There’s all kinds of news relating to the sun and space weather these days. First up, an odd lull in solar activity, accompanying a total absence of visible sunspots. As SpaceWeather.com reports:
With the Sun’s disk almost completely devoid of sunspots, solar flare activity has come to a halt. Measurements by NOAA’s GOES 15 satellite show that the sun’s global x-ray emission, a key metric of solar activity, has flatlined. The quiet is unlikely to break this weekend. NOAA forecasters estimate a scant 1% chance of M- or X-class solar flares during the next 24-48 hours. The quiet spell is a bit strange because 2013 is supposed to be a year of solar maximum, with lots of flares and sunspots.
The only explanation for the oddity is the same used to explain the unexpectedly low levels of solar activity throughout most of the year: a double peaked solar maximum. We’ll soon see whether that is the case, or if we just have a long way to go to understand our live-giving yet volatile solar neighbor.
Helping with the latter will be the Deep Space Climate Observatory (DSCOVR). As the name indicates, DSCOVER started life as an Earth observation satellite, but fell prey to politics and languished in storage for over 10 years, after it escaped destruction when bumped from its intended launch aboard STS-107 in 2003. Space.com tells the tale:
Originally called Triana, the refrigerator-sized satellite was first approved in October 1998 and intended to launch aboard a space shuttle, but as the mission’s costs rose, it became entangled in political battles.
Opponents of the project in Congress characterized the satellite as an overpriced “screen saver,” seizing upon former Vice President Al Gore’s vision that the mission would produce live imagery of the sunlit side of Earth 24 hours a day.
DSCOVER was taken out and brushed off a few years back with a new mission: to monitor the Sun, replacing the aging Advanced Composition Explorer (ACE) solar satellite which launched in 1997. DSCOVER just passed a key review and is said to be on schedule for a 2015 launch to the Sun-Earth first Lagrange point from which it will watch for space weather events that could impact Earth systems.
Such monitoring is all the more critical in light of a new study attributing a series of 26 Inmarsat satellite glitches spanning 1996 to 2012 to solar events. Space.com reviewed the study out of MIT:
Most of the glitches, from 1996 to 2012, coincided with high-energy electron activity during declining phases of the solar cycle, the study found.
The researchers think these charged particles may have accumulated in the satellites over time. Despite protective shielding, the buildup likely caused internal charging that damaged the satellites’ amplifiers, which are needed to strengthen and relay a signal back to Earth. Over an extended mission, the researchers warn that this phenomenon could also cause the satellites’ backup amplifiers to fail.
Space weather can be much more dynamic than predicted by the models engineers use when crafting satellites, explained Kerri Cahoy, a co-author of the study and an assistant professor of aeronautics and astronautics at MIT. ”There are many different ways that charged particles can wreak havoc on your satellite’s electronics,” Cahoy said in a statement.
One puzzle of the study is that, contrary to expectation, most of the glitches occurred during times of low geomagnetic activity. This only highlights our need to extend understanding of solar phenomena and their impact on Earth and its satellites.
Image caption: This solar flare, recorded by NASA’s TRACE satellite in July 2012, shows more activity than we’ve seen from the Sun lately (Credits: NASA).