Simulations suggest interstellar objects could be captured by Earth's gravity

A quartet of space scientists, two from Carnegie Mellon University and two from Harvard University, has found via simulations that it should be possible for interstellar objects to be captured by Earth's gravity. The team, made up of Diptajyoti Mukherjee, Hy Trac, Amir Siraj and Abraham Loeb, has submitted a paper describing their work to the Monthly Notices of the Royal Astronomical Society—currently, it can be read on the arXiv preprint server.

Back in 2017, an object in the solar system (subsequently named 'Oumuamua) was discovered to have come from outside of the solar system, making it the first observed interstellar object (ISO). Two years later, comet 2I Borisov was found to have come from outside the solar system, as well.

The two visits to our solar system generated a wave of interest in the space community surrounding ISOs. Thus far, no more have been discovered, but many in the space science community believe that it is likely that some ISOs have traveled into our solar system, but instead of escaping, became trapped either in a loop around the sun or around one of the planets. In this new effort, the research team looked into the possibility of such occurrences using numerical analysis and simulations.

Prior research into the topic focused almost exclusively on ISOs being captured by the sun or by Jupiter. Because of that, the researchers chose to make their main focus capture of ISOs by Earth.

Via simulations, the team found that it should be possible for an ISO to be caught in a planetary orbit around Earth, but it was 1,000 times more likely to happen to Jupiter. Their simulations also showed that if an ISO were to be captured by Earth's gravity, it would likely have an unstable orbit, meaning its capture would likely be brief, mostly due to the pull of gravity from the other planets.

The researchers were not willing to make any guesses based on their simulations about the likelihood of ISOs currently residing in the solar system, but suggest future work should look into the possibility. They conclude by noting such work will be extremely difficult due to the small size of such objects.Children in Western countries have long been taught the virtues of recycling. Because plastic products never decompose on their own, kids are instructed to dispose of them in specially-designated bins so they can be reused. The thinking is that if plastic products are continuously repurposed instead of being simply thrown away, it will lessen the plastic pollution crisis currently choking off life on this planet.

"Many people think that more plastic recycling will resolve the plastics crisis, but plastics are made with toxic chemicals... so recycling plastic is recycling toxic chemicals."

Yet a new report by Greenpeace USA reveals that recycling plastic not only fails to help the problem — it may actually make things worse. More significantly, the report reviews dozens of previous studies about plastic pollution to arrive at a sobering conclusion: If humanity does not get plastic pollution under control, the entire Earth ecosystem could be placed in grave danger.

Foremost among the report's notable statistics: Less than 9% of global plastics even wind up getting recycled, according to the United Nations Environmental Programme (UNEP), indicating that the programs created to encourage plastic recycling have been minimally effective. Even if they were being more widely utilized, however, they do not offset the tons of new plastic products being created every year. Finally, there is evidence that the process through which plastics are recycled may actually make them more hazardous to humans who are subsequently exposed to them.