Posted on by Nancy Atkinson

Mapquesting the Solar System

Pictures of all the objects in the Solar System. Image credit: NASA/JPL

Map generators like Mapquest and Yahoo! Maps have bailed me out quite a few times, helping me get where I needed to go. So imagine in the future, navigating on other bodies in our solar system and having the ability to find landmarks and destinations to point you in the right direction. This type of technology is now under development and could create three-dimensional “super roadmaps” of other planets and moons. In addition it could also provide robots, astronauts and engineers details about atmospheric composition, biohazards, wind speed and temperature, and could help land future spacecraft and more effectively navigate roving cameras across a Martian or lunar terrain.

The Rochester Institute of Technology’s Rochester Imaging Detector Laboratory (RIDL), in collaboration with Massachusetts Institute of Technology’s Lincoln Laboratory are developing a new type of detector that uses LIDAR (LIght Detection and Ranging), a technique similar to radar, but which uses light instead of radio waves to measure distances.

This is a new generation of high resolution, low power consuming optical/ultraviolet imaging LIDAR detectors that will significantly extend NASA’s science capabilities for planetary applications by providing 3-D location information for planetary surfaces and a wider range of coverage than the single-pixel detectors currently combined with LIDAR.

The LIDAR imaging detector will be able to distinguish topographical details that differ in height by as little as one centimeter.

“The imaging LIDAR detector could become a workhorse for a wide range of NASA missions,” says Donald Figer, director of the RIDL. “You can have your pixel correspond to a few feet by a few feet spatial resolution instead of kilometer by kilometer,” Figer says. “And now you can take LIDAR pictures at fine resolutions and build up a map in hours instead of taking years at comparable resolution with a single image.”

The device will consist of a 2-D continuous array of light sensing elements connected to high-speed circuits. The $547,000 NASA-funded program also includes a potential $589,000 phase for fabrication and testing.

LIDAR works by measuring the time it takes for light to travel from a laser beam to an object and back into a light detector. The new detector can be used to measure distance, speed and rotation. It will provide high-spatial resolution topography as well as measurements of planetary atmospheric properties: pressure, temperature, chemical composition and ground-layer properties. The device can also be used to probe the environments of comets, asteroids and moons to determine composition, physical processes and chemical variability.

The imaging LIDAR detector will be tested at RIDL in environments that mimic aspects of operations in NASA space missions.

Orginal News Source: EurekAlert

Posted on by Nancy Atkinson

Elusive Molecule Found in Venus’ Atmosphere

Hydroxyl, an important but difficult-to-detect molecule, has been found in the upper atmosphere of Venus by the Venus Express spacecraft. This is the first time this molecule has been detected on another planet, and even though it is thought to be an “atmospheric cleanser,” knowing that it is part of Venus’ thick, greenhouse-like atmosphere will help scientists better understand the environment on our next-door planet. “Venus Express has already shown us that Venus is much more Earth-like than once thought. The detection of hydroxyl brings it a step closer,” said one of the Principal Investigators of the VIRTIS experiment on the Venus Express, Giuseppe Piccioni.

Hydroxyl is thought to be important for any planet’s atmosphere because it is highly reactive. On Earth it has a key role in cleaning pollutants from the atmosphere. On Mars, scientists believe it helps stabilize the carbon dioxide in Mars’ atmosphere, preventing it from converting to carbon monoxide. Also, hydroxyl is thought to play a vital role in sterilizing the Martian soil, making the top layers hostile to microbial life.

Hydroxyl is made up of a hydrogen and oxygen atom each. It has been seen around comets, but the method of production there is thought to be completely different from the way it forms in planetary atmospheres.

On Earth, the glow of hydroxyl in the atmosphere has been shown to be closely linked to the abundance of ozone. From this study, the same is thought to be true at Venus.

Venus Express has shown that the amount of hydroxyl at Venus is highly variable. It can change by 50% from one orbit to the next and this may be caused by differing amounts of ozone in the atmosphere.

“Ozone is an important molecule for any atmosphere, because it is a strong absorber of ultraviolet radiation from the Sun,” says Piccioni. The amount of the radiation absorbed is a key parameter driving the heating and dynamics of a planet’s atmosphere. On Earth, it heats the stratosphere (layer of the atmosphere) making it stable and protecting the biosphere from harmful ultraviolet rays.

Computer models will now be able to tell how this jump and drop in ozone levels over short intervals affects the Venus’ restless atmosphere.

Original News Source: ESA Press Release

Posted on by Nancy Atkinson

“Fusionman” Soars the Skies (Gallery)

A Swiss adventurer who calls himself Fusionman tried out a new jet powered carbon wing, and successfully flew for 5 minutes on May 15 before landing with a parachute. Yves Rossy, a 48-year-old former air force pilot lit the jets on his wing and then jumped from a plane over Bex, Switzerland. He is the world’s first man to fly with jet powered wings.

Rossy performed his first official demonstration of his wings, which are 2.5 meters in diameter and comes with four tiny jets. Once in full flight, Rossy can reach speeds of up to 200km/hr, but he can only stay in the air for a maximum of ten minutes due to the small fuel capacity of his jets.

Rossy, who now works for the Swiss airline, first unveiled his design in 2004. Today he flew like a rocketeer above the Swiss Alps.

Rossy hasn’t always had an easy ride though — during one jump in 2005, he lost control of his wing and didn’t open his parachute until he was just 500 meters above ground.

Since first designing his wing, Rossy has performed more than 30 motorized flights, improving this first prototype with the help of his team. He’s looking to one day have take-off capability with his jet-powered wings. His motto for his test flights: “Always have Plan B ready.”

For more information about Fusionman, see his website. , or the English version

Original News Source: Brisbane Times, AFP

Posted on by Nancy Atkinson

How to Escape From a Black Hole

Black Hole surrounded by dust. Credit: ESA / V. Beckmann (NASA-GSFC)

According to Einstein’s theory of general relativity, black holes are regions of space where gravity is so strong that not even light can escape. And in the 1970’s physicist Stephen Hawking asserted that any information sucked inside a black hole would be permanently lost. But now, researchers at Penn State have shown that information can be recovered from black holes.

A fundamental part of quantum physics is that information cannot be lost, so Hawking’s claim has been debated. His idea was generally accepted by physicists until the late 1990s, when many began to doubt the assertion. Even Hawking himself renounced the idea in 2004. Yet no one, until now, has been able to provide a plausible mechanism for how information might escape from a black hole. A team of physicists led by Abhay Ashtekar, say their findings expand space-time beyond its assumed size, providing room for information to reappear.

Ashtekar used an analogy from Alice in Wonderland: “When the Cheshire cat disappears, his grin remains,” he said. “We used to think it was the same way with black holes. Hawking’s analysis suggested that at the end of a black hole’s life, even after it has completely evaporated away, a singularity, or a final edge to space-time, is left behind, and this singularity serves as a sink for unrecoverable information.”

But the Penn State team suggest that singularities do not exist in the real world. “Information only appears to be lost because we have been looking at a restricted part of the true quantum-mechanical space-time,” said Ashtekar. “Once you consider quantum gravity, then space-time becomes much larger and there is room for information to reappear in the distant future on the other side of what was first thought to be the end of space-time.”

According to Ashtekar, space-time is not a continuum as physicists once believed. Instead, it is made up of individual building blocks, just as a piece of fabric, though it appears to be continuous, is made up of individual threads. “Once we realized that the notion of space-time as a continuum is only an approximation of reality, it became clear to us that singularities are merely artifacts of our insistence that space-time should be described as a continuum.”

To conduct their studies, the team used a two-dimensional model of black holes to investigate the quantum nature of real black holes, which exist in four dimensions. That’s because two-dimensional systems are simpler to study mathematically. But because of the close similarities between two-dimensional black holes and spherical four-dimensional black holes, the team believes that this approach is a general mechanism that can be applied in four dimensions. The group now is pursuing methods for directly studying four-dimensional black holes.

The team’s work will be published in the May 20, 2008 issue of the journal Physical Review Letters.

Original News Source: Penn State Press Release

Posted on by Fraser Cain

How Did Venus Get its Name?

Venus is one of the 5 planets visible with the unaided eye. This means that ancient people knew of Venus, and tracked its movements in the sky. Venus is the second planet away from the Sun and is the brightest object in the sky aside from the Moon and the Sun and it appears 10x brighter than the brightest star in the sky, Sirius. The clouds of Venus reflect the light of the sun like a giant mirror.

Venus was named after the Roman Goddess of Love (in Greek, Aphrodite). In ancient times, Venus was known to the Babylonians as Ishtar, the goddess of womanhood and love, so the planet has a long standing tradition of being associated with amore. Furthermore, the symbol for the planet Venus is the symbol for womanhood; a circle with a cross on the bottom.

The ancient Egyptians and Greeks thought Venus was two separate bodies and named them The Morning Star and the Evening Star until in Hellenistic times, people figured out that it was only one object.

Posted on by Fraser Cain

How Long is a Day on Mercury

Using radio waves to calculate Mercury's orbit. Image credit: NASA

Mercury has very very long days. How long is one day on Mercury? Each day on Mercury lasts as long as 58 days, 15 hours on Earth. This is quite a feat, considering a whole year on Mercury is only 88 days.

I recommend you to read these amazing books for more information about the planet Mercury.

It gets even stranger, though. Because the orbit of Mercury is very eccentric, it reaches a point in its orbit when the speed of its orbital velocity matches its angular rotational velocity. When this happens, the Sun will appear to go backwards in the sky before it resumes its regular direction.

Astronomers used to think that Mercury was tidally locked to the Sun. In other words, its period of rotation matched its orbital period. In this situation, Mercury would always show the same side to the Sun. But in the 1960s, this was shown to be incorrect.

Cuánto tiempo es un día de Mercurio

Posted on by Nancy Atkinson

Pole Shift on Europa?

Curved features on Jupiter’s moon Europa may indicate that its poles have wandered by almost 90°, a new study reports. Researchers believe the drastic shift in Europa’s rotational axis was likely a result of the build-up of thick ice at the poles. “A spinning body is most stable with its mass farthest from its spin axis,” says Isamu Matsuyama of the Carnegie Institution’s Department of Terrestrial Magnetism. “On Europa, variations in the thickness of its outer shell caused a mass imbalance, so the rotation axis reoriented to a new stable state” An extreme shift like this also suggests the existence of an internal liquid ocean beneath the icy crust.

The research team, led by Dr. Paul Schenk of the Lunar and Planetary Institute and joined by Matsuyama and Dr. Francis Nimmo of the University of California, Santa Cruz, used images from the Voyager, Galileo, and New Horizons spacecraft to map several large arc-shaped depressions that extend more than 500 kilometers across Europa’s surface. With a radius of about 1500 kilometers, Europa is slightly smaller than the Earth’s moon.

By comparing the pattern of the depressions with fractures that would result from stresses caused by a shift in Europa’s rotational axis, the researchers determined that the axis had shifted by approximately 80°. The previous axis of rotation is now located about 10° from the present equator.

Such a change is called “true polar wander” as opposed to apparent polar wander caused by plate tectonics. There is evidence for true polar wander on Earth, and also on Mars and on Saturn’s moon Enceladus. “Our study adds Europa to this list,” says Matsuyama. “It suggests that planetary bodies might be more prone to reorientation than we thought.”

The study also has implications for liquid water inside Europa. Many scientists believe Europa has an extensive subsurface ocean based on spacecraft photos showing a fractured, icy surface. The ocean beneath the crust would be kept liquid by heat generated by tidal forces from Jupiter’s gravity. The presence of heat and water may make life possible, even though the subsurface ocean is cut off from solar energy.

“The large reorientation on Europa required to explain the circular depressions implies that its outer ice shell is decoupled from the core by a liquid layer,” says Matsuyama. “Therefore, our study provides an independent test for the presence of an interior liquid layer.”

Original News Source: EurekAlert

Posted on by Nancy Atkinson

New NASA Study Links Humans to Changes On Earth

Changes in glaciers. Image courtesy of MSNBC
A new NASA-led study shows human-caused climate change has made an impact on a wide range of Earth’s natural systems, including permafrost thawing, plants blooming earlier across Europe, and lakes declining in productivity in Africa. Researchers at NASA’s Goddard Institute for Space Science and 10 other institutions have linked varying impacts since 1970 with rises in temperatures during that period. “Humans are influencing climate through increasing greenhouse gas emissions,” said Cynthia Rosenzweig, lead author of the study. “The warming is causing impacts on physical and biological systems that are now attributable at the global scale and in North America, Europe, and Asia.”
Continue reading “New NASA Study Links Humans to Changes On Earth”

Posted on by Nancy Atkinson

The Big Announcement: Chandra, VLA Find Youngest Supernova in Our Galaxy

Astronomers have found the remains of the youngest supernova, or exploded star, in the Milky Way Galaxy. The supernova occurred in 1868, but was hidden behind a thick veil of gas and dust. Using the Very Large Array (VLA) and NASA’s Chandra X-Ray Observatory, which could peer through the veil, astronomers have now found “G1.9+0.3,” the first example of what scientists believe are a “missing population” of young supernova remnants. This is NASA’s long awaited announcement, and astronomers have been searching for over 50 years for this type of young supernova.

From observing supernovae in other galaxies, astronomers estimate that about three such stellar explosions should occur in our Milky Way every century. However, the most recent one known until now occurred around 1680, creating the remnant called Cassiopeia A. The newly-discovered object is the remnant of an explosion only about 140 years ago.

“It’s great to finally track one of them down,” said David Green of the University of Cambridge in the UK, who led the VLA study.

Supernovas mark the violent death of a star, and release tremendous amounts of energy and spew heavy elements such as calcium and iron into interstellar space. This seeds the clouds of gas and dust from which new stars and planets are formed.

The lack of evidence for young supernova remnants in the Milky Way had caused astronomers to wonder if our Galaxy, which appears otherwise normal, differed in some unknown way from others, or if our understanding of the relationship between supernovae and other galactic processes was in error.

Cassiopeia A supernova remnant — from the year 1680.

The astronomers made their discovery by measuring the expansion of the debris from the star’s explosion. They did this by comparing images of G1.9+0.3, made more than two decades apart.

In 1985, astronomers led by Green observed G1.9+0.3 with the VLA and identified it as a supernova remnant. At that time, they estimated its age as between 400 and 1,000 years. It is near the center of our Galaxy, roughly 25,000 light-years from Earth.

In 2007, another team of astronomers, led by Stephen Reynolds of North Carolina State University, observed the object with the Chandra X-Ray Observatory. To their surprise, their image showed
the object to be about 16 percent larger than in the 1985 VLA image.

“This is a huge difference. It means the explosion debris is expanding very quickly, which in turn means the object is much younger than we originally thought,” Reynolds explained.

However, this expansion measurement came from comparing a radio image to an X-ray image.

To make an “apples to apples” comparison, the scientists sought and were quickly granted observing time on the VLA which confirmed the supernova remnant’s rapid expansion.

The object already has provided surprises. The velocities of its explosion debris and extreme energies of its particles are unprecedented. “No other object in the Galaxy has properties like this,” said Reynolds. “Finding G1.9+0.3 is extremely important for learning more about how some stars explode and what happens in the aftermath.”

Original News Sources: Chandra site , National Radio Astronomy Observatory

Posted on by Nancy Atkinson

This Week’s “Where in the Universe?” Challenge

Here’s your image for this week’s “Where in the Universe?” challenge. Take a look at the image and before proceeding to the end of this post, make your guess as to what location in the universe is represented here. It could be anywhere — nothing is off limits for this challenge! Near or distant, far and wide, Universe Today spares no expense when it comes to searching for unique and unusual images to test your visual knowledge of our universe! Give yourself an extra point for guessing (or knowing) the feature shown here, and another point for naming the spacecraft that took this image. Just a couple more ticks on the timer here before revealing the awesome power of this week’s image….

Have you made your guess?

Here’s the answer:

These are cloud vortices found near Alaska, here on Earth. These are called von Karman cloud vortices, named after Theodore von Karman, co-founder of the Jet Propulsion Laboratory. These vortices near the Aleutian Islands were photographed by an Expedition 15 crewmember on the International Space Station. The vortices are created by the wind encountering a barrier such as an island, then changing direction and velocity and forming eddies in the wind and subsequently, in cloud patterns. The image was taken almost a year ago, on May 23, 2007 and the location of the image is at 51.1 degrees north latitude and 178.8 degrees west longitude.

In the cloud image above, the islands disturb the wind flow. As a prevailing wind encounters the island, the disturbance in the flow propagates downstream of the island in the form of a double row of vortices which alternate their direction of rotation. The animation below (courtesy of Cesareo de la Rosa Siqueira at the University of Sao Paulo, Brazil) shows how a von Karman vortex develops behind a cylinder moving through a fluid.

For you camera buffs out there, the image was taken with a Kodak DCS760C Electronic Still Camera.

How’d you do?

Original Source: Gateway to Astronaut Photography of Earth