Solar surveyors

In order to better understand and anticipate solar weather, space agencies have sent up a family of orbiters and satellites

Solar Orbiter

Due to launch in 2020, it combines solar wind particle and magnetic field measurements with direct surface observation. It will monitor the Sun on highly elliptical orbits which will allow it to spend 10 to 15 days co-rotating with the Sun, providing uninterrupted coverage of sunspot, flare and storm development. RESULTS: Pending

IBEX

A NASA satellite launched in 2008 that aimed to map the boundary between the Solar System and interstellar space.

RESULTS: In 2013, IBEX results revealed the Sun’s heliosphere has a tail.

IRIS

A NASA satellite launched in 2013 to Investigate the physical conditions at the very edge of the Sun’s visible disc – known as the solar limb. In particular it has looked at the chromosphere layer, whose rosy-red colour is only usually visible to us on Earth during eclipses.

RESULTS: IRIS has shown that the interface region of the Sun is significantly more complex than previously thought and includes features described as solar heat bombs, high-speed plasma jets, nano-flares and mini-tornadoes.

Parker Solar Probe

The mission to ‘touch’ the Sun, this probe is the first man-made object to get within 6 million kilometres (4 million miles) of the Sun’s surface. At that distance it measures the pristine solar wind up close before the 'outburst' gets jumbled up in the journey towards Earth.

RESULTS: Pending

ACE

Launched back in 1997 to study the energetic particles from the solar wind, as well as providing the NOAA Space Weather Prediction Center with data for forecasts and warnings of solar storms.

RESULTS: Discovered that the current solar cycle, as measured by sunspots and coronal mass ejections, has been much less magnetically active than the previous cycle.

Wind

A NASA science spacecraft launched in 1994 to study radio waves and plasma that occur in the solar wind and in the Earth's magnetosphere.

RESULTS: Researchers have found evidence for a type of plasma wave moving faster than theory predicted within the solar wind using Wind data. The research suggests that a different process than expected may be driving the waves.

Hinode

A Japan Aerospace Exploration Agency-led satellite whose Sun-synchronous orbit over the day/night terminator allows near-continuous observation to explore the magnetic fields of the Sun.

RESULTS: In 2018 astronomers using the Hinode spacecraft observed the strongest magnetic field ever directly measured on the surface of the Sun.

STEREO

Two near-identical spacecraft launched in 2006 into orbits around the Sun ahead of and behind the orbit of the Earth. This enables stereoscopic imaging to provide in-depth information when observing solar phenomena, such as coronal mass ejections.

RESULTS: One of the STEREO craft – STEREO A – was in the path of the solar storm of 2012 which was similar in strength to the Carrington Event. Its instrumentation was able to collect and relay a significant amount of data about the event.

SOHO

One of the original craft still in operation, SOHO was launched in 1995 and combines imagers and spectrometry instruments to probe the layered structure of the Sun with in-situ measurements of the solar wind as it goes past. RESULTS: SOHO has also discovered over 3,400 comets as they orbit around the Sun, as well as providing the main source of near-real-time solar data for space weather prediction.

Solar Dynamics Observatory Launched in 2010 to investigate how the Sun's magnetic field is generated and structured and how this stored magnetic energy is converted and released into the heliosphere in the form of solar wind, energetic particles and variations in the solar irradiance. RESULTS: Has identified possible precursors to space weather in the behaviour of plasma within the regions encircling sunspots.

DSCOVR

Originally proposed by then-Vice President Al Gore, DSCOVR monitors variable solar wind conditions and their impact on the Earth, including changes in ozone, aerosols, dust and volcanic ash, cloud height, vegetation cover and climate.

RESULTS: Took the second picture of the entire Earth, following on from the final Apollo mission's famous Blue Marble picture.

Cluster II

Launched in 2000, the Cluster II mission is an in-situ investigation of the interaction between the solar wind and the magnetosphere by using four satellites.

RESULTS: Has developed the first models of the Earth's magnetic field and its interaction with the solar wind based on actual measurements rather than theory.