Science Pictures of the Week: Bleeding glacier, exploding star, flaring sunspot
Monday, March 16, 2015, 8:58 AM - In this Science Pictures of the Week, a 'bleeding' Antarctic glacier, the twisted remnants of a long-dead star, and the first X-class solar flare of 2015.
An Antarctic Glacier Bleeds
Along the coastline of eastern Antarctica, near where the Ross Ice Shelf meets the sea, there's a glacier that appears to be bleeding from an open wound.
Blood Falls at the terminus of Taylor Glacier results from the discharge of brine liquid through a channel from a source that comes from several kilometers away below the glacier. Credit: Peter Rejcek
This isn't some environmental message, though. This isn't from pollution. It probably has nothing to do with climate change. It's just due to extremely salty, iron-rich water under the glacier, and the extremophile microbes living in that water.
According to the The Antarctic Sun, a publication of the United States Antarctic Program (USAP):
A decade ago, [Jill Mikucki] first collected brine as it flowed from below the glacier into the surface of ice-covered Lake Bonney, located at the extreme western edge of Taylor Valley in the McMurdo Dry Valleys, which is the largest relatively ice-free area in Antarctica.
Mikucki and her team are investigating the source of the Blood Falls, using a maneuverable drill called the IceMole to bore down and collect samples of the water. The results of their research may help us understand extraterrestrial environments, like those beneath the icy crusts of moons like Europa, Ganymede, Enceladus and Titan, and how these moons may support primitive life forms.
For more on this project, and for a video featuring Mikucki and her team, read The Lifeblood of a Glacier.
The twisted veil of a long-dead star
The wispy remnants of an exploded star. Credit: NASA, ESA, and the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration.
This photo captures a small, but stunning portion of the Veil Nebula - a collection of expanding gases roughly 1,500 light years away, in the constellation Cygnus (the Northern Cross).
According to the ESA website:
Ten thousand years ago, the Veil Nebula did not exist. Back then, it was a star, much brighter and larger than our own Sun, burning furiously thanks to the nuclear furnace in its centre. As those reactions faltered when its fuel was exhausted, the star collapsed and exploded.
This is just one of the incredible images the Hubble Space Telescope has delivered to us in its nearly 25 years of service. Although captured in 2007, this was a featured image on the ESA website on March 9, 2015, as the agency (along with NASA) prepares for Hubble's silver anniversary on April 24.
The 1st X-class Flare of 2015
Our Sun is currently on the downswing from its latest solar max, when sunspot and solar flare activity reached its highest level since the last solar maximum in the year 2000. However, since it will be some time - at least until the year 2020 - before it completely calms down, it is still capable of blasting out some impressive flares.
The above image, captured by NASA's Solar Dynamics Observatory (SDO), shows just one of these, an X2.1-class solar flare, which exploded from the surface of the Sun on March 11, 2015, at around 12:30 pm, EDT. The image appears green, rather than the 'traditional' yellow of our Sun, because SDO uses filters to isolate different temperature levels, which allows scientists to study specific regions of the Sun's atmosphere, different structures (like filaments and coronal loops) and different events. This green filter captures light in the 'extreme ultraviolet/soft X-rays' range of the spectrum (94 Angstroms), which corresponds to a temperature of around 6 million degrees Kelvin. It is specifically used to study solar flares in detail.
This explosion from Sunspot AR2297 was, so far, the strongest solar flare of 2015. It caused a significant radio blackout on the daylight side of Earth (over North and South America), and it propelled a small eruption of solar material (a coronal mass ejection) into space. Space weather forecasters are predicting a potential 'sideswipe' of Earth's magnetic field by this CME, which could spark a minor geomagnetic storm on Sunday night.
Although the most powerful so far, there could be even stronger ones through the rest of the year, of course. Even though this 'Solar Mini-Max', as NASA scientists are calling it, is the weakest solar maximum in 120 years, 2015 could see some of the most intense flares and strongest geomagnetic storms. According to NASA solar physicist Dean Pesnell, of the Goddard Space Flight Center, historically, this 'declining phase' of the solar max has been when the most powerful events have occurred.
"We're not out of the woods yet," says Pesnell.