Comet Leonard, a mass of space dust, rock and ice about a kilometre across is heading for a close pass of the Sun on 3 January, and the ESA/NASA Solar Orbiter spacecraft has been watching its evolution over the last days.
The Solar Orbiter Heliospheric Imager (SoloHI) captured an animated sequence of images 17-19 December that shows comet Leonard streaking diagonally across the field of view with the Milky Way as a stunning backdrop. Venus and Mercury are also visible in the top right, Venus appearing brighter and moving from left to right.
The comet is currently on its inbound journey around the Sun with its tail streaking out behind. When SoloHI recorded these images, the comet was approximately between the Sun and the spacecraft, with its gas and dust tails pointing towards the spacecraft. Toward the end of the image sequence, our view of both of the tails improves as the viewing angle at which we see the comet increases, and SoloHI gets a side-on view of the comet.
A faint coronal mass ejection front is also visible moving from the right hand side of the frame in the final second of the movie.
SoloHI will continue observing the comet until it leaves its field of view on 22 December, and will be complemented by other instrument observations.
Ground-based telescopes and other spacecraft have also been following the comet on its journey through the Solar System and providing images, including NASA’s Solar Terrestrial Relations Observatory-A spacecraft – see here.
Comet Leonard, formally known as C/2021 A1 (Leonard), was discovered in January 2021 by Gregory Leonard, who spotted it in images taken from the Mt. Lemmon Observatory in Arizona. Its closest pass on 3 January 2022 will take it within 90 million kilometres of the Sun, slightly more than half Earth’s distance to the Sun. If it doesn’t disintegrate, its trajectory will fling it into interstellar space, never to return.
About Solar Orbiter
Solar Orbiter launched 10 February 2020 and is on a mission to provide the first views of the Sun’s uncharted polar regions, giving unprecedented insight into how our parent star works. It will investigate how intense radiation and energetic particles being blasted out from the Sun and carried by the solar wind through the Solar System impact our home planet, to better understand and predict periods of stormy ‘space weather’