All sorts of crazy things have been suggested about 3i/Atlas, the third known interstellar object we’ve discovered. Some are simply conspiracy theories about an alien spacecraft, while others have been well-thought-out suggestions, such as using a Mars-based probe to observe the comet as it passes the Red Planet.
A new paper previously published on Arxio and accepted by the American Astronomical Society Research Notes by Samuel Grand and Geraint Jones, of the Finnish Meteorological Institute and ESA, respectively, in the latter category, suggests that two spacecraft may already be used. , which may use separate routes to different destinations for the purpose of locating separate destinations in which separate destinations may be used for separate destinations. Which From their separate places they get from their separate places which reach their separate destinations.
A few weeks is not enough time to run a high-speed experiment for which neither spacecraft was designed. But sometimes science means doing the best with what you’ve got, and in this case, these two spacecraft are our best bet for studying the tails of interstellar comets.
The tail has been growing steadily since the comet’s discovery in early June. Recent reports of its “profound” water show how massive the tail has become, leaving behind a tangle of water particles, but possibly more importantly, the ions it leaves behind. The comet also recently lost sight of Earth-based systems, although its tail is assumed to continue growing until it reaches perihelion on October 29.
As the paper explains, ending up in a part of its tail isn’t as easy as passing straight behind it as it passes through the Solar System — the solar wind pushes particles away from the Sun into the Sun, following a curved path away from the comet. The speed at which the wind hits these particles plays an important role in where they will be, and therefore where the spacecraft has to pass to collect data directly on the tail.
To make these estimates, the authors used a model called “telicature” that predicts where the humoral ions will travel based on different wind speeds. The “minimum miss distance” for a given spacecraft was then calculated for the central axis of the comet’s tail. Unfortunately, the model is only as accurate as the solar wind data, which is usually only collected ex post facto — and certainly not long enough to help the mission achieve that goal.
Even with the program’s best estimate, both spacecraft would be millions of kilometers from the central axis — 8.2 million for Hera and 8 million for Europa Clipper. However, it is still possible to collect data on ions from the tail because they can be spread over millions of kilometers from very active comets like 3i/Atlas.
The downside to the project is that at least one of the spacecraft – Hera – has no instruments that could potentially detect the ions expected in the tail, nor the magnetic “dropping structure” that characterizes what the comet’s atmosphere does to the magnetic field carried by the solar wind. However, Europa Clipper does – it’s a plasma instrument and the magnetometer is exactly what would be needed to directly detect these ions and changes in the magnetic field.
Difficult to say the least – but also very time limited. It’s unclear whether mission controllers for Hera, or more importantly, Europa Clipper, will see the message in time to do anything about its potential trip through Coma. But if they do, they could be the first in human history to directly sample and tail an interstellar comet — and wouldn’t that be something to brag about that has nothing to do with their original intended mission?
The original version This article was published in The universe today.
