Archive

Archive for the ‘Solar System’ Category

NASA Research Reveals Europa’s Mystery Dark Material Could Be Sea Salt


 Image Credit: NASA/JPL-Caltech/SETI Institute

Image Credit: NASA/JPL-Caltech/SETI Institute

NASA laboratory experiments suggest the dark material coating some geological features of Jupiter’s moon Europa is likely sea salt from a subsurface ocean, discolored by exposure to radiation. The presence of sea salt on Europa’s surface suggests the ocean is interacting with its rocky seafloor — an important consideration in determining whether the icy moon could support life.

The study is accepted for publication in the journal Geophysical Research Letters and is available online.

“We have many questions about Europa, the most important and most difficult to answer being is there life? Research like this is important because it focuses on questions we can definitively answer, like whether or not Europa is inhabitable,” said Curt Niebur, Outer Planets Program scientist at NASA Headquarters in Washington. “Once we have those answers, we can tackle the bigger question about life in the ocean beneath Europa’s ice shell.”

Link To Full Story

Ceres Animation Showcases Bright Spots


Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

The mysterious bright spots on the dwarf planet Ceres are better resolved in a new sequence of images taken by NASA’s Dawn spacecraft on May 3 and 4, 2015. The images were taken from a distance of 8,400 miles (13,600 kilometers). The animation is available at:

http://www.jpl.nasa.gov/spaceimages/details.php?id=pia19547

In this closest-yet view, the brightest spots within a crater in the northern hemisphere are revealed to be composed of many smaller spots. However, their exact nature remains unknown.

“Dawn scientists can now conclude that the intense brightness of these spots is due to the reflection of sunlight by highly reflective material on the surface, possibly ice,” said Christopher Russell, principal investigator for the Dawn mission from the University of California, Los Angeles.

Link To Full Story

NJIT’s New Solar Telescope Unveils The Complex Dynamics Of Sunspots’ Dark Cores


NJIT’s Big Bear Solar Observatory

NJIT’s Big Bear Solar Observatory

Groundbreaking images of the Sun captured by scientists at NJIT’s Big Bear Solar Observatory (BBSO) give a first-ever detailed view of the interior structure of umbrae – the dark patches in the center of sunspots – revealing dynamic magnetic fields responsible for the plumes of plasma that emerge as bright dots interrupting their darkness. Their research is being presented this week at the first Triennial Earth-Sun Summit meeting between the American Astronomical Society’s Solar Physics Division and the American Geophysical Union’s Space Physics and Aeronomy section in Indianapolis, Ind.

The high-resolution images, taken through the observatory’s New Solar Telescope (NST), show the atmosphere above the umbrae to be finely structured, consisting of hot plasma intermixed with cool plasma jets as wide as 100 kilometers.

“We would describe these plasma flows as oscillating cool jets piercing the hot atmosphere. Until now, we didn’t know they existed. While we have known for a long time that sunspots oscillate – moderate resolution telescopes show us dark shadows, or penumbral waves, moving across the umbra toward the edge of a sunspot – we can now begin to understand the underlying dynamics,” said Vasyl Yurchyshyn, a research professor of physics at NJIT and the lead author of two recent journal articles based on the NST observations.

Link To Full Story

Dawn Glimpses Ceres’ North Pole


Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

After spending more than a month in orbit on the dark side of dwarf planet Ceres, NASA’s Dawn spacecraft has captured several views of the sunlit north pole of this intriguing world. These images were taken on April 10 from a distance of 21,000 miles (33,000 kilometers), and they represent the highest-resolution views of Ceres to date.

Subsequent images of Ceres will show surface features at increasingly better resolution.

Dawn arrived at Ceres on March 6, marking the first time a spacecraft has orbited a dwarf planet. Previously, the spacecraft explored giant asteroid Vesta for 14 months from 2011 to 2012. Dawn has the distinction of being the only spacecraft to orbit two extraterrestrial targets.

Link To Full Story

The Origin Of The Magnetic Field Covering The Sun Has Been Discovered

February 20, 2015 1 comment

The magnetic field that covers the Sun and determines its behavior –the eleven year cycles no less than such conspicuous phenomena as solar spots and solar storms– also has another side to it: a magnetic web that covers the entire surface of the Sun at rest and whose net magnetic flow is greater than that of the active areas. A study led by the Institute of Astrophysics of Andalusia (IAA-CSIC) has revealed where the flow that feeds this web comes from.

The outline of the solar magnetic web coincides with the boundaries of the so-called supergranules, structures linked to the existence of hot gas rising to the surface (similar to the bubbles made by boiling water) some twenty thousand kilometers in diameter.

“We have discovered that inside these supergranules, in what is known as intranetwork, small magnetic elements appear which travel toward the outer boundaries and interact with the web”, says Milan Gosic, IAA researcher in charge of the study.

Link To Full Story And Video

A New View Of The Solar System: Astrophysical Jets Driven By The Sun

February 19, 2015 Leave a comment

As the sun skims through the galaxy, it flings out charged particles in a stream of plasma called the solar wind, and the solar wind creates a bubble extending far outside the solar system known as the heliosphere. For decades, scientists have visualized the heliosphere as shaped like a comet, with a very long tail extending thousands of times as far as the distance from the Earth to the sun.

New research suggests that the sun’s magnetic field controls the large-scale shape of the heliosphere “much more than had been previously thought,” says Merav Opher, associate professor of astronomy and director of the Center for Space Physics at Boston University (BU). In the new model, the magnetic field squeezes the solar wind along the sun’s North and South axes, producing two jets that are then dragged downstream by the flow of the interstellar medium through which the heliosphere moves.

Link To Full Story

Close Pairing Of Venus And Mars On February 20-21

February 18, 2015 Leave a comment

Credit: Sky & Telescope Diagrame.

Credit: Sky & Telescope Diagrame.

Look west in twilight this Friday and Saturday (February 20th and 21st), and an unusual astronomical sight will await you.

Brilliant Venus and faint Mars will be paired remarkably close in the sky. And on Friday evening, the crescent Moon joins them in a tight bunch, a beautiful sight. On Saturday Venus and Mars appear even closer together, with the crescent Moon now looking down on them from above.

When it comes to “eyeball astronomy,” nothing is more satisfying than to see a pair of celestial objects appear close together in the sky, what astronomers call a conjunction. And 2015, notes Sky & Telescope’s longtime contributing editor Fred Schaaf, truly deserves to be called the “Year of the Conjunctions.” In January we watched Venus and Mercury come together in the evening twilight, and now comes a similarly close pairing of Venus and Mars. On Saturday they’ll appear 1/2° apart for viewers in North America. That’s about the width of a pencil held at arm’s length.

Link To Full Story