Proba-3: Detection of the Sun’s Wispy Outer Atmosphere on Earth and in Space

Researchers in North America are gearing up for their chance to observe the Sun’s corona — its wispy outer atmosphere — like never before. The solar corona, which is normally hidden by the Sun’s glare, will be visible to millions when the Moon blocks the solar disk on 8 April. It is important to note that the solar maximum occurs every 11 years and coincides with the event. During this time, the Sun’s magnetic fields intensify, creating sunspots, fiery loops of plasma and exciting structures in the corona.

The two craft will fly down to millimetre accuracy using satellite navigation, radio-based satellite interlinks, cameras, and a laser beam. The two will need to act as if they are a 150-m long instrument in order to be succesful, said Dietmar Pilz in the statement. Each of the crafts is being targeted for six-hour eclipse observations.

One reason scientists are so eager to study the Sun’s corona is its role in our solar system’s weather. It contributes to solar wind and its mass ejections have the potential to cause widespread electrical outages, as well as causing the dancing lights of the planet’s auroras. The ESA says one of the goals of the mission, known as Proba-3, is to measure the Sun’s total energy output to inform climate modeling.

There are coronagraphs on Earth and in space, but the ESA says they’re limited in what they can accomplish because the light has a tendency to diffract or spill over the edge of the light-blocking disk. Building a single occluding disk is impractical, but putting it farther away helps. The ESA says in its release that NASA attempted to pull something similar off by using an Apollo capsule to block out the Sun for a Soviet Soyuz spacecraft in 1975.

Proba-3 is going to see the sun during eclipses from South Texas to Maine: Forecasting the Sun with high-resolution satellite and cloud simulations

The agency hopes to launch the Proba-3 mission in September. On April 8th, people in the US are getting ready to watch a total eclipse of the Sun that will take place from South Texas to Maine.

Sometimes, these prominences can snap explosively to form a coronal mass ejection. The solar corona’s temperature can reach 1,000,000 C during one of these events, as hundreds of billions of tons of relatively cool solar plasma are expelled from the solar surface. Habbal says that there is a good chance that viewers will be able to see a mass ejection from the sun. Eclipses provide “the best opportunity to figure out how these plasmas co-exist and interact”, she adds.

Earth experiences total eclipses roughly once every 18 months. Their paths cross many remote areas where little people can see them. The last time a full eclipse happened in the US was in September of 2017: Viewers along that eclipse’s ‘path of totality’ — in which the Moon completely blocks the solar disk — “wouldn’t have seen the same Sun as we’re seeing” during this one, says Marcel Corchado-Albelo, a solar physicist at the University of Colorado Boulder, who will participate in a public-outreach programme on 8 April aimed at marginalized communities in Texas. During the previous eclipse, the Sun was closer to its solar minimum.

A preview of how it might appear during a eclipse was released by a San Diego based research and product development firm. Staff members, including astrophysicist Cooper Downs, used real-time satellite data of the Sun’s surface magnetic fields and intensive supercomputer simulations to make the prediction. Downs says that the Sun is chaotic. So forecasting the corona’s appearance is as difficult as predicting cloud movement — the mention of which is a source of anxiety for eclipse chasers. Clouds could obscure the eclipse from the view of many on 8 April.

Downs says that the firm’s scientists will be able to improve their model for space-weather forecasting by comparing streamers and holes in the simulation and the actual eclipse.

Habbal and his team of 40 researchers are going to capture some changes in the corona during the eclipse by using high-speed cameras and high-resolution sensors. The scientists will be spread across three sites in order to maximize the chance of a cloudless observation.

One group of people that are not worried about the clouds is the Airborne Coronal Emission Surveyor (ACES). These scientists will fly in a Gulfstream V jet above the clouds, at an altitude exceeding 13 kilometres. This will put them over a layer of water vapour in Earth’s atmosphere that absorbs infrared light and would interfere with their measurements of the corona. Chad Madsen, an astrophysicist at the Harvard–Smithsonian Center for Astrophysics in Cambridge, Massachusetts, and an ACES participant, says the team is interested in studying one particularly long streamer in the Predictive Science forecast.

The team will use the light from the streamer to measure the strength of the magnetic fields in the part of the corona where it appears, and the makeup of ionized material in the streamer. The magnetic fields in the corona have an affect on the light coming out of the projector.

Source: Total solar eclipse 2024: how it will help scientists to study the Sun

The Moon’s Shadow in the Moose: On-Soon Observations of a Long-Duration Flight through the Tauri Desert

Their flight will chase the Moon’s shadow along the path of totality through Texas, adding 90 more seconds of observation time to the maximum of 4 minutes and 30 seconds that viewers on the ground will get.