The European Space Agency's (ESA) Solar Orbiter spacecraft has captured stunning images on its way to its first orbit near the Sun.
This image was taken on March 7 as the Solar Orbiter passed directly between Earth and the Sun. There was an explicit reason for this, namely that the science team wanted to calibrate and compare Earth-based images and missions in Earth orbit, to include the Inouye solar observatory, NASA's Solar Dynamics Observatory, and ESA/NASA's Solar Heliospheric Observatory (SOHO), located at the Lagrange point. (L1) Sun-Earth.
"From this point onwards, we are 'entering the unknown,' as far as the Solar Orbiter observes the Sun," said Solar Orbiter Project Scientist Daniel Müller.
Instruments used in the spacecraft include the Extreme Ultraviolet Imager (EUI) and the Spectral Imaging of the Coronal Environment (SPICE) imager. The EUI image itself represents the highest full disk resolution image of the Sun, and details capture of the Sun's corona and outer atmosphere.
This image captures the Sun at the Lyman-beta wavelength in the ultraviolet, and is one of the first images of its kind taken in the last 50 years, since the Sun-observing experiments aboard Skylab.
Solar Orbiter took these images over a 4-hour session, and the probe is 75 million kilometers from the Sun, interior to Venus' orbit. The sun is large enough (two degrees wide) from that distance that the EUI requires 25 mosaic images to cover the entire disk of the Sun. The end result is laid out in a 9148 x 9112 grid of 83 million pixels, with a resolution 10 times better than a 4K TV screen.
The images include the filaments, nano-flares, and spicules visible on the turbulent surface of the Sun. The Solar Orbiter observations will answer key questions about how eruptions are born on the Sun's surface, by characterizing the Sun's apparent temperature through successive layers.
The SPICE sequence in particular shows the temperature layers in color versus elemental composition: yellow (neon) at 630,000 degrees Celsius, green (oxygen) at 320,000 degrees Celsius, blue (carbon) at 32,000 degrees Celsius, and purple (hydrogen) at 'cool' 10,000 degrees. Celsius.
Launched on February 10, 2020 aboard an Atlas V rocket from the Cape Canaveral Space Force Station (then, Air Force), Solar Orbiter had a major seven-year mission to study the Sun.
The mission comes at an opportune time, as Solar Cycle 25 takes place this year, on its way to a culmination around 2025, in what may be one of the most powerful in decades.
The Solar Orbiter just reached its closest perihelion last weekend, passing 50 million kilometers from the Sun's interior into Mercury's orbit. A trajectory near Venus will gradually change the slope of the Solar Orbiter's path and gradually provide us with an elusive view of the Sun's polar regions.