Observing Sunrise: Solar scientists review Hinode findings

Japan has a long tradition in solar physics and in 2006 launched one of the major space observatories – Hinode, which means 'sunrise' in Japanese.

For almost six years this satellite has been constantly monitoring our local star with a suite of three telescopes: the Solar Optical Telescope, X-ray Telescope and Extreme Ultraviolet Imaging Spectrometer (EIS).

Solar Optical Telecope

Together, they enable the study of how magnetic energy is generated and released in the atmosphere of our Sun.

This week in St. Andrews over 150 scientists from around the world gathered for the "Hinode 6" conference to celebrate what has been learnt using the Hinode satellite.

Although launched and led by Japan, the satellite has major contributions from the UK, the USA and Norway.

Extreme Ultraviolet Imaging Spectrometer (EIS)

Unexpectedly, St. Andrews has a connection to Hinode’s modern observing methods that dates back to the late 1600s.

The Scottish mathematician James Gregory upon walking along the beach in St. Andrews, Scotland, picked up a feather and wondered what would happen if a beam of light were shone through it.

Isaac Newton was conducting similar experiments with glass prisms in Cambridge.

Back in his lab, Gregory saw that the feather split the light into its component colours in a process now known as diffraction – a simple technique that is used today in many solar telescopes as it allows us to measure the properties of sunlight and in turn learn about the star that emitted it.

The Solar Science department at UCL led the development of the EIS telescope - a modern equivalent to the bird’s feather - which splits the ultraviolet light emitted from atmospheric gases into the component colours.

A major topic for discussion at the conference has been how magnetic fields that emanate up from the Sun’s surface into the atmosphere, create structures that glow in ultraviolet and X-rays and produce activity such as solar flares and coronal mass ejections (CME).

A large X-class flare captured by the X-ray telescope on Hinode. Image credit: JAXA/Hinode

High-speed gas flows associated to solar flares have been observed, helping scientists understand the processes that convert energy stored in the magnetic fields into energy of gas motions.

Computer models have been combined with observations to understand how currents surge along the magnetic structures, supported by the charged particles of the atmospheric gases, heating the atmospheric gases to very high temperatures.

Read the full article here at SEN: Solar scientists review Hinode findings

NASA's Degradation Free Spectrometers - Successful launch

On July 24, 2012, NASA successfully launched a pair of newly developed spectrometers aboard a sounding rocket from the White Sands Missile Range, New Mexico to an altitude of 323.8 km (201.2 mi).

This may not seem to have much to do with extending the life of a satellite floating between the Sun and Earth about 1.5 million kilometers (932,000 mi) away, but it does.

That’s because the tests' purpose was both to test new instruments for a potential future replacement of the SOHO solar observatory satellite and to recalibrate SOHO’s existing instruments.

See NASA ESA SOHO's Latest Images Here

It’s great when a space mission lasts longer than expected. Though the history of space exploration has been punctuated by failure and even tragedy, some missions shine out, such as the Viking and Opportunity Mars Landers, which operated years beyond their very short mission objectives and, of course, Voyager, a craft that is still working a generation after its launch.

However, success can bring its own problems. One of these is that a still-functioning craft may have to work with instruments never meant to last so long and are now showing their age.

A case in point is the Solar and Heliospheric Observatory (SOHO). This joint project between the European Space Agency (ESA) and NASA was launched on December 2, 1995 and is currently parked at the Lagrange point between the Earth and the Sun where gravitational forces balance, leaving it forever in the one spot.

Since its launch, it’s been studying the Sun and has discovered over 2,200 comets. Originally planned as a two-year mission, SOHO continues to send back data.

It’s done a great job and, more importantly, is the main source of near-real time data that helps look out for solar flares. Trouble is, the instruments weren’t designed to run for 18 years and they show it. Filters degrade, surfaces become contaminated, telescope mirrors dim... In other words, it’s going slowly blind.

There isn’t much that can be done to repair SOHO, but future missions will benefit from more durable instruments. That is the purpose of the sounding rocket test.

Among its payload were two Degradation Free Spectrometers (DFS). These are similar to the spectrometers used by SOHO, but where the satellite’s are gradually failing, these are designed to avoid that fate on a future mission.

Instead of conventional optics, they use a rare gas photoionization-based Optics-Free Spectrometer (OFS) {pdf} and a Dual Grating Spectrometer (DGS) {pdf}. These are made filter-free and optics-free by using rare-gas chambers, photoelectron focusing techniques, gratings and light baffles to exclude unwanted light without filters.

The mission was mainly to test the spectrometers, which are capable of, in the words of NASA’s press release, “high cadence measurements of the highly variable Extreme Ultraviolet (EUV) solar flux and have minimal degradation over multi-year time scales while observing the sun 24/7."

What that means is that the spectrometers can make precise observations of the Sun at the extreme end of the ultraviolet spectrum for years on end without the mechanism wearing out.

The other purpose was to help calibrate SOHO. In addition to the new spectrometers, the sounding rocket also carried a clone of SOHO’s Solar Extreme Ultraviolet Monitor (SEM) {pdf}.

This was calibrated at the National Institute of Standards and Technology both before and after flight to provide a calibration check for SOHO, so observations from the satellite can be corrected. If all goes well, it may give SOHO a little more life and its successor a lot more time.

LAMIS: A Green Chemistry Alternative for Remote-Controlled Laser Spectroscopy

LAMIS uses the energy of a high-powered laser beam to ablate a tiny spot on a sample, creating a plasma plume for spectroscopic analysis that reveals chemical elements and their isotopes. 

(Image courtesy of Applied Spectra, Inc.)

At some point this year, after NASA's rover Curiosity has landed on Mars, a laser will fire a beam of infrared light at a rock or soil sample.

This will "ablate" or vaporise a microgram-sized piece of the target, generating a plume of ionised gas or plasma, which will be analysed by spectrometers to identify the target's constituent elements.

Future Mars rovers, however, will be able to do even more. Researchers with the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab), in collaboration with Applied Spectra, Inc., have developed an advanced version of this laser technology that can also analyze a target's constituent isotopes.

This expanded capability will enable future rovers for the first time to precisely date the geological age of Martian samples.

From left, Alexander Bol'shakov, Xianglei Mao and Rick Russo are part of the research team that developed LAMIS, a green chemistry laser spectroscopy technology that can be operated across vast distances. (Photo by Roy Kaltschmidt, Berkeley Lab)

Rick Russo, a scientist with Berkeley Lab's Environmental Energy Technologies Division and a pioneer in laser ablation spectroscopy, led the development of LAMIS - for Laser Ablation Molecular Isotopic Spectrometry.

As with the earlier Laser Induced Breakdown Spectroscopy (LIBS) technology being used on rover Curiosity, the basic premise is to use the energy of a high-powered laser beam focused to a tiny spot on the surface of a sample to create a plasma plume for analysis.

Each species of atoms or ions within the plasma will emit light with signature spectral emission peaks.

However, whereas LIBS only measures the optical emission spectra of atoms and ions, LAMIS measures the emission spectra of molecules and molecular ions.

This enables LAMIS to identify the specific isotopes of a chemical element within the plasma plume.

"Relative to atomic emission, molecular spectra can exhibit significantly larger isotopic shifts due to the contributions of the vibrational and rotational motion in the molecule," Russo says.

"The trick is to be patient and wait for the hot atoms and ions in the plasma to collide and merge with the ambient environment to form an oxide, or a nitride or fluoride, and then collect the molecular light emissions."

Isotopes of Strontium
Russo and his research group have been using LAMIS to study isotopes of strontium, an alkaline earth metal commonly found in geological and natural materials.

Although strontium's major isotopes are stable (strontium-90 being a notable exception), the percentage of strontium-87 will naturally increase over time as a result of the decay of radioactive rubidium.

Comparing the ratio of strontium-87 to strontium-86 is a standard tool for age dating in geochronology, oceanography and archeology. The ratio of these strontium isotopes is also used to date the origin of historic or forensic samples.

Currently, the standard means of measuring strontium isotopic ratios is by mass spectrometry technologies that involve time-consuming, labour-intensive laboratory sample dissolution work with an extensive array of instrumentation.

This sample dissolution work generates substantial chemical waste. LAMIS offers a green chemistry alternative that is faster, less expensive and can be carried out from across vast distances.

"LAMIS is not yet as sensitive or precise as mass spectrometry but unlike mass spectrometry it does not require chemical dissolution sample preparation, vacuum chambers and a laboratory infrastructure," Russo says.

"All we need is a laser beam and an optical spectrometer and we can perform real-time isotopic analyses of samples at ambient pressures and temperatures."

LAMIS represents what may be the only practical means of determining the geochronology of samples on Mars or other celestial bodies in the Solar System.

Current age estimates of such bodies suffer from uncertainties in the billions of years. That said, LAMIS also has many important applications here on Earth.

Strontium isotope ratios have been a focus in the field of medicine for both treatment and diagnostic purposes.

NuStar: The Nuclear Spectroscopic Telescope Array

NuSTAR, The Nuclear Spectroscopic Telescope Array, will image the sky for the first time in the high energy X-ray (6-79 keV) region of the electromagnetic spectrum.

Our view of the universe in this spectral window has been limited previously. NuSTAR is scheduled to launch March 14, 2012, from an aircraft operating out of Kwajalein Atoll in the Marshall Islands.

Here, NuSTAR is seen undergoing a solar array illumination test.

Credit: NASA

ESA INTEGRAL deciphers diffuse signature of cosmic-ray electrons

This image shows the entire sky at hard X-ray energies, between 50 and 100 keV, as observed with the Spectrometer on board INTEGRAL (SPI). The image is based on six years worth of data collected with this instrument.

The two main contributions to the emission at these energies are clearly visible: point sources, galactic and extragalactic alike, and diffuse emission. 

Point sources are scattered across the sky, albeit mainly concentrated along the Galactic Plane; the diffuse emission also traces the Galactic Plane and is fainter, at these energies, than the emission arising from point sources.

To study the diffuse emission in great detail and to break it down into the individual physical processes that contribute to it, astronomers need to carefully scrutinise the data and remove the contamination due to point sources. Credits: ESA/INTEGRAL/SPI.

ESA & NASA's Hubble Confirms That Galaxies Recycle

Distant quasars shine through the gas-rich "fog" of hot plasma encircling galaxies. 

At ultraviolet wavelengths, Hubble's Cosmic Origins Spectrograph (COS) is sensitive to absorption from many ionized heavy elements, such as nitrogen, oxygen, and neon.

COS's high sensitivity allows many galaxies that happen to lie in front of the much more distant quasars. The ionized heavy elements serve as proxies for estimating how much mass is in a galaxy's halo.

(Credit: NASA; ESA; A. Feild, STScI).

New observations by NASA's Hubble Space Telescope are expanding astronomers' understanding of the ways in which galaxies continuously recycle immense volumes of hydrogen gas and heavy elements. This process allows galaxies to build successive generations of stars stretching over billions of years.

This ongoing recycling keeps some galaxies from emptying their "fuel tanks" and stretches their star-forming epoch to over 10 billion years.

This conclusion is based on a series of Hubble Space Telescope observations that flexed the special capabilities of its Cosmic Origins Spectrograph (COS) to detect gas in the halo of our Milky Way and more than 40 other galaxies.

Data from large ground-based telescopes in Hawaii, Arizona and Chile also contributed to the studies by measuring the properties of the galaxies.

Astronomers believe that the color and shape of a galaxy is largely controlled by gas flowing through an extended halo around it. The three studies investigated different aspects of the gas-recycling phenomenon.

Extreme Space Weather at Mercury Blasts the Planet's Poles

The solar wind sandblasts the surface of planet Mercury at its poles, according to new data from a University of Michigan instrument on board NASA's MESSENGER spacecraft.

The sodium and oxygen particles the blistering solar wind kicks up are the primary components of Mercury's wispy atmosphere, or "exosphere," the new findings assert.

Through interacting with the solar wind, they become charged in a mechanism that's similar to the one that generates the Aurora Borealis on Earth.

The findings are published in the Sept. 30 edition of Science.

The Fast Imaging Plasma Spectrometer (FIPS,) made by U-M scientists, has taken the first global measurements of Mercury's exosphere and magnetosphere in an effort to better understand how the closest planet to the sun interacts with its fiery neighbor.

The measurements confirmed scientists' theories about the composition and source of the particles in Mercury's space environment.

"We had previously observed neutral sodium from ground observations, but up close we've discovered that charged sodium particles are concentrated near Mercury's polar regions where they are likely liberated by solar wind ion sputtering, effectively knocking sodium atoms off Mercury's surface," said FIPS project leader Thomas Zurbuchen, a professor in the Department of Atmospheric, Oceanic and Space Sciences and Aerospace Engineering at the U-M College of Engineering.

Earth and Mercury are the only two magnetized planets in the solar system, and as such, they can somewhat deflect the solar wind around them.

The solar wind is a squall of hot plasma, or charged particles, continuously emanating from the sun. Earth, which has a relatively strong magnetosphere, can shield itself from most of the solar wind. Mercury, which has a comparatively weak magnetosphere and is 2/3 closer to the sun, is a different story.

"Our results tell us is that Mercury's weak magnetosphere provides very little protection of the planet from the solar wind," Zurbuchen said.

Studying Mercury's magnetosphere and space environment helps scientists understand fundamental science about the sun.

Herschel Finds Hot Water Vapour Around a Carbon Star

The red giant pulsating carbon star CW Leonis as seen by the PACS and SPIRE cameras and spectrometers on board Herschel.

The star itself is too bright to be seen well but it is releasing material in a violent stellar wind, some of which is seen in a 'bow shock' to the left of the star in this image.

Observations have shown that water vapor is being formed deep down near the surface of the star; a place where it was previously thought to be impossible to appear.

This means that the stellar wind must be much more 'clumpy' than previously foreseen, with some regions having a much weaker wind than others.

This allows ultraviolet light from interstellar space to reach the deeper, warmer regions and trigger the creation of water vapor. Credit: ESA / KU Leuven / LUTH / Observatoire de Paris