NASA Helps Unravel Mysteries of Venusian Atmosphere

by Karen C. Fox
NASA’s Goddard Space Flight Center

Underscoring the vast differences between Earth and its neighbor Venus, new research shows a glimpse of giant holes in the electrically charged layer of the Venusian atmosphere, called the ionosphere. The observations point to a more complicated magnetic environment than previously thought – which in turn helps us better understand this neighboring, rocky planet.

Planet Venus, with its thick atmosphere made of carbon dioxide, its parched surface, and pressures so high that landers are crushed within a few hours, offers scientists a chance to study a planet very foreign to our own. These mysterious holes provide additional clues to understanding Venus’s atmosphere, how the planet interacts with the constant onslaught of solar wind from the sun, and perhaps even what’s lurking deep in its core…

(read more: NASA - Goddard)

Scientists Find Evidence for Tectonic Plates on Jupiter’s Moon Europa

Scientists have found evidence of plate tectonics on Jupiter’s moon Europa. This indicates the first sign of this type of surface-shifting geological activity on a world other than Earth.

Researchers have clear visual evidence of Europa’s icy crust expanding. However, they could not find areas where the old crust was destroyed to make room for the new. While examining Europa images taken by NASA’s Galileo orbiter in the early 2000s, planetary geologists Simon Kattenhorn, of the University of Idaho, Moscow, and Louise Prockter, of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, discovered some unusual geological boundaries.

"We have been puzzled for years as to how all this new terrain could be formed, but we couldn’t figure out how it was accommodated," said Prockter. "We finally think we’ve found the answer."

Plate tectonics is the scientific theory that Earth’s outer layer is made up of plates or blocks that move, which accounts for why mountain and volcanoes form and earthquakes happen…

(read more: Jet Propulsion Laboratory)

Image: Noah Kroese, I.NK

The Hubble Ultra-Deep Field (HUDF) is an image of a small region of space in the constellation Fornax, composited from Hubble Space Telescope data accumulated over a period from September 24, 2003, through January 16, 2004, and released in 2004. Covering 2.4 arcminutes to an edge, the area was selected because of the low density of bright stars in the near-field, allowing much better viewing of dimmer, more distant objects. It required 400 rotations and a million seconds (11.6 days) of exposure to obtain sufficient light for producing this image, which contains an estimated 10,000 galaxies.
 Image: NASA
(via: Wikipedia)

The Hubble Ultra-Deep Field (HUDF) is an image of a small region of space in the constellation Fornax, composited from Hubble Space Telescope data accumulated over a period from September 24, 2003, through January 16, 2004, and released in 2004. Covering 2.4 arcminutes to an edge, the area was selected because of the low density of bright stars in the near-field, allowing much better viewing of dimmer, more distant objects. It required 400 rotations and a million seconds (11.6 days) of exposure to obtain sufficient light for producing this image, which contains an estimated 10,000 galaxies.

Image: NASA

(via: Wikipedia)

The Carina Nebula is a large bright nebula that has within its boundaries several related open clusters of stars. Discovered by Nicolas Louis de Lacaille in 1751–52, it is only visible from the Southern Hemisphere. Located an estimated distance between 6,500 and 10,000 light years from Earth, it is one of the largest diffuse nebulae in the planet’s skies and home to such stars as Eta Carinae and HD 93129A.
 Photo: European Southern Observatory/T. Preibisch
(via: Wikipedia)

The Carina Nebula is a large bright nebula that has within its boundaries several related open clusters of stars. Discovered by Nicolas Louis de Lacaille in 1751–52, it is only visible from the Southern Hemisphere. Located an estimated distance between 6,500 and 10,000 light years from Earth, it is one of the largest diffuse nebulae in the planet’s skies and home to such stars as Eta Carinae and HD 93129A.

Photo: European Southern Observatory/T. Preibisch

(via: Wikipedia)

A solar flare, a sudden flash of brightness observed over the Sun's surface or the solar limb which is interpreted as a large energy release, recorded on August 31, 2012. Such flares are often, but not always, followed by a colossal coronal mass ejection; in this instance, the ejection traveled at over 900 miles (1,400 km) per second.
Photo: On August 31, 2012 a long filament of solar material that had been hovering in the sun’s atmosphere, the corona, erupted out into space at 4:36 p.m. EDT. The coronal mass ejection, or CME, traveled at over 900 miles per second. The CME did not travel directly toward Earth, but did connect with Earth’s magnetic environment, or magnetosphere, causing aurora to appear on the night of Monday, September 3. Pictured here is a lighten blended version of the 304 and 171 angstrom wavelengths taken from the Solar Dynamics Observatory.
(via: Wikipedia)

A solar flare, a sudden flash of brightness observed over the Sun's surface or the solar limb which is interpreted as a large energy release, recorded on August 31, 2012. Such flares are often, but not always, followed by a colossal coronal mass ejection; in this instance, the ejection traveled at over 900 miles (1,400 km) per second.

Photo: On August 31, 2012 a long filament of solar material that had been hovering in the sun’s atmosphere, the corona, erupted out into space at 4:36 p.m. EDT. The coronal mass ejection, or CME, traveled at over 900 miles per second. The CME did not travel directly toward Earth, but did connect with Earth’s magnetic environment, or magnetosphere, causing aurora to appear on the night of Monday, September 3. Pictured here is a lighten blended version of the 304 and 171 angstrom wavelengths taken from the Solar Dynamics Observatory.

(via: Wikipedia)

On August 24, 2014, the sun emitted a mid-level solar flare, peaking at 8:16 a.m. EDT.

Here are some captured images of the flare, which erupted on the left side of the sun. Solar flares are powerful bursts of radiation. Harmful radiation from a flare cannot pass through Earth’s atmosphere to physically affect humans on the ground, however — when intense enough — they can disturb the atmosphere in the layer where GPS and communications signals travel.

This flare is classified as an M5 flare. M-class flares are ten times less powerful than the most intense flares, called X-class flares.

Credit: NASA/Goddard/SDO

More here: NASA Little Solar Dynamics Observatory

Water Clouds Tentatively Detected Just 7 Light Years From Earth
by Ken Crosswell
Astronomers have found signs of water ice clouds on an object just 7.3 light-years from Earth—less than twice the distance of Alpha Centauri, the nearest star system to the sun. If confirmed, the discovery is the first sighting of water clouds beyond our solar system. The clouds shroud a Jupiter-sized object known as a brown dwarf and should yield insight into the nature of cool giant planets orbiting other suns.
Kevin Luhman, an astronomer at Pennsylvania State University, University Park, recently discovered the nearby object by using images from NASA’s WISE infrared space telescope, which scanned the sky from 2010 to 2011. A brown dwarf is a failed star and has so little mass that it can’t sustain nuclear reactions, so after its birth it fades and cools. This brown dwarf, named WISE J0855-0714, is the coldest known. Its temperature is slightly below the freezing point of water, so it’s colder than Earth’s mean temperature but warmer than Jupiter’s…
(read more: Science News/AAAS)
illustration: Rob Gizis, CUNY BMCC

Water Clouds Tentatively Detected Just 7 Light Years From Earth

by Ken Crosswell

Astronomers have found signs of water ice clouds on an object just 7.3 light-years from Earth—less than twice the distance of Alpha Centauri, the nearest star system to the sun. If confirmed, the discovery is the first sighting of water clouds beyond our solar system. The clouds shroud a Jupiter-sized object known as a brown dwarf and should yield insight into the nature of cool giant planets orbiting other suns.

Kevin Luhman, an astronomer at Pennsylvania State University, University Park, recently discovered the nearby object by using images from NASA’s WISE infrared space telescope, which scanned the sky from 2010 to 2011. A brown dwarf is a failed star and has so little mass that it can’t sustain nuclear reactions, so after its birth it fades and cools. This brown dwarf, named WISE J0855-0714, is the coldest known. Its temperature is slightly below the freezing point of water, so it’s colder than Earth’s mean temperature but warmer than Jupiter’s…

(read more: Science News/AAAS)

illustration: Rob Gizis, CUNY BMCC

The Cosmic Web:
Observations and simulations of the intergalactic medium reveal the largest structures in the universe
by Robert Simcoe

There is no such thing as empty space. The idea of absolute emptiness realizes its closest approximation in the barren expanses between the stars and the galaxies, but even the most remote corners of the universe are suffused with very low density gas—which becomes increasingly rarefied as one ventures farther away from the places where galaxies consort.
Consider this fact: In the air we breathe, each cubic centimeter contains roughly 5 X 1019 atoms. In contrast, the intergalactic medium has a density of only 10–6 particles per cubic centimeter—each atom inhabits a private box a meter on each side.
This would seem to suggest that there is not much matter in the intergalactic medium. But, given the enormous volume between the galaxies, it quickly adds up: The combined atomic mass of intergalactic gas exceeds the combined atomic mass of all the stars and galaxies in the universe—possibly by as much as 50 percent! There is indeed something in empty space.
As cosmologists construct new narratives of the universe’s evolution from its beginning—the Big Bang—to the present day, it is becoming clear that we must understand the physics of intergalactic matter if we are to write the history of how the galaxies, stars and planets formed. In the past decade, rapid advances in both the design of telescopes and computing power have allowed us to study the remote corners of intergalactic space in unprecedented detail. These new results deepen our understanding of how the grandest structures in the universe formed and evolved…
(read more: American Scientist)
Images courtesy of Renyue Cen, Princeton University

The Cosmic Web:

Observations and simulations of the intergalactic medium reveal the largest structures in the universe

by Robert Simcoe

There is no such thing as empty space. The idea of absolute emptiness realizes its closest approximation in the barren expanses between the stars and the galaxies, but even the most remote corners of the universe are suffused with very low density gas—which becomes increasingly rarefied as one ventures farther away from the places where galaxies consort.

Consider this fact: In the air we breathe, each cubic centimeter contains roughly 5 X 1019 atoms. In contrast, the intergalactic medium has a density of only 10–6 particles per cubic centimeter—each atom inhabits a private box a meter on each side.

This would seem to suggest that there is not much matter in the intergalactic medium. But, given the enormous volume between the galaxies, it quickly adds up: The combined atomic mass of intergalactic gas exceeds the combined atomic mass of all the stars and galaxies in the universe—possibly by as much as 50 percent! There is indeed something in empty space.

As cosmologists construct new narratives of the universe’s evolution from its beginning—the Big Bang—to the present day, it is becoming clear that we must understand the physics of intergalactic matter if we are to write the history of how the galaxies, stars and planets formed. In the past decade, rapid advances in both the design of telescopes and computing power have allowed us to study the remote corners of intergalactic space in unprecedented detail. These new results deepen our understanding of how the grandest structures in the universe formed and evolved…

(read more: American Scientist)

Images courtesy of Renyue Cen, Princeton University

A giant, 100-foot-diameter (30 meters) telescope has been green-lighted for construction on the island of Hawaii.

When it begins operations, TMT will enable astronomers to explore objects inside the solar system, stars throughout the Milky Way and neighboring galaxies, and forming galaxies at the farthest edge of the observable universe…

Cassiopeia A - A Star Explodes and Turns Inside Out
A new X-ray study of the remains of an exploded star indicates that the supernova that disrupted the massive star may have turned it inside out in the process. Using very long observations of Cassiopeia A (or Cas A), a team of scientists has mapped the distribution of elements in the supernova remnant in unprecedented detail. This information shows where the different layers of the pre-supernova star are located three hundred years after the explosion, and provides insight into the nature of the supernova…
(read more: Chandra X-Ray Observatory)
image: Illustration: NASA/CXC/M.Weiss; X-ray: NASA/CXC/GSFC/U.Hwang & J.Laming

Cassiopeia A - A Star Explodes and Turns Inside Out

A new X-ray study of the remains of an exploded star indicates that the supernova that disrupted the massive star may have turned it inside out in the process. Using very long observations of Cassiopeia A (or Cas A), a team of scientists has mapped the distribution of elements in the supernova remnant in unprecedented detail. This information shows where the different layers of the pre-supernova star are located three hundred years after the explosion, and provides insight into the nature of the supernova…

(read more: Chandra X-Ray Observatory)

image: Illustration: NASA/CXC/M.Weiss; X-ray: NASA/CXC/GSFC/U.Hwang & J.Laming

Planetary Nebulas - Fast Winds From Dying Stars
This panel of composite images shows part of the unfolding drama of the last stages of the evolution of sun-like stars.
Dynamic elongated clouds envelop bubbles of multimillion degree gas produced by high-velocity winds from dying stars. In these images, Chandra’s X-ray data are shown in blue, while green and red are optical and infrared data from Hubble.
Planetary nebulas - so called because some of them resemble a planet when viewed through a small telescope - are produced in the late stages of a sun-like star’s life. After several billion years of stable existence (the sun is 4.5 billion years old and will not enter this phase for about 5 billion more years) a normal star will expand enormously to become a bloated red giant. Over a period of a few hundred thousand years, much of the star’s mass is expelled at a relatively slow speed of about 50,000 miles per hour…
(read more: Chandra X-Ray Observatory)

Planetary Nebulas - Fast Winds From Dying Stars

This panel of composite images shows part of the unfolding drama of the last stages of the evolution of sun-like stars.

Dynamic elongated clouds envelop bubbles of multimillion degree gas produced by high-velocity winds from dying stars. In these images, Chandra’s X-ray data are shown in blue, while green and red are optical and infrared data from Hubble.

Planetary nebulas - so called because some of them resemble a planet when viewed through a small telescope - are produced in the late stages of a sun-like star’s life. After several billion years of stable existence (the sun is 4.5 billion years old and will not enter this phase for about 5 billion more years) a normal star will expand enormously to become a bloated red giant. Over a period of a few hundred thousand years, much of the star’s mass is expelled at a relatively slow speed of about 50,000 miles per hour…

(read more: Chandra X-Ray Observatory)

A Watery, Extraterrestrial Ocean Is Submerged Beneath Enceladus’s Blankets of Ice
by Allison Eck
Move over, Mars. In the search for extraterrestrial life, moons are now in the limelight.
Enceladus, one of the Ringed Planet’s icy and austere orbiters has been on astronomers’ shortlist of potential hosts of alien life, especially since they discovered geysers of ice crystals shooting out of its south pole in 2005. They hypothesized that a deep ocean the size of Lake Superior sits underneath its highly tectonic and veiny surface, potentially feeding those gushers.
Normally, liquid water couldn’t exist that far out in the solar system, but the gravitational pull of Enceladus’s neighbor, Dione, bends the icy moon’s outer layer, creating heat through friction. NASA’s Cassini spacecraft has repeatedly flown by the surface of Enceladus to better understand the temperature dynamics that create these explosive geysers…
(read more: Nova Next - PBS)

A Watery, Extraterrestrial Ocean Is Submerged Beneath Enceladus’s Blankets of Ice

by Allison Eck

Move over, Mars. In the search for extraterrestrial life, moons are now in the limelight.

Enceladus, one of the Ringed Planet’s icy and austere orbiters has been on astronomers’ shortlist of potential hosts of alien life, especially since they discovered geysers of ice crystals shooting out of its south pole in 2005. They hypothesized that a deep ocean the size of Lake Superior sits underneath its highly tectonic and veiny surface, potentially feeding those gushers.

Normally, liquid water couldn’t exist that far out in the solar system, but the gravitational pull of Enceladus’s neighbor, Dione, bends the icy moon’s outer layer, creating heat through friction. NASA’s Cassini spacecraft has repeatedly flown by the surface of Enceladus to better understand the temperature dynamics that create these explosive geysers…

(read more: Nova Next - PBS)