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16Jul 2012

Solar Winds – Energy From Space

The relationship between the Earth and Sun is interwoven and intimate. The high temperature and pressure creates disturbances in the Sun’s corona that produce solar winds. These winds affect the atmosphere not only on Earth, but also other planets throughout the solar system as well. The image above displays solar winds around Venus. Stunning!

What Are Solar Winds?

Solar winds are streams of high-speed particles that are ejected from the upper atmosphere of the Sun. They consist mainly of protons and electrons that blow out in every direction from the Sun’s corona.

What Causes Solar Winds?

Scientists are still studying the cause of these solar ejections. They appear to occur in relationship to loss of mass in the Sun’s surface. The particles are flung outward from the corona in a thin, plasma stream. When these charged particles reach the terminal velocity of 400 kilometers per second, they begin to feed the solar wind. The particles escape the Sun’s gravity through kinetic energy and the extremely high temperatures of the corona.

Components of Solar Wind

Solar wind generally comes in two types: slow solar wind and fast solar wind. Slow solar winds are thought to originate near the Sun’s equator. These winds are associated with closed solar field lines that cause them to move slower. Fast solar winds extend eject from coronal holes through open magnetic field lines. The lines do not impede the speed of the charged particles, and therefore they move faster.

Solar Winds and CMEs

Coronal mass ejections, often called CMEs, are bubbles of charged gas that erupt from the Sun’s corona. They occur when magnetic field lines twist to form solar flares and become so warped that they stretch like rubber bands. These flares will eventually snap, break and reconnect at other points. The gaps that form when this happens can no longer hold the Sun’s plasma on its surface and it explodes into space. The constant stream of charged particles that are the solar wind then carries this hot plasma cloud to the Earth’s magnetic sphere. CMEs bring increased radiation to our atmosphere, as well as charged particles of matter that interact with the magnetic field that surrounds the Earth. CMEs generally reach the Earth within 1 to 5 days or eruption.

Effects of Solar Winds

Solar winds cause effects that can be detected on Earth. The increase energy from the winds flows into the magnetosphere that surrounds the Earth, causing magnetospheric substorms in the polar regions. When the solar wind collides with the Earth’s ionosphere, atmospheric particles become excited. They must release this additional energy to return to their normal state. When the energy is released, they cause the aurora, or northern lights, that are seen as bursts of colored, dancing light. The wind also brings increased radiation to the atmosphere, which can damage electronic equipment and can be a hazard to astronauts in space.

Image Credit: ESA (Image by C. Carreau)

Solar Storm Bombarding Earth(thesciencebulletin.wordpress.com)
Incoming! CME On Its Way Toward Earth(universetoday.com)
Moon patterns explained(sciencenews.org)
Laura Bruno – Mercury Retrograde, X-Class Flare, and Aura, Oh, My! – 14 July 2012(lucas2012infos.wordpress.com)
Jamers Tyberonn – On X-Class In Mercury Retro – Fasten Your Seat Belts – 14 July 2012(lucas2012infos.wordpress.com)

09May 2012

VISTA Views a Vast Ball of Stars

Jason Carr ⋅ Leave a Comment

Globular clusters are held together in a tight spherical shape by gravity. In Messier 55, the stars certainly do keep close company: approximately one hundred thousand stars are packed within a sphere with a diameter of only about 25 times the distance between the Sun and the nearest star system, Alpha Centauri. Read More →

13Apr 2012

A New First – Uranus Auroras Glimpsed from Earth

Jason Carr ⋅ 3 Comments

These composite images show Uranus auroras,

For the first time, scientists have captured images of auroras above the giant ice planet Uranus, finding further evidence of just how peculiar a world that distant planet is. Detected by means of carefully scheduled observations from the Hubble Space Telescope, the newly witnessed Uranian light show consisted of short-lived, faint, glowing dots – a world of difference from the colorful curtains of light that often ring Earth’s poles. Read More →

09Apr 2012

Spotting Something New On the Sun

Jason Carr ⋅ Leave a Comment

One day in the fall of 2011, Neil Sheeley, a solar scientist at the Naval Research Laboratory in Washington, D.C., did what he always does – look through the daily images of the sun from NASA’s Solar Dynamics Observatory (SDO).

But on this day he saw something he’d never noticed before: a pattern of cells with bright centers and dark boundaries occurring in the sun’s atmosphere, the corona. These cells looked somewhat like a cell pattern that occurs on the sun’s surface — similar to the bubbles that rise to the top of boiling water — but it was a surprise to find this pattern higher up in the corona, which is normally dominated by bright loops and dark coronal holes. Read More →

26Mar 2012

NASA Measures Impact of Solar Flare on Earth’s Atmosphere

Jason Carr ⋅ Leave a Comment

A key NASA instrument that can directly measure the impact of solar events on the Earth’s upper atmosphere has weighed in on the huge flare that impacted Earth last week.

The flare was considered one of the largest solar events in years even though its impact on the power grid and communications was minimal due to the angle it hit Earth.

Its direct interaction with the upper atmosphere was measured by NASA’s SABER (Sounding of the Atmosphere using Broadband Emission Radiometry) instrument orbiting on the TIMED (Thermosphere, Ionosphere, Mesosphere, Energetics and Dynamics) satellite.

The upper atmosphere heated up, and huge spikes occurred in infrared emission from nitric oxide and carbon dioxide, said Marty Mlynczak, SABER’s associate-principal investigator at NASA’s Langley Research Center in Hampton, Va.

Sol ‘waking up’

“It’s been seven years since we’ve had a storm like that,” he said. “This is the first major storm event since the deep solar minimum of 2008-2009. We are finally seeing the Sun ‘wake up’ as it proceeds to the next solar maximum.”

A solar maximum is a period of increased activity on the Sun, and minimum-to-maximum-to-minimum cycles generally last 11 years each. Solar activity began to pick up in 2010, is steadily increasing and should peak in late 2014.

As the Sun becomes more active, Mlynczak said, it emits more ultraviolet radiation and produces more solar flares – coronal mass ejections (CMEs) – which are absorbed in the atmosphere. “More heating results, and the atmosphere gets warmer, and the infrared emission increases,” he said.

“We don’t know yet how these affect weather or climate — likely there is not any direct effect,” he said, “but there may be, over time, influences on ozone that affect climate.”

“These results are very timely,” said James Russell, SABER’s principal investigator at Hampton University in Hampton, Va. ”SABER is cataloging the atmospheric response to solar forcing and is providing a solid baseline for examining long-term changes in the climatology of the upper atmosphere.”

“The data set is a vital resource for study of atmospheric trends, for validating atmospheric models of the region, and for evaluating our understanding of solar/atmosphere coupling, he said.

Unique Record

SABER is one of four instruments on the TIMED spacecraft launched in December 2001. TIMED studies the Earth’s mesosphere and lower thermosphere, the least explored and least understood region of our atmosphere.

“SABER has a unique, continuous record of over 3,700 days observation of the climate and energy balance of the Earth’s upper and outer atmosphere,” Mlynczak said.

“From this, we are learning with each event how sensitive this region of the Earth’s atmosphere is to short- and long-term variability of the Sun,” he said. “We have documented the decline of the prior solar cycle, the deep minimum and the ‘ground state’ of the atmosphere during that time, and are now seeing the uptick.”

TIMED was designed to operate for two years but has operated flawlessly for more than 10 years. Another NASA review is planned in 2013 to determine if SABER will continue operating for at least three more years.

“This is well before the predicted solar maximum,” Mlynczak said. There are no other measurements like it, and the entire SABER science team is working hard to make the scientific case to keep the mission operating.”

Partners in the SABER mission include Hampton University in Hampton, Va.; Science Systems and Applications, Inc.; GATS Inc.; NASA’s Goddard Spaceflight Center in Greenbelt, Md.; and Johns Hopkins University Applied Physics Laboratory in Laurel, Md. Utah State University Space Dynamics Laboratory built SABER.

Michael Finneran
NASA Langley Research Center

For more information about Langley go to http :// www . nasa . gov / langley

Source: NASA

Image Credit: Credit: NASA/JHU/APL

Earth-Like Atmospheric Waves Found on Jupiter (news.softpedia.com)
Solar Storm Dumps Gigawatts into Earth’s Upper Atmosphere (physicsforme.wordpress.com)
NASA sees second biggest flare of the solar cycle (eurekalert.org)
Japan shares space station SMILES via atmospheric data distribution (sciencedaily.com)
March 6 flares second biggest of solar cycle (scienceblog.com)
Two powerful ‘X-class’ flares erupt on sun (csmonitor.com)
NASA’s Footage of a Massive X-Class Solar Flare (theatlantic.com)
Sun Fires Off 2 Huge Solar Flares in One-Two Punch (livescience.com)

18Feb 2012

Let’s Explore Photosynthesis on Exoplanets

Jason Carr ⋅ 2 Comments

Imagine an astronaut stepping out of a spacecraft onto the surface of an extrasolar planet that is capable of sustaining life. Now imagine the astronaut is greeted by the sight of red colored trees and grass. Such a scenario could be more reality than science fiction because of the variances in photosynthesis theorized to exist in other parts of the Milky Way Galaxy.

Photosynthesis occurs in plants when they use sunlight to create foods from carbon dioxide and water. This process of converting energy from sunlight into chemical energy produces oxygen and causes chlorophyll to form. It is chlorophyll that is responsible for imbuing plants with a healthy green color. The reason this happens is because chlorophyll absorbs more blue and red light waves and fewer green light waves from sunlight. Reflecting the green light waves is what causes the plants to appear green to the human eye.

When the Sun in our solar system radiates light, it reaches the Earth in a particular distribution of colors. As this sunlight passes through the Earth’s atmosphere, the various gases that comprise the atmosphere filter out certain colors before they strike the surface of the Earth. Much of the color that is not absorbed in the atmosphere is red, blue or green. Plants tend to absorb a greater amount of red and blue rays and reflect back green.

Some scientists think that plant life growing under the rays of an extraterrestrial sun could reflect colors other than green after the photosynthesis process is completed. The color that is most commonly visible on alien plants correlates with how colors are distributed in the light radiated by the parent star that strikes the surface of the extraterrestrial world.

The spectral type of a main sequence star can have a direct impact on the coloring of plants. For that reason, coloring can vary from star to star if the spectral type for each star also shows some variance. In a scientific paper published in the March, 2007 issue of Astrobiology magazine, a team of scientists examined how light emitted by another sun would appear from the vantage point of a planet orbiting that host star. Nancy Kiang, author of the paper, said the scientific team determined that the atmosphere of any extrasolar Earth-like planet would feature a chemical composition that is compatible with the chemical composition of its host star. How light from that star is seen on the planet’s surface would be affected by how it is filtered through the atmosphere as it reaches the surface.

Kiang, who works with the Goddard Institute for Space Sciences at NASA, and her team conducted an extensive study where they modeled how sunlight would reach the surface of Earth-sized planets that are hospitable to life from stars of varying spectral types. Kiang’s team speculated that each planet could experience different dominant colors that emerge in plants through photosynthesis based on how hot or cool the sun is that is anchoring that solar system.

Plant life existing on other worlds is not guaranteed to mimic the appearance of plants we are accustomed to seeing on Earth. Planets revolving around a blue star could feature plant life that has a dominant color of yellow or orange and this could lend to forests that boast autumn type colors throughout the growing season on those planets. If a habitable world is located in a binary star system or multi-star system, it could cause some exotic variations in how the plant life grows and appears to the human eye after going through photosynthesis. These planets could have plants that are almost black in color.

In the case of habitable planets around red dwarf stars, all plant life would likely exist underwater. The proximity of the habitable zone around the star would make it difficult for plants to fend off ultraviolet radiation because they could not generate enough energy from infrared light through photosynthesis to create sufficient oxygen to block ultraviolet radiation penetrating the atmosphere.

The idea that differences exist in the photosynthesis process from one planet to the next changes how astrobiologists search for evidence of life on other worlds outside our own solar system. It reinforces the idea that plant and animal life alike have evolved and adapted to fit the unique conditions of this Earth as well as reinforcing the notion that life on other habitable planets would evolve to survive and thrive in a similar manner on other planets. What do you think? Is photosynthesis the same on all planets or do you think it will be vastly different?

References:
Kiang, N., Siefert, J., Govindjee, ., & Blankenship, R. (2007). Spectral Signatures of Photosynthesis. I. Review of Earth Organisms Astrobiology, 7 (1), 222-251 DOI: 10.1089/ast.2006.0105

Kiang, N., Segura, A., Tinetti, G., Govindjee, ., Blankenship, R., Cohen, M., Siefert, J., Crisp, D., & Meadows, V. (2007). Spectral Signatures of Photosynthesis. II. Coevolution with Other Stars And The Atmosphere on Extrasolar Worlds Astrobiology, 7 (1), 252-274 DOI: 10.1089/ast.2006.0108