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Scientists Detect the Cause of the Sun’s “Perfect Storm”

By David Reneke

Astronomers have deduced the cause of a massive solar storm, and set standards to prevent profiteering from the naming of space objects.

An international team of scientists has uncovered the origin and cause of an extreme space weather event that occurred on the Sun in 2012 and generated the fastest solar wind speed ever recorded directly by a solar wind instrument.

The formation of the rare, powerful storm showed striking, novel features that were detected by an instrument on NASA’s twin satellite Solar TErrestrial RElations Observatory (STEREO) mission.

The storm on 22 July 2012 was so powerful that had it been aimed at Earth instead of at the STEREO spacecraft, which was located 120° off to the side of Earth, the consequences would have been dramatic – widespread aurora, satellite mal­functions, and the potential failure of electricity grids.

To date it has been unclear how extreme space weather storms form and evolve. Developing a better understanding of their causes is vital to protecting modern society and its technological infrastructures – one of the goals of the STEREO mission.

“These results provide a new view crucial to solar physics and space weather as to how an extreme space weather event can arise from a combination of multiple solar eruptions,” says research assistant professor Noé Lugaz of the University of New Hampshire (UNH).

The researchers suggest that a successive one-two punch of solar eruptions, known as coronal mass ejections, was the key to the event blasting away from the Sun at 3000 km/s – a speed that would circle the Earth five times in a minute!

In a sense, this was the “perfect storm”. The first eruption was a primer for the quick propagation of the subsequent eruptions through interplanetary space.

“Remarkably, this is reminiscent of the great solar flare in 1859, the famous Carrington Event, and the geomagnetic storm of unheard of intensity in Earth’s magnetosphere, or magnetic field, that occurred less than 1 day later,” said UNH research professor Charles Farrugia.

The STEREO mission, launched in October 2006, has dramatically improved our understanding of the powerful solar eruptions that can send more than a billion tonnes of the Sun’s outer atmosphere hurtling into space.

Astronomers Agree on Standards for Naming Space Objects

Astronomers from the International Astronomical Union (IAU) have agreed on common standards for naming space objects, features or phenomena so that they can be easily located, described and discussed.

In recent times there has been a proliferation of initiatives capitalising on the public’s interest in space and astronomy by putting a price tag on naming space objects and their features, such as Mars craters. However, the IAU says that these initiatives go against the spirit of free and equal access to space, as well as internationally recognised standards. As a result, none of the names purchased can ever be used on official maps and globes.

Instead, the IAU wants the public to become involved in the naming process of space objects and their features by following the officially recognised (and free) methods.

For instance, features on a given planet or satellite receive names chosen from a particular theme. Only those features that are deemed to be of significance to science are given a name by the community, thus leaving other features to be named by future generations.

Although the present rules are that the general public cannot request that a particular feature is named, they can suggest that specific names be considered for formal adoption, or they can do so following a public invitation from a space agency or from the discoverers.

This was the case for NASA’s 1989 Magellan Venus mapping mission, when the public was invited to offer the names of women who had made outstanding or fundamental contributions to their fields as the potential names of Venusian craters.

A recent example was the naming of the two most recently discovered satellites of Pluto in 2013, which was the result of an IAU-approved public vote. The IAU also played a key role in getting the USSR and the USA to agree on naming rules for lunar features during the space race of the 1960s.

David Reneke is an astronomy lecturer and teacher, a feature writer for major Australian newspapers and magazines, and a science correspondent for ABC and commercial radio. Subscribe to David’s free Astro-Space newsletter at www.davidreneke.com