Comet C/2022 E3 (ZTF) is baffling to see through a telescope, but what will it look like up close?
Scientists have no way of getting a spacecraft this stunning green comet during its swing through the interior Solar System —but in the next decade, they will, thanks to the European Space Agency’s (ESA) Comet Interceptor. This mission, scheduled for launch in 2029, will spend a few years floating about 1 million miles (1.5 million km) from Earth. a land, waiting for an interesting comet to venture deep enough into the inner solar system to fly through. But if the Comet Interceptor was really in space, scientists might have sent it buzzing towards it. Comet C / 2022 E3 (ZTF).
Michael Kuipers, ESA’s Comet Interceptor study scientist, said at a meeting of NASA’s Small Object Evaluation Group on Wednesday (Jan. 26).
Related: Stunning images of the brilliant green comet C/2022 E3 (ZTF)
Kuipers said the science team has been preparing for the mission by evaluating “hypothetical targets” — things the Comet Interceptor team could consider visiting if the probe was already in space. Whichever comet it ends up with will be subject to a thorough, albeit brief, examination by the main spacecraft and two smaller probes.
Mission scientists hope to target an active comet that has not passed before the sun Before. Such a thing would descend from the ice Oort cloud beyond the orbit of Pluto. By capturing an object in its first ring from the sun, scientists will be able to see the original material responding to the sun’s heat.
Or, if Comet Interceptor is particularly lucky, scientists will discover another interstellar object, a successor to Oumuamua And Comet Borisov This makes a one-time short trip through our solar system.
It’s an unusual situation for a mission to be in — although a lot of spacecraft acquire additional targets after launch, the Comet Interceptor will be in space before scientists see its main target.
The spacecraft will cruise with ESA’s Extrasolar Infrared Atmosphere Remote Sensing Mission (Ariel), which will spend four years analyzing the atmosphere of up to 1,000 outer planets.
After launch, Comet Interceptor will head for Earth-sun Lagrangian point 2 (L2), the same deep-space “parking spot” in which it is located James Webb Space Telescope orbits. At Lagrangian points, the tugs of gravity balance out, so it would be relatively cheap to keep the spacecraft at its station while scientists wait to locate a promising target. The team will need to outline its plans at least six months before exiting L2 for a rendezvous with a comet.
But imagine the Comet Interceptor was already at its station in early March 2022, when scientists first detected Comet C/2022 E3 (ZTF). Interested mission personnel may have started playing with the trajectories Comet Interceptor could use to meet the object. They found that if the spacecraft had lifted off in late August, it could fly by the comet on February 12, just a month after the snowball approached the sun, and just under a year after the object was discovered.
But Kuipers pointed out that C/2022 E3 is not an ideal target. The team will need to prepare for departure very quickly, and the flyby will happen a little farther from the Sun than scientists prefer. And while mission personnel hope to catch a comet that has never visited the inner solar system before, C/2022 E3 did, albeit some 50,000 years ago.
“Maybe it’s not dynamically new,” Kuipers said. “It’s reasonably active, so we might take it, but it depends on the activity.”
And if this scenario were played out during a real Comet Interceptor mission, the time to prepare for departure probably wouldn’t be an issue. That’s thanks Vera Rubin Observatory in Chile, which will conduct a 10-year Legacy Survey of Space and Time (LSST) starting in early 2025. The LSST is expected to discover about 6 million objects in the solar system, and much of what it discovers will come relatively early in this survey.
“The detection is a little bit late, but we’re not worried about that because we expect those comets to be detected significantly earlier with the LSST,” Kuipers said of the hypothetical C/2022 E3 scenario.
The analysis highlights the kinds of decisions scientists will need to make during the Comet Interceptor mission. They only get one shot, not knowing in advance what the solar system will send their way. If they get too excited, they may end up missing out on a more interesting target; If they were too careful, they could find themselves still at Level 2 several years after launch, running out of time with no target in sight. While the dream is an active, long-period comet, the team will have to figure out what’s going on, and whether an object like C/2022 E3 will snag a visit.
“Statistically, we would expect to have a few candidate targets, not dozens,” Kuipers said. “We also can’t rely on a new comet dynamically, so we’ll probably use a comet like ZTF.”
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