Equinox Sun, Spring Star Arcturus rising, Solar Orbiter’s closest approach
SA/NASA’s Solar Orbiter spacecraft captured this largest solar prominence eruption ever observed in a single image together with the full solar disc on 15 February 2022. This latest event … extended millions of kilometres into space.
Photo credit European Space Agency/National Aeronautics and Space Agency
The first day of Spring is when the rising Sun marked due east on the horizon and the setting Sun marked due west, while tracing an arc in the sky that brings about equal day and night. The Vernal Equinox (aequus = equal and nox = night) is the astronomical first day of spring in the northern hemisphere. As seen in the illustration, below, our star’s equinox trajectory is halfway between the winter and summer solstices, the shortest and longest days of the year, respectively.
While we align with the movement of the Sun in relation to Earth, astronomers are observing our parent star through the eyes of a spacecraft that is approaching closer to the Sun than ever in human history.
The Solar Orbiter, a project of the European Space Agency and our National Aeronautics and Space Agency, crossed the Earth-Sun line – halfway point between our planet and the Sun – on March 8.
The brilliant flying machine arrives at perihelion, the name for closest approach to the Sun, next Saturday, March 26. Solar Orbiter will be less than one-third of the distance from the Sun to Earth and is designed to survive for relatively extended periods of time this close to the upper layer of the Sun’s atmosphere, the corona, which is millions of degrees Celsius.
Stargazers all, we observe the change-of-season Sun by day and the equally stirring changing positions of the stars in the nighttime sky. Spring stars and constellations rise in the east and travel the celestial dome all night while winter celebrities command the west, setting around midnight. Most dramatic, winter’s Sirius the Dog Star, the brightest star in Earth’s skies, appears at nightfall (see diagram), then wildly twinkles, flashing rainbows as it nears the southwestern skyline from about 10pm. until midnight. Opposite, above the eastern horizon, second brightest star in northern skies, golden Arcturus the Spring Star, rises with a brilliant flourish in the east at around 8pm.
