Tag: field (page 6 of 43)

More People Reporting Wi-Fi Is Making Them Sick

Marco Torres, Prevent DiseaseWi-Fi signals are, unlike TV and radio signals, strong enough to penetrate concrete walls. Many health experts consider Wi-Fi radiation to be extremely dangerous to long-term health. Based on the existing science, many public health experts believe it is possible we will face an epidemic of cancers in the future resulting from uncontrolled use of cell phones and increased population exposure to Wi-Fi and other wireless devices. Now more people than ever are repo [...]

View Full Article   Read More

Spring Cleaning Tips for Body, Mind and Spirit

Excerpt from huffingtonpost.comAn extended winter throughout much of the U.S. and Canada really cut into the enjoyment of the spring season this year for many. One of our coaching students sent me photos of over a foot of snow this past May weekend...

View Full Article   Read More

Sea Salt Discovered on Jupiter’s Moon Europa

This image shows a view of the trailing hemisphere of Jupiter's ice-covered satellite, Europa, in approximate natural color. Long, dark lines are fractures in the crust, some of which are more than 3,000 kilometers (1,850 miles) long.   Image via Galileo spacecraft in 1996.

Europa is thought to have a subsurface ocean. Salt from this hidden sea might be emerging in long fractures visible in the moon’s crust.



Excerpt earthsky.org


Laboratory experiments have lead to new information about the chemical composition of the mysterious dark material in the long, dark fractures on the surface of Europa, a large moon of Jupiter. Researchers at NASA’s Jet Propulsion Laboratory (JPL) mimicked conditions on Europa’s surface. They now say that the dark material is discolored salt, likely sea salt from below the moon’s icy crust. The journal Geological Research Letters published their study on May 15, 2015.

The scientists say this new insight is important in considering whether this icy moon might be hospitable for extraterrestrial life. The life question is a key one for Europa, since this world is believed to have a liquid ocean beneath its crust. The presence of sea salt on Europa’s surface suggests the ocean is interacting with its rocky seafloor.

Scientists have been intensely curious about Europa since Galileo discovered it in 1610. In recent years, they’ve puzzled over the dark material coating the long, linear fractures on Europa’s observable surface. The material was associated with young terrain on this moon of Jupiter, suggesting that it had erupted from within Europa.
However, the chemical composition of the dark material remained elusive, until now.
Planetary scientist Kevin Hand at JPL led the new study. He said in a statement:
If it’s just salt from the ocean below, that would be a simple and elegant solution for what the dark, mysterious material is.
Europa is immersed radiation from Jupiter’s powerful magnetic field, causing high-powered electrons to slam into the moon’s surface. Hand and his team created a laboratory test that mimicked the conditions of Europa’s temperature, pressure, and radiation exposure. They tested a variety of samples including common salt – sodium chloride – and salt water in a vacuum chamber at Europa’s chilly surface temperature of minus 280 degrees Fahrenheit (minus 173 Celsius). They also bombarded the samples with an electron beam to imitate Jupiter’s influence. 

After several hours – a time period corresponding to over a century on Europa, the researchers said – the salt samples were observed to go from white to a yellowish brown, the color similar to the features on the icy moon. Hand said:
This work tells us the chemical signature of radiation-baked sodium chloride is a compelling match to spacecraft data for Europa’s mystery material.
A
A “Europa-in-a-can” laboratory setup at NASA-JPL mimics conditions of temperature, near vacuum and heavy radiation on the surface of Jupiter’s icy moon. Image via NASA/JPL-Caltech


A close-up of salt grains discolored by radiation following exposure in a
Close-up of salt grains discolored by radiation following exposure in a “Europa-in-a-can” test setup at JPL. Image via NASA/JPL-Caltech


Until now, telescopic observations have only shown glimpses of irradiated salts. No telescope on Earth can observe Europa’s surface with enough resolution to identify them with certainty. Researchers suggest additional spacecraft observation to gather more evidence.
A visit to this icy world would help answer the most tantalizing questions about Europa. Long believed to have a liquid ocean of salt water below its icy surface, this moon continues to display promising conditions for extraterrestrial life. 

As Europa orbits Jupiter, it experiences strong tidal forces similar to Earth and the Moon. These forces from Jupiter and the other Jovian moons cause Europa to flex and stretch, which creates heat, and results in Europa having a warm internal temperature than it would with just the heat from the Sun alone. 

Recent observable geological activity also creates strong evidence that the subsurface ocean interacts directly with Europa’s rocky interior, making geothermal vents, like those in Earth’s oceans, a strong possibility as well. 

These hydrothermal vent ecosystems on Earth thrive with no energy from the sun. Bacteria, shrimp and crustaceans have all been observed in these extreme environments, surviving on what researchers have deemed chemosythesis.

With Europa’s enormous amount of liquid salt water, essential chemical elements and geological activity, this long discovered icy moon appears to be one of the solar systems most promising locations for habitable requirements for life. 

However, until a devoted spacecraft visit’s, nothing beyond hopeful speculation can be proven, the researchers say.

Bottom line: Researchers at NASA’s Jet Propulsion Laboratory created laboratory conditions that mimicked those on Jupiter’s large moon Europa, to learn the chemical compositions of the material in long, dark fractures in the moon’s surface. They now believe this material is sea salt, which has emerged to Europa’s surface from its liquid ocean below.

View Full Article   Read More

Super Alien Civilizations: What Do They Really Want?

Excerpt from huffingtonpost.comHighly advanced aliens seem MIA, according to a recent study by astronomers at Penn State University. These researchers checked out a huge gob of cosmic real estate -- roughly 100,000 galaxies -- and failed to find cl...

View Full Article   Read More

Mercury’s Mysterious Magnetic Past Goes Back 4 Billion Years

 Excerpt from sci-tech-today.com Examining rocks on Mercury's surface, scientists using data from NASA's Messenger spacecraft have revealed that the planet probably had a much stronger magnetic field nearly 4 billion years ago.  The fi...

View Full Article   Read More

What astronomers learned when Messenger space probe crashed into Mercury



Excerpt from statecolumn.com


On April 30, NASA concluded an historic voyage known as the Mercury Surface, Space Environment, Geochemistry and Ranging mission. The mission came to an end when the spacecraft carrying analytical instruments, Messenger, crashed into the planet’s surface after consuming all of its fuel.
The mission was far from a waste, however, as NASA rarely expects to see the majority of the spacecraft they launch ever again. According to Discovery, The probe sent back a spectacular photo of the surface of Mercury, using the craft’s Narrow Angle Camera in tandem with the Mercury Dual Imaging System. The photo shows a mile-wide view of the nearby planet’s surface in 2.1 meters per pixel resolution.
Right after the probe delivered the photo to NASA’s Deep Space Network, which is a collection of global radio antennae that tracks data on the agency’s robotic missions around the solar system, the signal was lost in what scientists assume was the craft’s final contact with the closest planet to the sun.
The four-year mission came to an end when the craft could no longer maintain its orbit around the solar system’s innermost planet due to lack of fuel. Mercury is just 36 miles from the sun, compared to Earth, which is 93 million miles away from the center of the solar system. Mercury is a peculiar world, with both frigid and extremely hot temperatures. Messenger also revealed that Mercury has a magnetic field similar to that of Earth’s, created by the motion of metallic fluids within the planet’s core.
The main challenge the Messenger mission faced was getting the space probe into orbit around Mercury. Due to the planet’s proximity to the sun, it was extremely difficult for flight engineers to avoid its gravitational pull. In addition to the challenge of catching Mercury’s comparatively weak gravitational force, high temperatures also made things tricky. Messenger was equipped with a sunshield designed to protect the spaceship cool on the side that faced the sun. NASA engineers also attempted to chart a long, elliptical orbit around Mercury, giving Messenger time to cool off as it rounded the backside of the planet.
Messenger made over 4,000 orbits around Mercury between 2011 and 2015, many more than the originally planned one-year mission would allow.
With the close-up shots of Mercury’s surface provided by Messenger, NASA scientists were able to detect trace signals of magnetic activity in Mercury’s crust. Using clues from the number of impact craters on the surface, scientists figured that Mercury’s magnetized regions could be as old as 3.7 billion years. Astronomers count the craters on a planet in order to estimate its age – the logic being that younger surfaces should have fewer impact sites than older surfaces.
The data sent back by Messenger has caused astronomers to reconsider their understanding of Mercury’s magnetic history. They now date the beginning of magnetism on Mercury to about 700 million years after the planet was formed. They cannot say for sure, however, if the magnetic field has been consistently active over this timeframe.
According to Messenger guest investigator Catherine Johnson, geophysicist at the University of British Columbia in Vancouver, that it was possible the magnetic field has been active under constant conditions, though she suspects it might also oscillate over time, like Earth’s. Information for the time period between 4 billion years ago and present day is sparse, though Johnson added that additional research is in the pipeline.
Johnson was pleased, however, with the insight offered into Mercury’s formation provided by these new magnetic clues. Magnetism on a planetary scale typically indicates a liquid metal interior. Since Mercury is so tiny, scientists originally believed that its center would be solid, due to the rate of cooling. The presence of liquid in the planet’s center suggests other materials’ presence, which would lower the freezing point. This suggests that a totally solid core would be unlikely.
Mercury’s magnetic field offers valuable insight into the formation of the planet, the solar system, and even the universe. Magnetism on Mercury indicates that it has a liquid iron core, according to Messenger lead scientist Sean Solomon of Columbia University.

View Full Article   Read More

Take a spaceship journey to a galaxy cluster five billion light-years away


Annotated image of the field around CLASS B1608+656

Most of the galaxies visible in this Hubble image are members of a huge cluster called CLASS B1608+656, which lies about five billion light-years away. But the field also contains other objects that are both significantly closer and far more distant — including two gravitational lenses dubbed Fred and Ginger.

These contain enough mass to visibly distort the light from objects behind them. Fred, also known more prosaically as [FMK2006] ACS J160919+6532, lies near the lens galaxies in CLASS B1608+656, while Ginger ([FMK2006] ACS J160910+6532) is markedly closer to us. Despite their different distances from us, both can be seen near to CLASS B1608+656 in the central region of this Hubble image, and are labelled.
Credit:ASA, ESA


Click to zoom

View Full Article   Read More

Astronomers Measure Distance to Farthest Galaxy Yet



The farthest confirmed galaxy observed to date was identified in this Hubble image of a field of galaxies.  The inset image of the galaxy has been colored blue as suggestive of its young stars. Credit NASA/European Space Agency/Yale/University of California, Santa Cruz


Excerpt from nytimes.com

Leapfrogging backward in time to when the universe was apparently feeling its oats, a group of astronomers reported Tuesday that they had measured a bona fide distance to one of the farthest and thus earliest galaxies known.

The galaxy, more than a few billion light-years on the other side of the northern constellation Boötes, is one of the most massive and brightest in the early universe and goes by the name of EGS-zs8-1. 
It flowered into stardom only 670 million years after the Big Bang.
The light from that galaxy has taken 13 billion years to reach telescopes on Earth. By now, however, since the universe has continued to expand during that time, the galaxy is about 30 billion light-years away, according to standard cosmological calculations.
The new measurements allow astronomers to see the galaxy in its infancy. Despite its relative youth, however, it is already about one-sixth as massive as the Milky Way, which is 10 billion years old. And it is getting bigger, making stars 80 times faster than the Milky Way is making them today. The discovery was reported in The Astrophysical Journal by Pascal Oesch of Yale University and his colleagues.

By the rules of the expanding universe, the farther away a galaxy is, the faster it is retreating from us, measured by the “redshift” of its light being broadened to longer wavelengths, the way an ambulance siren seems to lower its pitch as it goes by.

In the past few years, as astronomers have raced one another into the past with instruments like the Hubble Space Telescope, galaxies have been found that appear even more distant. Those measurements, however, were estimates based on the colors of the objects — so-called photometric redshifts.

The new galaxy stuck out in a survey of distant galaxies by the Hubble and Spitzer space telescopes known as Candels, for Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey. Its redshift was precisely measured with a powerful spectrograph known as Mosfire — Multi-Object Spectrometer for Infrared Exploration — on Keck 1, one of a pair of 10-meter-diameter telescopes on Mauna Kea in Hawaii. That makes it the highest redshift confirmed in this way, said Garth Illingworth, of the University of California, Santa Cruz, one of the astronomers in the study.

How galaxies were able to form and grow so rapidly after the lights came on in the universe is a mystery that will be addressed by a coming generation of instruments like the James Webb Space Telescope and the Thirty Meter Telescope, a goliath planned for Mauna Kea, already home to a dozen telescopes.

Recently, however, construction of the Thirty Meter Telescope, a $1.4 billion project, has been halted by protests by Hawaii residents who feel their mountain has been abused. An echo of that controversy appears in the new paper, in which Dr. Oesch and his colleagues write: “The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Mauna Kea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain.”

View Full Article   Read More

Older posts Newer posts

Creative Commons License
This work is licensed under a
Creative Commons Attribution 4.0
International License
.
unless otherwise marked.

Terms of Use | Privacy Policy



Up ↑