A total solar eclipse will occur in North America on April 8. These events occur when the Moon comes between the Sun and the Earth and completely covers the face of the Sun. This plunges observers into a darkness similar to dawn or dusk. During the upcoming eclipse, the path of totality, where observers will experience the darkest part of the lunar shadow (shadow), crosses Mexico, arcs northeastward through Texas and the Midwest, and briefly enters Canada before ending in Maine.

Total solar eclipses occur approximately every 18 months at a specific point on Earth. The last total solar eclipse to cross the United States occurred on August 21, 2017. An international team of scientists led by Aberystwyth University will conduct experiments at a site near Dallas on the path to wholeness. The team includes graduate students and researchers from Aberystwyth University, NASA Goddard Space Flight Center in Maryland, and Cal Institute of Technology in Pasadena.

There is valuable scientific research during eclipses that can match or exceed what we can achieve with space missions. Our experiments may also shed light on a long-standing mystery about the corona, the outermost part of the Sun’s atmosphere.

During a total solar eclipse, the intense light of the Sun is blocked by the Moon. This means we can observe the Sun’s faint corona with incredible clarity from distances very close to the Sun, down to several solar radii. A radius is a distance of approximately 696,000 km (432,000 mi), equivalent to half the diameter of the Sun.

It is extremely difficult to measure the corona without an eclipse. This requires a special telescope called a coronagraph, which is designed to block direct sunlight. This allows fainter light to be distinguished from the corona. The resolution of eclipse measurements surpasses even coronagraphs in space.

We can also observe the corona with a relatively small budget compared to spacecraft missions, for example. A continuing mystery about the corona is that it is much hotter than the photosphere (the visible surface of the Sun).

When we move away from a hot object, the ambient temperature should decrease, not increase. How the corona heats up to such high temperatures is a question we will investigate. We have two main scientific instruments. The first of these is Cip (coronal polarimeter). Jeep is also a Gaelic word meaning ‘to look’ or ‘a quick look’. The device creates an image of the Sun’s corona using a polarizer.

The light we want to measure from the corona is strongly polarized, meaning it consists of waves vibrating in the same geometric plane. A polarizer is a filter that allows light of a certain polarization to pass while blocking light of other polarizations.

Jeep images will allow us to measure basic properties of the corona, such as its density. It will also shed light on phenomena such as the solar wind. This is a stream of subatomic particles in the form of plasma (superheated matter) that constantly flows outward from the Sun. Jeep can help us identify the sources of certain solar wind currents in the Sun’s atmosphere.

Direct measurement of the magnetic field in the solar atmosphere is difficult. However, eclipse data will allow us to study its small-scale structure and track the direction of the field. We will be able to see how far from the Sun magnetic structures, called large “closed” magnetic loops, extend. This will give us information about the large-scale magnetic conditions in the corona.

The second instrument is CHILS (high resolution coronal linear spectrometer). It collects high-resolution spectra where light is broken down into its component colors. Here we are looking for the specific spectral signature of iron emitted by the corona.

It consists of three spectral lines in which light is emitted or absorbed within a narrow range of frequencies. Each is produced in a different temperature range (millions of degrees), so their relative brightness tells us about the temperature of the corona in different regions.

Mapping the corona’s temperature tells advanced computer models about its behavior. These models should include the mechanisms of how the coronal plasma is heated to such high temperatures. Such mechanisms may involve, for example, the conversion of magnetic waves into plasma thermal energy. This can be repeated in models if we show that some regions are warmer than others.

This year’s eclipse also occurred during a period of increased solar activity, so we were able to see the coronal mass ejection (CME). These are huge clouds of magnetized plasma that are ejected into space from the Sun’s atmosphere. They can affect near-Earth infrastructure, causing problems for vital satellites.

Many aspects of CMEs are not fully understood, including their early evolution near the Sun. Spectral information about CMEs will allow us to learn about their thermodynamics, as well as their speed and expansion near the Sun.

Our dimming devices were recently proposed for a space mission called Solar Occlusion Moon (Mesom). The plan is to fly around the moon to observe eclipses more frequently and for longer periods of time. It is planned as a multi-country UK space agency mission, but is led by University College London, the University of Surrey and Aberystwyth University.

We will also have an advanced commercial 360-degree camera to collect video footage of the April 8 eclipse and viewing locations. Video is valuable for community events where we highlight our work and helps spark public interest in our local star, the Sun.