As Comet Leonard bid farewell to Earth and flew previous Venus, a sun-studying spacecraft flew through the comet’s lengthy tail, giving people a brand new perspective on the icy wanderer.
Discovered final January and also referred to as Comet C/2021 A1, Comet Leonard was maybe the most spectacular customer for skywatchers in 2021. The object placed on fairly a present because it zoomed towards the sun, significantly in the days main as much as its closest method to Earth on Dec. 12. And coincidentally, the European Space Agency (ESA) Solar Orbiter mission flew through the comet’s tail as the spacecraft continued its personal journey to review the sun, providing scientists fairly a bonus.
“The big advantage is that for basically no effort on the spacecraft’s part, you get to sample a comet at a massive distance,” Samuel Grant, a postgraduate pupil at University College London, mentioned in an ESA statement. “That’s pretty exciting.”
The spacecraft gathered cometary knowledge “for several days” surrounding Dec. 17, in line with the assertion. At the time, Comet Leonard was shifting away from Earth towards the sun, which it approached most intently on Jan. 3.
Meanwhile, Solar Orbiter had accomplished an Earth flyby on Nov. 27 and was additionally headed out to the sun, which it can fly previous in March. Although the nucleus of the comet was close to Venus and about 27.7 million miles (44.5 million kilometers) away from the spacecraft in mid-December, the comet’s tail stretched previous Earth’s orbit, in line with ESA.
Grant realized upfront that Solar Orbiter would fly through the comet’s tail because of a pc program that comes with spacecraft trajectories, comet orbits and the solar wind — the fixed stream of charged particles that flows out from the sun and throughout the solar system, shaping the ion tails of comets.
The program was developed by scientists behind ESA’s Comet Interceptor mission, which is able to launch in 2029 and execute a flyby of a long-period comet. Although Solar Orbiter was designed to review the sun fairly than comets, the spacecraft does carry some devices that had been in a position to collect knowledge about Comet Leonard’s tail throughout the crossing.
For instance, the spacecraft’s Solar Wind Analyzer instrument suite detected ions and compounds that belong to the comet fairly than the solar wind, together with oxygen ions and carbon dioxide. In addition, the probe’s magnetometer picked up indicators of magnetic perturbations which will have been brought on by the comet’s interplay with the sun’s magnetic subject.
And, of course, Solar Orbiter snapped some photographs as effectively. In explicit, the spacecraft gathered ultraviolet photographs that would assist scientists research water in the comet and visible-light photographs that would supply extra particulars about the comet’s mud exercise.
Although Solar Orbiter is the solely mission that immediately crossed through Comet Leonard’s tail, lots of different spacecraft in the interior solar system had been in a position to research the comet throughout its go to, together with NASA’s STEREO-A and Parker Solar Probe spacecraft and the joint NASA/ESA SOHO mission.
The encounter marked Solar Orbiter’s second crossing of a comet’s tail; the spacecraft additionally handed through the tail of Comet ATLAS in 2020, shortly after launching.
“This kind of additional science is always an exciting part of a space mission,” Daniel Müller, ESA undertaking scientist for Solar Orbiter, mentioned in the assertion.
“When the Comet ATLAS crossing was predicted, we were still calibrating the spacecraft and its instruments,” Müller mentioned. “Also, the comet fragmented just before we got there. But with Comet Leonard we were totally ready — and the comet didn’t fall apart.”