Clouds Detected on Alien Planet –New Hubble Discovery | TheDailyGalaxy
Weather forecasters on exoplanet GJ 1214b would have an easy job. Today’s forecast: cloudy. Tomorrow: overcast. Extended outlook: more clouds. A team of scientists led by researchers in the Department of Astronomy and Astrophysics at the University of Chicago report they have definitively characterized the atmosphere of a super-Earth class planet orbiting another star for the first time.
This is the first high-resolution footage of a spectacular phenomenon called a magnetic flux rope that occurs on the sun’s surface. The S-shaped rope’s twisting, writhing structure is a surface instability made of current-carrying magnetic fields that explode out of the surrounding solar atmosphere. It emerged and evolved from the second of three layers in our star’s atmosphere called the chromosphere.
Researchers recorded the event in August 2013 using the recently built New Solar Telescope at Big Bear Solar Observatory east of Los Angeles. Imagery and analysis of the event appeared yesterday in the journal Nature Communications.
“These twisting magnetic loops have been much studied in the Sun’s corona, or outer layer, but these are the first high-resolution images of their origination in the chromosphere below it,” said Haimin Wang, the lead author of the study and a physics professor at the New Jersey Institute of Technology, which runs the observatory. "For the first time, we can see their twisting motion in great detail and watch how it evolves."
On August 24th at 12:17 UT, NASA’s Solar Dynamics Observatory recorded this M5.6-category explosion near the eastern limb of the sun.
The source of the blast was sunspot AR2151. As the movie shows, an instability in the suspot’s magnetic canopy hurled a dense plume of plasma into space. If that plasma cloud were to hit Earth, the likely result would be strong geomagnetic storms. However, because of the sunspot’s location near the edge of the solar disk, Earth was not in the line of fire.
Even so, the flare did produce some Earth effects. A pulse of extreme UV radiation from the explosion partially ionized our planet’s upper atmosphere, resulting in a Sudden Ionospheric Disturbance (SID). Waves of ionization altered the normal propagation of VLF (very low frequency) radio transmissions over the the dayside of Earth, an effect recorded at the Polarlightcenter in Lofoten, Norway: data.
To the casual observer, the Sun may appear unimpressive from 93 million miles
(150 million km - 1 AU) away but upon closer examination – in the extreme ultraviolet region of the spectrum, it becomes evident that it’s characterized by
unpredictable and explosive surface activity. The Sun creates highly variable and complex conditions in the space, as well. We call these conditions ‘space weather’. Space weather is an emerging multidisciplinary field within space sciences that studies how solar activity influences Earth’s space environment.
Our Sun continuously bathes Earth in solar energy, in the forms of:
electromagnetic radiation (visible light, microwaves, radio waves, infrared, ultraviolet, X-ray, gamma rays) and corpuscular radiation (streams of subatomic particles such as protons, electrons, and neutrons). The Sun is a magnetic variable star, and like most stars, it’s composed of superheated plasma; a collection of negatively charged electrons and positively charged ions. Its magnetic fields are produced by electric currents that are generated by the movement of the charged particles. The electrically conductive solar plasma acts like a viscous fluid, so the plasma near the poles rotates slower than the plasma at the equator. This differential rotation results in a twisting and stretching of the magnetic field lines, leading to the formation of sunspots, solar flares and CMEs.
The Sun’s overall magnetic field is quite weak compared tosunspots, which are localized regions of intense magnetism (magnetic loops that poke out of the photosphere), and they can be 1000 times stronger than the Sun’s average field. Above sunspot regions, the Sun’s magnetic field lines twist and turn like rubber bands, and when the field lines interact, the confined coronal plasma is accelerated to several million miles per hour in a powerful magnetic eruption. The cloud of extremely hot and electrically charged plasma expelled from the active region is called a coronal mass ejection, or CME for short. CMEs aimed at Earth are called halo events or halo CMEs because of the way they look in coronagraph images; the coronagraph instrument will detect it as a gradually expanding ring around the Sun. As the CME moves away from the Sun, it pushes an interplanetary shock wave before it, amplifying the solar wind speed, and magnetic field strength, as well. The Sun’s magnetic field isn’t confined to the star, the interplanetary magnetic field (IMF) is carried into interplanetary space by the solar wind and CMEs.
Depending on how the IMF is aligned in relationship to our geomagnetic field, there can be various results when the CME arrives. Some particles get deflected around Earth – thanks to the invisible magnetic “bubble”, called the magnetosphere (it’s actually non-spherical), but a small amount of ionized particles can still get into our near-Earth environment (geospace), mostly via the magnetotail. The magnetosphere is formed when the flow of the solar wind impacts the Earth’s magnetic (dipole) field. The overall shape of Earth’s magnetosphere is influenced by the speed, density and temperature of the solar wind: the dayside is continuously compressed by the solar wind, and the nightside is stretched out into a tear drop shaped magnetotail. Our magnetosphere is an extremely dynamic regionand it’s filled with a variety of current systems.
When a powerful CME hits Earth, electrons in the magnetosphere cascade into the ionosphere at the polar regions, creating the so-called Birkeland or field-aligned current that flows along the main geomagnetic field. If the CME’s polarity matches that of Earth’s magnetic field (Northward
IMF), our magnetosphere may deflect some of the highly charged
particles. The problems occur when the CME’s polarity is the opposite of
Earth’s (Southward IMF) because it can cause a geomagnetic storms and
brief magnetospheric substorms that disrupt Earth’s own magnetic
Changes in the ionosphere trigger bright aurorae that are, in fact, the
visual manifestation of the interaction between solar energetic
particles and the high-altitude atmosphere. Solar energetic particles
are high-energy charged particles, they can induce voltages and currents in power grids and
cause large-scale power and radio blackouts, temporary operational anomalies, damage to spacecraft electronics. During geomagnetic storms, the energy transferred into the ionosphere by the Birkeland current heats up (Jouleheating) the atmosphere, which consequently rises and increases drag on low-altitude satellites.
Fortunately, there is a fleet of observing spacecraft monitoring the Sun’s activity across a wide range of electromagnetic wavelengths. Their continuous observations and measurements of solar and geospace variability gives us the ability to prepare and respond to potentially harmful space weather events.
Our Sun recently emitted a mid-level solar flare, known as an M-class flare, that peaked on June 25, 2015. NASA’s Solar Dynamics Observatory, which
watches the sun constantly, captured an image of the event. The SDO helps us understand ‘Space Weather‘ and gather useful data that will help us protect spacecraft and future Astronauts from dangerous radiation.
The sun is a huge thermo-nuclear reactor, fusing hydrogen atoms into helium and producing million degree temperatures and intense magnetic fields. The outer layer of the sun near its surface is like a pot of boiling water, with bubbles of hot, electrified gas—electrons and protons in a fourth state of matter known as plasma—circulating up from the interior and bursting out into space. The steady stream of particles blowing away from the sun is known as the solar wind.
“The Earth is the only world known, so far, to harbor life. There is
nowhere else, at least in the near future, to which our species could
migrate. Visit, yes. Settle, not yet. Like it or not, for the moment,
the Earth is where we make our stand. It has been said that astronomy is
a humbling and character-building experience. There is perhaps no
better demonstration of the folly of human conceits than this distant
image of our tiny world. To me, it underscores our responsibility to
deal more kindly with one another and to preserve and cherish the pale
blue dot, the only home we’ve ever known.”
Here on terrestrial Earth, the polar vortex is making all of our lives miserable, from frostbite-inducing chills in the North, to snow and ice blanketing Florida, to drivers in Atlanta getting stuck in traffic for 22 hours and comparing the scene to a zombie movie. As visualized from space, though, the polar vortex is a beautiful, panchromatic cyclone of endlessly flowing eddies and currents. It’s mesmerizing.
Solar flares are powerful bursts of radiation. Harmful radiation from a flare cannot pass through Earth’s atmosphere to physically affect humans on the ground, however – when intense enough – they can disturb the atmosphere in the layer where GPS and communications signals travel.
To see how this event may affect Earth, please visit NOAA’s Space Weather Prediction Center at http://spaceweather.gov, the U.S. government’s official source for space weather forecasts, alerts, watches and warnings.
This flare is classified as an X1.8-class flare. X-class denotes the most intense flares, while the number provides more information about its strength. An X2 is twice as intense as an X1, an X3 is three times as intense, etc.