NASA gets red-hot shots of Sun in action as IRIS goes online
Latest telescope could spot our doom
NASA's latest solar observatory is online and sending back pictures of the Sun's inner atmosphere that could help answer some of the essential questions about our closest star and its effects on Earth.
IRIS opens up
"My teachers at the University of Chicago instilled in me a real wonder at the mystery of the Sun," said John Grunsfeld, associate administrator of the Science Mission Directorate at NASA at a press conference on Thursday.
"It's the star for which everything that happens here on Earth depends on," Grunsfeld said, "and there are some real deep mysteries in the Sun and how it works, and especially how the corona is heated. All missions are nail-biters, but we were incredibly excited that we launched the IRIS mission."
The mystery behind the Sun's corona is that it's a thousand times hotter than the surface of the Sun itself – around 1 million kelvin (about 1.8 million °F). Working out how the Sun's mass projects this energy to the corona is key to understanding the effects of solar flares on humanity.
The Interface Region Imaging Spectrograph (IRIS) satellite is studying the solar transition region, the layer below the corona. The telescope is a dainty little thing – just 400 pounds, seven feet long, and 12 feet wide with its solar panels – and was launched from Vandenberg Air Force Base on June 27 and inserted into a polar orbit along the sunrise and sunset line of Earth to give maximum viewing time of our star.
After reaching orbit, the telescope spent 20 days equalizing its internal vacuum with the outside space, and running through diagnostic checks. On July 17 the viewing doors were opened and the first images received to the dual-function device have now been shared by NASA.
Hot sunspot action
The signals coming into the telescope are split and fed to an ultraviolet telescope and a spectrograph. The telescope takes images of the Sun's atmosphere that can resolve features down to 150 miles across, and the spectrograph measures the wavelengths of light received and maps those against the images.
Thanks to its advanced electronics, IRIS can shoot images of the Sun at a resolution ten times better than anything NASA has in orbit to date, and take snapshots 20 times faster. As a result, the telescope is tracking sunspots moving over the surface of our star in unprecedented detail.
"The quality of images and spectra we are receiving from IRIS is amazing. This is just what we were hoping for," said Alan Title, IRIS principal investigator at Lockheed Martin, which built telescope. "There is much work ahead to understand what we're seeing, but the quality of the data will enable us to do that."
Spectrum activity at the heart of our sun
IRIS is designed to last for a two-year mission, he said, but could last for years beyond that thanks to its design. It only uses 350W of power and has few easily-breakable moving parts, so should be providing data for years to come. It might also provide a useful early-warning system of harmful solar activity.
Every now and then, for reasons not fully understood, the Sun's atmosphere sends out flares that often cause a coronal mass ejection – a storm of charged particles can burn out satellites or even electronic ground equipment here on Earth, somewhat similar to the electromagnetic pulse of a nuclear weapon.
Welcome back to the Victorian era
The vast majority of these ejections occur on a different directional cone from Earth, but we've been hit before. On September 1, 1859, English amateur astronomers Richard Carrington and Richard Hodgson simultaneously reported a huge solar flare that a day later caused the largest geomagnetic storm yet recorded, which extended the Aurora Borealis briefly as far south as the Caribbean.
Electricity was still in its infancy back then, but telegraph systems across the US and Europe either burnt out, sent gibberish, or shocked their operators when the flare hit. In today's age of electronics the effects on a highly wired society could be catastrophic, destroying not only electronic networks themselves but also the fabs necessary to manufacture replacements.
But there's really no sense in worrying about the issue just yet. IRIS is intended to try to understand how these processes occur, but there are ages of human technological development needed before we can predict such a threat, let alone mitigate against it. In the meantime, let's think about getting off the rock and having a nose around. ®
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