Van Allen Probes Surf through Waves in Space

The two populations of hiss, low and high frequency, inhabit two separate regions in near-Earth space.
Credits: NASA’s Goddard Space Flight Center/Mary Pat Hrybyk-Keith

The space surrounding our planet is full of restless charged particles and roiling electric and magnetic fields, which create waves around Earth. One type of wave, plasmaspheric hiss, is particularly important for removing charged particles from the Van Allen radiation belts, a seething coil of particles encircling Earth, which can interfere with satellites and telecommunications. A new study published in Journal of Geophysical Research using data from NASA’s Van Allen Probes spacecraft has discovered that hiss is more complex than previously understood.

The new study looked at a newly identified population of hiss waves at a lower frequency than usually studied. These low-frequency hiss waves are particularly good at cleaning out high-energy particles — those that can cause damage to satellites — from the radiation belts. The authors of the study noticed that low-frequency waves are actually a separate and unique population, tending to cluster in different regions around Earth compared to their high-frequency counterparts.

The complete article is found here.

2017 Novato Space Festival

Mark your calendars for the Annual Novato Space Festival, Sunday August 6th, from 10:00 AM to 4:00 PM. Meet legendary Astronauts from the Apollo, Space Shuttle and International Space Station Programs.

NEW THIS YEAR…
EARLY ENTRANCE at 9:30am for families with CHILDREN 12 & UNDER
You’ll get to browse the exhibit area first,
THEN you’ll get to meet Astronaut Jerry Ross and he will read to you from his children’s book!

Parker Solar Probe – Cool Power

The solar panels are shown here on this artist rendering of Parker Solar Probe; they are the black squares with gray rectangles on the center of the spacecraft. Credit: NASA/JHUAPL

As NASA’s Parker Solar Probe spacecraft begins its first historic encounter with the sun’s corona in late 2018—flying closer to our star than any other mission in history—a revolutionary cooling system will keep its solar arrays at peak performance, even in extremely hostile conditions.

Every instrument and system on board Parker Solar Probe (with the exception of four antennas and a special particle detector) will be hidden from the sun behind a breakthrough thermal protection system (TPS)—an eight-foot diameter shield that the spacecraft uses to defend itself against the intense heat and energy of our star.

Every system will be protected, that is, except for the two solar arrays that power the spacecraft. When the spacecraft is closest to the sun, the solar arrays will be receiving 25 times the solar energy they would while orbiting Earth, and the temperature on the TPS will reach more than 2,500°F (1,370°C). The cooling system will keep the arrays at a nominal temperature of 320°F (160°C) or below.

The complete article is found here.

1,000 Days in Orbit: MAVEN’s Top 10 Discoveries at Mars

This artist concept shows the MAVEN spacecraft and the limb of Mars.
Credits: NASA’s Goddard Space Flight Center

“MAVEN has made tremendous discoveries about the Mars upper atmosphere and how it interacts with the sun and the solar wind,” said Bruce Jakosky, MAVEN principal investigator from the University of Colorado, Boulder. “These are allowing us to understand not just the behavior of the atmosphere today, but how the atmosphere has changed through time.”

During its 1,000 days in orbit, MAVEN has made a multitude of exciting discoveries. Here is a countdown of the top 10 discoveries from the mission:

10. Imaging of the distribution of gaseous nitric oxide and ozone in the atmosphere shows complex behavior that was not expected, indicating that there are dynamical processes of exchange of gas between the lower and upper atmosphere that are not understood at present.

9. Some particles from the solar wind are able to penetrate unexpectedly deep into the upper atmosphere, rather than being diverted around the planet by the Martian ionosphere; this penetration is allowed by chemical reactions in the ionosphere that turn the charged particles of the solar wind into neutral atoms that are then able to penetrate deeply.

See the remaining eight discoveries here:

NuSTAR’s First Five Years in Space

This artist’s concept shows NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR) spacecraft on orbit. Credit: NASA/JPL-Caltech

Five years ago, on June 13, 2012, Caltech’s Fiona Harrison, principal investigator of NASA’s NuSTAR mission, watched with her team as their black-hole-spying spacecraft was launched into space aboard a rocket strapped to the belly of an aircraft. The launch occurred over the Kwajalein Atoll in the Marshall Islands. Many members of the team anxiously followed the launch from the mission’s operations center at the University of California, Berkeley, anxious to see what NuSTAR would find.

Now, Harrison shares her take on five of the mission’s many iconic images and artist—ranging from our flaring sun to distant, buried black holes. NuSTAR is the first telescope capable of focusing high-energy X-rays—and it has taken the most detailed images of the sky in this energy regime to date.

Read the complete article and see the images.

Parker Solar Probe – Follow Up

The Parker Solar Probe, our first mission to touch the sun, was renamed on May 31st in honor of astrophysicist Eugene Parker. Here is a short video showing the mission and its objectives.

NASA Renames Solar Probe Mission to Honor Pioneering Physicist Eugene Parker

Illustration of the Parker Solar Probe spacecraft approaching the sun. Credit: NASA/JHUAPL

CHICAGO – NASA has renamed the Solar Probe Plus spacecraft – humanity’s first mission to a star, which will launch in 2018 – as the Parker Solar Probe in honor of astrophysicist Eugene Parker. The announcement was made at a ceremony at the University of Chicago, where Parker serves as the S. Chandrasekhar Distinguished Service Professor Emeritus, Department of Astronomy and Astrophysics.

In 1958, Parker—then a young professor at the university’s Enrico Fermi Institute—published an article in the Astrophysical Journal called “Dynamics of the interplanetary gas and magnetic fields.” Parker believed there was highly energized matter and radiation constantly escaping the sun, and that it affected the planets and space throughout our solar system.

This phenomenon, now known as the solar wind, has been proven to exist repeatedly through direct observation. Parker’s work forms the basis for much of our understanding about how stars interact with the worlds that orbit them.

Read the complete news release.

Space Weather Model Simulates Solar Storms From Nowhere

Our ever-changing sun continuously shoots solar material into space. The grandest such events are massive clouds that erupt from the sun, called coronal mass ejections, or CMEs. These solar storms often come first with some kind of warning — the bright flash of a flare, a burst of heat or a flurry of solar energetic particles. But another kind of storm has puzzled scientists for its lack of typical warning signs: They seem to come from nowhere, and scientists call them stealth CMEs.

Now, an international team of scientists, led by the Space Sciences Laboratory at University of California, Berkeley, and funded in part by NASA, has developed a model that simulates the evolution of these stealthy solar storms. The scientists relied upon NASA missions STEREO and SOHO for this work, fine-tuning their model until the simulations matched the space-based observations. Their work shows how a slow, quiet process can unexpectedly create a twisted mass of magnetic fields on the sun, which then pinches off and speeds out into space — all without any advance warning.

The complete article is found here.