Despite all the research and theorizing, there’s no concrete proof that aliens have or have not visited Earth.

You may have heard that aliens have visited Earth, and you may be wondering how they got here. Are they big-headed creatures who love to poke us with needles? Are they little green men? Do they live on the moon?

The truth is, we don’t know. We can’t know for sure. There’s no way of knowing what an alien looks like or how it moves around or where it lives or if it even exists in our universe at all!

Planetary scientist Dr. Jim Green

“Of course they can reach us from another star system,” says Dr. Jim Green, the Planetary Science Division Director at NASA’s National Aeronautics and Space Administration (NASA).

“There are billions of planets in the universe that could support life, so yes aliens could travel between stars.” It is good to note that this is purely speculation on his part as we have not discovered the bounds to the universe. There could be more or less.

Interstellar travel may be possible. Here are some hypothetical options aliens could use.

One method involves the use of a hypothetical technology called hyperspace. When you’re moving through it, you’re not actually traveling at all—you’re just existing at a different point in space-time. It’s also known as “warp drive” or “faster-than-light travel” depending on which sci-fi franchise you prefer (I like Star Trek). In theory, once this technology is perfected, it could allow us to travel faster than light without breaking any laws of physics (thanks to Einsteinian relativity). But, no real progress has been made on this front.

Another way is by making use of wormholes—a kind of tunnel that connects two points in space without actually traversing the distance between them; they’re basically portals into another dimension where time and gravity don’t exist. Theoretically, if we were able to find one and then build a spaceship capable of traveling through it safely, we could get around pretty quickly since there would be no need for fuel or oxygen onboard: Just hop on over!

The third method involves harnessing subspace radio waves generated by pulsars—superdense neutron stars that rotate rapidly enough to emit electromagnetic radiation across vast distances in space at regular intervals (hence why they’re sometimes called “pulsating radio sources”). These waves can carry information far beyond our solar system with less distortion than other forms of communication; however there are still plenty of barriers preventing us from tapping into their power: We need better equipment and better understanding about how these signals work before we start sending messages into deep space via subspace transmission.

In 2014, a huge water-filled crater was found in Greenland’s icecap using NASA’s IceBridge data. This could provide proof of alien life visiting Earth in the last 100,000 years.

The crater was discovered by Dr. Henning Dahl and his team from the University of Copenhagen in Denmark. It is about 1km wide and has been filled with water for at least 100,000 years after it impacted Earth’s surface during one of its many ice ages.

The scientists say that this “impact” may have been caused by an asteroid or comet which then created a massive explosion upon impact that destroyed everything around it (or so they think). The surrounding areas were completely covered with tons of dust and debris which led to much speculation regarding what might have caused such destruction!

The Roswell incident, which took place in 1947, is possibly the most well-known UFO event to date. The U.S. government claims a crashed weather balloon was mistaken for an alien spacecraft by locals.

According to legend, the military recovered bodies from inside the wreckage and kept them at Area 51 in Nevada before they were allegedly whisked away by helicopter to Wright-Patterson Air Force Base near Dayton, Ohio. A few hours later — not long enough for scientists to conduct any tests or autopsies — an Air Force press release stated that the corpses were those of aliens who’d been recovered from a flying saucer that had crashed on a nearby ranch.”

Many believe that one day humans will be able to prove whether aliens exist or not through scientific means such as mathematical physics and astrobiology. But until then, perhaps we should look at the stars and wonder…

“There are more stars in the universe than grains of sand on this planet. It would be foolish to believe that we are alone,” says physicist Neil deGrasse Tyson. But he’s not the only one who believes that humans could meet intelligent life from another planet someday. Even Stephen Hawking has said, “Life on Earth is at risk from a sudden asteroid strike, a new pandemic or catastrophic global warming.”

Many Christians, however, do not think alien life exists and there is no conclusive evidence to prove its existence either way. If aliens did exist and came down to Earth with hostile intentions—as depicted in popular culture—it wouldn’t be wise for people who believe aliens exist (or don’t) to try to fight them off with their bare hands… Just read any science fiction story!