Surprisingly it's not the fear of UFO's from outer space touching down on the continent of Antarctica, but fear of the human race. Tourists that accidentally bring seeds and plants with them could threaten the ecosystem of the frozen land.

According to the BBC, researchers have been studying clothing and boots of scientists and tourists alike, and have discovered that most were bringing plant seeds with them. The team who discovered the travelling alien seeds wrote in the Proceedings of the National Academy of Sciences (PNAS) that these foreign plants are more likely to spread as the climate warms.

While many don't see the threat of the alien seeds spreading due to the ice-covered region, lead research Steven Chown of Stellenbosch University in South Africa begs to differ. [They're forgetting that probably less than one percent, but still a significant area, is ice-free - some of that's in the peninsula region, and it's been warming very quickly, said Shown.

According to Fox News, the deliberate introduction of foreign species to the continent is forbidden by the Antarctic Treaty. In the 2007-2008 field seasons the researchers used a vacuum to discover what seeds were being brought onto the continent unknowingly by 1,0000 visitors. The researchers found over 2,800 seeds, which roughly came out to 9.5 seeds per alien invader.

Chown said that an alien plant has already invaded the icy land of Antarctica. Poa annua, a grassy weed to most in the United States is growing on the continent. According to the BBC, the peninsula has already warmed up by about 3C in the last half of the century, much faster than the global average. With the Antarctic region being one of the fastest warming places on Earth, the alien plant invasion is more likely to spread due to the dwindling ice covering the land.

The widespread of these alien species may be too late to just weed out. In order to prevent future and more widespread foreign plants, the International Association of Antarctic Tour Operators (IAATO) is taking the time to make sure all visitors to the region arrive seed-free. While no legal obligation exists to clean up the alien plants, scientists believe in a moral obligation. According to Chown, if no precautions are taken, the  continent could end up looking like sub-Antarctic islands such as South Georgia where alien plants and animals, particularly rats, have dramatically changed the local ecology.