of ocean sediments, ice cores and surface deposits. Some of these influences are the use of fossil fuels and the growth of large cities.

British Geologist Jan Zalasiewicz and several colleagues argue that the International Commission on Stratigraphy should officially mark the end of the current epoch. That would be the Holocene (“entirely recent”), which started after the end of the last ice age, about 10,000 years ago. The new epoch would be the Anthropocene.

The evidence the geologists cite include the dramatic increase in lead concentration in the soil and water since about 1800 and the increase of carbon dioxide in the atmosphere. They claim that human processes now vastly outpace the equivalent natural forces. “A reasonable case can be made for the Anthropocene as a valid formal unit,” Zalasiewicz says.

The argument has merit, says American geologist Richard Alley. “In land, water, air, ice, and ecosystems, the human impact is clear, large, and growing,” he says. “A geologist from the far distant future almost surely would draw a new line, and begin using a new name, where and when our impacts show up.”

Original News Source: AAAS ScienceNow

January 26, 2008December 26, 2015 by Nancy Atkinson

First Images of Near Earth Asteroid 2007 TU24

In case you had any doubts, it’s now official: Asteroid 2007 TU 24 will not impact or have any affect on Earth. Astronomers have obtained the first images of the near earth asteroid using high-resolution radar data. “With these first radar observations finished, we can guarantee that next week’s 1.4-lunar-distance approach is the closest until at least the end of the next century,” said Steve Ostro, Jet Propulsion Laboratory astronomer and principal investigator for the project. “It is also the asteroid’s closest Earth approach for more than 2,000 years.”

The radar images indicate the asteroid is somewhat asymmetrical in shape, with a diameter roughly 250 meters (800 feet) in size. Asteroid 2007 TU24 will pass within 1.4 lunar distances, or 538,000 kilometers (334,000 miles), of Earth on Jan. 29 at 12:33 a.m. Pacific time (3:33 a.m. Eastern time). So, while this image is pretty faint, (about 20 meters per pixel) as the asteroid gets closer, NASA will be able to obtain better images and more details about the object.

And just to repeat for anyone who still has any doubts, the scientists at NASA’s Near-Earth Object Program Office at JPL have determined that there is no possibility of an impact with Earth in the foreseeable future.

Asteroid 2007 TU24 was discovered by NASA Oct. 11, 2007. The asteroid should be visible to amateur astronomers using 3 inch (7.6 centimeter) telescopes. It will be brightest on January 29-30, reaching an approximate apparent magnitude of 10.3, and then become fainter as it moves farther from Earth. Anyone looking for the asteroid with amateur telescopes will need dark and clear skies. An object with a magnitude of 10.3 is about 50 times fainter than an object just visible to the naked eye in a clear, dark sky.

NASA detects and tracks asteroids and comets passing close to Earth. The Near Earth Object Observation Program, commonly called “Spaceguard,” discovers, characterizes and computes trajectories for these objects to determine if any could be potentially hazardous to our planet. They use several different tracking devices including the Goldstone’s 70-meter diameter (230-foot) antenna that is capable of tracking a spacecraft traveling more than 16 billion kilometers (10 billion miles) from Earth.

Ostro and his team plan further radar observations of asteroid 2007 TU24 using the National Science Foundation’s Arecibo Observatory in Puerto Rico on Jan. 27-28 and Feb. 1-4.

Original News Source: JPL Press Release

January 25, 2008January 24, 2021 by Nancy Atkinson

No Humanoid on Mars, Just Rocks

Okay, once and for all, let’s make this clear. In the words of our esteemed Bad Astronomer, Phil Plait, “repeat after me:” A humanoid was not photographed on the surface of Mars. And NASA is not covering up this photo in the name of national security. Furthermore, human missions to Mars have not been cancelled because of this photo. These outrageous notions keep popping up in the media. The photograph, which was taken by Spirit, one of the Mars Exploration Rovers, is just another example of pareidolia, our ability to see patterns in random shapes.

As happens frequently, people tend to see faces or human forms in things like clouds, wood grain, and pancakes. This is only an optical illusion. If you need proof of this, for those of you in the US, look at one of the state-themed quarters from New Hampshire. There you can see the Man in the Mountain, a case of pareidolia that became an historic site (which has since crumbled.)

The photo shown here is the very large panoramic image from which a teeny, tiny rock formation was found that looks kind of human-like. Someone had to be looking really close to see it, as the rock formation is only about 6 centimeters high, and in the image you can also see a hill that’s over 8 kilometers (5 miles) away.

If you have any doubts in your mind that this is nothing more than just a very small, unusual rock formation, please, please, please see Emily Lakdawalla’s thorough explanation of the image at the Planetary Society’s website, which includes 3-D pictures that really make it clear this is not a humanoid. It’s a rock with a funny shape. And Phil the Bad Astronomer has more info on it as well here and here.

And, okay, here’s the really zoomed in image crop that has caused such a hubbub. Just remember how small this rock really is.

January 25, 2008December 26, 2015 by Nancy Atkinson

Researchers Observe Extra-galactic Meteor

The common belief is that all meteors come from inside our solar system. Most meteors are thought to be pieces of comet dust or fragments of asteroids that enter Earth’s atmosphere and burn up before they hit the ground, leaving a fiery trail we call “shooting stars.” But a recent observation might put a hole in the idea that these space rocks only come from the immediate vicinity of our solar system. A group of astronomers in Russia believe they observed a meteor of extragalactic origin.

On July 28, 2006, Victor Afanasiev from the Russian Academy of Sciences was making observations using a 6 meter telescope equipped with a multi-slit spectrometer. By chance, he observed the spectrum of a faint meteor as it burned up in the Earth’s atmosphere, and in looking at the data, found several anomalies. First was the speed at which the meteor was traveling. This meteor hit the atmosphere at about 300 kilometers per second, which is quite extraordinary. Only about 1% of meteors have velocities above 100 km/sec, and no previous meteor observations have yielded velocities of several hundred km/s. So where did this one come from?

Since the Earth moves around the galactic center at about 220 km/s, Afanasiev says the meteor’s origin cannot easily be explained by reference to the Milky Way. It appears that it came from the direction in which the Earth and the Milky Way is travelling towards the center of our local group of galaxies. “This fact leads us to conclude that we observed an intergalactic particle, which is at rest with respect to the mass centroid of the Local Group and which was ‘hit’ by the Earth,” Afanasiev and his team say in their paper.

Afanasiev also noted that the spectra of this meteor showed it was made of iron, magnesium, oxygen, iodine and nitrogen. These materials, particularly the metals, form inside stars. Additionally, spectral analysis showed features typical from the materials being strongly heated with the temperatures of 15000 – 20000K. Afanasiev says this differs widely from materials of terrestrial-type rocks and is suggestive of extrasolar or presolar materials.

Another difference was the size of the meteor. The researchers calculated that the meteor was several tens of a millimeter in size. This is two orders of magnitude larger than common interstellar dust grains in our galaxy. They estimated its size by integrating the equation of mass loss jointly with the equation of the variation of the density of the atmosphere. The research team noted that their size estimate, which they admit come from “rather coarse assumptions,” agrees with the expected parameters of the speed of interstellar meteors, which could be as high as 500 km/s.

The team subsequently made other observations to see if other meteors could perhaps be from outside our galaxy. In a total observing time of 34.5 hours during Oct-Nov 2006, they observed 246 meteors, 12 of which had velocity and direction to possibly have come from outside our galaxy.

Afanasiev and his team say there are many questions to be answered about their findings. For example, how metal-rich dust particles came to be in the extragalactic space, and why the sizes of extragalactic particles are larger by two orders of magnitude (and their masses greater by six orders of magnitude) than common meteors. Also, if extragalactic dust surrounds galaxies, could this be observed with infrared telescopes like the Spitzer Space Telescope? And is this dust spread out evenly in the universe or could it be found in clumps that might show up in the form of irregularities on the cosmic microwave background, observed by WMAP (Wilkinson Microwave Anisotropy Probe)?

With all our incredible observatories like Hubble, Spitzer, Chandra, etc, we have the opportunity to see outside of our galaxy. But now we have evidence that we actually might be interacting with extragalactic material as well.

Original News Source: Arxiv

January 24, 2008December 26, 2015 by Nancy Atkinson

New Chandra Image Is Eye Candy

This picture is too gorgeous not to share it. A new Chandra X-ray telescope image shows a beautiful, dense region of massive stars in the Centaurus constellation. It almost appears as though someone threw a handful of colored candies out into space. Known as Westerlund 2, this star cluster has been a mysterious region of our galaxy, filled with dust and gas that have obscured our vision of what lies inside. But new X-ray observations with Chandra have revealed some of the hottest, brightest and most massive known stars, and this is now regarded as one of the most interesting star clusters in the Milky Way galaxy.

About 20,000 light years from Earth, Westerlund 2 is a young star cluster with an estimated age of about one or two million years. An extremely massive double star system called WR20a is visible in the image, the bright yellow point just below and to the right of the cluster’s center. This system contains stars with whopping masses of 82 and 83 times that of the Sun. The dense streams of matter steadily ejected by these two massive stars, called stellar winds, collide with each other and produce large amounts of X-ray emissions. But alas, no chocolate candies.

This collision is seen at different angles as the stars orbit around each other every 3.7 days.

Several other bright X-ray sources may also show evidence for collisions between winds in massive binary systems.

The Chandra image of Westerlund 2 shows low energy X-rays in red, intermediate energy X-rays in green and high energy X-rays in blue. This is an area that is incredibly dense with massive stars, and bright with X-rays.

Image is 8.4 arc minutes across and was taken by the Chandra Advanced CCD Imaging Spectrometer, which can study temperature variations from x-ray sources.

Download this image for your desktop here.

Original News Source: Chandra Photo Album

January 24, 2008December 26, 2015 by Nancy Atkinson

NASA Astronaut Survey: No Launch Day Drinking

A NASA survey of astronauts and flight surgeons released on January 23, 2008 turned up no evidence of launch day drinking by flight crews, contradicting an earlier report by a health care panel that disclosed two instances of drunken astronauts. NASA surveyed 87 of all 98 astronauts as well as all 31 flight surgeons. None reported seeing a crew member heavily drinking alcohol on launch day, or within 12 hours of liftoff.

However, the anonymous survey did find one report of “perceived impairment” in an astronaut during the days preceding launch, which was later was traced to an interaction between prescription medication and alcohol. That astronaut was ultimately cleared for flight and launched into space.

“We really never understood from the beginning exactly what might have led to the comment in the health care report,” said Ellen Ochoa, deputy director of Johnson Space Center and a former shuttle astronaut. “We’ve tried to run it to ground. We haven’t uncovered anything. I don’t know of any issues associated with alcohol before flight.”

The healthcare report was conducted in mid-2007 in the wake of astronaut Lisa Nowak’s arrest. Nowak, who traveled from Houston to Florida to confront another woman about a romantic rivalry involving another astronaut, was arrested for attempted kidnapping and burglary with assault. She has yet to stand trial.

NASA established a panel of aerospace medicine experts, led by U.S. Air Force Col. Richard Bachmann, Jr., to look into astronaut mental health. The panel, citing unidentified sources, reported heavy drinking by two astronauts right before launches; one before a shuttle launch and another prior to the launch of a Russian Soyuz rocket. The panel reported that the flight surgeon’s concerns about the astronauts’ impairment were supposedly overruled by management, which created an atmosphere where both astronauts and flight surgeons were reluctant to report improper conduct.

In the new survey, however, conducted in August-December 2007, astronauts and flight surgeons indicated they were not afraid to raise concerns of flight safety, and they felt there is a healthy relationship between astronauts and doctors. But a small number of respondents acknowledged that some astronauts still feel they could lose out on a space assignment if they expressed concerns.

The astronaut survey was conducted and analyzed using both NASA specialists and external academic experts to ensure the study’s validity. “The response rate of the survey was 91 percent, a rate well above what you would normally expect in a survey,” Ochoa said. “That indicates the seriousness with which astronauts and flight surgeons approached this survey.”

The survey focused four areas: the relationship between astronauts and flight surgeons regarding openness of communication, level of trust, and understanding of safety responsibilities; concerns with raising and responding to issues of flight safety and/or crew suitability for flight; knowledge and implementation of policies and procedures detailing astronaut performance and crew assignment; and determining if there was personal knowledge of a US astronaut presenting a risk to flight safety due to alcohol use on launch day.

The 12-hour ban on drinking, which originally an “unwritten rule” is now standard policy. A new astronaut code of conduct is being written, as well.

Dr. Richard Williams, NASA’s chief health and medical officer said that NASA is in a better position today than it was a year ago to detect serious behavioral health problems facing astronauts, and to intervene before it’s too late.

Original News Source: NASA News Release

January 23, 2008January 24, 2021 by Nancy Atkinson

Near Earth Asteroid 2007 TU24 Will Make a Close Approach on January 29, 2008

An asteroid between 150-160 meters in diameter will pass within 540,000 kilometers (334,000 miles) of Earth on January 29 at 08:33 UT (3:33 EST). Hopefully this news won’t cause any alarmist cries of doom, as the asteroid has no chance of hitting Earth. But there is one reason to get excited about this close approach by an asteroid: it will be close enough to likely be visible to amateur astronomers.

Asteroid 2007 TU24 was discovered by the Catalina Sky Survey on October 11, 2007 and will approach the Earth to within 1.4 lunar distances. During its closest approach, it will reach an approximate apparent magnitude 10.3 on Jan. 29-30 before quickly becoming fainter as it moves further from Earth. So, for a brief time the asteroid will be observable in dark and clear skies with amateur telescopes of 3 inch apertures or larger.

According to NASA’s Near Earth Object Program, since the estimated number of near-Earth asteroids of this size is about 7,000 discovered and estimated undiscovered objects, an object the size of 2007 TU 24 would be expected to pass this close to Earth, on average, about every 5 years or so. They also say the average interval between actual impacts of Earth for an object of this size would be about 37,000 years. But rest assured, for the January 29th encounter, near Earth asteroid 2007 TU24 has no chance of hitting, or affecting, Earth.

2007 TU24 will be the closest currently known approach by an asteroid of this size or larger until 2027. Plans have been made for the Goldstone planetary radar to observe this object Jan 23-24 and for the Arecibo radar to observe it Jan 27-28, as well as Feb 1-4. The NEO office says they should be able to image the object with high resolution radar, and if so, 3-D shape reconstruction images should be possible. Way cool.

The illustration below is courtesy of amateur astronomer Dr. Dale Ireland from Silverdale, WA. The illustration shows the asteroid’s track on the sky for 3 days near the time of the close Earth approach as seen from the city of Philadelphia. Since the object’s parallax will be a significant fraction of a degree, observers are encouraged to use the NEO office’s on-line Horizons ephemeris generation service for their specific locations.

Now, we’re aware that there are some alarmists out there trying to freak people out about this asteroid visit. They’re posing the usual conspiracy theories about the astronomy community’s cover up. Don’t worry, there’s absolutely nothing to fear except a little cold weather as you stand outside, hoping to see the asteroid pass by with your telescope. If you want a more detailed debunking of this myth, check out Bad Astronomy’s excellent coverage.

Original News Source: NEO Program Press Release

January 23, 2008December 26, 2015 by Nancy Atkinson

Researchers Plan to Launch Paper Airplane from ISS

This is from the “why is anyone spending money on this?” department. Researchers from the University of Tokyo have teamed up with members of the Japan Origami Airplane Association to develop a paper aircraft capable of surviving the flight from the International Space Station to the Earth’s surface. The only problem is that no one knows where the paper airplane might land, and no tracking device is in the works to be used. So, the plan is to do an experiment with no way of gathering any data.

The researchers began testing the strength and heat resistance of an 8 centimeter (3.1 in) long prototype on January 17 in an ultra-high-speed wind tunnel at the University of Tokyo. In the tests, the origami glider — which is shaped like the Space Shuttle and has been treated to withstand intense heat — will be subjected to wind speeds of Mach 7, or about 8,600 kilometers (5,300 miles) per hour.

The researchers claim this paper airplane will come down more slowly than say, a real spacecraft, and it is not expected to burn up on re-entry.

No launch date has been set for the paper spaceplane, but Shinji Suzuki, an aerospace engineering professor at the University of Tokyo, is thinking ahead. “We hope the space station crew will write a message of peace on the plane before they launch it,” says Suzuki. “We don’t know where in the world the plane will land, but it would be nice to send a message to whoever finds it.”

Even if the paper airplane does make it through the atmosphere unscathed, given that our planet is 70% water, don’t hold out much hope for it being found.

Original News Source: Pink Tentacle

January 23, 2008December 26, 2015 by Nancy Atkinson

Mercury in Living Color

The MESSENGER science team released more pictures from the Jan. 14 flyby, including what we’ve all been waiting for, the first one in color! But if you’re looking for spectacular, eye-catching color, well, sorry, its just not part of Mercury’s make-up.

The color image was created by combining three separate images taken through MESSENGER’s Wide Angle Camera (WAC) filters in the infrared, far red, and violet wavelengths (red, green, and blue filters for this image.) MESSENGER’s eyes can see far beyond the color range of the human eye, and the colors seen in this image are somewhat different from what a human would see.

Creating a false-color image in this way brings out color differences on Mercury’s surface that cannot be seen in the black and white images released earlier.

The WAC has 11 narrow-band color filters, in contrast to the two visible-light filters and one ultraviolet filter that were on Mariner 10’s camera. By combining images taken through different filters in the visible and infrared, the MESSENGER data allow Mercury to be seen in a variety of high-resolution color views not previously possible. This visible-infrared image shows an incoming view of Mercury, about 80 minutes before MESSENGER’s closest pass of the planet from a distance of about 27,000 kilometers (17,000 miles).

I love this image of Mercury’s south pole limb. It shows the terminator; the transition from the sunlit, day side of Mercury to the dark, night side of the planet. In the region near the terminator, the sun shines on the surface at a low angle, causing the rims of craters to cast long shadows, which brings out the height differences of the surface features. This image was acquired about 98 minutes after MESSENGER’s closest approach to Mercury, when the spacecraft was at a distance of about 33,000 kilometers (21,000 miles).

And here’s one for the scientist in you: the first data returned from MESSENGER’s Mercury Atmospheric and Surface Composition Spectrometer (MASCS). What the image on the right shows with the bar-graph type lines is a high-resolution spectra of the planet’s surface in ultraviolet, visible, and near-infrared light. The image on the left shows a portion of the ground-track along which the MASCS instrument took over 650 observations of the surface. The area is about 300 kilometers (190 miles) across. For those of you not fluent in spectra-ese, this shows the relative amount of sunlight reflected from the surface at wavelengths from the ultraviolet to the visible (rainbow) to the infrared.

Original News Source: MESSENGER Press Releases

January 22, 2008December 26, 2015 by Nancy Atkinson

Should NASA Overhaul Its Vision?

Is the moon really “so yesterday?” An article in the Jan. 18 issue of Aviation Week and Space Technology reported that a group of influential people in the space community will meet in early February to discuss alternatives to NASA’s current Vision for Space Exploration of returning to the moon to prepare for future missions to Mars. But a subsequent letter to the editor in AWST written by Planetary Society President Lou Friedman and Scott Hubbard of Stanford University tried to put the brakes on any notion that the group has already come to a consensus that NASA’s VSE should change direction and destination.

In the letter, Friedman and Hubbard state that the article created “the misperception that the workshop we are organizing at Stanford University has already decided upon a new path for the human and robotic exploration of space. We wish to make it clear that the purpose of the workshop is to examine critically the Vision for Space Exploration in order to prepare for future space policy considerations in a new Administration and new Congress.”

The Aviation Week article reported that the purpose of the February meeting is “to offer the next U.S. president an alternative to President Bush’s ‘vision for space exploration’–one that would delete a lunar base and move instead toward manned missions to asteroids along with a renewed emphasis on Earth environmental spacecraft.”

But Friedman and Hubbard’s letter said, “This point of view is undoubtedly the personal opinion of some participants – but such an opinion is neither a premise nor a presumed outcome of the workshop.” Instead, they said, the workshop will address a many issues of space exploration and the workshop has no predetermined conclusions.

“We have deliberately included a wide range of participants with disparate views, including those who would maintain the status quo. We personally do not know what the conclusions of the workshop will be – or even if there will be a definitive consensus,” said Friedman and Hubbard.

Examining the current Vision is surely a good idea. A Business 101 rule is that once a plan is put into action, you should always stay on top of changing conditions and adjust your plan accordingly, constantly updating and improving. Should NASA consider missions to asteroids instead of the moon? Will going to asteroids get us to Mars more quickly, or is the moon a good, safe place to get our space legs back before moving on?

Hopefully the group meeting at Stanford University in February, as well as the upcoming new political administration in the US, will examine the VSE with open minds, considering both human and robotic missions, and without political agendas.

Another Business 101 tenet is that communication is vital to success. It’s good to see that space exploration is something people are talking about.”

Original News Source: Planetary Society Press Release