The First Interstellar Asteroid is Found

Our solar system contains over a million asteroids that travels in the asteroid belt. Each asteroid is actually a chunk of rock that orbits the Sun in between the orbits of Mars and Jupiter. They usually travel around in the asteroid belt, only to sometimes break off and fall into the atmospheres of Earth and other nearby planets. Most asteroids are so small that they will burn up because our atmosphere has so much pressure, that it causes the asteroids to heat up and eventually burn out. However, every few thousand years, an asteroid will make it through our atmosphere and will hit the surface. Once breaks through, it is no longer called an asteroid, but instead a meteoroid. NASA has had a satellite located in the asteroid belt for several years now. It is called the Dawn mission, and it has been collecting data about asteroids, including what they are made of and how they travel through space, since 2015.

Photo Above: Diagram of the asteroid belt’s location in the solar system. (Not to Scale)

Image source: https://spaceplace.nasa.gov/t-shirt/sp/

It is very important to track asteroids because if a very large asteroid were to make its way into the Earth’s atmosphere, it could potentially cause serious damage to our planet. To do this, astronomers have to take many pictures of the same spot in the sky. If they see something that is moving, they have to check it with a list of objects that they have already been identified. If that object does not match anything on the list, then it gets moved to a smaller list where more astronomers are working to track where the object will go. Objects that look like they will pass very close to Earth are made a priority and require a lot of people to come together to predict its path. Usually, asteroids will just pass by the Earth, and only about every 50 million years will we get hit by an asteroid that will threaten all life on Earth. After all, it has been 65 million years since the last one.

Photo Above: Artist’s rendition of NASA’s Dawn spacecraft.

Image source: NASA/JPL-Caltech

All asteroids are known to come from our solar system, but on October 19th, 2017, Rob Weryk, a researcher at the University of Hawaii, identified an object that was moving very fast toward our solar system. The object did not have a definite orbit, and seemed to come from above our solar system. Additionally, it passed in between Mercury’s orbit and seemed to use the gravity from the Sun to be slingshotted in the direction of the constellation Pegasus. "We have long suspected that these objects should exist, because during the process of planet 📷formation a lot of material should be ejected from planetary systems. What's most surprising is that we've never seen interstellar objects pass through before," said Karen Meech, an astronomer at the IfA. The object, which has been designated “A/2017 U1” for the time being, is a very important discovery because it is the first object to come from another solar system that we have seen. Astronomers will continue to study the data they gathered from the object to find out more about what lies beyond our own solar system.

Press Release: https://www.jpl.nasa.gov/news/news.php?release=2017-278

Additional Source: https://www.nasa.gov/mission_pages/asteroids/overview/fastfacts.html